German Plant Nutrition 2016

International Conference of the German Society for Plant Nutrition – DGP (Annual Meeting)

and the Institute of Crop Science, University of Hohenheim

Resource efficiency: from model plants to crops and crop systems

28 – 30 September 2016, Stuttgart-Hohenheim, Germany

Scientific Committee:

Prof. Dr. Uwe Ludewig, University Hohenheim, Germany

Prof. Dr. Torsten Müller, University Hohenheim, Germany

Prof. Dr. Christian Zörb, University Hohenheim, Germany

Prof. Dr. Günter Neumann, University Hohenheim, Germany

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Table of Contents:

Scientific Program

Oral presentations

• S I: Mineral uptake/Stress physiology • S II: Physiologic and agronomic use efficiency • S III: Rhizosphere • S IV: Mineral nutrition& stress • S V: Nutrient uptake • S VI: Open topics • S VII: Nutrient Cycles

Poster presentations (numeral order)

• TOP 1: Physiologic and agronomic use efficiency NO 1-8 • TOP2: Rhizosphere NO 10-18 • TOP3: Mineral nutrition& stress NO 20-42E • TOP4: Nutrient uptake/Sensing NO 44-47 • TOP 5: Nutrient Cycles / BioFectors NO 48-55 • TOP 6: Free topics NO 56-63

List of participants

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Scientific Program Registration opens Wed. 28.09.16, 8:00h, FOYER: EUROFORUM

Conference starts: Wed.28.09.16, 9:00h

Conference ends: Fr 30.09.16, 12:30h

Wednesday, 28 September 2016

Room: Katharinasaal EUROFORUM

9:00-9:30 Welcome & Opening remarks

Representatives of the University of Hohenheim

Head of DGP

Session I: Mineral uptake / Stress physiology

Room: Katharinasaal EUROFORUM – Chair: Christian Zörb

9:30–10:05 Torsten Müller, Stuttgart Phosphate: a future challenge !?

10:05–10:40 Joachim Kopka, Golm Plant nutrient dependent metabolite profiles and patterns

10:40–11:00 coffee break

11:00-11:15 LB Wu, Bonn Physiological tolerance mechanisms to iron toxicity in rice (Oryza sativa L.)”

11:15-11:30 N Moradtalab, Stuttgart Interactions of silicone and micronutrients in the improvement of cold tolerance in maize

11:30-11:45 M Wimmer, Bonn Repeated drought stress cycles exhaust anti-oxidative capacity and alter soluble sugar pools of young sugar beets

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11:45–12:00 E Becker, Munich

High-throughput phenotyping of hybrid wheat under drought and heat stress

12:00–13:30 lunch

Session II: Physiologic and agronomic use efficiency

Room: Katharinasaal EUROFORUM – Chair: Uwe Ludewig

13:30–14:05 Malcolm Hawkesford, Rothamsted, GB Diversity and stability of NUE in wheat

14:05–14:40 Lixing Yuan, Bejing, China Root-based approaches to improve nutrient use efficiency in maize

14:40–14:55 BW Hütsch, Giessen Improving the nutrient and water efficiency of grain maize

14:55–15:10 F Gnädinger, München

Discriminating nitrogen uptake parameters of maize cultivars with high-throughput phenotyping at the reproductive phase

15:10-15:25 A Araujo de Franca, Freising Short-term response and nitrogen use efficiency of biogas residue application to winter wheat

15:25-15:40 PM Nkebiwe, Stuttgart Placement of P and N to improve crop nutrient acquisition and yield: a meta analysis

15:40–16:00 Coffee break

16:00–16:15 Poster presentations “pecha kucha style”

16:15–17:00 Poster session I (in Castle, Aula, 1st Floor)

17:00-19:00 Meeting of DGP members (Euroforum, Katharinasaal)

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Thursday, 29 September 2016

Session III: Rhizosphere

Room: Katharinasaal EUROFORUM – Chair: Günter Neumann

8:30–9:05 Kornelia Smalla, Braunschweig Microbes in rhizoshere and impact on root health

9:05–9:20 SRGA Blaser, Halle

Combination of X-ray micro tomography and soil solution studies to analyze root system development and soil chemistry in situ as a response to different N-forms

9:20-9:35 M Sanaullah, Göttingen

Impact of climate change on spatial distribution and catalytic efficiencies of extracellular enzymes in the rhizosphere

9:35-9:50 N Weber, Stuttgart

Triggering Plant Responses to P limitation – A novel mode of action for microbial plant growth promotion?

9:50-10:05 M Nabel, Jülich

Digestate patch-fertilization of Sida hermaphrodita on marginal soil

10:05–10:30 Coffee break

Session IV: Mineral nutrition & stress

Room: Katharinasaal EUROFORUM – Chair: Torsten Müller

10:30–11:05 S Kopriva, Köln

Natural variation in nutrient content

11:05–11:30 G Schaaf, Tübingen

Inositol phosphates: novel regulators of P-nutrition and stress responses”

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11:30–11:45 S Jung, Giessen

Reduced apoplastic acidification caused by altered PM H+-ATP-ase activity is responsible for early growth reduction of maize under Mg deficiency

11:45–12:00 F Ulas, Turkey

Effect of different pH levels on growth, biomass partitioning and leaf mineral composition of various gourd genotypes and watermelon cultivars

12:00–13:30 Lunch

Session V: Molecular Nutrient uptake

Room: Katharinasaal EUROFORUM – Chair: Benjamin Neuhäuser

13:30–14:05 Mark Aarts, Wageningen NL

Analysis of natural genetic variation for the response to Zn deficiency in Arabidopsis thaliana

14:05-14:25 P Bienert, Gatersleben

Identification of Mechanisms contributing to boron efficiency in rapeseed and Arabidopsis genotypes

14:25-14:45 B Neuhäuser, Stuttgart

Ammonium transport inhibition by calcineurin B-like interacting Kinase 23 (CIPK23)

14:45-15:05 M Hinrichs, Hannover

Silicon reduces iron uptake in rice

15:05–15:25 B Schönberger, Stuttgart

Epigenetic control of site-specific establishment of poplar cuttings and its relation to P nutrition

15:25–15:45 X Chen, Stuttgart

Zinc controls leaf size by promotion of Flowering locus T in early flowering Arabidopsis thaliana

15:45–16:15 Coffee break

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16:15–18:00 Poster session II (in castle, Aula, 1st Floor)

18:00 Conference Dinner – Mensa, University of Hohenheim

Friday, 30 September 2016

Session VI: Open topics

Room: Katharinasaal EUROFORUM – Chair: N.N.

8:30-8:45 J Burkhardt, Bonn

Hydraulic activation of stomata – consequences for foliar nutrition, plant water relations, and drought tolerance

8:45-9:00 D Eticha, Dülmen

Are hungry crops more thirsty ?

9:00-9:15 H El-Ramady, Kafr-El Sheikh

Role of selenium in microbial remediation of nicotine contaminated soils

9:15-9:30 O. Zaytseva, Stuttgart

Dual effects of carbon nanotubes on soybean (Glycine max.)

9:30–10:00 Presentation of PhD price winner

10:00–10:25 Coffee break

Session VII: Nutrient Cycles

Room: Katharinasaal EUROFORUM – Chair: Tobias Hartmann

10:25–11:00 Friederike Lang, Freiburg

Phosphorus ecosystem nutrition: High P use efficiency as an unrecognised service of forest ecosystems”

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11:00–11:25 K Möller, Stuttgart

Improved Phosphorus Recycling: Navigating between constraints

11:25–11:40 S Mancarella, Bologna (I)

Sewage sludge hydrolyzates for phosphate plant nutrition

11:40 –11:55 I Wollmann, Stuttgart

Phosphorus availability of recycled fertilizers from urban residues – results from pot and field experiments

11:55–12:30 Resume & Concluding remarks

from 12:30: lunch, departure

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ABSTRACTS

Oral presentations • S I: Mineral uptake/Stress physiology • S II: Physiologic and agronomic use efficiency • S III: Rhizosphere • S IV: Mineral nutrition& stress • S V: Nutrient uptake • S VI: Open topics • S VII: Nutrient Cycles

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PHYSIOLOGICAL TOLERANCE MECHANISMS TO IRON TOXICITY IN RICE (Oryza sativa L.)

Lin-Bo Wu1, Michael Frei1

1Plant Nutrition, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn; linbowu@uni-bonn.de

Iron (Fe) is a pivotal microelement involved in many processes including photosynthesis and respiration in plant cells (Kobayashi and Nishizawa, 2012). However, Fe toxicity is a frequently observed abiotic stress in flooded lowland rice fields due to excess ferrous Fe (Fe2+) in soil solution. To cope with high level of Fe2+, rice plants employ different mechanisms to either limit the uptake of excess Fe2+ into shoot tissue or limit cell damage caused by reactive oxygen species (ROS) produced through the Fenton reaction (Becker and Asch, 2005). Quantitative trait loci (QTL) associated with Fe tolerance in rice were reported by a number of studies including both bi-parental mapping approaches (Dufey et al., 2015; Wu et al., 2014) and genome-wide association study (Matthus et al., 2015). However, the physiological aspects of the tolerance mechanisms to Fe toxicity still remain ambiguous. In our previous study, two tolerant recombinant inbred lines, FL510 and FL483 were selected from a IR29 (sensitive) × Pokkali (tolerant) population tested in 1,000 ppm Fe2+ stress conditions (Wu et al., 2014). Compared to the sensitive parent IR29, FL510 showed significantly lower shoot Fe concentration indicating that tolerance was conferred by root-based mechanism, i.e., limiting the Fe transport into the shoot. Further investigations showed that the exclusion mechanism in FL510 was linked with the root oxidizing power favored by larger diameters of shoot pith cavity and primary root, and a higher density of lateral fine roots. To elucidate mechanisms of shoot tolerance, transcriptomic analyses were performed on the contrasting genotypes of IR29 and FL483, which differed significantly in stress symptom formation despite similar shoot Fe concentration (Wu et al., 2016). Different pathways were investigated, including (1) Fe uptake, partitioning and storage; (2) antioxidants biosyntheses; and (3) enzymatic activities for ROS scavenging and antioxidants turn-over. Glutathione S-transferase and ascorbate oxidase genes showed differential expression and FL483 possessed higher ascorbate oxidase and lower dehydroascorbate reductase activity than IR29 suggesting that higher rates of ascorbate oxidation conferred Fe toxicity tolerance. Further experiments involved external foliar applications of reduced ascorbic acid and its biosynthetic precursor on rice plants, and demonstrated a pro-oxidant and thus damaging effect of reduced ascorbic acid in the presence of high levels of Fe. In summary, the tolerance mechanisms to Fe toxicity in rice were classified into both root- and shoot-based aspects, and the understanding of tolerance mechanisms would contribute to the breeding of more adaptive cultivars in Fe toxic fields.

References

Becker M., Asch F. (2005) Iron toxicity in rice-conditions and management concepts. Journal of Plant Nutrition and Soil Science 168:558-573. DOI: 10.1002/jpln.200520504.

Dufey I., Mathieu A.-S., Draye X., Lutts S., Bertin P. (2015) Construction of an integrated map through comparative studies allows the identification of candidate regions for resistance to ferrous iron toxicity in rice. Euphytica 203:59-69. DOI: 10.1007/s10681-014-1255-5.

Kobayashi T., Nishizawa N.K. (2012) Iron Uptake, Translocation, and Regulation in Higher Plants. Annual Review of Plant Biology 63:131-152. DOI: doi:10.1146/annurev-arplant-042811-105522.

Matthus E., Wu L.-B., Ueda Y., Höller S., Becker M., Frei M. (2015) Loci, genes, and mechanisms associated with tolerance to ferrous iron toxicity in rice (Oryza sativa L.). Theoretical and Applied Genetics:1-14. DOI: 10.1007/s00122-015-2569-y.

Wu L.-B., Ueda Y., Lai S.-K., Frei M. (2016) Shoot tolerance mechanisms to iron toxicity in rice (Oryza sativa L.). Plant, Cell & Environment. DOI: 10.1111/pce.12733.

Wu L.-B., Shhadi M., Gregorio G., Matthus E., Becker M., Frei M. (2014) Genetic and physiological analysis of tolerance to acute iron toxicity in rice. Rice 7:1-12. DOI: 10.1186/s12284-014-0008-3.

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NoTrt Zn/Mnseed Algavyt1X Algavyt3X Si

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NoTrt Zn/Mnseed Algavyt1X Algavyt3X Si

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Interactions of silicone and micronutrients in the improvement of cold tolerance in maize plants Narges Moradtalab*1, Markus Weinmann1, Klara Bradacova, Nino F. Weber, Muhammad Imran2, Günter Neumann1 1Institute of Crop Science (340h), Universität Hohenheim, Stuttgart, Germany *n.moradtalab@uni-hohenheim.de 2 Institut für Pflanzenernährung und Bodenkunde, Christian-Albrechts-Universität zu Kiel, Germany

Low soil temperature in spring is a major constraint for cultivation of tropical crops in temperate climates and is associated with

inhibition of root growth and activity. In this study, the effects of supplementation with nutrients involved in stress defense

adaptations (Zn, Mn, Zn/Mn-enriched seaweed extract, Si) were studied in maize (Zea mays cv. Colisee) plants exposed to low

root zone temperatures (RZT) during early growth. Plants were cultivated in a root cooling system for regulation of the RZT.

After germination at 20 °C, the cold stress treatment (12-14 °C) started at 14 days after sowing to simulate a cold period in

spring. Si (K2SiO3) and seaweed extract (Algavyt) were applied by fertigation and Zn/Mn as seed dressing. At the end of the

experiment, leaf damage, biomass production, relative chlorophyll content (SPAD), root length, nutritional status and superoxide

dismutase (SOD) activity in the shoot and roots were determined. Positive effects on plant growth and particularly on root

development at low RZT were detected for all supplements in a similar order of magnitude. Leaf damage and plant growth

inhibition in cold-stressed plants were associated with a low Zn/Mn nutritional status, which was improved by the treatments

with external micronutrient supply to the plants but surprisingly also by Si application. This was associated with an increased

activity of superoxide dismutase in shoot and roots, as a key enzyme for detoxification of reactive oxygen species, depending on

Zn and Mn, as cofactors. First field experiments with Zn/Mn and Si as seed priming and foliar application also revealed improved

plant performance under spring cold stress. The findings suggest that Si can interact with Zn/Mn nutrition in maize plants

exposed to low temperature stress thereby promoting oxidative stress defense. However, the underlying mechanisms of this

interaction remain to be elucidated.

Keywords: Silicon, Cold stress, Maize, Antioxidative defense, Nutrients deficiency,

Fig 1. (A) Shoot growth of maize exposed to low root zone temperature12-14 °C (B) Effects of micronutrient and Si application on total root length of maize exposed to low root zone temperature at 6 weeks after sowing. Significant differences are indicated by different characters (P<0.05).

B

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REPEATED DROUGHT STRESS CYCLES EXHAUST ANTI-OXIDATIVE CAPACITY AND ALTER SOLUBLE SUGAR POOLS OF

YOUNG SUGAR BEETS

Monika A. Wimmer1, Heiner E. Goldbach1 1 Institute of Crop Science and Resource Conservation – Plant Nutrition, University of Bonn; m.wimmer@uni-

bonn.de

In most drought experiments, plants are exposed to single stress events. However, drought stress in Central Europe is often not terminal, but intermittent, which means that plants typically undergo non-lethal, but repeated drought stresses throughout their development. Little is known about the physiological and metabolic impacts of consecutive drought cycles, and how they may affect the plants’ ability to respond to subsequent stresses.

In the present experiment, sugar beets were grown in pots for 6 weeks, and subjected to no stress (control), or one (D1), two (D2) or three (D3) drought cycles preceding harvest. Each drought cycle consisted of 6 days of water cutoff, followed by 4 days of re-watering. At harvest, all plants were of the same age, and only differed in their drought history. Parameters of water relations, soluble sugars, starch and anti-oxidative metabolites were determined at two day intervals during drought and recovery.

In all drought treatments, visible wilting occurred between day 4 and 6, when relative water content and osmotic potential dropped to similar levels. However, both parameters did not recover to control levels in D2/D3 plants. Ascorbate pools were depleted more quickly in subsequent drought cycles, and only D1 plants recovered to control levels. We also observed highly dynamic changes in soluble sugars and starch, which were most prominent during the recovery period and clearly distinct between D1 and D2/D3 plants.

Collectively, our results indicate that repeated drought cycles can exhaust the anti-oxidative capacity and soluble sugar pools of young sugar beet plants, even though all plants visibly recovered during re-watering. Ongoing work aims to identify genotypic differences in the ability to fully and quickly recover from non-lethal drought stress. If sufficient genetic variability is present, this trait might be valuable for breeding of drought tolerant varieties in Central Europe.

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HIGH-THROUGHPUT PHENOTYPING OF HYBRID WHEAT UNDER DROUGHT AND HEAT STRESS

Elisabeth Becker and Urs Schmidhalter Technical University of Munich, Chair of Plant Nutrition,

Emil-Ramann-Str. 2, 85350 Freising, Germany, ebecker@wzw.tum.de

ABSTRACT

Drought and heat represent one of the major limiting factors of plant growth and production worldwide and hence play a crucial role in global food security (Turner et al. 2011). With a rising population, the pressure of food production on arable land available per capita is increasing. Due to the progress of climate change, this problem is becoming increasingly serious. In most countries cereals, especially wheat, are the basis of daily carbohydrate intake (Shiferaw et al. 2011). Therefore, breeders all around the world are focusing on the development of tolerant wheat cultivars regarding drought and heat stress. Wheat hybrids seem to be promising and occasional reports exist, indicating an enhanced drought stress tolerance. Heterosis is leading to an increased grain yield and to an advantage regarding yield stability to abiotic stress (Jordaan 1996). It is to be expected that yield increases under drought due to heterosis in hybrids do not only depend on a single mechanism but also on a combination of various properties. However, detailed data about responsible mechanisms have not yet been elucidated. At present, breeding efforts are considerable and prospective varieties need to be tested in multi-annual field experiments. Spectral and thermal measurements offer new approaches to make non-destructive measurements of, e.g. the plant water status (Hackl et al., 2014). In 2014 and 2015, 14 high performance wheat varieties and six wheat hybrids were grown under a rain-out shelter at the research station Dürnast in Bavaria. Drought stress was conducted during anthesis and grain filling by withholding rainfall. Heat stress was generated under the shelter during warm and sunny days. To compare the impact of drought and heat stress, control plants were grown outside the shelter. During the stress period morphological and physiological parameters such as plant ground cover, relative leaf water content, N-translocation, carbon-isotope discrimination and plant height were measured. Furthermore, plant reflection was assessed with 5 passive and active sensors in a high-throughput mode with the mobile phenotyping platform PhenoTrac 4 (Erdle et al., 2011), developed by the Chair of Plant Nutrition from the Technical University of Munich. Additionally, plant temperature was measured with a thermal camera and IR-Sensors. Results, illustrating the drought and heat tolerance of wheat hybrids and lines, will be presented.

References

Erdle , Mistele B, Schmidhalter U, 2011. Field Crops Research, 124: 74-84.

Hackl H, Hu Y, Schmidhalter U, 2014. Functional Plant Biology 41: 860-873.

Jordaan JP, 1996. Increasing Yield Potential in Wheat: Breaking the Barriers. Mexico, D.E. 66-74

Shiferaw B, Prasanna B, Hellin J, Bänziger M, 2011. Food Security, 3: 307-327.

Turner N C, Li F M, Xiong Y C, Siddique K H M, 2011. Crop and Pasture Science, 62: i-ii.

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IMPROVING THE NUTRIENT AND WATER EFFICIENCY OF GRAIN MAIZE

Hütsch, B.W., Jung, S., Schubert, S. Institute of Plant Nutrition (iFZ), Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany, e-mail: Birgit.W.Huetsch@ernaehrung.uni-giessen.de

During the last decades, the harvest index (HI) of many agricultural crops was genetically (by breeding) or agronomically (by the use of growth regulators) increased. A prominent example is wheat (Triticum aestivum L.). For this crop species, an average increase of the HI by 50% (from 0.34 to 0.51) was related to an increase in average yield by 60% (Hay, 1995). In contrast to wheat, the HI of maize was already 0.40 to 0.50 in the 1930’s, when hybrids were widely introduced, and it has not increased ever since. There is a lack of increase in grain yield per plant, as the sole method of increasing yield per unit area has been to increase plant density (Duvick, 2005). In maize, opposite to wheat, a close positive correlation between dry matter accumulation and grain yield exists (Tollenaar and Lee, 2006). However, the production of vegetative biomass which is usually not utilized requires high amounts of water and nutrients. The increase of the HI may thus improve water and nutrient efficiency, allowing a more sustainable production. In future, this will be particularly important as water for irrigation becomes less available, and as farmers may be forced to reduce application of fertilizers in order to meet environmental limits.

There are two possible ways to increase maize HI: Firstly, one could try to reduce vegetative shoot growth without negatively affecting grain yield by manipulation of specific plant hormones (e.g. gibberellins). Secondly, one could try to increase grain yield by improved kernel setting. Even under growth conditions without source limitation, a high percentage of kernels is aborted around pollination (Hütsch et al., 2014). There is evidence that the activity of acid invertase and thus the supply of hexoses is also not necessarily limited, but the transport of hexoses from the apoplast into the developing kernel via H+-cotransport (sink limitation; Hütsch et al., 2015). For this transport the activity of the plasmalemma H+-ATPase is essential. In salt-stressed maize plants, which are particularly prone to kernel abortion, we found a decrease in ATPase activity in maize kernels around pollination.

We conducted container experiments, growing maize under optimal growth conditions und under salt or drought stress. The container technique, which was developed in our institute, allows to simulate the cultivation of plants under field-like conditions with a soil profile of 90 cm. Under drought stress the HI was 29% higher than in the control, the water use efficiency was improved by 42%, and the grain yield was unchanged. Thus, also in maize it is possible to break the close correlation between dry matter accumulation and grain yield. Knowledge about the underlying mechanisms will provide tools for improvement of water and probably nutrient efficiency, contributing to more sustainable crop production.

References: Duvick, D.N. (2005): The contribution of breeding to yield advances in maize (Zea mays L.). Adv. Agron. 86, 83-

145. Hay, R.K.M. (1995): Harvest index: a review of its use in plant breeding and crop physiology. Annals of Appl.

Biol. 126, 197-216. Hütsch, B.W., Saqib, M., Osthushenrich, T., Schubert, S. (2014): Invertase activity limits grain yield of maize

under salt stress. J. Plant Nutr. Soil Sci. 177, 278-286. Hütsch, B.W., Jung, S., Schubert, S. (2015): Comparison of salt and drought-stress effects on maize growth and

yield formation with regard to acid invertase activity in the kernels. J. Agron. Crop Sci. 201, 353-367. Tollenaar, M., Lee, E.A. (2006): Dissection of physiological processes underlying grain yield in maize by

examining genetic improvement and heterosis. Maydica 51, 399-408.

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DISCRIMINATING NITROGEN UPTAKE PARAMETERS OF MAIZE CULTIVARS WITH HIGH-THROUGHPUT PHENOTYPING AT THE REPRODUCTIVE PHASE Friederike Gnädinger, Urs Schmidhalter Chair of Plant Nutrition, Technical University of Munich (TUM), Munich, Friederike.Gnaedinger@wzw.tum.de Friederike Gnädinger Key Words Hyperspectral, Nitrogen Content, Nitrogen uptake, Nitrogen Nutrition Index, Phenotyping Abstract With the continuous rise of the world population better performing and resilient cultivars are required to match the needs for food, feed and fibre. The application of mineral nitrogen fertilizers is the most important input factor to achieve high yields of biomass and grain. However, high N-input farming associated with low nitrogen use efficiency (NUE) may lead to great N-losses affecting the environment, whereas low input farming systems rely strongly on the soil fertility and lead in the long-run to nutrient depletion. The aim of this work is to develop efficient phenotyping procedures to assess differences in nitrogen uptake and nitrogen use efficiency at the reproductive stage of maize cultivars grown at different nitrogen levels. Both, active and passive sensor systems were tested to assess such traits and the spectral information was related to destructively determined parameters of the aboveground biomass and nitrogen uptake at flowering, the kernel dough stage and at grain harvest. In general, spectral indices obtained from the hyperspectral sensor were better related to the biomass or the nitrogen uptake of maize cultivars than those obtained from active sensors. Among the active sensors, only the CropCircle (Cc) exhibited a weak correlation, with no correlations being observed for the other tested active sensors Greenseeker and ALS. The best correlations were obtained at wavebands around 700 nm at flowering and the kernel dough stage with improved correlations being observed at the kernel dough stage. In general nitrogen uptake could better be detected than biomass at flowering and at the kernel dough stage with enhanced relationships found at the latter stage. During flowering better relationships were found for total biomass compared to leaf biomass, however, this was reversed at the kernel dough stage (Table 2). PLSR models were calculated for two experimental years, using data from 2015 as calibration data set and from 2014 as validation data set and allowed to predict leaf nitrogen uptake with R2 = 0.70 and an RMSE of 10.8 kg N ha-1. The results illustrate that spectral indices are useful for describing the nitrogen status of maize canopies at the reproductive stage until maturity with the nitrogen nutrition index providing particularly useful information, by valuing the nitrogen uptake in relation to the aboveground biomass. The phenotyping platform PhenoTrac 4 from TUM allowed to obtain enhanced information of the complex traits nitrogen uptake and nitrogen use efficiency. In combination with improved algorithms using both optimized indices as well as PLSR models promising results were obtained to further narrow the gap between genomics and phenomics.

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SHORT-TERM RESPONSE AND NITROGEN USE EFFICIENCY OF BIOGAS RESIDUE APPLICATION TO WINTER WHEAT

Amanda Araujo de França, Karolin Kunz, Sabine v.Tucher and Urs Schmidhalter

Technical University of Munich, Chair of Plant Nutrition,

Emil-Ramann-Str. 2, 85350 Freising, Germany, franca@wzw.tum.de

ABSTRACT

The demand of renewable sources for energy production has increased rapidly

around the world during the last years. Driving forces are government incentives, since these

sources represent a potential way to meet the growing energy demands and to reduce

emissions of greenhouse gases, which are associated mainly with the use of fossil fuels. In

Germany biogas energy, produced from agricultural, industrial or urban wastes, is one of the

faster growing renewable sources, chiefly because in many cases it entails a small carbon

footprint. Although biogas looks like a great idea to produce green energy, it creates a great

amount of residues. These residues can be used as an attractive organic

fertilizer, since they enable the recovery of valuable elements that were used previously for

crop fertilization. For an efficient use of biogas residues and to minimize environmental

impacts, it is fundamental to understand how they behave under different soil and climatic

conditions. Despite the use of N mineral fertilizers in agriculture is well-known, studies

evaluating the use of biogas residue as a source of N on the field level are still scarce.

Therefore, the objective of this study is to evaluate the N-use efficiency of biogas

residues, moreover to investigate the impact of different soils on the fate of N from biogas

residue in the soil-plant system in the short-term. The field experiments were conducted

in Dürnast at the experimental station of the Chair of Plant Nutrition, where pits with 1.5 x 2.0

x 0.3 m were excavated and re-filled with soils originating from eight different regions in

Bavaria. Winter wheat is grown in the plots. For the sake of comparison, additionally to the

biogas residue application, plots without fertilization and plots fertilized with ammonium

sulfate were also studied. The treatments consist of the application of each fertilizer with an

equal amount of NH4+-N and are applied at two different growing stages of wheat. In order to

evaluate the dynamics of N, the fertilizers were enriched with the isotope 15N. In different

growing stages, plants were sampled to measure the N content, plant weight, biomass and

grain yield, as well as to quantify the 15N, which permits the identification of the N

source. Spectral reflectance measurements were assessed in the field to track the

development of the plants. In addition, the soil temperature of the plots was constantly

monitored and soil samples were collected and analyzed chemically. Results from the two-

years´ experiment will be presented.

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PLACEMENT OF P AND N TO IMPROVE CROP NUTRIENT ACQUISITION AND YIELD: A META-ANALYSIS

Peteh Mehdi Nkebiwe1, Markus Weinmann2, Asher Bar-Tal3, Torsten Müller1

Mehdi.Nkebiwe@uni-hohenheim.de

Affiliations and addresses:

1: Fertilisation and Soil Matter Dynamics (340 i),

2: Nutritional Crop Physiology (340 h),

Institute of Crop Science,

University of Hohenheim,

70593 Stuttgart,

Germany

3: Institute of Soil, Water and Environmental Sciences, The Agricultural Research Organisation of Israel (ARO) – The Volcani Centre,

P.O.B. 6,

Bet Dagan 50250,

Israel

In farming soils, plant-available nitrogen (N) and phosphorous (P) may be insufficient for crop

production although total N or P concentrations are high. Therefore, N and/or P fertilizer is

commonly applied to field soil by broadcast although broadcast does not ensure that a significant

part of applied fertilizer is available for optimal root uptake. Fertilizer placement in soil, which refers

to precise application of specific fertilizer formulations close to seeds or plant roots to ensure high

nutrient availability, may be a more effective alternative to broadcast application. The objectives of

our study were: (1) to compile existing techniques for fertilizer placement in soil and identify

fertilizers suitable for subsurface placement; and (2) to quantify the relative effects of subsurface

fertilizer placement to fertilizer broadcast on crop performance. We reviewed literature on fertilizer

placement and performed a meta-analysis according to baseline contrasts on the relative effects of

fertilizer placement to fertilizer broadcast on crop yield, nutrient concentration and content in

above-ground plant parts. For the meta-analysis, we used 1022 datasets published in 40 field studies

from 1982 to 2015 (85 % of studies from 2000). Results revealed that fertilizer placement led to 3.7 %

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higher yield, 3.7 % higher concentration of nutrients in plant parts and 11.9 % higher nutrient uptake

than fertilizer broadcast. For urea+sphosphate, ammonium+phosphate, urea, ammonium and

soluble phosphate uncombined, fertilizer placement of led respectively to 27.3 %, 14.7 %, 11.6 %, 3.8

% and 0.0% increase in yield in comparison to broadcast. Increase in relative yield and relative

nutrient uptake from subsurface placement of urea, urea+phosphate, ammonium or

ammonium+phosphate to increase with increasing placement depth down to more than 10 cm.

Effects of placing of sparingly soluble alternative P fertilizers combined with ammonium or urea in

subsurface soil has been hardly investigated and remains unknown. Results show that deep

subsurface placement of ammonium (±P) or urea (±P), solid or liquid manure is more effective to

improve nutrient uptake and yield than broadcast.

Keywords: fertilizer placement; meta-analysis; yield; nutrient mobilization; nutrient uptake

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COMBINATION OF X-RAY MICRO TOMOGRAPHY AND SOIL SOLUTION STUDIES TO ANALYSE ROOT SYSTEM DEVELOPMENT AND SOIL CHEMISTRY IN SITU AS A RESPONSE TO DIFFERENT N-FORMS

Blaser, S.R.G.A.1, Vetterlein D.1

1Helmholtz Centre for Environmental Research – UFZ, Department of Soil Physics, Theodor-Lieser-Str. 4, 06120 Halle (Saale), Germany, sebastian.blaser@ufz.de

Only 30-50% of the applied N fertilizers are captured by crops. Therefore increasing both, N use efficiency and crop production is a major challenge for sustainable agriculture. Urea is the most widely used N fertilizer. Urea undergoes rapid hydrolisation applied at the soil, after which ammonium is oxidized to nitrate. Due to the use of nitrification inhibitors, the importance of NH4

+ as N source has increased. NH4+ is more protected against nitrification

creating benefits for environment and plant growth.

Application of urea granules with or without inhibitors is expected to result in a spatially heterogeneous and temporally dynamic distribution of different N-forms in the soil matrix. Plasticity of root growth can be observed when roots are exposed to localized sources of nitrogen. Two general ways of response seem to be common including systemic repression of lateral root growth by high N status of the plant and local stimulation by initiation and elongation or inhibition of lateral root growth by availability of NO3 or NH4. These effects are related to the nutritional and signalling effect of the respective ion but dynamics are difficult to observe due to the opaque nature of soil.

The aim of this work is to verify hypotheses, derived from studies with flow-through-systems or gel plates, for soil systems, using X-ray micro tomography to visualize and characterize dynamic root system development in soil as a response to different N-forms in situ. These analyses are combined with soil chemical studies in the same temporal resolution. Micro suction cups are installed to extract soil solution with known distance to roots and localized fertilizer. This setup is applied to answer the questions when, where and why do modifications of root system architecture occur in relation to soil chemical and N-nutritional conditions.

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TRIGGERING PLANT RESPONSES TO P LIMITATION – A NOVEL MODE OF ACTION FOR MICROBIAL PLANT GROWTH PROMOTION?

Nino F. Weber1, Shikta Khar1, Nicole Probst1, Mira Kuhlmann1, Uwe Ludewig1, Günter Neumann1

1: Universität Hohenheim, Stuttgart, niweb@uni-hohenheim.de

Since many years various modes of action for plant growth promotion by PGPRs have been discussed. Indirect mechanisms comprise an improvement of plant nutrient supply via mobilization of sparingly available nutrients in the rhizosphere. Other mechanisms directly stimulate plant growth by interference with phytohormonal balances via production of bacterial auxin derivatives, reduction of plant hormones with growth-inhibitory functions (ethylene) or triggering internal plant-hormonal signaling by bacterial metabolites, such as AHLs.

In this study, we treated maize (Zea mays cv Colisee) grown on natural field soil under greenhouse conditions with two commercially available products, containing well-characterized PGPRs, such as Pseudomonas sp. DSMZ 13134 (Proradix®) and the Bacillus amyloliquefaciens strain FZB42. RNA-Seq analysis of RNA extracted from two week old maize roots, that did not yet show any significant plant growth stimulation, and a subsequent transcriptomic profiling using the PageMan/MapMan tool, revealed an up-regulation of various abiotic and biotic stress induced genes, particularly many genes connected with ethylene production as well as ethylene-, and jasmonate-induced signaling. However, auxin-regulated genes or genes involved in auxin biosynthesis were down-regulated or remained unchanged, suggesting no typical plant-microbial interactions at the hormonal level. Additionally, the secondary metabolism (phenolics), lipid and protein degradation and the PEP carboxylase pathway were activated, whereas genes involved in the TCA cycle and in DNA or nucleotide synthesis were repressed.

The observed gene expression patterns are very similar to those induced by phosphorus (P) limitation. This may indicate a P competition of PGPRs and host plant during early plant development. This competition was confirmed by various experiments conducted on soils with low P availability. A lower metabolic Pi status of plants treated with PGPRs supports the hypothesis that PGPRs may induce a moderate P limitation during early plant development with subsequent stimulation of root growth as a typical and well-documented response. On soils with moderate P availability, this may be an advantage for acquisition of P and other nutrients finally leading to a stimulation of plant growth.

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Figure 1: Digestate patch-fertilization of Sida hermaphrodita, grown on a sandy substrate. First roots avoid the digestate patch but finally form a root cluster.

DIGESTATE PATCH-FERTILIZATION OF SIDA HERMAPHRODITA ON MARGINAL SOIL

Nabel M1, Poorter H1, Temperton V1,2, Schrey S1, Koller R1, Jablonowski ND1

1Forschungszentrum Jülich, IBG-2: Plant Science, Germany, m.nabel@fz-juelich.de

2Institute of Ecology, Leuphana University Lüneburg, Germany

Abstract submitted for an oral presentation; thematic focus: Rhizosphere and Nutrient cycles

Improving fertility of marginal soils for non-food biomass production is a strategy for reducing land use conflicts between food and energy crops. Perennial energy crops like Sida hermaphrodita allow for a continuous energy-crop production without the need of soil cultivation and its accompanied disturbance of the soil fertility. Following the idea of closed nutrient-loops, biogas digestates are applied as fertilizer and soil amendment. However, adverse effects on root growth and nitrogen losses via leaching are known to hamper plant growth, when digestates are applied on marginal soils. Further, its conventional application comes along with soil cultivation, disturbing the development of the soil fertility.

We propose digestate patch fertilization. We show that it minimizes negative effects of digestate fertilization by reducing the phytotoxic effect on the root growth and increasing nutrient use efficiency. Further, its application in the field would reduce the soil disturbance to a minimum.

We grew S. hermaphrodita in large mesocosms outdoors and in rhizotrons filled with a marginal sandy substrate (Fig. 1), and compared conventional digestate application with digestate patch-fertilization and a mineral fertilizer control.

As expected, in rhizotrons root-growth was hampered in the conventional digestate treatment and around the digestate patch in the first 30 days after planting. We will correlate this phytotoxic effect to the concentrations of organic acids, ammonia and nitrite in the rhizosphere. However after 60 days, roots formed a root cluster surrounding the digestate patch (Fig. 1) indicating foraging for delayed mobilized N from the patch.

In outdoor mesocosms, the biomass yield of digestate patch-fertilized S. hermaphrodita on a marginal substrate was increased by 15% compared to conventional digestate fertilization.

We conclude that digestate patch fertilization may contribute to a sustainable use of marginal soils for an improved cultivation of perennial energy-crops.

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Reduced apoplastic acidification caused by altered PM H+-ATPase activity

is responsible for early growth reduction of maize under Mg deficiency

Stephan Jung, Franziska Faust, and Sven Schubert

Institute of Plant Nutrition (iFZ), Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392

Giessen (Germany)

Stephan.Jung@agrar.uni-giessen.de

Abstract

Magnesium (Mg) deficiency is frequently observed in agricultural crops with an insufficient

Mg fertilization regime, which finally results in yield depression. Earlier studies dealt with the

effect of Mg deficiency on physiological processes after a prolonged time of more or less

severe Mg deficiency (Hermans et al., 2004; Mengutay et al., 2013; Jezek et al., 2015). Here,

the development of magnesium deficiency in maize (Zea mays L.) was studied in order to

identify the physiological process that is most sensitive to insufficient Mg supply. A focus

was on the master enzyme plasma membrane (PM) H+-ATPase since it is sensitive to low Mg

conditions (Hanstein et al., 2011). Two treatments were applied to maize grown in

hydroponics: A sufficient and a low Mg concentration were used in time-course experiments

to investigate parameters which are considered important to characterize key physiological

processes. The leaf area was reduced first by Mg supply, concomitant with a decrease in

apoplastic acidification, changes in PM H+-ATPase activity, as well as the respective RNA

isoform abundance and cell-extension growth. Sugar and protein concentrations remained

unchanged in growing tissue suggesting neither source nor sink limitation for the growing leaf

tissue. Cell extension rather than cell division or assimilate availability in sink tissue was the

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most sensitive process under developing Mg deficiency in maize. It is demonstrated for the

first time that reduced apoplastic acidification primarily limited plant growth of maize under

Mg deficiency. PM H+-ATPase activity from Mg-deficient plant material was higher in vitro

compared to control under high Mg assay concentrations (5 mM), implicating an adaption of

the enzyme. This adaptation was not beneficial under low Mg concentrations in vivo:

Apoplastic acidification was reduced regardless of the adaptation, resulting in reduced

extension growth of maize under Mg deficiency.

References:

Hanstein S, Wang X, Qian X, Friedhoff P, Fatima A, Shan Y, Feng K, Schubert S (2011) Changes in cytosolic Mg2+ levels can regulate the activity of the plasma membrane H+-ATPase in maize. Biochem J 435: 93–101

Hermans C, Bourgis F, Faucher M, Strasser RJ, Delrot S, Verbruggen N (2004) Magnesium deficiency in sugar beets alters sugar partitioning and phloem loading in young mature leaves. Planta 220: 541–549

Jezek M, Geilfus C-M, Bayer A, Mühling K-H (2015) Photosynthetic capacity, nutrient status, and growth of maize (Zea mays L.) upon MgSO4 leaf-application. Front Plant Sci. 5: 781

Mengutay M, Ceylan Y, Kutman UB, Cakmak I (2013) Adequate magnesium nutrition mitigates adverse effects of heat stress on maize and wheat. Plant Soil 368: 57–72

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EFFECT OF DIFFERENT PH LEVELS ON GROWTH, BIOMASS PARTITIONING AND LEAF MINERAL COMPOSITION OF VARIOUS GOURD GENOTYPES AND WATERMELON CULTIVARS Firdes Ulas1, Halit Yetisir1 and Abdullah Ulas2

1 Department of Horticulture, Faculty of Agriculture, Erciyes University, Kayseri- TURKEY 2 Department of Soil Science and Plant Nutrition, Faculty of Agriculture, Erciyes University, Kayseri-TURKEY, firdescetin84@hotmail.com Abstract Soil pH is one of the important factors determining soil fertility and physicochemical state of the soil. A plant’s ability to tolerate various pH levels depends on it’s ability to take in and use nutrients at changeable concentrations in the soil solution. Crop yields are much lower than expected when cultivated on acid or alkaline soil conditions. The aim of the study was to screen for the genotypic differences in different pH levels in relation to growth and morphology of different gourd genotypes and watermelon cultivars under greenhouse conditions. Two watermelon cultivars (Crimson Tide and Crisby) and 20 different gourd (Lagenaria siceraria landraces Cucurbita maxima) genotypes were grown in 8 L pots filled continuously aerated nutrient solution under three different pH levels (8.5, 6.5 and 4.5) with three replications. The results indicated that shoot (stem and leaf fresh and dry matter, leaf area) and root (root fresh and dry matter, root length) growth significantly (P<0.001) affected by different pH levels. Highly significant (P<0.001) genotypic variation in shoot and root growth was found among genotypes and cultivars. Growth response to supplied pH, i.e. the interaction between pH and genotype, was also highly significant (P<0.001) in some shoot and root growth parameters. Also, shoot mineral element composition (P, K, Ca, Mg, Fe, Mn, Zn, B) was also significantly affected (P<0.001) by different levels of pH supply. Highly significant interaction (P<0.001) between pH and genotype was found in shoot mineral element composition. Key words: nutrient solution, gourd genotypes, genotypic difference, pH tolerance

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IDENTIFICATION OF MECHANISMS CONTRIBUTING TO BORON-EFFICIENCY IN RAPESEED AND ARABIDOPSIS GENOTYPES

Benjamin Pommerrenig1, Annett Bieber1, Jacqueline Fuge1, Till Arvid Diehn1, M. Desiree Bienert1, Renate Schmidt1, Michael Melzer1, Astrid Junker1, Thomas Altmann1

and Gerd P. Bienert1

1: Leibniz Institute of Plant Genetics and Crop Plant Research, 06466 Gatersleben, Germany, E-Mail: bienert@ipk-gatersleben.de

Boron (B) is an essential micronutrient for plants. Our group addresses the question of how B deficiency-sensitive Brassica crops process and regulate their B status during vegetative and reproductive growth. To work in exactly defined B-deficient conditions with plants in early developmental stages is very difficult as B occurs as a trace contaminant essentially everywhere. Therefore the identification of B deficiency tolerant Brassica napus genotypes demanded the development of high-throughput compatible “B-free” growth conditions. We identified a soil-substrate, which has B levels below the detection limit of 0.1 mg B (kg soil)-1. Subsequently, we established two independent screening conditions which allow i) a phenotypic description of B-efficiency shoot traits in soil-substrate pot conditions and ii) the quantitative assessment of B efficiency via the evaluation of parameters describing the rapid root- growth inhibition and system architecture under B deficiency in in vitro growth assays. We screened 599 rapeseed cultivars from the IPK Genebank North for B deficiency tolerance. Both screens resulted in the identification of three highly B deficiency tolerant cultivars. These three highly B deficiency tolerant and three representative B deficiency sensitive cultivars were selected for further comparative analyses. Elemental analysis revealed significant differences in B contents and B compartmentalization of B deficiency tolerant and sensitive plants when grown under B-deficient conditions but not under standard conditions. These results indicate that the B deficiency tolerant cultivars can grow with a very limited amount of B. The genetic, morphological, physiological and molecular differences between B-efficient and -inefficient cultivars are currently analysed. A special focus is on the identification of transport processes to and within the highly B-demanding reproductive organs. Nodulin26-like Intrinsic Proteins (NIPs) and Boron transporters (BORs) are essential for plant B uptake and distribution. The systematic focus on the characterization of BnaNIPs and BnaBORs will clarify their role in the B response network. A second high throughput phenotyping experiment was performed with 188 Arabidopsis accessions in order to identify B deficiency tolerant varieties. B deficiency tolerant accessions have been identified and are currently analysed for the expression of B transport protein-encoding genes and root system architecture traits under B deficient conditions. Currently, we compare mechanisms (B transport and cell wall regulation) in Arabidopsis and its closely related sister crop genus B. napus under B sufficient and B deficient conditions in efficient and inefficient genotypes in detail and aim for identifying the genes being responsible for the B deficiency tolerance.

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AMMONIUM TRANSPORT INHIBITION BY CALCINEURIN B-LIKE INTERACTING KINASE 23 (CIPK23) Tatsiana Straub1, Uwe Ludewig1 and Benjamin Neuhäuser1

1; Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Fruwirthstr. 20, D-70599 Stuttgart, Germany, e-mail: benjamin.neuhaeuser@uni-hohenheim.de Ion transport in plants is not only strictly regulated on a transcriptional, but also posttranslational level. Enzyme modifications like phosphorylation provide a rapid regulation mechanism for many plant ion transporters and channels. Upon elevated ammonium concentrations in the rhizosphere the high affinity AMmonium Transporters (AMT) in Arabidopsis thaliana are efficiently inactivated by phosphorylation to avoid toxic accumulation of cytoplasmic ammonium. External ammonium stimulates the phosphorylation of a conserved threonine in the cytosolic AMT1 C-terminus, which allosterically inactivates the AMT1 trimers. Using a genetic screen, we identified that CalcineurinB-like interacting kinase 23 (CIPK23), a kinase also regulating the most abundant NO3

- transporter NRT1;1 and activating the K+ channel AKT1, modulates ammonium transport and growth sensitivity to ammonium. Loss of CIPK23 increased root NH4

+ uptake after ammonium shock and conferred hypersensitivity to ammonium and the transport analog methylammonium. AtAMT1;2 is inactivated by direct interaction with active CIPK23. CBL1 is needed to regulate the kinase activity. Since K+, NO3

- and NH4+ are quantitatively the major ions taken

up by plants, CIPK23 appears to occupy a key position in controlling ion balance and ion homeostasis in the plant cell.

AMT1;2 regulation by CIPK23 and CBL1. At low external ammonium concentrations, AMTs are not phosphorylated and conduct NH4

+ into root cells. Elevated external NH4+ triggers CBL1 mediated activation of

the CIPK23 kinase and relocation of the kinase to the plasma membrane and into the AMT/CBL1/CIPK23 complex, where CIPK23 phosphorylates AMT1;2. This phosphorylation inactivates AMT1;2 and prevents ammonium accumulation to toxic levels.

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Silicon reduces iron uptake in rice.

Martin Hinrichs and Manfred K. Schenk

Institute of Plant Nutrition, Leibniz Universität Hannover, Herrenhäuserstraße 2, 30419 Hanover, Germany, hinrichs@pflern.uni-hannover.de

Silicon nutrition enhances the development of exodermal Casparian Bands (CB) in rice resulting

in a decreased radial oxygen loss under anaerobic conditions. By means of a custom made

microarray twelve differentially regulated genes were identified (Fleck et al., 2015). To get full

insight in the molecular changes induced by Si a 45k gene chip approach was used. Rice plants

were grown with Si (30 mg/L) and without Si (< 3 mg/L) for 28 days in the growth chamber.

Sections of 2-6 cm behind the tip of adventitious roots were harvested for RNA extraction. The

transcriptomic data revealed the regulation of genes related to the phenylpropanoid-pathway

which is essential for CB formation. Surprisingly, also an up regulation of genes involved in Fe

homeostasis of strategy II plants was observed, indicating a shortage of Fe. We hypothesized that

the enhancement of exodermal CB by Si reduces the Fe flow into the root cortex and thus Fe

uptake of plants.

Therefore, the influence of Si supply on apoplasmic Fe content in the root cortex was

investigated at different Fe levels (0.2, 2 and 10 mg/L in form of FeEDDHA) and with different Fe

forms (2 mg/L given as EDDHA, EDTA and sulfate) according to Bienfait et al. (1985). The

experiments contained six replicates. Si supply reduced the Fe concentration in shoot matter

regardless of Fe level and Fe form and decreased as well the concentration of root apoplasmic

Fe. In line with this Si enhanced the expression of Fe homeostasis genes such as NAS2, NAAT1,

OsYSL2/15/16, OsHRZ1, TOM1 and ENA1. The obtained results support the hypothesis that Si

decreased Fe uptake of plants since the exodermal CB formation reduced the Fe flow into the

apoplast thus stimulation the expression of Fe homeostasis genes. In the apoplast of root cortex

Fe is mobilized by the release of DMA (Yehuda et al., 1996; Zhang et al. 1991).

References

Bienfait, H. F., van den Briel, W., & Mesland-Mul, N. T. (1985): http://doi.org/10.1104/pp.78.3.596

Fleck, A. T., Schulze, S., Hinrichs, M., Specht, A., Waßmann, F., Schreiber, L., & Schenk, M. K. (2015): http://doi.org/10.1371/journal.pone.0138555

Yehuda, Z., Shenker, M., Romheld, V., Marschner, H., Hadar, Y., & Chen, Y. (1996): http://doi.org/10.1104/pp.112.3.1273

Zhang, F. S., Römheld, V., & Marschner, H. (1991): http://doi.org/10.1104/pp.97.4.1302

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SITE-DEPENDENT DIFFERENCES IN DNA METHYLATION AND THEIR IMPACT ON

PLANT ESTABLISHMENT AND PHOSPHORUS NUTRITION IN POPULUS

TRICHOCARPA

Brigitte Schönberger1 and Uwe Ludewig1

1 University of Hohenheim, Institution of Crop Science, Department of Nutritional Crop

Physiology, D-70599 Stuttgart, Germany, Brigitte_Schoenberger@uni-hohenheim.de

Abstract

Higher plants, like trees, have a repertoire of mechanisms to increase phosphorus (P)

acquisition when P supply is low. The genetic and physiological basis of these mechanisms

has been studied extensively. In addition, phosphorus starvation was recently suggested to

transiently affect DNA methylation in two annual plant species. However, the impact of

differential DNA methylation and microRNAs (miRNAs) on gene expression, as well as on

P-related physiology, is largely unknown in perennials.

In this study, clonal Populus trichocarpa (cv. Muhle Larson) starting material (cuttings) from

two different locations was grown in hydroponic culture with different P levels. These clones

established differently in common growth chambers, suggesting epigenetic site-dependent

memory. Using bisulfite sequencing, site-specific genome-wide methylomes were determined

and the gene and miRNA expression of differentially methylated regions (DMRs) was

quantified via qPCR. Methylation differences were nucleotide context-specific and a few

genes encoded in top-differentially methylated regions were differentially expressed.

Furthermore, miRNAs and their target genes in DMRs were extensively regulated in an

organ-specific way. A general site-dependent transcriptional repression by DNA methylation

was detected, but differential DNA methylation was not related to P nutritional genes,

although recent studies described P-starvation induced DNA methylation changes. However,

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a few differentially methylated miRNAs, together with their target genes, showed P-

dependent expression profiles, indicating miRNA expression differences as a P-related

epigenetic modification in poplar. Hence, it was shown that differences in DNA methylation

or differentially methylated miRNAs might influence plant establishment and partially

correlate with P acquisition, and thus be responsible for a site-dependent adaptation and

growth performance.

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ZINC CONTROLS LEAF SIZE BY PROMOTION OF FLOWERING LOCUS T IN EARLY-FLOWERING ARABIDOPSIS THALIANA

Xiaochao Chen and Uwe Ludewig

Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim

Fruwirthstr. 20, 70593 Stuttgart, Germany

xiaochao.chen@uni-hohenheim.de

Plant growth is generally limited if an essential element is insufficiently available in

soil. However, a subset of Arabidopsis accessions, including Columbia (Col-0),

produced larger rosettes in soil low in Zn than in Zn-amended soil. Vegetative growth

repression by Zn was genome-wide associated with flowering genes, including the

key flowering integrator FLOWERING LOCUS T (FT). Both in early and late-flowering

genotypes, Zn stimulated FT expression, but in certain early-flowering accessions, Zn

repressed the rosette size. This was overcome in a loss-of-function mutant of FT, but

not in mutants promoting early flowering. The Zn-induced decrease in maximal leaf

size temporally coincided with the transition to flowering, followed by a gradual

decline in cell divisions. Interestingly, the leaf repression by Zn was not observed in

environmental conditions that repressed FT and delayed flowering. Our results

uncover an unusual vegetative biomass increase under nutrient deficiency that

masks the full genotypic yield potential because of Zn-dependence of early flowering.

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HYDRAULIC ACTIVATION OF STOMATA – CONSEQUENCES FOR FOLIAR NUTRITION, PLANT WATER RELATIONS, AND DROUGHT TOLERANCE

Juergen Burkhardt Institute of Crop Science and Resource Conservation, University of Bonn, Germany

The stomata of plants are functionally responsible for gas exchange, but there is increasing evidence that they can become activated for the bidirectional transport of water, solutes, and hydraulic signals. Accumulation of soluble particles on the leaf surface from atmospheric deposition or agricultural sprays presumably are the most important activation mechanisms. Hygroscopic particles can form persistent, highly concentrated solutions within the humid leaf boundary layer, and specifically chaotropic ions may reduce water surface tension and migrate into the stomata. This hydraulic activation of stomata (HAS) happens to individual stomatal pores but increases with the number of chaotropic ions on the leaf surface.

HAS can potentially explain a considerable part of the observed success and variability of foliar nutrition. Experimental addition and exclusion of particles showed augmented transpiration of leaves with increasing amount of hygroscopic particles, presumably due to established pathways of stomatal liquid water transpiration along thin films following HAS. Increased minimum epidermal conductance (gmin) with increasing leaf surface particles indicated decreased drought tolerance.

HAS may thus cause unwanted effects of air pollution on plant water relations. Understanding the processes involved in HAS can potentially be used to improved planning and control of stomatal fertilizer uptake.

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ARE HUNGRY CROPS MORE THIRSTY?

Dejene Eticha, Joachim Lammel, and Anke Kwast

YARA International, Research Center Hanninghof, Hanninghof 35, D-48249 Dülmen e-mail: dejene.eticha@yara.com

Water and mineral nutrients are essential factors for crop growth and realization of yield. Nutrient elements are transported to the root through two major processes: i) mass flow of water driven by transpiration, and ii) diffusion of nutrients driven by a concentration gradient. However, there are conflicting reports regarding the role of transpiration for crop nutrient acquisition. Cramer et al. (2008) observed that plants enhance their transpiration rate in order to increase nutrient uptake particularly when nutrient concentration near the root is low. On the contrary, Tanner and Beevers (2001) stated that transpiration is not required for uptake and long-distance transport of nutrients. The objective of the current study was to investigate how nitrogen (N) concentration modulates plant transpiration rate. Bell pepper (Capsicum annuum) plants were grown in nutrient solutions of either 1 mM or 4 mM N concentration but with equal quantity of N (10 mmol N/pot). This was obtained by using pot sizes of either 10 L or 2.5 L. Although the total plant available N supply was equal, plants grown in high N concentration solution yielded 35% higher shoot dry weight than those grown in diluted N solution. Similarly, N uptake was significantly higher for plants grown in 4 mM N solutions than those grown in 1 mM N solution. This is possibly due to adaptive expression of different N uptake systems (HATS vs. LATS) which operate at different ranges of N concentration. We conclude that, not the total N quantity in the root zone but solution concentration is decisive for optimal nutrient uptake and better crop growth. The transpirational water use efficiency of plants increased with increasing N concentration. However, N concentration in the root zone did not affect crop transpiration rate. Plants grown at low N concentration did not transpire at higher rates than those grown at high N concentration. This indicates that bell pepper does not enhance its transpiration rate for the purpose of improving nutrient acquisition.

Reference:

Cramer MD, Hoffmann V, Verboom GA (2008) Nutrient availability moderates transpiration in Ehrharta calycina. New Phytol 179:1048–1057

Tanner W, Beevers H (2001) Transpiration, a prerequisite for long-distance transport of minerals in plants? Proc Natl Acad Sci USA 98:9443–9447

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ROLE OF SELENIUM IN MICROBIAL REMEDIATION OF

NICOTINE CONTAMINATED SOILS

Hassan R. El-Ramady (1)*, Neama A. Abdalla (2), Hussein Taha (2), Ahmed S. El-Henawy (1), Tarek Alshaal (1), Megahed Amer (3), Abdelgawad S. Elsadany (3) and Dirk

Selmar (4)

(1) Soil and Water Sciences Dept., Faculty of Agriculture, Kafrelsheikh Uni., Kafr El-Sheikh, Egypt

(2) Plant Biotechnology Dept., Genetic Engineering Division, National Research Center, Giza, Egypt

(3) Soil, Water & Environment Research Institute (SWERI), Sakha Agricultural Research Station, NRC, Egypt

(4) Applied Plant Science Dept., Institute for Plant Biology, TU Braunschweig, Braunschweig, Germany

*Corresponding author: Hassan El-Ramady (ramady2000@gmail.com) Abstract

Environmental pollution is considered a global issue. This pollution can be resulted from different anthropogenic activities including industrial, agricultural and other sectors. Nicotine (C10H14N2) is a pale yellow to dark brown liquid, water-soluble and alkaloid highly toxic heterocyclic compound. It is estimated that, wastes of tobacco contain nicotine about 18 g per kg DW. Furthermore, it is expected that smoking (nicotine) will cause annually about 9 million deaths by the year 2020 (Gurusamy and Natarajan 2013). On the other hand, nicotine pollution may be resulted in water, sediments and soils causing a serious problem worldwide. This nicotine can dissolve easily in aquatic environments leading to the groundwater pollution making a lot of disturbs in soil system. Therefore, remove nicotine from tobacco polluted soil and aquatic environments is an emerging issue for human health (Gurusamy and Natarajan 2013; Ruan and Liu 2015).

Due to use nicotine as a source for nitrogen and carbon in microbial growth, several nicotine-degrading microorganisms have been identified e.g., Pseudomonas sp. (e.g., Ruan et al. 2005; Chen et al. 2008; Zhao et al. 2012; Raman et al. 2014). This bioremediation for nicotine is a promising method in cleaning up polluted environments using very highly efficient microbes through some specific enzymes and biochemical pathways (Gurusamy and Natarajan 2013; Liu et al. 2015; Ruan and Liu 2015). It is reported that, nicotine can be easily soluble in soils, then plants may uptake from the soil and translocated it into leaves (Selmar et al. 2015; El-Ramady et al. 2015a). On the other hand, selenium is essential for lower plants like bacteria (El-Ramady et al. 2014; 2015b). This element is very important in tolerating several stresses like the oxidative stress from nicotine as well as soil salinity (El-Ramady et al. 2016).

Therefore, different treatments including control (without any additions), selenium (50 mg kg-1 as Na3SeO3), nicotine (commercial cigarette tobacco named "Matosian"), selenium in combined with nicotine were used in a field experiment under salt affected soils. This research aimed to study the effect of selenium supply and/or nicotine on soil microbial communities in the presence of dill (Anethum graveolens L.) plants. It is found that the highest values of the microbial communities (total bacterial counts; total nitrogen fixing bacteria and N-fixing cyanobacteria etc.) were belong selenium then selenium in the presence of nicotine, whereas nicotine recorded the lowest values of these previous microbial

35

communities. These results reflect the importance of selenium in bioremediation from soil polluted with nicotine. Key words: Nicotine, selenium, microbial remediation, dill Acknowledgments Authors thank the outstanding contribution of STDF research teams (Science and Technology Development Fund, Egypt) and MBMF/DLR (the Federal Ministry of Education and Research of the Federal Republic of Germany), (Project ID 5310) for their help. Great support from this German-Egyptian Research Fund (GERF) is gratefully acknowledged.

Fig. 1: Dill plants cultivated in salt affected soils under experimentation References Chen C., X. Li, J. Yang, X. Gong, B. Li, K.-Q. Zhang (2008). Isolation of nicotine-

degrading bacterium Pseudomonas sp. Nic22, and its potential application in tobacco processing. International Biodeterioration & Biodegradation, 62 (3): 226-231.

El-Ramady H, Abdalla N, Alshaal T, Domokos-Szabolcsy É, Elhawat N, Prokisch J, Sztrik A, Fári M, El-Marsafawy S, Shams MS (2015b) Selenium in soils under climate

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change, implication for human health. Environmental Chemistry Letters, 13 (1): 1–19. DOI 10.1007/s10311-014-0480-4

El-Ramady H, Domokos-Szabolcsy É, Abdalla NA, Alshaal TA, Shalaby TA, Sztrik A, Prokisch J, Fári M (2014) Selenium and nano-selenium in agroecosystems. Environmental Chemistry Letters, 12 (4): 495-510. DOI 10.1007/s10311-014-0476-0

El-Ramady H., N. Abdalla, T. Alshaal, A. El-Henawy, M. Amer, A. S. Shehata, J. Paulsen, M. Kleinwächter, D. Selmar and H. Taha (2015a). Contamination of Plant Foods with Nicotine: An Overview. German Soil Science Society Congress (Our soils – our life) 5 – 10 September 2015, München.

El-Ramady, H., N. Abdalla, H. S. Taha, T. Alshaal, A. El-Henawy, S. E.-D. A. Faizy, M. S. Shams, S. M. Youssef, T. Shalaby, Y. Bayoumi, N. Elhawat, S. Shehata, A. Sztrik, J. Prokisch, M. Fári, É. Domokos-Szabolcsy, E. A. Pilon‑Smits, D. Selmar, S. Haneklaus and E. Schnug (2016). Selenium and nano-selenium in plant nutrition. Environ Chem Lett, 14 (1):123–147. DOI: 10.1007/s10311-015-0535-1

Gurusamy R. and S. Natarajan (2013). Current Status on Biochemistry and Molecular Biology of Microbial Degradation of Nicotine. Hindawi Publishing Corporation, The ScientificWorld Journal Volume 2013, Article ID 125385, 15 pages, http://dx.doi.org/10.1155/2013/125385

Liu J., G Ma, T Chen, Y Hou, S Yang, K-Q Zhang and J. Yang (2015). Nicotine-degrading microorganisms and their potential applications. Appl Microbiol Biotechnol 99: 3775–3785. DOI: 10.1007/s00253-015-6525-1

Raman G., K N Mohan, V Manohar and N Sakthivel (2014). Biodegradation of nicotine by a novel nicotine-degrading bacterium, Pseudomonas plecoglossicida TND35 and its new biotransformation intermediates. Biodegradation 25:95–107. DOI: 10.1007/s10532-013-9643-4

Ruan A. and C. Liu (2015). Analysis of effect of nicotine on microbial community structure in sediment using PCR-DGGE fingerprinting. Water Science and Engineering, 8 (4): 309-314

Ruan A., H. Min, X. Peng and Z. Huang (2005). Isolation and characterization of Pseudomonas sp. strain HF-1, capable of degrading nicotine. Research in Microbiology, 156 (5–6): 700-706.

Selmar D., U. H. Engelhardt, S. Hänsel, C. Thräne, M. Nowak and M. Kleinwächter (2015). Nicotine uptake by peppermint plants as a possible source of nicotine in plant-derived products. Agron. Sustain. Dev. 35: 1185–1190. DOI: 10.1007/s13593-015-0298-x

Wang M., G. Yang, H. Min, Z. Lv, X. Jia (2009). Bioaugmentation with the nicotine-degrading bacterium Pseudomonas sp. HF-1 in a sequencing batch reactor treating tobacco wastewater: Degradation study and analysis of its mechanisms. Water Research, 43 (17): 4187-4196.

Zhao L., C. Zhu, Y. Gao, C. Wang, X. Li, M. Shu, Y. Shi and W. Zhong (2012). Nicotine degradation enhancement by Pseudomonas stutzeri ZCJ during aging process of tobacco leaves. World J Microbiol Biotechnol 28: 2077–2086. DOI: 10.1007/s11274-012-1010-9

37

DUAL EFFECTS OF CARBON NANOTUBES ON SOYBEAN (GLYCINE MAX.)

Zaytseva O1, Neumann G1

1 Institute of Crop Science (340h), Hohenheim University, Stuttgart, 70593, Germany (Corresponding author: olga.zaytseva@uni-hohenheim.de)

Carbon nanomaterials used in numerous industrial and technical applications are increasingly released into the environment and can exert extremely variable effects on living organisms. In higher plants, both, positive and negative responses on growth and development have been reported but the related mechanisms are still not entirely understood. In this study we used soybean (Glycine max) as a model plant, which shows positive responses in germination after short-term (36h) exposure to carbon nanotube (CNT) suspensions in moderately high concentrations (100 and 1000 mg L-1 equivalent to 50 and 500 µg seed-1) during seed imbibition, turning into negative effects during further seedling development, characterised by growth depressions. While stimulation of germination could be related to slower water uptake, counteracting imbibition damage, later inhibition of shoot and root growth was induced by oxidative stress, as indicated by reversion of plant damage in response to external supplementation with antioxidants, particularly proline. I nduction of oxidative stress by CNT application was detectable already after the 36 h imbibition, period particularly in the tips of the radicle as indicated by accumulation of superoxide anions, reduced triphenyltetrazoliumchloride vital staining, and induction of superoxide dismutase. The induction of the physiological oxidative stress indicators coincided with preferential accumulation of CNTs in the cells of the root tip and was reverted by external application of proline as antioxidant. Similarly, CNT-induced plant damage could be also reverted by external supplementation of micronutrients (Zn, Cu, Mn) as important cofactors for various enzymes involved in oxidative stress defence (SOD, biosynthesis of antioxidative phenolics). Accordingly, SOD activity increased in seedling roots after Zn supplementation. During germination, the CNT treatments reduced particularly Zn translocation from the cotyledons to the growing seedling and CNTs exhibited a selective adsorption potential for Zn and Cu, which may be involved in internal immobilisation of micronutrients. Therefore, this study demonstrates for the first time that phytotoxicity of CNTs is linked with disturbances of micronutrient homeostasis during seedling development.

We acknowledge Ministry of Science, Research and the Arts of Baden-Württemberg (Germany) and the Education, Audiovisual and Culture Executive Agency of the European Union for financial support.

38

IMPROVED PHOSPHORUS RECYCLING: NAVIGATING BETWEEN CONSTRAINTS

Kurt Möller

Institute of Crop Science, Fertilization and Soil Matter Dynamics, University of Hohenheim, Stuttgart, kurt.moeller@uni-hohenheim.de

Abstract:

In order to develop and evaluate sustainable strategies for increased recycling of phosphorus (P) from recycled P fertilizers (RPFs) a transnational team within the IMPROVE-P project assessed potential sources for P recycling, and the implication of their treatment on the agronomical and environmental performance in order to assess the suitability of RPFs for use in agriculture. The evaluation includes:

- A chemical characterization and assessment of the plant P availability.

- The assessment of the environmental impacts of their production processes (by life cycle

assessments).

- A risk assessment.

- A compilation of the main criteria for assessment of RPFs and approaches in order to get a

balance among the different aspects that should be considered for evaluation of P recycling

techniques.

The compiled data show a high relative P effectiveness for struvite, calcined ashes and most organic P sources like composts and biologically treated biosolids. The P fertilizer value of non-apatitic Ca-phosphates, ashes and meat and bone meal is low to moderate, while for slags a moderate P fertilizer value was found. Furthermore, the P fertilizer value of ashes, meat and bone meal and Ca-phosphates is highly dependent on the test soil pH, while for struvite and biosolids no dependency on soil pH was found.

Each approach of P recycling has its own strengths and weaknesses, resulting in sometimes contradictory rankings. For example, the incineration of wastes enables high P recovery rates and will destroy almost all the organic pollutants (short-term risk reduction). However, incineration can increase the environmental impact of waste recycling which may result in long-term problems and impacts from recycling. Furthermore, incineration leads to a reduction of the fertilizer value by reducing the overall P availability, and the removal of organic matter and volatile nutrients like N and S. On the other hand, the direct use of biosolids means an overall high recycling efficiency of nutrients, high P use efficiency combined with organic matter additions, and reductions in GHG emissions.

We conclude that any decision not to use a P source has potential for unintended consequences. Most of these compromise the ability of future generations to meet their own needs (e.g. loss of

39

nutrients like N, P, K, and S, increased GHG emissions, and increased abiotic resources depletion potential) while minimizing risks for current generations (e.g. reducing risks of contamination with organic pollutants, etc.).

Reference:

Möller, K., E. Bünemann, J. Cooper, J. Friedel, N. Glæsner, S. Hörtenhuber, A.-K. Løes, P. Mäder, G. Meyer, T. Müller, A. Oberson, S. Symanczik, L. Weissengruber, I. Wollmann, J. Magid: Improved phosphorus recycling in organic farming: navigating between constraints. Advances in Agronomy (submitted).

40

SEWAGE SLUDGE HYDROLYZATES FOR PHOSPHATE PLANT NUTRITION

Mancarella S.1, Sciubba L.1, Grigatti M. 1, Orsini F. 1, Cavani L. 1, Marzadori C. 1, Ciavatta C. 1, Gianquinto G. 1

1 DipSA - Department of Agricultural Science, University of Bologna, Bologna (Italy)

silvia.mancarella@unibo.it

Phosphorus (P) is a macronutrient essential for the plant growth [1]; nowadays, phosphate fertilizers are generally obtained from phosphate rocks, which are not renewable resources and probably will be exhausted in 100 years at the current consumption rate [2]. Organic wastes, such as sewage sludge, may contain a considerable amount of P (about 3%), thus, they could close the phosphorus cycle as a renewable resource for P fertilizers [3]. Therefore, the objective of this work was to evaluate the efficiency of different extractants in recovering P from sewage sludge and the use of the resulting hydrolyzates as P source for lettuce grown in floating system. Sulfuric acid, potassium hydroxide, citric and maleic acids were evaluated alone and in combination with different enzymes, such as acid and alkaline phosphatase. The higher efficiency was reached by H2SO4 (more the 90%), which however showed high extraction of toxic elements such as Al, Cd, Cu and Zn. High P recovery efficiency was found in citric acid (47%) and citric acid in combination with acid phosphatase (80%). Then, lettuce plants were grown in a floating system with a standard nutrient solution (ST) [4] or with only N and K (NK). Citric acid (ST+C and NK+C) and citric acid with acid phosphatase (ST+CP and NK+CP) were used in a floating system as source of P, whereas KH2PO4 was used as mineral control (ST-Ctrl). The solutions were replaced after 2 weeks. Trace metals, phosphate and nitrate concentration in the nutrient solution were periodically determined, as well as metal concentration in the leaves after destructive harvest. The results of dry matter production did not show significant differences between the treatments, showing that the production was not decreased by the use of the organic products. Furthermore, the growth remained unchanged also in NK+C and in NK+CP, revealing that the organic products provided also the essential meso and micronutrients. Consistently, nutrient solution analyses showed that NK+C and NK+CP contained similar amounts of Ca, Mg and Mn and higher amount of Fe compared to ST-Ctrl. Higher Al and Na were also detected in the solution with the organic products which, however, remained beyond toxic limits in the leaf tissue. Nitrate content showed a fast decrease in the solution with organic products probably due to a high C:N ratio, promoting high microbial growth. Therefore, sewage sludge hydrolyzates are promising products for effective and sustainable supply of P and nutrients to plants.

[1] [1] Grigatti M., Boanini E., Cavani L., Ciavatta C., Marzadori C. (2015). Phosphorous in digestate-based compost: chemical speciation and plant- availability. Waste and Biomass Valorization.

[2] Cordell, D., Drangert, J. O., & White, S. (2009). The story of phosphorus: global food security and food for thought. Global environmental change, 19(2), 292-305.

[3] Koppelaar R.H.E.M., Heiward H.P. (2014). Assessing phosphate rock depletion and phosphorous recycling options. Environ. Chang. 23:1454-1466

[4] Sonneveld, C. (1981). Voedingsoplossingen voor groenten en bloemen geteeld in water of substraten. Informatiereeks-Proefstation Naaldwijk (Netherlands). no. 69.

[5] Murphy, J., Riley, J. P. (1962). A modified single solution method for the determination of phosphate in natural waters. Analytica chimica acta, 27, 31-36.

41

Phosphorus availability of recycled fertilizers from urban residues – results

from pot and field experiments

I. Wollmann1, K. Möller1 1 University of Hohenheim, Institute of Crop Science, Fruwirthstrasse 20, 70599 Stuttgart, Germany; i.wollmann@uni-hohenheim.de

Phosphorus (P) fertilizer production basically relies on Phosphate Rock (PR) which is a limited and often heavily polluted resource. To secure future P supply for agricultural crop production, there is a strong need to recycle P from our human food chain. Eleven million tons of sewage sludge dry mass is available in the European Union every year and there are several techniques to recover P from waste water treatment. Different recycled P fertilizers were tested in pot and field experiments with Zea mays L., and in a cropping sequence of Trifolium pratense L., Zea mays and Lolium perenne L. for their P-availability in comparison to Ca(H2PO4)2 and PR. The investigated recycled P-fertilizers included two struvites, P-RoC, slag-P (Mephrec), thermochemically treated sewage sludge ash (SSA), and P-coal. Control treatments were unfertilized, fertilized with PR and Ca(H2PO4)2. The used soil substrate was a silty loam with PCAL (mg P 100 g-1 soil) 2.2 (pot) and 3 (field), and pH (CaCl2) 7.2 (pot) and 6.6 (field). Fertilizers were applied according to 50 mg P kg soil-1 in pot experiments and 80 kg P ha-1 in the field. Biomass and P-content of plant tissue was determined. Additional pot experiments were carried out to investigate P mobilization potential of red clover for subsequent grown maize from different recycled P fertilizers. Distinct differences in P availability were found between different recycled P fertilizers in the pot experiment with maize. Concerning biomass and P-content of plant tissue, three treatment groups could be distinguished: The SSA, P-coal and PR treatment performed in the same, lowest range of the unfertilized treatment. Intermediate values were found in the treatments slag-P, P-RoC and one of the struvites, while a second struvite reached significantly higher values and was not different from the Ca(H2PO4)2 control. No differences could be found between tested fertilizers in biomass production and P content of maize plant tissue in the field experiment. P mobilization potential of red clover for subsequent grown maize was negligible and the underlying mechanisms remained unclear. Results from pot experiments suggest Struvite being a promising supplement for conventional P-fertilizers in future, while SSA seems less suitable under alkaline soil conditions.

42

Abstracts

Poster Presentations ( according to numeral order )

• TOP 1: Physiologic and agronomic use efficiency (No 1-8) • TOP2: Rhizosphere (No 10-18) • TOP3: Mineral nutrition& stress (No 20-42E) • TOP4: Nutrient uptake/Sensing (No 44-47) • TOP 5: Nutrient Cycles / BioFectors (No 48-55) • TOP 6: Free topics (No 56-63)

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TOP 1: Physiologic and agronomic use efficiency NO

Prey, Lukas Spectral high-throughput phenotyping the

nitrogen use efficiency of German hybrid and line wheat cultivars

1

Mahmood, Asim Micronutrient seed priming to improve nutrient depot exploitation through root growth stimulation in oilseed rape

2

Lingner, Annika Productivity and water use in mixed cropping systems

3

Araya, Alejandro Aguirre Characterizing the impact on cereals of urea fertilizers in combination with urease inhibitor

4

v.Tucher, Sabine Long-term effect of varying P fertilizer and lime applications on yield and P uptake of winter wheat, winter barley and sugar beet

5

Schuster, Konrad The long-term lime fertilization experiment at the Julius-Kühn-Field in Halle (Saale)

6

Krippner, Johanna Zinc biofortification of spinach (Spinacia Oleracea) and parsley (Petroselinum Crispum): Genotypic differences in zinc tissue tolerance

7

Herr, Christina Effect of application and nitrification inhibitors on trace gas fluxes from a maize field after cattle slurry amendment

8

44

SPECTRAL HIGH-THROUGHPUT PHENOTYPING THE NITROGEN USE EFFICIENCY OF GERMAN HYBRID AND LINE WHEAT CULTIVARS

[Agronomic/physiologic efficiency]

Prey, L., Hu, Y., Schmidhalter, U.

Department of Plant Sciences, Chair of Plant Nutrition, Technische Universität München, Emil-Ramann-Straße 2,

85354 Freising-Weihenstephan; prey@wzw.tum.de

Improving nitrogen use efficiency (NUE) for crop production is becoming increasingly important in order to overcome economic, ecological and regulatory constraints. Hybrid wheat cultivars have shown the potential to gain more stable grain yield than line cultivars under unfavorable conditions. There is evidence for heterosis effects also under nitrogen deficiency (Garnett et al. 2015; Górny et al.

2011). NUE is determined by uptake and translocation of nitrogen and the efficiency of its use for grain formation (Noulas et al. 2013). Still, little is known about the performance of commercial hybrid wheat cultivars under field conditions. Spectral phenotyping has proven useful for identifying traits of nitrogen nutrition and biomass (Erdle et al. 2011). In a multi-annual field experiment, we are assessing traits of NUE of hybrid and line wheat cultivars and the potential of detecting these traits using spectral phenotyping methods.

Eighteen high-performance line cultivars and six hybrid cultivars were grown in a field experiment with three nitrogen fertilization rates (N1: 30/30/40 kg N/ha, N2: 60/60/40 kg N/ha, and N3: 90/90/40 kg N/ha, applied at the beginning of vegetation, and at Zadoks growth stages 32 and 45, respectively) in 4 replications at the TUM research station Dürnast in 2014/2015. Biomass was sampled at flowering, milk ripeness, dough ripeness and maturity in N2 and N3. Plant samples were separated into leaves, culms, grains and chaff. During grain filling, canopy spectral reflectance was measured almost weekly using a passive bi-directional hyperspectral spectrometer mounted at a mobile tractor platform (PhenoTrac 4). Samples were oven-dried, weighted and ground. Total nitrogen content was analyzed using NIR spectroscopy. Translocation of nitrogen and dry matter into grains was calculated as difference in the nitrogen content and dry matter of the above-ground vegetative organs between anthesis and maturity. NUE defined as the product of uptake efficiency and utilization efficiency for grain yield was calculated. We are developing partial least squares regression (PLSR) models for estimating nitrogen uptake, partitioning and NUE, and will present the results with respect to the evaluated nitrogen rates and cultivar groups. Preliminary results show pronounced differences among cultivars in grain nitrogen uptake by 40 and 50 kg N/ha for N1 and N3, respectively. However, the ranking of cultivars for NUE differed substantially with nitrogen levels, suggesting there is a need for cultivars to be tested under different nitrogen regimes. For N1, nitrogen uptake was highest for two hybrid cultivars but no general differentiation in NUE could be

45

found by cultivar groups. Spectral phenotyping appears promising for identifying NUE traits for breeding and cultivar testing. The conclusions will be reassessed by the follow-up experiment in 2016.

References

Erdle, Klaus, Bodo Mistele, and Urs Schmidhalter. "Comparison of active and passive spectral sensors in discriminating biomass parameters

and nitrogen status in wheat cultivars." Field Crops Research 124.1 (2011): 74-84.

Garnett, T., Plett, D., Heuer, S., & Okamoto, M. (2015). Genetic approaches to enhancing nitrogen-use efficiency (NUE) in cereals:

challenges and future directions. Functional Plant Biology, 42(10), 921-941.

Górny, Andrzej G., et al. "Inheritance of the efficiency of nitrogen uptake and utilization in winter wheat (Triticum aestivum L.) under

diverse nutrition levels." Euphytica 177.2 (2011): 191-206.

Noulas, C., Alexiou, I., Herrera, J. M., & Stamp, P. (2013). Course of dry matter and nitrogen accumulation of spring wheat genotypes

known to vary in parameters of nitrogen use efficiency. Journal of plant nutrition, 36(8), 1201-1218.

46

MICRONUTRIENT SEED PRIMING TO IMPROVE NUTRIENT DEPOT

EXPLOITATION THROUGH ROOT GROWTH STIMULATION IN OILSEED

RAPE

Mahmood. A1; Iqbal J1, Neumann. G1

(1) Institute of Crop Science (340h), University of Hohenheim, 70599 Stuttgart Germany , email:

a.mahmood@uni-hohenheim.de

As non-mycorrhizal crop, oilseed rape (Brassica napus L.) is particularly dependent on rapid

establishment of an efficient root system, both, for water and nutrient acquisition via fine root

structures and for nutrient storage in a tap root. Due to root-attracting properties of various

mineral nutrients, fertilizer placement strategies offer an option to optimize root development

towards improved nutrient acquisition, while various micronutrients such as Zn, Mn or Fe

exhibit root-growth stimulating properties with protective effects under abiotic stress.

Therefore, the present study was focused on perspectives to combine nutrient zinc seed

priming with ammonium-phosphate depot fertilization for improved nutrient acquisition

during early growth of winter rape.

In a rhizobox experiment on a sandy loam pH 6.0, diammonium phosphate (NH4)2PO4

stabilised with the nitrification inhibitor “3, 4-dimethylpyrazole phosphate (DMPP)” was used

as fertilizer depot placed at 8 cm below the seeds. Seeds of the winter rape hybrid “Avatar”

were primed with three concentrations of zinc sulfate (ZnSO4.7H2O) as 25µM, 50µM and

75µM for 24 hours prior to sowing.

Although oil seed rape is generally considered as a Zn-efficient plant species, already at 5

days after sowing (DAS), Zn shoot contents were almost doubled (0.35 ng) as compared with

the total Zn seed content (0.19 ng), demonstrating low Zn seed reserves and a high

dependency on root-mediated Zn acquisition already during germination. However, Zn seed

priming increased the seed reserves by almost 300% and the corresponding seedlings

exhibited higher root biomass, total root length and fine root production (0.0.-0.02mm

diameter) in the fertilizer depot area as compared with the unprimed control (and/or broadcast

fertilization) during the first 2-3 weeks of seedling development, indicating early and faster

exploitation of the fertilizer depot. An increase in root hair density (13-19%) was also noted.

47

The results suggest that micronutrient seed priming may not be only used as a tool to maintain

root growth under stress conditions but also for improving root system establishment and

nutrient acquisition in fertilizer placement strategies.

48

PRODUCTIVITY AND WATER USE IN MIXED CROPPING SYSTEMS

Annika Lingner1,2, Mehmet Senbayram3, Klaus Dittert1,4

1 Institute of Applied Plant Nutrition, University of Göttingen, Germany, alingne@agr.uni-goettingen.de

2 Centre of Biodiversity and Sustainable Land Use, University of Göttingen, Germany

3 Institute for Plant Nutrition and Soil Science, Harran University of Sanliurfa, Turkey

4 Department of Crop Science, Division of Plant Nutrition, University of Göttingen, Germany

Improving the sustainability and productivity of agricultural systems is a major concern of agronomists facing global change. Under these challenging conditions, altering management systems that are characterized by optimized resource use efficiency are highly demanded. Cropping systems like multi-species crop stands with legumes are likely to be less dependent on external inputs, such as nitrogen fertilizer. However, due to the complexity of mixed cropping systems, knowledge of resource use efficiency (water, light and nutrients) is essential to understand their performance.

Ressource use efficiency can be evaluated by quantification of photosynthesis and transpiration, where whole canopy measurements and non-destructive multi-sensing approaches which integrate thermography and normalized difference vegetation index (NDVI) have been used successfully. Recently, the use of unmanned aerial vehicles (UAV) as remote sensing technique with lightweight sensors has become a useful tool in applied agricultural science and provides information of high spatial resolution in a noninvasive manner.

The overall aim of the present work is to test whether novel genotypes designed for mixed cropping show improved productivity whithout increasing inputs by trait expressions that are favorable under drought conditions.

To this end net-photosynthesis and evapotranspiration were measured by covering the vegetation with a transparent field chamber while the concentrations of CO2 and H2O inside the chamber were measured by a gas exchange system (GFS-3000, Heinz Waltz GmbH, Germany). In addition, the field experiments were screened by a Quadrocopter (Raptor Einzelsystem, EagleLive Systems GmbH, Germany) which was equipped with an NDVI-sensitive camera system (ADC Micro, Tetracam Inc., California).

The preliminary gas exchange data showed that in arable land, water use efficiency was highest in mixed cropping especially at the end of the vegetation period of 2015. In the grassland domain, water use efficiency was mostly affected by the sequential harvests but highest for mixed cropping during a temporal drought in May 2015. The images taken by UAV showed higher NDVI values for legumes and thus higher productivity, whereas non-legumes have lowest NDVI values, most likely

49

because of lack of nitrogen fertilizer application. Both gas exchange and UAV data suggested that mixed cropping improved productivity and biomass formation.

50

CHARACTERIZING THE IMPACT ON CEREALS OF UREA FERTILIZERS IN COMBINATION WITH UREASE INHIBITOR

Alejandro Aguirre1, Heike Hahn2, Nicolaus von Wirén1

1 Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Gatersleben, aguirrea@ipk-gatersleben.de

2 SKW Stickstoffwerke Piesteritz GmbH, Lutherstadt Wittenberg

In the past years, urease inhibitors have become important amendments for urea-based nitrogen fertilizers applied in agricultural plant production. Urease inhibitors reduce the hydrolysis of urea to carbamate and ammonia through the inhibition of urease, which is an enzyme released by plants and soil microorganisms. While the protective effect of urease inhibitors on urea hydrolysis and subsequent ammonia emissions is well documented, it is still unclear to what extent urea with urease inhibitors influence plant growth and metabolism. Therefore, field experiments with winter wheat were conducted at two different locations in Germany, Cunnersdorf (Saxony) and Gatersleben (Saxony-Anhalt), using a urea-based fertilizer with the urease inhibitor 2-NPT (developed by SKW-Piesteritz) to investigate and quantify its influence on plant development, growth, metabolism, yield formation and grain quality. Measurements were taken for urease activity, urea, minerals, N forms, phytohormones, metabolites, chlorophyll concentrations in plants, yield and quality parameters as well as for N forms in soil samples. A high effectiveness of the urease inhibitor was observed in Cunnersdorf with more urea and less ammonium determined in the soil solution after each fertilization time point as well as higher urea concentrations in wheat leaves when urease inhibitor was added. However, the results also showed a strong influence of the experimental location. Site-specific effects and the impact of urea with urease inhibitor on physiological and agronomical plant traits will be presented and discussed.

Acknowledgement: This work was supported by the Agrochemical Institute Piesteritz (AIP) e.V.

51

LONG-TERM EFFECT OF VARYING P FERTILIZER AND LIME APPLICATIONS ON YIELD AND P UPTAKE OF WINTER WHEAT, WINTER BARLEY AND SUGAR BEET

Sabine von Tucher1, Dorothea Hörndl1 and Urs Schmidhalter1

1: Chair of Plant Nutrition, TUM, Freising, tucher@wzw.tum.de

Most of the agricultural soils in Germany are sufficiently or even highly supplied with P, particularly in regions with intensive livestock husbandry, the latter posing a high risk for P losses to water bodies. However, in soils where P application was decreased or omitted in the last decades, P availability may become too low for a sufficient crop production. For such situations it still remains to be answered which soil P concentrations are adequate. Due to the different strategies to mobilize sparingly soluble soil P, plant species differ in their susceptibility to low soil P values. In addition, soil P binding and release behavior depends on soil pH and may therefore be affected by liming.

The effects of different P application and liming doses on yield and P uptake of winter wheat, winter barley and sugar or forage beet were analyzed using data from a long-term factorial P and liming experiment started in 1978 and located in the Bavarian tertiary hills (790 mm, 8.4°C; silty loam; 1.1% Corg, 0.12% Nt). Soil pH differs according to the liming treatments between about 5.0 (no liming), 6.2 (lime level 1) and 6.6 (lime level 2). Besides the control treatment receiving no P water soluble P fertilizer was annually applied with 22 or 44 kg P ha-1. Nitrogen, K, Mg and S applications were kept at adequate levels.

The analysis of the results from the long-term trials indicates that compared to the limed and P fertilized treatments the reduction of yield and P uptake by omitted P application was more pronounced with beet than with barley. Winter wheat yield and P uptake over time were neither affected by a low soil pH nor by the reduced soil P level.

In the most recent crop rotation cycle from 2012 to 2014 yields and P uptake of all three crops were significantly reduced by both the omitted liming and omitted P application, but no yield difference between the two levels of either liming or P fertilization was observed. The relationship between soil P content (CAL extraction) and crop yield showed that very low soil P levels decreased yields especially at low soil pH values. It is evident that in the investigated soil P levels lower than currently recommended will be sufficient to achieve adequate yields if soil pH is kept at a site-specific optimal level. Crop specific requirements should be included into future P fertilizer recommendations.

52

THE LONG -TERM LIME FERTILIZATION EXPERIMENT AT THE JULIUS-KÜHN-FIELD IN HALLE (SAALE)

Konrad Schuster1, Edgar Peiter1, Wolfgang Gans1

1 Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Betty-Heimann-Str. 3, 06120 Halle (Saale), Germany

konrad.schuster@gmx.de

A lime fertilization experiment ("Field A") was initiated by Karl Schmalfuß in 1949. It is one of originally six long-term experiments (Fields A – F), two of which were termined in the past (Merbach et al., 2000). On Field A, the effects of four differentiated lime application rates on soil and plants are tested. Every third year, 0, 0.5, 1, or 2 t CaO ha-1 are applied as CaCO3. The 2x3-year crop rotation consists of pea, sugar beet, spring barley, followed by faba bean, potato, spring barley, whereby lime is applied after cultivation of spring barley. The experimental design of three identical blocks allows the simultaneous cultivation of three crops each year (see the table).

The presence of nine replicates per lime treatment in each block allowed the introduction of further experimental factors. Thus, in the second and third subplot-row of each block, the P fertilization has been omitted since 1980 in order to test the effect of soil pH on the availability of soil phosphate. Furthermore, since 2002 each first and second row has been fertilized with 100 kg Mg ha-1, as Mg deficiency occurred at high lime application rates.

In the present investigations, we survey archived data and analyse new soil samples with the aim to examine the influence of long-term lime application on the pH in three soil layers (0 - 20, 20 - 40, and 40 - 60 cm) and on the availability of macro nutrients (phosphorus, magnesium, potassium), micro nutrients (manganese, zinc, molybdenum), and toxic elements (aluminum). In addition, the impact of

2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0

1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

0 0 0 0 0 0 0 0 0

2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0

1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

0 0 0 0 0 0 0 0 0

2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0

1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

0 0 0 0 0 0 0 0 0

+P -P -P +P -P -P +P -P -P

+Mg +Mg -Mg +Mg +Mg -Mg +Mg +Mg -Mg

53

differentiated lime fertilization on cation exchange capacity and base saturation of the soil, as well as on the yield and mineral contents of crops is being analysed.

Merbach W, Garz J, Schliephake W, Stumpe H, Schmidt L (2000) The long-term fertilization experiments in Halle (Saale), Germany - Introduction and survey. J. Plant Nutr. Soil Sci. 163: 629-638

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ZINC BIOFORTIFICATION OF SPINACH (SPINACIA OLERACEA) AND PARSLEY (PETROSELINUM CRISPUM): GENOTYPIC DIFFERENCES IN ZINC TISSUE TOLERANCE Johanna Krippner1 and Sven Schubert1 1Institute of Plant Nutrition (iFZ), Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany: johanna.krippner@ernaehrung.uni-giessen.de

Zinc is essential for all organisms and consequently important for healthy growth of plants, animals,

and humans (Broadley et al., 2007). Dietary zinc deficiency is quite common in the world’s

population. Therefore, biofortification is a current field of research for developing plants with

increased concentrations of bioavailable nutrients in their edible parts (Velu et al., 2014). Zinc uptake

and translocation in plants depends on many factors including physicochemical soil properties and

plant-related storage and/or detoxification strategies such as compartmentalization or complexation.

Foliar application is an attractive strategy to get zinc straight into plant tissues of interest

(Cakmak, 2008). However, biofortification efficiency and bioavailability differ among plant species

and foliar zinc fertilizers.

Twelve spinach (Spinacia oleracea L.) and twelve parsley (Petroselinum crispum Mill. convar.

crispum) cultivars were screened in a nutrient solution experiment. The experiment was set up in a

completely randomized design with four replications in 125 L screening pots. Plants were sprayed for

several times with a zinc solution containing 2.0 mM ZnCl2 for spinach and 3.0 mM ZnCl2 for

parsley, respectively. When zinc-toxicity symptoms were observed, plant shoots were harvested,

weighed, and washed with diluted nitric acid to remove apoplastically bound zinc. A differentiation of

the toxicity levels was done by evaluation during harvest: Intensity of the toxicity symptoms and their

distribution on the whole leaf surface were evaluated. After drying at 90°C, dry weights of shoots were

determined and homogenized plant material was wet-ashed for total zinc determination using atomic

absorption spectrometry.

Parsley cultivar “Gigante d’Italia” and spinach cultivar “Camaro” were identified as most efficient

cultivars for zinc biofortification with foliar application: These cultivars showed a high biomass

production and the highest zinc concentrations of shoots, while no or only sporadic toxicity symptoms

were observed on the leaf surface.

To understand zinc binding and compartmentalization in spinach and parsley, the zinc-resistant and a

zinc-sensitive cultivar of each plant species will be analyzed for zinc fractions to identify different

mechanisms among cultivars and plant species influencing the zinc tolerance of shoot tissues.

55

References

Broadley, M. R., White, P. J., Hammond J. P., Zelko, I., Lux, A. (2007) Zinc in plants. New Phytol. 173, 677–

702

Cakmak, I. (2008) Enrichment of cereal grains with zinc: agronomic or genetic biofortification? Plant Soil 302,

1–17

Velu, G., Ortiz-Monasterio, I., Cakmak, I., Hao, Y., Singh, R. P. (2014) Biofortification strategies to increase

zinc and iron concentrations in wheat. J. Cereal Sci. 59, 365-372

56

EFFECT OF APPLICATION AND NITRIFICATION INHIBITORS ON TRACE GAS FLUXES FROM A MAIZE FIELD AFTER CATTLE SLURRY AMENDMENT 1Christina Herr, 2T. Mannheim, 1T. Müller, and 1R. Ruser

1Institute of Crop Science 340i, University of Hohenheim, Stuttgart, Germany; Christina.Herr@uni-hohenheim.de

2EuroChem Agro GmbH, Mannheim, Germany; thomas.mannheim@eurochemagro.com

Abstract

Efficient use of organic N-fertilizers is a main global challenge. Strategies reducing gaseous N losses after application of organic fertilizers are still required.

Injection of slurry efficiently reduces ammonia losses. Unfortunately, slurry injection strongly enhances the N2O emissions, probably due to the anaerobic conditions in the injection slot.

The main aim of our study was to test the applicability of the nitrification inhibitors (NIs) DMPP, DMPP + DMPSA and DCD to reduce N2O emissions from a maize field on a Haplic Luvisol in South Germany, by desynchronizing carbon availability in the injection slot and NO3

- release from nitrification of the slurry ammonium. We further tested the effect of different application techniques (surface application + incorporation and injection) on N2O and CH4 fluxes after slurry amendment.

The results showed that cumulative N2O emissions are significantly increased by slurry injection compared with the control, the mineral fertilization or the slurry surface application + incorporation after application. N2O emissions from the injection slot were strongly reduced by NIs. The different N2O reduction potential might be due to their different chemical and physical characteristics (Fig.1).

The strong correlations between N2O emissions and soil water content, NO3-

availability and CO2 emissions strongly suggests that denitrification was the main source for N2O emissions.

Furthermore, CH4 emissions were also significantly increased by slurry injection compared with the non-injection treatments. NIs strongly reduced CH4 emissions (Fig. 1). The reason for this reduction remains unclear and will be focus of further research.

Comparing the slurry injector treatments, NIs tended to decrease N2O emission from 21 % up to 41 %. Significantly lower N2O emissions were measured, when slurry was applied on the soil surface and subsequently incorporated. A surface application and subsequently incorporation might be the best management practice to reduce gaseous nitrogen losses on soils, which are characterized by a high clay content.

57

However, this application technique needs a further individual operation and it holds the risk of increasing ammonia losses as long as the slurry is not incorporated.

References:

Flessa, H., Dörsch, P., Beese, F. (1995): Seasonal variation of N2O and CH4 fluxes in differently managed soils in southern Germany. J. Geophys. Res. 100, 23115 – 23124.

Pfab, H., Palmer, I., Buegger, F., Fiedler, S., Müller, T., Ruser, R. (2011): N2O fluxes from a Haplic Luvisol under intensive production of lettuce and cauliflower as affected by different N-fertilization strategies. J. Plant Nutr. Soil Sci. 174, 545-553

B

Fig. 1: cumulative N2O emissions (A) and cumulative CH4 emissions (B) between 30.04.2015 and

16.04.2016. Different superscript letters indicate statistically significant differences between groups (Student-Newman-Keuls Test, p < 0.05).

A A

B

58

TOP 2: Rhizosphere

NO

Dietrich, Charlotte The effect of nitrification inhibitors on root architecture and nutrient uptake in juvenile sugarcane

10

Nabel, Moritz Digestate patch-fertilization of Sida Hermaphrodita on marginal soil

11

Zickenrott, Ina-Maria Role of soils spatial organization for replant disease

12

Schultze, Nico New radial flow setup to derive soil hydraulic conductivity- Case study with calcium-polysalacturonic acid as a model for plant root mucilage

13

Gierth, Diana Influence of rooting behavior and nutrient scavenging abilities of different catch crops on health and yield of maize

14

Robles Aguilar, Ana A. Variation of root architecture and rhizosphere bacterial community in response to recycled nitrogen

15

Afzal, Afzal Joshua Long-term exposure to sub-toxic levels of the glyphosate metabolite AMPA can explain plant damage in no-tillage winter wheat production systems with long-term glyphosate use in south-west Germany

16

Dreyer, Michael Influence of stabilized and non-stabilized nitrogen fertilizers on manganese supply of wheat (Triticum Aestivum)

17

Lang, Carina Interaction of grapes and trees in the rhizosphere: N-nutrition, N-absorption and water supply

18

NN NN 19

59

THE EFFECT OF NITRIFICATION INHIBITORS ON ROOT ARCHITECTURE AND NUTRIENT UPTAKE IN JUVENILE SUGARCANE

Dietrich, C.C.*; Koller, R.*; Nagel, K.A.*; Schickling, A.*; Schrey, S.D.*; Jablonowski N.D.*

*Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.

Cultivating sugarcane on more than 4.5 million hectares, the Brazilian ethanol production generates an enormous quantity of organic residues annually, as each ton of sugarcane creates ~30kg of filter cake, high in major plant nutrients. Herein, we evaluate its fertilizing effect on sugarcane root architecture and biomass production, further assessing the interplay with nitrification inhibitors in optimizing nutrient uptake and minimizing nitrate leaching. We test the effect of spatial nutrient availability by applying filter cake homogeneously, as a layer or as a depot and of nitrification through either the pre- or absence of inhibitors. In order to monitor root and shoot development in real-time, we use the non-invasive phenotyping platform, GROWSCREEN-Rhizo using rhizotrons (Nagel et al., 2012). Regular automated measurements estimated above-ground biomass, as well as root length and their spatial distribution in response to spatial nutrient availability. Root diameters were quantified after the destructive harvest. Our results indicate that the spatial distribution of nutrients is more important for root architecture than the presence of nitrification inhibitors. Nutrient depots result in a shallower root distribution, while nutrients homogeneously mixed in or applied as a layer produce a more prolific root system. While nitrification inhibitors promote biomass accumulation across all applications, their application in a layer results in the highest jump in biomass production, when compared to non-inhibited nutrient application. On average, homogeneously mixed in nutrients with nitrification inhibitors produce the highest shoot biomass values. Concluding, this study provides insight into the interplay of spatial nutrient availability and nitrification on the below-ground dynamics of sugarcane. It is also among the first to implement a systematic imaging approach for the typically highly variable root system of sugarcane. It further represents a necessary first step in optimizing biomass production for sugarcane using organic residues from the bioethanol production and closing local nutrient loops.

References

Nagel, K.A.; Putz, A.; Gilmer, F.; Heinz, K.; Fischbach, A.; Pfeifer, J., Faget, M.; Blossfeld, S.; Ernst, M.; Dimaki, C.; Kastenholz, B.; Kleinert, A.-K.; Galinski, A., Scharr, H.; Fiorani, F.; Schurr, U.: GROWSCREEN-Rhizo is a novel phenotyping robot enabling simultaneous measurements of root and shoot growth for plants grown in soil-filled rhizotrons. Functional plant biology 39(11), 891-904 (2012).

60

Figure 2: Digestate patch-fertilization of Sida hermaphrodita, grown on a sandy substrate. First roots avoid the digestate patch but finally form a root cluster.

DIGESTATE PATCH-FERTILIZATION OF SIDA HERMAPHRODITA ON MARGINAL SOIL

Nabel M1, Poorter H1, Temperton V1,2, Schrey S1, Koller R1, Jablonowski ND1

1Forschungszentrum Jülich, IBG-2: Plant Science, Germany, m.nabel@fz-juelich.de

2Institute of Ecology, Leuphana University Lüneburg, Germany

Improving fertility of marginal soils for non-food biomass production is a strategy for reducing land use conflicts between food and energy crops. Perennial energy crops like Sida hermaphrodita allow for a continuous energy-crop production without the need of soil cultivation and its accompanied disturbance of the soil fertility. Following the idea of closed nutrient-loops, biogas digestates are applied as fertilizer and soil amendment. However, adverse effects on root growth and nitrogen losses via leaching are known to hamper plant growth, when digestates are applied on marginal soils. Further, its conventional application comes along with soil cultivation, disturbing the development of the soil fertility.

We propose digestate patch fertilization. We show that it minimizes negative effects of digestate fertilization by reducing the phytotoxic effect on the root growth and increasing nutrient use efficiency. Further, its application in the field would reduce the soil disturbance to a minimum.

We grew S. hermaphrodita in large mesocosms outdoors and in rhizotrons filled with a marginal sandy substrate (Fig. 1), and compared conventional digestate application with digestate patch-fertilization and a mineral fertilizer control.

As expected, in rhizotrons root-growth was hampered in the conventional digestate treatment and around the digestate patch in the first 30 days after planting. We will correlate this phytotoxic effect to the concentrations of organic acids, ammonia and nitrite in the rhizosphere. However after 60 days, roots formed a root cluster surrounding the digestate patch (Fig. 1) indicating foraging for delayed mobilized N from the patch.

In outdoor mesocosms, the biomass yield of digestate patch-fertilized S. hermaphrodita on a marginal substrate was increased by 15% compared to conventional digestate fertilization.

We conclude that digestate patch fertilization may contribute to a sustainable use of marginal soils for an improved cultivation of perennial energy-crops.

61

ROLE OF SOIL SPATIAL ORGANIZATION FOR REPLANT DISEASE

Ina-Maria Zickenrott1 , Doris Vetterlein1

1Department of Soil Physics, Helmholtz Centre for Environmental Research – UFZ, Theodor-Lieser-

Str. 4, D-06120 Halle/Saale, Germany, ina-maria.zickenrott@ufz.de

Abstract

Apple replant disease (ARD) is a complex phenomenon that affects young trees in replanted orchard sites causing necrotic lesions on roots, stunted tree growth and reduced yields (Rumberger et al., 2007). One assumption to explain this phenomenon is that through soil cultivation spatial organization/differentiation created by previous crops is lost and hence new roots cannot grow in favorable sites or avoid unfavorable sites. Unfavorable conditions could be high toxin concentrations, signaling substances or high number and abundance of pathogens. The aim of our work is to detect the spatial distribution of possible ARD causing factors, both in the bulk soil and in the rhizosphere.

Therefore 4 different treatments consisting of acryl glass cylinders filled with undisturbed ARD soil (intact field structure), homogenous ARD soil, sterilized homogenous ARD soil and virgin homogenous soil without expression of ARD (control) are established. The ARD and control soil were taken from Ellerhoop in southern Schleswig-Holstein. On each cylinder an apple seedling (M 26) is planted and grown for 4 weeks in a climate chamber. In situ measurements of roots and shoots were conducted during the experiment, i.e. determination of leaf area and SPAD value (amount of chlorophyll in leaves), extraction of soil solution. Furthermore apple root growth is observed in situ by X- ray computed tomography. After CT scanning, the observed root growth can be considered in relation to soil structure and conclusions can be drawn on ARD causing factors and their spatial distribution in the soil. In addition, roots and shoots were sampled destructively after termination of the experiment. Destructive sampling enables the determination of leaf areas and root length and root diameters classes with WinRHIZO. Further chemical analysis of bulk and rhizosphere soil, nutrient analysis of shoots and determination of pH, conductivity and chemical compounds of soil solution will be conducted.

The experimental approach and first results on root and shoot growth in the different treatments will be presented.

References

RUMBERGER, A., MERWIN, I. A., & THIES, J. E. (2007). Microbial community development in the rhizosphere of apple trees at a replant disease site. Soil Biology and Biochemistry, 39(7), 1645-1654.

62

NEW RADIAL FLOW SETUP TO DERIVE SOIL HYDRAULIC CONDUCTIVITY – CASE STUDY WITH CALCIUM-POLYGALACTURONIC ACID AS A MODEL FOR PLANT ROOT MUCILAGE

Nico Schultze1, Eva Kroener2, Andrea Carminati3 and Doris Vetterlein1

1Department of Soil Physics, Helmholtz Centre for Environmental Research – UFZ, Theodor-Lieser-Str. 4, D-06120 Halle/Saale, Germany 2Department of Environmental and Soil Chemistry, University Koblenz-Landau, Forststr. 7, D-76829 Landau, Germany 3Division of Soil Hydrology, Georg-August-University Goettingen, Buesgenweg 2, D-37077 Goettingen, Germany Abstract Roots are hypothesized to alter rhizosphere hydraulic properties by release of mucilage. This mechanism is expected to have strong implications for root water uptake under drought conditions. Direct measurement of rhizosphere hydraulic properties is hindered by the dynamic nature of the components involved; root hydraulics change with ontology; mucilage production, composition and diffusion are not constant; soil water content changes. An experimental approach was developed which enables to simultaneously measure hydraulic conductivity and water retention curve around artificial roots covered with mucilage or modified model substances mimicking individual properties of mucilage. The methods consist in extracting water at constant suction using a suction cup covered with mucilage or analogues and recording the soil matric potential and the outflow. The system accounts for the radial geometry of root water uptake. To determine soil hydraulic conductivity we inversely fitted the outflow curves and soil matric potential by solving the Richards’ equation in radial coordinates. Verification was done by measuring hydraulic properties of a sandy soil saturated with distilled water and comparison of results with classical evaporation method. Furthermore sandy soil was amended with increasing amounts of calcium-polygalacturonic acid gel (Ca-PGA) to mimic viscose nature of mucilage. Experiments show a decrease in soil hydraulic conductivity in orders of magnitudes by increasing Ca-PGA concentration in the wet range; the reverse is observed in the dry range, when Ca-PGA increases the unsaturated conductivity. Contrary to many mucilage observations, Ca-PGA seems not to change water retention curve, which suggests that the gel stays in the mobile phase. Hence Ca-PGA is a suitable model to mimic influence of mucilage viscosity, but disregards other mucilage properties. In the future the setup will be used to study the local distribution of natural root mucilage around the artificial root. Key words mucilage, rhizosphere, hydraulic properties, root water uptake

63

INFLUENCE OF ROOTING BEHAVIOUR AND NUTRIENT SCAVANGING ABILITIES OF DIFFERENT CATCH CROPS ON HEALTH AND YIELD OF MAIZE

Diana Gierth and Nicolaus von Wirén

Leibniz Institute of Plant Genetics and Crop Plant Research, Dept. Physiology and Cell Biology, Molecular Plant Nutrition, Corrensstr. 3, 06466 Gatersleben, Germany Email: gierth@ipk-gatersleben.de

Catch crops are rapidly growing plants which are cultivated between two major crops [1] with the aim of scavenging nutrients that would otherwise leach out into deeper soil layers. Besides this, catch-cropping has manifold further advantages for the agricultural system, such as soil protection, soil improvement, disease and weed control, but lost its importance during the last century mainly due to the use of pesticides and chemical fertilizers in plant production. Recent environmental and legal constraints on crop production have increased the attractiveness for growing catch crops [2]. The nutrient-scavenging ability of individual catch crop species is dependent on their root system architecture [3] and mechanisms for nutrient acquisition, such as rhizosphere acidification, release of root exudates like chelators or interaction with microorganisms in the rhizosphere [2]. However, available information is very poor with regard to the distribution and depth of the root system of catch crops. It is the goal of this project to study the distribution of the root system within the soil profile, as it represents one important prerequisite for nutrient uptake. This will be done by quantifying root mass of different catch crop species in soil cores from two field sites using qRT-PCR with species-specific primers. Thereby, vertical root biomass distribution of pure stands will be compared to mixed cultivation of mustard, phacelia, bristle oat and Egyptian clover as well as to a commercial mixture in order to identify potential niche differentiation. Such a niche differentiation has not been described in detail until now, but could be a reason for the often observed superior biomass production of catch crops when grown in a mixture [4]. So far, differences in nutrient uptake and biomass formation of a catch crop species in mono- compared to mixed culture appeared only to be visible when plant development was progressed to a considerable extent. The release of scavenged nutrients from the catch crops after their incorporation into the soil can support the nutrition of the following crop. Besides this, the beneficial action of catch-cropping on the following crop might rely on manifold further biological, chemical and physical mechanisms, e.g. pores left by dead catch crop roots could facilitate root growth of the following crop or catch crops might release growth-stimulating substances to the soil. To what extent such processes depend on catch crop variation and improve growth, health and yield formation of the target crop maize will be investigated in a long-term wheat - catch crop - maize rotation.

Literature

64

[1] Lockhart, J.A.R. and A.J.L. Wiseman, Introduction to Crop Husbandry 5ed. 1983, Kronberg-Taunus: Pergamon Press GmbH.

[2] Thorup-Kristensen, K., J. Magid, and L.S. Jensen, Catch crops and green manures as biological tools in nitrogen management in temperate zones, in Advances in Agronomy. 2003, Academic Press. p. 227-302.

[3] Thorup-Kristensen, K., Are differences in root growth of nitrogen catch crops important for their ability to reduce soil nitrate-N content, and how can this be measured? Plant and Soil, 2001. 230(2): p. 185-195.

[4] Kramberger, B., et al., Environmental advantages of binary mixtures of Trifolium incarnatum and Lolium multiflorum over individual pure stands. Plant Soil Environ., 2013. 59(1): p. 22-28.

65

VARIATION OF ROOT ARCHITECTURE AND

RHIZOSPHERE BACTERIAL COMMUNITY IN RESPONSE

TO RECYCLED NITROGEN

Ana A. Robles Aguilar1, Oliver Grunert2, 3, Silvia Schrey1, Johannes Postma1, Vicky

Temperton4, Stephan Blossfeld1, Nico Boon3 and Nicolai D. Jablonowski1

1 Forschungszentrum Jülich GmbH, Institute of Bio- and Geoscience, IBG-2:Plant sciences, 52425

Jülich, Germany

2 Peltracom, Skaldenstraat 7a, 9042 Desteldonk, Belgium

3Center of Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000

Gent, Belgium

4Institute of Ecology, Leuphana University, Lüneburg, Germany

Recycling of nutrients from waste is an important approach to contribute to a more sustainable crop production. The use of recovered products, such as organic compounds or struvite (MgNH4PO4.6H2O) are promising examples of green fertilizers which can serve as a clean and reliable nitrogen and phosphorus sources. However, so far, detailed belowground studies with a clear quantification of root responses to different fertilizer types and the differences in the associated bacterial communities in the soil are scarce despite the recognized importance of root architecture and soil microbial activity to plant productivity.

Crops often show plasticity in their root architecture to varying environmental factors, particularly soil physical, chemical and biological properties. The application of mineral or organic fertilizers leads changes in soil chemistry, for example the amount of ammonia, phosphorus, or pH. These changes will affect several root traits, e.g. the number of lateral roots or total root length, and may also affect the biological properties like the abundance or activity of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB).

In our study we compared the effect of an organic source of nitrogen (amino acids) with the

66

inorganic N source struvite on root architecture and microbial community composition in the rhizosphere of tomato (Solanum lycopersicum) and lupine (Lupinus angustifolius) a legume that harbors N-fixing bacteria in the roots. The experiment was conducted in rhizotrons allowing visualisation of roots and including planar optodes for non-invasive in situ measurements of pH dynamics in the rhizosphere. Further, the effect of the fertilizers on the bacterial communities in the rhizosphere and the bulk soil was analysed by high throughput sequencing analysis. Plant shoot/root biomass was also determined.

Results show that plant species and fertilizer type had an effect on total root length and the ratio of primary to secondary roots. Plant species seemed to drive the overall bacterial community in the growing medium, while particular groups (AOB, NOB) may rely on the physical and chemical characteristics of the environment to create a niche (p< 0.05). Finally, biomass in both species was higher when fertilized with organic N than with struvite, even though struvite increased biomass compared with no N application.

Understanding the factors that promote root development and modify microbial communities, may eventually lead to better management practices geared towards greater nutrient use efficiency at the farm gate.

No fertilizer Organic fertilizer Struvite

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67

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2D im

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68

LONG-TERM EXPOSURE TO SUB-TOXIC LEVELS OF THE GLYPHOSATE METABOLITE AMPA CAN EXPLAIN PLANT DAMAGE IN NO-TILLAGE WINTER WHEAT PRODUCTION SYSTEMS WITH LONG-TERM GLYPHOSATE USE IN SOUTH-WEST GERMANY

Afzal A, Müller D, Jocher F, Tesfamariam T, Bott S, Römheld V, Neumann G.

Institute of Crop Science (340h), Universität Hohenheim, Stuttgart, phyto_pak@yahoo.co.uk

No-tillage is considered as a promising alternative for conventional farming by saving energy input

and time, reducing groundwater pollution and counteracting soil erosion and losses of soil-organic

matter. However, no tillage farmers in Southwest Germany repeatedly reported problems particularly

in winter wheat production, characterized by stunted plant growth in early spring, chlorosis, impaired

fine root development and increased disease susceptibility. These effects were particularly apparent by

comparing field sites with long-term (10 years) no-tillage history (LT) and adjacent short-term (2

years) no-tillage plots (ST) and could be reproduced in pot experiments. Gamma-ray soil sterilization

had no effect on the expression of damage symptoms, suggesting an abiotic cause for plant damage.

Soil analysis revealed higher levels of glyphosate residues in LT soils, which was intensively used for

pre-crop weed control. Particularly on LT plots with strong expression of plant damage, high

concentrations of 2-4 mg glyphosate kg-1 soil and of its metabolite AMPA were detected in the 10 cm

top-soil layer. Traces were detectable even in the soil solution, while the levels in ST soils were below

the detection limit (0.05 mg kg-1 soil).

Nutrient solution experiments with 3-6 weeks exposure of winter wheat to the residual herbicide

concentrations detected in the LT soil solution (0.0015- 0.005 mg L-1) revealed a 30%-50% reduction

in fine root production associated with chlorosis development, which was surprisingly induced mainly

by AMPA and to a lesser extent by glyphosate itself. A RNAseq gene expression analysis of the root

tissue just prior to the appearance of visible plant damage symptoms revealed a downregulation of

genes involved in general stress responses, downregulation of aquaporine genes (PIPs TIPs) with

functions in water uptake and root elongation, down-regulation of ethylene-related genes but

upregulation of cytokinin-related gene expression indicating interferences with hormonal balances.

These changes in gene expression patterns relative to the untreated control were detected in plants

treated with AMPA, glyphosate+AMPA but not with glyphosate alone. The findings suggest that long-

term exposure to sub-toxic levels of AMPA as major glyphosate metabolite accumulating in soils can

finally interfere with metabolic processes essential for normal root development.

69

INFLUENCE OF STABILIZED AND NON-STABILIZED NITROGEN FERTILIZERS ON MANGANESE SUPPLY OF WHEAT

(TRITICUM AESTIVUM)

Michael Dreyer, Marie Rischen, Merle Wichmann, Annika Ehmke, Bruno Görlach and Karl H. Mühling

Institute of Plant Nutrition and Soil Science, Christian Albrechts University Kiel, Hermann-Rodewald-Str. 2, 24118 Kiel, Germany

Manganese availability to plants is highly dependent on the soil pH. Particularly on the calcareous soils of Northern Germany, manganese deficiency is often a yield limiting factor, although the total soil manganese content is usually sufficient. The reduction of the pH in soil by ammonium-dominated fertilizers is a possibility to increase the manganese availability. If ammonium fertilizers are supplemented with nitrification inhibitors, ammonium oxidation is temporarily hampered and thus proton release into the soil reduced. In this context, an increased acidification of the rhizosphere due to the primary ammonium nutrition can be expected. To test whether the latter effect indeed increases the micronutrient supply of wheat, several field and pot trials were conducted.

The most obvious effect on Mn-supply was caused by interaction between N-form and nitrification inhibitor addition. Hereby, an ammonium dominated fertilization (without nitrification inhibitor) generally resulted in an improved Mn-supply of plants when compared with nitrate fertilization. In contrast, when ammonium fertilizers were supplemented with nitrification inhibitors, the Mn-supply of plants was not increased but strongly decreased. It was proved that is rather the nitrification than a physiological acidification of the rhizosphere, caused by ammonium uptake, which is the crucial factor for an improved Mn-availability in soil. In this respect, a reduced Mn-supply of wheat can be attributed to the inhibition of nitrification after the use of stabilized ammonium fertilizers. From all ammonium fertilizers used in the study the highly reductive ammonium thiosulfate resulted in the highest increase of plant Mn-supply.

Furthermore, the application of ammonium fertilizers resulted in a reduced uptake of cationic macronutrients (K, Mg, Ca), which is suggested to be a result of an antagonistic effect. This effect was even more intense when nitrification inhibitors were supplied together with ammonium.

It can be concluded that the use of stabilized ammonium fertilizers should be avoided on marginal sites when Mn is already limited. The same accounts to fields which are deficient in K and Mg. In contrast, the application of nitrogen in form of ammonium thiosulfate is a promising tool to improve the Mn supply of wheat on such locations.

70

INTERACTION OF GRAPES AND TREES IN THE RHIZOSPHERE: N- NUTRITION, N-ABSORPTION AND WATER SUPPLY

Carina Paola Lang¹, Nikolaus Merkt¹, Cornelia Blessing², Heinz Rennenberg², Christian Zörb¹

¹ Institute of Crop Science, Quality of Plant Products (340e), University of Hohenheim, Emil-Wolff-Str. 25, 70599 Stuttgart, langca@uni-hohenheim.de ² Institute of Tree Physiology, University of Freiburg, Georges-Köhler Allee, Geb. 53/54

Agriculture, combined with forestry components, so called agroforestry, forms a unit, which causes a change in microclimate, eutrophication, water and nitrogen use efficiency. Trees were also used as a stabilizer and shade. We established an agroforestry system, consisting of grapevines (Vitis vinifera L. subspecies. vinivera cv. Riesling and cv. Sauvignon Blanc) together with trees of the varieties oak (Quercus petraea) and poplar (Populus tremula & Populus alba ). Trees with a comparatively low net photosynthesis per tree mass shading the grapes and resulting in a negative influence on development and growth. There might be a competition, for water and certain nutrients, initial in the rhizosphere. Most of the native trees are associated with mycorrhiza. This contributes to an improved impact in nutrient uptake by the roots. For instance, due to the supply of poorly soluble phosphates, trees receive photoassimilates as a symbiosis performance of the vine, e.g. their exudates. The aim of the project is to identify specific interactions of trees and grapevines in the rhizosphere, as well as in leaves. Using a stable isotope discrimination (δN¹⁵) the absorption capacity for nitrogen compounds and the distribution of various nitrogen forms within the grapevine were analyzed. Moreover a carbon isotope discrimination (δC¹³) in grape vine leaves and tree leaves will provide information on the water supply of both plant species. An associated competition or synergy of both will be evaluated on the basis of this information. Furthermore, the effects of agroforestry on the quality of berries and wine will be evaluated by sensory tastings and biochemical analysis.

71

Top 3: Mineral nutrition& stress

Kirchner, Thomas Down-regulation of candidate genes by

CRISPR/CAS9 to reveal their role in PI deficiency-induced root hair elongation in Brassica Carinata

20

Ali, Basharat Does free intracellular zinc mediate programmed cell death in different genotypes of rice?

21

Bach, Mareike Influence of different recycled digestate fertilizers on P-uptake of maize plants and soil biological processes in different soils

22

Höller, Stefanie Does Thiamethoxam influence nitrogen use efficiency of rice?

23

Behr, Jan Helge Physiologic and metabolic characterization of sugar beet under high salinity

24

Zhao, Wenting Is the three-phase model of growth response to salt stress applicable to Arabidopsis?

25

Faust, Franziska Substrate limitation is not responsible for the inhibition of protein synthesis during the substitution for K+ by Na+ in the nutrition of sugar beet

26

Geilfus, Christoph-Martin Silicon-enhanced oxalate exudation contributes to alleviation of cadmium toxicity in wheat

27

Mirzaeitalarposhti, Reza Effect of different sources and rates of Zn fertilizers on physiological traits of saffron (Crocus sativus L.)

28

Richter, Julia Annika Different salts cause different metabolic profiles in Vicia Faba L.

29

Khan, Nufaid The role of spermine in drought tolerance of barley (Hordeum Vulgare)

30

Gao, Wei Effect of localized NH4+ -N and P application

on maize growth on non-calcareous soils with contrasting texture

31

Saqib, Muhammad Functional characterization of plasma-membrane H+-ATPase isoforms for salt resistance in maize (Zea Mays L.)

32

72

Wollmer, Anna-Catharina Effects of waterlogging on growth, nutrient

status and yield of rapeseed (Brassica napus L.)

33

Richter, Julia Annika Different salts cause different metabolic

profiles in Vicia Faba L. 34

Chen, Xiaochao Zinc starvation induced DNA demethylation is

independent of transcriptional response in Arabidopsis Thaliana

35

Mohammed, Kassem A.S. Effect of N, K. and Mg supply on the nutritional value of tomato fruits

36

Ulas, Abdullah Effects of organo-mineral and mineral fertilizers and nitrogen doses on yield an quality of sugar beet (Beta Vulgaris L.)

37

Amer, Megahed Effect of organic and inorganic mixture applications on rice production under salt affected soil conditions

38

Steingrobe, Bernd The effect of light intensity on the root exudation pattern of sugar beet under phosphorus deficiency

39

BioFectors

42

Weinmann, Markus Application strategies for microbial bio-effectors: comparison for rhizosphere colonization and improved plant growth in pot and field experiments

42A

Moradtalab, Narges Interactions of silicone and micronutrients for the improvement of cold tolerance in maize (no abstract)

42B

Moradtalab, Narges Silicone, micronutrients and microbial inoculants as cold stress protectants during early growth of maize under field conditions (no abstract)

42C

Weber, Nino Frederik PGRP-Induced stimulation of root growth and nutrient acquisition in maize: do root hairs matter?

42D

Bandari, Sara Microbial bio-effectors for improved phosphorus acquisition from rock phosphates in wheat

42E

73

74

DOWN-REGULATION OF CANDIDATE GENES BY CRISPR/CAS9 TO REVEAL THEIR ROLE IN PI DEFICIENCY-INDUCED ROOT HAIR ELONGATION IN BRASSICA CARINATA

Thomas W. Kirchner, Markus Niehaus, Marco Herde and Manfred K. Schenk

Institute of Plant Nutrition, Leibniz Universität Hannover, Herrenhäuserstraße 2, 30419 Hanover, Germany, kirchner@pflern.uni-hannover.de

The deficiency of inorganic P induces long root hairs in Brassica carinata cv. Bale. The aim of the present study was the functional characterization of putatively responsible candidate genes for this process, which were identified in prior studies. For it, transgenic roots were generated for knock-down / knock-out of the candidate genes using the CRISPR/ CRISPR-associated protein 9 nuclease (Cas9) system in combination with the endogenous tRNA-processing system to enable multiplex editing according to Xie et al., 2015. Two guide RNAs for Cas9 were used per construct and one construct without guide RNAs served as control (referred as wild type). The CRISPR/Cas9 constructs were transiently transformed with the hairy root technique. Plants harboring transgenic roots as identified by GFP co-expression were further cultivated in nutrient solutions under deficient (0 mM) P conditions for eight days. Root tips with a length of two centimeters were harvested and used for root hair length measurement and gene expression analysis. The remaining root was used for genomic DNA extraction to verify the gene editing.

Amongst the candidate genes fasciclin-like arabinogalactan protein 27 (fla27) had clearly shorter root hairs under deficient P conditions compared to the wild type, indicating a role of BraFLA27 during P deficiency-induced root hair elongation. qRT-PCR not only confirmed the down-regulation of BraFLA27, but revealed also a reduced expression of most of the other candidate genes in the fla9 knock-down mutant compared to the wild type. This may indicate an upstream role of BraFLA27 in the pathway leading to the P deficiency-induced root hair elongation. FLAs are likely to be involved in abiotic stress responses and plant development (Johnson et al., 2003). Because of their fasciclin domain they are able to play a key role in cell-cell and cell-environment communication (Faik et al., 2006). Therefore, BraFLA27 has the potential to transmit the signal of low P conditions at the beginning of the signal transduction cascade leading to longer root hairs under P-deficient conditions.

References Faik A, Abouzouhair J, Sarhan F. 2006. Putative fasciclin-like arabinogalactan-

proteins (FLA) in wheat (Triticum aestivum) and rice (Oryza sativa): identification and bioinformatic analyses. Molecular genetics and genomics MGG 276, 478–494.

75

Johnson KL, Jones BJ, Bacic A, Schultz CJ. 2003. The fasciclin-like arabinogalactan proteins of Arabidopsis. A multigene family of putative cell adhesion molecules. Plant physiology 133, 1911–1925.

Xie K, Minkenberg B, Yang Y. 2015. Boosting CRISPR/Cas9 multiplex editing capability with the endogenous tRNA-processing system. Proceedings of the National Academy of Sciences 112, 3570–3575.

76

Does free intracellular zinc mediate programmed cell death in

different genotypes of rice?

Basharat Ali * and Michael Frei

Institute of Crop Science and Resource Conservation (INRES), Abiotic Stress Tolerance in

Crops, University of Bonn, Karlrobert-Kreiten Strasse 13, 53115 Bonn, Germany

* basharat@uni-bonn.de; basharat2018@yahoo.com

Abstract: Zinc (Zn) deficiency is a major nutrient imbalance affecting yields of cereals and

other crops, and affects around 35 million hectares of agricultural land worldwide. Zn

deficiency symptoms appear as brown spots on the leaves (leaf bronzing), and plants show

stunted growth which results in substantial yield losses. The leaf symptoms are thought to

occur due to an imbalance of the production of reactive oxygen species (ROS) and their

removal via antioxidants in plant tissue, which implies passive or ‘traumatic’ necrosis.

Whether Zn deficiency also leads to active programmed cell death (PCD) termed as apoptosis

has not been investigated previously. The aim of this study was to contribute to the

understanding of cell death processes associated with Zn deficiency in contrasting rice (Oryza

sativa L.) genotypes. For this purposes, a range of different staining and (fluorescence)

microscopy techniques is being applied, including trypan blue staining for cell death,

detection of nuclear DNA fragmentation indicating PCD using a TUNEL assay, a root hair

PCD assay using fluorescein diacetate (FDA) and in-situ Zn localization with zinquin.

Preliminary results obtained from method development experiments demonstated that trypan

blue did not pass through intact cell membranes of live cells, however it selectively stained

dead cells. We also observed that Zn deficiency greatly reduced cell survival, and staining of

plant cells (leaf and root) with zinquin clearly illustrated less accumulation of Zn in the plant

cells. Currently, more systematic experiments are being conducted in order to resolve

differences in Zn distribution, PCD and ROS development in contrasting rice genotypes.

These experiments will add to the understanding of cell death processes under Zn deficiency

and contribute to the breeding of more adapted crop varieties.

77

Influence of different recycled digestate fertilizers on P-uptake of maize plants and soil biological processes in

different soils

Inga-Mareike Bach1 and Torsten Müller1 1 Institute of Crop Science (340), University of Hohenheim, 70593 Stuttgart, Germany

Mareike.Bach@uni-hohenheim.de

Abstract Digestates of biogas fermentation are nutrient-rich particularly for Phosphor (P). Limited P-rockphosphate stocks call for a recycling of digestate as alternative P-fertilizers. The project “General optimization of biogas processes” aims on the production of a customized design fertilizer from recycled digestates by chemical and thermal processing. The influences of recycled P-fertilizers resulting from differing digestate treatments on plants and soil microbial functions in comparison to common Triplesuperphosphate (TSP) fertilization is crucial for the assessment of their fertilizer value. We hypothesize higher P-availability of the recycled P-Salt and a positive fertilization effect when combining P-Salts with separated solid matter (SM) compared to TSP. Furthermore the different drying process of air dried and steam dried SM (Air SM and Steam SM resp.) may show differences in their influence on soil microbial functions. A seven week greenhouse pot experiment with different recycled digestate products (P-Salt, separated solid matter dried at 40°C (Air SM) or 120°C (Steam SM) were investigated in a fully randomized block design with different soils (silty loam (loess), clayey loam, sand) on maize in four repetitions. The recycled digestate products were applied separately and combined (Air SM + P-Salt/Steam SM + P-Salt) in different ratios (1:1/1:2). Combined application was performed with and without mixing of the two components before addition to the soil. All recycled digestate products were applied in amounts equivalent to 150 mg P/kg soil. Soil samples were taken simultaneously from each pot after fertilisation and after harvest to analyse phosphatase activity and plant available P (CAL-P). Plant dry matter and P content in shoots were measured. Shoot P in maize plants increased with P-Salt application compared to a commercial TSP. Combinations of SM and P-Salt increased shoot P contents, particularly the application technique without prior mixing. The different ratios (1:1 or 1:2) did not influence shoot P contents. After fertilization, the level of phosphatase activity was higher than after harvest. Especially the Air SM induced an increase compared to P-Salt, TSP and Steam SM, which was similar to a fertilization with the Air SM + P-Salt combinations. After harvest, the phosphatase activity equaled each other, but higher phosphatase activity was still measured in the combinations of SM + P-Salt fertilization. In conclusion this study showed that recycled P-Salt and even combination of SM and P-Salt from digestates were equally effective to TSP. They have a high potential to reduce the dependency of agricultural P fertilizers derived from rockphosphate.

78

DOES THIAMETHOXAM INFLUENCE NITROGEN USE EFFICIENCY OF RICE? Höller S1, Heck C1, Goldbach HE 1 and Eichert T1 1 Institute of Crop Science and Resource Conservation, Division Plant Nutrition, University of Bonn, Karlrobert-Kreiten-Str. 13, 53115 Bonn, shoeller@uni-bonn.de

Low nitrogen (N) efficiency is commonly found in Asian rice production systems. Still, N application is required to maintain and increase plant growth and yield. To increase N efficiency, we investigated the effect of Thiamethoxam (TMX) on rice (Nipponbare) under different N levels in a greenhouse based experiment. TMX is usually used as a broad-spectrum insecticide but has shown to exhibit additional positive effects on plant vigor especially under abiotic stress situations, including nutrient deficiencies. To examine the effect of TMX on N efficiency we conducted an experiment under 4 different N levels (70%, 80%, 90% and 100% (40 g N/l) of the N-level supplied via the Yoshida solution), TMX-treatment was applied as seed coating and controls without. We observed significant TMX treatment effects for root length, fresh and dry weight of shoots and dry weight of roots. The relative amount of chlorophyll was significantly higher in plants treated with TMX at 70% N. Additionally, TMX treatment resulted in an increased number of panicles compared to control plants at all N-levels except for 80% N. In general we were not able to detect major differences of plant performance and yield between the N treatments, as TMX improved the analyzed traits alike at all N-levels. Analysis of N content of roots,shoots and grains is still in progress. TMX treated plants were able to maintain better root growth as it has been shown before in different studies in which TMX altered root development of different plants like Brachiaria (Macedo et al., 2013) and soybean (Pereira et al., 2010). Likewise, the positive influence of TMX on photosynthetic pigments can improve plant growth as it has been shown for cotton seedlings (Lauxen et al., 2016). TMX-treated plants with the lowest N-level showed the most consistent increase in chlorophyll contents compared to the controls throughout the development, while there was almost no difference between the 80-100% N treatments. We thus suggest that N efficiency can be improved by TMX, especially under N limited conditions. Macedo et al. (2013) described an increased activity of nitrate reductase in TMX treated Brachiaria plants, accompanied by an increase in crude protein. Thus, TMX might have the potential to stimulate nitrogen uptake and alter the physiological response of crops under N limited conditions. In conclusion TMX had positive effects on important traits like yield, root growth and chlorophyll content and might increase N efficiency under lower N-levels.

Lauxen, L. R., Almeida, A. D. S., Deuner, C., Meneghello, G. E., & Villela, F. A. (2016). Physiological response of cotton seeds treated with thiamethoxam under heat stress. Journal of Seed Science, 38(2), 140-147.

Macedo, W. R., Fernandes, G. M., Possenti, R. A., Lambais, G. R., & e Castro, P. R. D. C. (2013). Responses in root growth, nitrogen metabolism and nutritional quality in Brachiaria with the use of thiamethoxam. Acta physiologiae plantarum, 35(1), 205-211.

Pereira, J. M., Fernandes, P. M., & Veloso, V. R. S. (2010). Efeito fisiológico do inseticida thiamethoxam na cultura da cana-de-açúcar. Arquivos do Instituto Biológico , 77, 159-164.

79

PHYSIOLOGIC AND METABOLIC CHARATERIZATION OF SUGAR BEET

UNDER HIGH SALINITY

Behr Jan Helge1, , Zörb Christian1

1 University of Hohenheim, Institute of Crop Science, Quality of Plant Products, Emil-Wolff-Str. 25, 70599 Stuttgart

(Jan.Behr@uni-hohenheim.de)

ABSTRACT

Salinity is the present of electrolytic mineral solutes in concentrations that are harmful to many crops. Therefore, salinity and especially sodicity is an important limiting factor in modern agriculture. Halophytic plants like the sugar beet (Beta vulgaris L.) show moderate tolerance to salt stress. Due to its tolerance it is possible to substitute a certain amount of potassium fertilizer with sodium in practical agriculture. However, it is still unclear in what extent K+ ions are favored by the plant and how the ionic homeostasis is altered during different degrees of substitution under high salt concentrations. The main goal of this study is to investigate the physiological and metabolic adaption mechanisms of beta vulgaris to different types and degrees of cations. The plants were grown in a hydroponic culture under controlled conditions. After 4 weeks the plants were treated with different concentrations of NaCl, KCl and LiCl to clarify the various impact of each specific cation to the ionic balance of the plant and its stress tolerance mechanisms.

80

IS THE THREE-PHASE MODEL OF GROWTH RESPONSE TO SALT STRESS APPLICABLE TO ARABIDOPSIS? Wenting Zhao1, Sven Schubert1

1 Institute of Plant Nutrition (iFZ), Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany: wenting.zhao@ernaehrung.uni-giessen.de Abstract In this study, salt-induced changes in Arabidopsis thaliana (ecotype: Col-0) were investigated according to the three-phase model (Schubert, 2011). During phase I, shoot dry weight was reduced by 23% in the presence of 200 mM NaCl, while no big difference was found in root growth. Meanwhile, a slight increase of chlorophyll concentration was observed, which was detected by N-tester. There was no wilting symptom during Phase I. Five treatments (control, 200 mM NaCl, 200 mM KCl, 100 mM CaCl2, 100 mM Na2SO4) were conducted in order to find out which ion is responsible for the ionic toxicity symptom in Phase II. During Phase II, shoot dry weight was reduced by 38% under 200 mM NaCl treatment; 45% and 33% reduction were found in 200 mM KCl and 100 mM CaCl2, respectively. The young leaves developed chlorosis after 8 d in the presence of NaCl and KCl. Damages with 200 mM KCl treatment were more severe than with NaCl and CaCl2 treatments. Cl- content was increased 98 fold under KCl treatment, which was higher than under NaCl and CaCl2 treatments (53% and 42% fold, respectively). Therefore, those damages which are caused by different salt treatments (200 mM NaCl, 200 mM KCl, 100 mM CaCl2) are probably due to Cl- accumulation. Symptoms induced by salt stress in Arabidopsis during Phase I and Phase II are in agreement with the three-phase model. Reference: Schubert, S.: Salt resistance of crop plants – Physiological characterization of a multigenic trait. In: The Molecular and Physiological Basis of Nutrient Use Efficiency in Crops (M. J. Hawkesford, and P. Barraclough, Eds). Wiley Blackwell, Ames, USA, pp. 443-455 (2011)

81

Substrate limitation is not responsible for the inhibition of protein synthesis during the substitution of K+ by Na+ in the nutrition of sugar beet

Franziska Faust1 and Sven Schubert1

1: Institute of Plant Nutrition (iFZ), Justus Liebig University, Giessen, Franziska.Faust@ernaehrung.uni-giessen.de

Although potassium ions (K+) and sodium ions (Na+) show many similarities, their

exchangeability in the nutrition of plants is restricted. Due to its larger hydration shell Na+

cannot completely fulfill the key functions of K+ in plants (Schubert, 2015). We showed

that net protein synthesis was most sensitive to the substitution of K+ by Na+ in young

sugar beet and hence limited the extent of the substitution (Faust and Schubert, 2016). It

is hypothesized that the net protein synthesis was inhibited due to substrate limitation

induced by the substitution of K+ by Na+.

Sugar beet plants were grown in hydroponics. Four substitution treatments were

established: The treatments contained (at the level of full-strength nutrient solution) 1.00

mM K+/3.00 mM Na+ (for the 75.00% substitution), 0.10 mM K+/3.90 mM Na+(for the

97.50% substitution), 0.05 mM K+/3.95 mM Na+ (for the 98.75% substitution), and 0.01

mM K+/3.99 mM Na+(for the 99.75% substitution). Twenty-five days after sowing, the

plants were harvested. The soluble protein content, which was chosen as a parameter

for net protein synthesis, was already significantly decreased by the substitution of

97.50% of K+ by Na+ in the nutrient solution. The supply of sugars was not affected at

this level of substitution. An increase in the concentration of free amino acids was

observed. The concentration of free amino acids was determined according to the

method of Rosen (1957). Although this method is very fast and easy, the specificity of

this ninhydrin-based assay is limited. Polyamines are also detected with this method. It is

reported in the literature that K+ deficiency caused the accumulation of polyamines in

plant leaves. Therefore, the ninhydrin-based method is not conclusive enough to quantify

the concentration of free amino acids. In order to ensure that the translation was not

limited by a shortage of any amino acid, the determination of the concentration of each

single proteinogenic free amino acid was necessary. It was found that the supply of all

proteinogenic amino acids was not affected by the substititution of K+ by Na+, the

concentrations of the free amino acids even increased with the extent of the substitution.

82

We conclude that protein synthesis was not limited by substrate limitation. The

accumulation of free amino acids indicates that the activity of peptidyl transferase may

be inhibited when K+ is substituted by Na+ and reduced peptidyl transferase activity limits

protein synthesis. This hypothesis has to be confirmed by further experiments.

References:

Faust, F., Schubert S., 2016. Protein synthesis is the most sensitive process when potassium is substituted by sodium in the nutrition of sugar beet (Beta vulgaris). Plant Physiol. Biochem. 107, 237-247.

Rosen, H., 1957. A modified ninhydrin colorimetric analysis for amino acids. Arch. Biochem. Biophys. 67, 10–15.

Schubert, S., 2015. Sodium, in: Pilbeam, D.J., Barker, A. V. (Eds.), Handbook of Plant Nutrition. CRC Press, Boca Raton, pp. 697–710.

83

SILICON-ENHANCED OXALATE EXUDATION CONTRIBUTES TO ALLEVIATION OF CADMIUM TOXICITY IN WHEAT

Jiawen Wu, Christoph-Martin Geilfus, Britta Pitann and Karl-Hermann Mühling

Institute of Plant Nutrition and Soil Science, University of Kiel, Kiel, Germany, jwwu@plantnutrition.uni-kiel.de

Cadmium (Cd) contamination is a threat to agricultural plant production. Silicon

(Si) supply to Cd-stressed plants is known to ameliorate growth by decreasing

the concentrations of Cd in plant tissues. To elucidate the underlying

mechanism in wheat, hydroponic experiments were conducted under Cd

stressed conditions in the presence or absence of Si, with special emphasis on

root morphology, root exudation of oxalate and Cd allocation. We found that Si

supply decreased Cd accumulation in plant, which resulted in better plant

growth. Further studies of subcellular distribution showed that Si did not

accelerate Cd accumulation into cell walls or vacuoles. Since acropetal

translocation of Cd was not affected regardless of Si addition as well, we reason

the Si-related decrease in leaf Cd concentrations was based on exclusion at the

root side. This effect can be traced back to oxalate exudation by roots. In this

study, the ability to exude oxalate through the root apex in Cd-stressed plants

was weakened, while Si addition recovered the ability, thus reducing Cd uptake

by roots. To our knowledge, we showed the first time that Si decreases Cd

uptake by the increase of root oxalate exudation as an avoidance mechanism.

84

Meanwhile, we also found Si supply increased total number of root tips which

might facilitate root oxalate exudation.

Keywords: cadmium, oxalate exudation, silicon, Cd translocation, wheat

85

EFFECT OF DIFFERENT SOURCES AND RATES OF Zn

FERTILIZERS ON PHYSIOLOGICAL TRAITS OF SAFFRON (Crocus

sativus L.)

Reza Mirzaei P

1P, Majid Rostami P

2

P

1,P Assistant Professor, Department of Agroecology, Environmental Science Research Institute, Shahid Beheshti

University, G.C., Tehran Iran

Corresponding Author: rezamirzaei57@gmail.com

P

2P, Assistant Professor, Department of Agronomy, Faculty of Agriculture, Malayer University, Iran

Abstract Considering the environmental concerns and also because of limitation in agricultural land and water resources farmer have to improve fertilizers use efficiency. Therefore foliar application of fertilizers which have less negative effect on environment has been considered as an efficient method in recent years. Saffron is an important herbaceous medicinal plant form the Iridaceae family. In order to evaluate the effects of different sources and concentration of Zn fertilizers on some of the physiological characteristics of saffron the current experiment was conducted at Malayer University during 2015 growing season. The study was performed based on randomized complete block design (RCBD) with three replications. The experimental treatments were two different types of Zn fertilizer (nano ZnO and normal ZnO) and three levels of foliar application of these fertilizers (3, 6 and 9 Kg. haP

-1P).

Effects of experimental treatments on leaf length, total chlorophyll, chlorophyll a, chlorophyll a/b ratio, relative water content of leaf, Catalase and Proxidase activity were significant but there was no significant effect on anthocyanins and carotenoids content and also proline content. Based on results all of the experimental treatment increased the length and relative water content of leaf comparing to control, but the positive effects of normal ZnO was higher than nano ZnO. By increasing the amount of normal ZnO total chlorophyll and chlorophyll a content increased linearly whereas in nano ZnO treatments the highest amount of total chlorophyll and chlorophyll a observed after application of 3 Kg. haP

-1P. By increasing the

application rate of both types of fertilizers Proxidase activity increased but the highest activity of Catalase in normal ZnO and nano ZnO measured after application of 3 and 6 Kg. haP

-1P,

respectively. Based on observed results it could be conclude that optimum amount of nano ZnO for saffron is 3 Kg. haP

-1 Pwhearse the optimum rate for normal ZnO is 9 Kg. haP

-1 P. We

conclude that the application of nano ZnO has significant positive effect on saffron physiological traits but a great caution must be taken into consideration when applying in higher amounts. Key word: Foliar application, chlorophyll, fertilizer, nano-technology, plant nutrition.

86

DIFFERENT SALTS CAUSE DIFFERENT METABOLIC PROFILES IN VICIA FABA L. Julia Annika Richter1, Alexander Erban2, Joachim Kopka2 and Christian Zörb1 1: University of Hohenheim, Institute of Crop Science, Quality of Plant Products, 70599 Stuttgart, juliaannika_richter@uni-hohenheim.de 2: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam- Golm

Salinity reduces plant growth and therefore the yield of crops. This fact provokes the need for an understanding of underlining physiological processes of salt stress. In the past decades, NaCl- stress science focused mainly on the understanding of the physiological effect of sodium, whereas chloride based approaches produced equivocal results; ranging from the denial of a chloride effect at all up to a complete different effect of chloride in comparison to sodium. In this battlefield, we choose Vicia faba L., known as sensitive to sodium and chloride and grew them hydroponically. Furthermore, we stressed plants with NaCl for a simulation of combined sodium and chloride stress, NaSO4 for a simulation of single sodium stress and KCl for a simulation of single chloride stress. After one week of salt stress, we applied a gas chromatography/ time-of-flight– mass spectrometry approach (metabolomics), which generates a maximum complete picture of the physiological processes in the plants at a given time point. Following calculations compare the metabolic changes due to the different salts indicating similarities and differences between the given salts as well. In conclusion, a simulation of a single sodium or chloride effect with NaCl, Na2SO4 and KCl seams methodologically inadmissible and offers simultaneously new insights in overdosing effects of macronutrients such as sulfate and potassium. These ions can also be found in high concentrations in salinity affected soils.

87

THE ROLE OF SPERMINE IN DROUGHT TOLERANCE OF BARLEY (HORDEUM

VULGARE)

Nufaid Khan1, Nancy Nowak1, Edgar Peiter1

1 Plant Nutrition Laboratory, Institute of Agriculture and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Betty-Heimann-Strasse 3, D-06120 Halle (Saale), Germany

Nufaid.Khan@landw.uni-halle.de

As key regulators of transpiration, stomatal guard cells are principal determinants of crop performance under limited water availability. The synthesis of polyamines has been shown to be induced under drought conditions, and there is evidence that polyamines, in particular spermine, are involved in the regulation of stomatal aperture. Cytosolic free calcium ([Ca2+]cyt) is a universal second messenger, also integrated in guard cell signalling networks. We hypothesized that spermine may alter [Ca2+]cyt and thereby act as regulator of stomatal aperture. In stomatal bioassays with Arabidopsis and barley, the application of polyamines, especially spermine, was found to induce stomatal closure in a concentration-dependent manner and to trigger changes in guard cell [Ca2+]cyt levels by Ca2+ influx as well as release of Ca2+ from internal stores. Pharmacological analyses indicated that this response was at least partially exerted by H2O2 generated by the oxidation of spermine by Polyamine Oxidase (PAO). Experiments with a membrane-permeable fluorescent pH indicator indicated that intracellular pH may also play a role in the spermine-triggered generation of Ca2+ signals.

To directly determine the role of spermine in barley, we generated transgenic barley overexpressor and knockdown lines for the Spermine Synthase (SPMS) genes. Those lines were analysed genotypically, and lines with highest overexpression or knockdown levels were selected. In overexpressors, SPMS expression and concentration of spermine was increased at different developmental stages as compared to the wild type. Phenotypic analyses under non-stress conditions revealed a reduced stomatal conductance in SPMS overexpressors and a reduced water loss from excised leaves, whereas relative water content and chlorophyll concentration of the leaves were increased. Stomatal bioassay experiments on epidermal strips confirmed the partial closure of stomata in SPMS-overexpressing transgenic lines. Drought stress experiments with these transgenic lines showed a significantly increased relative water content under extreme stress, going along with increased chlorophyll concentration and PSII efficiency. An improved water conservation was indicated by increased stomatal conductance and excised leaf water loss under those conditions. The altered plant performance by SPMS overexpression was confirmed in hydroponics experiments with drought stress simulated by addition of PEG6000 to the nutrient solution.

88

EFFECT OF LOCALIZED NH4+-N AND P APPLICATION ON MAIZE GROWTH ON

NON-CALCAREOUS SOILS WITH CONTRASTING TEXTURE

Wei Gao1,2, Jianbo Shen1 and Doris Vetterlein2

1: China Agricultural University, Beijing, China, 2: Helmholtz Centre for Environmental Research – UFZ, Halle

(Saale), Germany, E-mail: gao.wei@ufz.de

Overuse of fertilizer in agriculture in China contributes to environmental damages such as soil

acidification and eutrophication of water. There is an urgent need to decrease fertilizer input

and improve resource use efficiency. Localized nutrients supply, specifically ammonium plus

phosphorus, can improve N and P uptake efficiency by regulating root morphological and

physiological plasticity (Jing et al. 2010, 2012). Studies about combined localized NH4+-N

plus P application have mainly focused on calcareous loam soil (Li et al. 2012; Ma et al.

2014a, 2014b, 2015). Our study investigated the effect of localized NH4+-N plus P application

on maize growth on non-calcareous sandy and clay soils at a pH value of 6.0. Field

experiments were conducted in northeast China with the following treatments: no fertilizer,

broadcast fertilizer (N2P2-B), localized NH4+-N plus P application with decreasing one-third

phosphorus rate (N2P1-L), localized NH4+-N plus P application with decreasing one-third

nitrogen rate (N1P2-L), and localized NH4+-N plus P application with same fertilizer rate as

in the broadcast treatment (N2P2-L). Compared with N2P2-B, leaf chlorophyll content was

significantly increased in treatments N2P1-L, N1P2-L, and N2P2-L at 54 days after sowing

(DAS 54) on both soils. Root length density (RLD) within the area of fertilizer application in

treatment N2P2-L was greater than N2P2-B at DAS 54 on both soils; however, the positive

effect on RLD didn’t appear in treatment N1P2-L on sandy soil and in N2P1-L on clay soil.

Plant N and P uptake were higher in N2P1-L, N1P2-L, and N2P2-L than N2P2-B on sandy

and clay soils at DAS 85, except that there was no difference of plant P uptake between

N2P2-B, N2P1-L, and N1P2-L on sandy soil. Compared with N2P2-B, shoot dry weight

89

improved by 33.9%, 33.0% and 35.5% on sandy soil and by 16.7%, 18.3%, and 16.2% on

clay soil in treatments N2P1-L, N1P2-L and N2P2-L before harvest (at DAS 142). Grain yield

in all localized NH4+-N plus P supply treatments were higher than in the broadcast treatment

on both soils. Furthermore, the partial factor productivity (kg grain per kg fertilizer applied)

of N and P were higher in all localized NH4+-N plus P application treatments than in N2P2-B.

The results indicated that localized ammonium plus phosphorus application is an efficient

way to enhance maize grain yield and N, P use efficiency on both sandy and clay soils and

even allows to reduce the total fertilizer application rate.

References:

Jing J, Rui Y, Zhang F, Rengel Z, Shen J. 2010. Localized application of phosphorus and ammonium

improves growth of maize seedlings by stimulating root proliferation and rhizosphere

acidification. Field Crops Research 119: 355-364.

Jing J, Zhang F, Rengel Z, Shen J. 2012. Localized fertilization with P plus N elicits an ammonium-

dependent enhancement of maize root growth and nutrient uptake. Field Crops Research 133:

176-185.

Li H, Zhang F, Shen J. 2012. Contribution of root proliferation in nutrient-rich soil patches to nutrient

uptake and growth of maize. Pedosphere 22(6): 776-784.

Ma Q, Wang X, Li H, Li H, Cheng L, Zhang F, Rengel Y, Shen J . 2014. Localized application of

NH4+-N plus P enhances zinc and iron accumulation in maize via modifying root traits and

rhizosphere processes. Field Crops Research 164: 107-116.

Ma Q, Tang H, Rengel Z, Shen J. 2014. Banding phosphorus and ammonium enhances nutrient uptake

by maize via modifying root spatial distribution. Crop and Pasture Science 64(10): 965-975.

Ma Q, Wang X, Li H, Li H, Zhang F, Rengel Z, Shen J. 2015. Comparing localized application of

different N fertilizer species on maize grain yield and agronomic N-use efficiency on a

calcareous soil. Field Crops Research 180: 72-79.

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FUNCTIONAL CHARACTERIZATION OF PLASMA-MEMBRANE H+-ATPASE

ISOFORMS FOR SALT RESISTANCE IN MAIZE (ZEA MAYS L.)

Muhammad Saqib1,2, Franziska Faust1, and Sven Schubert1

1:Institute of Plant Nutrition, Justus Liebig University, Giessen, Germany, 2:Institute of

Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan

e-mail: Muhammad.Saqib@ernaehrung.uni-giessen.de

Salinity is an important environmental stress that limits plant growth through osmotic stress

(first phase;days to weeks) and ion toxicity (second phase; weeks and more) (Saqib et al.

2005, 2006; Munns and Tester, 2008; Schubert, 2011). The osmotic stress impairs plant

growth earlier and with a greater effect than ion toxicity. Therefore, it is essential to identify

the physiological processes which are responsible for growth reduction in the first phase of

salt stress. The plant extension growth is determined by the effective turgor pressure and cell-

wall extensibility which depends on plasma membrane (PM) H+-ATPase-mediated cell-wall

acidification (Hager et al., 1971; Dünser and Kleine-Vehn, 2015).

The turgor pressure of salt-resistant and salt-sensitive maize genotypes remains unaffected by

salt stress (De Costa et al., 2007) but salt-sensitive maize genotypes cannot maintain

apoplastic acidification under salt stress (Pitann et al., 2009). This indicates that salt stress

may have effects on cell-wall extensibility which depends on plasma membrane (PM) H+-

ATPase-mediated cell-wall acidification. The PM H+-ATPase belongs to a family of proton

pumps driven by the hydrolysis of ATP and different isoforms are suggested to occur in

plasma membranes. The proof of efficiency of these individual isoforms in maize under salt

stress is still missing and is the focus of the present study. This study found 12 candidate

regions with predicted gene models while blasting cDNA of AHA2 against sequence data base

of B73 RefGen_v3. Six of these candidate regions were found to be transcribed in shoots and

may have functions relevant to cell- extension growth under salt stress. The relative

transcription of these isoforms in young maize shoots was studied in salt-resistant (SR-03)

and salt-sensitive (Pioneer 3906) maize hybrids under non-saline (1 mM NaCl) and saline

conditions (125 mM NaCl). These hybrids significantly differed for their shoot growth under

saline conditions. It is further planned to study the heterologous expression and enzyme

kinetics of single isoforms in yeast to characterize the contribution of specific isoform(s) to

salt resistance.

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References

De Costa et al., 2007. Physiol. Plant. 131: 311-321.

Dünser and Kleine-Vehn, 2015. Curr. Opin. Plant Biol. 28: 55–59.

Hager et al., 1971. Planta 100: 47-75.

Munns and Tester, 2008. Ann. Rev. Plant Biol. 59: 651-681.

Pitann et al., 2009. J. Plant Nutr. Soil Sci. 172: 535-543.

Saqib et al., 2005. Plant Sci.169: 959-965.

Saqib et al., 2006. J. Plant Nut. Soil Sci. 169: 542-548.

Schubert, 2011. In: The Molecular and Physiological Basis of Nutrient Use Efficiency in

Crops. John Wiley & Sons, Inc., pp. 443–455.

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Effects of waterlogging on growth, nutrient status and yield of rapeseed

(Brassica napus L.)

Anna-Catharina Wollmer1 , Britta Pitann1, Karl-H. Mühling1

1 Institute of Plant Nutrition and Soil Science, Kiel University, Hermann-Rodewald-Straße 2, 24118 Kiel, Germany

(acwollmer@plantnutrition.uni-kiel.de)

As a result of climate change, a significant increase of heavy rainfalls and abundant continuous rain can actually observed in the temperate latitudes. This is increasingly problematic, since such extreme weather events tremendously affect crop production by temporary waterlogging.

This is due to the fact that waterlogging events mainly occur especially in critical periodes of plant development, e.g. in autuum after emergence of the seedlings or in spring during stem elongation. In order to estimate the risk of possible harvest losses and, associated therewith, financial losses, the effects of very early (EC 21/22), early (EC 31/32) and late (EC 55/57) waterlogging on growth, nutrient status and yield of rapeseed (Brassica napus L.) were analysed.

Since it is not possible to temporarily regulate waterlogging events at determined developemental stages in the field, rapeseed plants (cv. Avatar) were grown both in small pots (1.7 L) and large containers (120 L), and were waterlogged in the respective developmental stage for one or two weeks. A special challenge was, to regulate the water content in the containers as needed, which was achieved by the use of faucets, so that sensitive developmental stages can be specifically waterlogged. After harvest, growth, yield and quality parameters were measured and concentrations of macronutrients were analysed.

Waterlogging at the developmental stage EC 21/22 led to a reduced shoot and root growth and resulted in a significant impairment of the vegetative development of the rapeseed plants. Not only the growth rate but also the concentrations of the macronutrients nitrogen

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(N) and sulfur (S) were significantly reduced in the very early waterlogged rapeseed plants. This is especially problematic, because reduced root growth and the lack of nutrient reserves could impair the hibernation of rapeseed. In contrast, plants, which were flooded at emerging stage (EC 31/32) showed no significant growth reductions. No yield reductions could be measured after early waterlogging. In the main raceme, but not in the shoot, significantly reduced concentrations of N and S were measured. This was again in contrast to late waterlogging at flowering stage, in which the largest impacts on the rapeseed plants occurred. The main racemes wilted and folded over, and dry weight of shoots and main racemes were significantly reduced. Rapeseed plants could not completely recover from the late waterlogging, so that yield was significantly reduced. Analysis of the quality parameters oil and glucosinolate content showed a significantly lower quality of oilseeds from plants that had been waterlogged at EC 55/57. Oilseeds of these plants had significant higher glucosinolate contents and consequently significantly lower oil content. In following experiments these preliminary results should be confirmed.

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DIFFERENT SALTS CAUSE DIFFERENT METABOLIC PROFILES IN VICIA FABA L. Julia Annika Richter1, Alexander Erban2, Joachim Kopka2 and Christian Zörb1 1: University of Hohenheim, Institute of Crop Science, Quality of Plant Products, 70599 Stuttgart, juliaannika_richter@uni-hohenheim.de 2: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam- Golm

Salinity reduces plant growth and therefore the yield of crops. This fact provokes the need for an understanding of underlining physiological processes of salt stress. In the past decades, NaCl- stress science focused mainly on the understanding of the physiological effect of sodium, whereas chloride based approaches produced equivocal results; ranging from the denial of a chloride effect at all up to a complete different effect of chloride in comparison to sodium. In this battlefield, we choose Vicia faba L., known as sensitive to sodium and chloride and grew them hydroponically. Furthermore, we stressed plants with NaCl for a simulation of combined sodium and chloride stress, NaSO4 for a simulation of single sodium stress and KCl for a simulation of single chloride stress. After one week of salt stress, we applied a gas chromatography/ time-of-flight– mass spectrometry approach (metabolomics), which generates a maximum complete picture of the physiological processes in the plants at a given time point. Following calculations compare the metabolic changes due to the different salts indicating similarities and differences between the given salts as well. In conclusion, a simulation of a single sodium or chloride effect with NaCl, Na2SO4 and KCl seams methodologically inadmissible and offers simultaneously new insights in overdosing effects of macronutrients such as sulfate and potassium. These ions can also be found in high concentrations in salinity affected soils.

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ZINC-STARVATION INDUCED DNA DEMETHYLATION IS INDEPENDENT OF TRANSCRIPTIONAL RESPONSE IN ARABIDOPSIS THALIANA

Xiaochao Chen, Brigitte Schönberger and Uwe Ludewig

Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim

Fruwirthstr. 20, 70593 Stuttgart, Germany

xiaochao.chen@uni-hohenheim.de

Plants have developed a number of strategies to adapt environmental stress. Cytosine DNA methylation is a genome modification to regulate gene expression or maintain genome stability in response to environmental cues. Nutritional deficiencies are a common environmental stress, but little is known about how this alters DNA methylation and whether this regulates gene expression. Here, we investigated the whole-genome methylation profiles and transcriptional changes in response to Zn starvation in the Arabidopsis root. Zinc (Zn) is an essential micronutrient that is widely involved in many molecular and metabolic functions, and its deficiency activates a small set of well-known genes. Ionome and transcriptome data confirmed the specific Zn effect. Widespread differentially methylated regions were identified to adapt Zn starvation, which were hypomethylated and preferentially localized in transposable elements (TEs). Furthermore, higher-expression genes were more methylated in CpG context, whereas low-expression genes were predominantly methylated in non-CpG contexts. Genic regions were hypomethylated in Zn starvation irrespective the methylation contexts. Unexpectedly, we found that transcriptional changes were independent of methylation differences. S-adenosyl methionine and micro RNA level were also quantified in response to Zn starvation. Overall, Zn is beneficial to maintain DNA methylation level, but the relation between differential transcription and differential methylation upon Zn-deficiency is complex. Details of this relationship will be presented.

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EFFECT OF N, K, AND Mg SUPPLY ON THE NUTRITIONAL VALUE OF TOMATO FRUITS

Kassem A. S. Mohammed1; Christof Engels2 kassem.mohammed@alumni.hu-berlin.de

1National Research Centre, Cairo, Egypt. 2Humboldt University of Berlin Tomato fruits are an important source of health-promoting substances including vitamins, minerals and antioxidants. It is well documented that the nutritional value of tomato is dependent on genotype, environmental factors and agronomic measures. In this study we compared the effects of different rates of N, K and Mg supply on the concentrations of mineral elements, soluble sugars, ascorbic acid, carotenoids, and phenols in fruits. Plants were cultured in nutrient solution. In the control treatment (optimal supply, 100% biomass growth), growth limitation was prevented by continuously high nutrient supply. In the nutrient-limitation treatments, either K or Mg or N were supplied at rates which reduced total biomass to about 80% (moderate deficiency) or 60% (severe deficiency) of the control.

In comparison to well supplied plants, fruit fresh mass was reduced by 30-40% in moderately deficient and 40-50% in severely deficient plants. Deficiency of K and Mg did not much affect the fruit index (fruit dry mass to shoot dry mass), whereas in N deficient plants the fruit index was increased indicating nutrient-specific effects on biomass allocation among plant organs.

As expected, low N and K supply did not only reduce N and K concentrations in roots, leaves and stems but also in fruits. In Mg deficient plants, in contrast, Mg concentrations in fruits were not reduced despite of strongly decreased Mg concentrations in vegetative plant organs. This indicates tight Mg homeostasis in tomato fruits irrespectively of external Mg supply and Mg nutritional status of leaves, stems and roots. Fruit concentrations of Fe and Zn were not influenced by the rate of Mg and K supply. In contrast, low N supply significantly decreased Fe and Zn concentrations in fruits. In N deficient plants, low fruit Fe concentrations were associated with low Fe uptake and concentrations in the vegetative plants organs, whereas Zn concentrations were specifically reduced in fruits but not in other plant organs.

In mature fruits, the concentration of total phenols was not dependent on the rate of nutrient supply. Fruit sugar concentrations were higher at low rates of nutrient supply, in particular at low rate of N supply. Lycopene concentration increased in fruits of nutrient-deficient plants irrespective of the specific nutrient (N, K or Mg). Lycopene concentrations are known to be particularly high in the peel. Therefore, increased lycopene concentrations in fruits of nutrient deficient plants were possibly due to reduced fruit volume, and thus increased peel to total fruit mass ratio. Ascorbic acid concentrations in fruits were reduced by K and Mg deficiency, but strongly increased in N deficient plants.

The data indicate that the nutritional value of tomato fruits is strongly dependent on N, K and Mg nutrition. With regard to micro-element (Fe and Zn) concentrations, high N nutrition had beneficial effects, whereas concentrations of health-promoting organic compounds were reduced at high N supply. The rate of Mg and K supply had no effect on micro-element concentrations, whereas concentrations of health-promoting organic compounds were increased at high supply.

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EFFECTS OF ORGANO-MINERAL AND MINERAL FERTILIZERS AND NITROGEN DOSES ON YIELD AND QUALITY OF SUGAR BEET (BETA VULGARIS L.) Abdullah Ulas

Erciyes University, Agricultural Faculty, Department of Soil Science and Plant Nutrition, Kayseri-TURKEY,agrulas@erciyes.edu.tr

Abstract The objective of the present study was to compare the effect of different types of base fertilizers and the nitrogen doses on crop yield and quality of sugar beet (Beta vulgaris L.) crop grown in a two-year field experiment (2013 and 2014) conducted in Kayseri Province in Turkey. Two different types of base fertilizers (Organo-mineral: 7% N - 18% P2O5 -7% K2O, Mineral: 13% N - 24% P2O5 -18%) and four different nitrogen doses (N150: 150 kg N ha-1, N190: 190 kg N ha-1, N230: 230 kg N ha-1, N280: 280 kg N ha-1) were compared in randomized block design with four replications. On November (2013 and 2014), a surface area of 10 m2 of each plot was harvested and crop yield (fresh root weight, sugar content and white sugar yield) and quality parameters (α-amino N, sodium and potassium content) were measured. Averaged over N doses, fresh root weight and white sugar yield significantly differed between two different base fertilizers in 2013 and 2014. Application of Organo-mineral fertilizer significantly increased the fresh root weight (t ha-1) by 12.3% in 2013 and by 9.9% in 2014 as compared to Mineral fertilizer. However, interestingly, no significant differences were found in sugar content (%) between two base fertilizers. On the other hand, compared to Mineral fertilizer, the white sugar yield (t ha-1) was significantly increased by 12.0% in 2013, and by 9.7% in 2014 under application of Organo-mineral fertilizer. In terms of quality parameters, averaged over N rates, except K content (mmol 100 g-1) in root, no significant differences were found in α-amino N and sodium contents between two base fertilizers. Generally, increasing N doses increased fresh root weight, white sugar yield, α-amino N, sodium and potassium content but reduced the sugar content (%) in 2013 and 2014 experimental years. The lowest fresh root weight and white sugar yield was found at N150 while the highest fresh root weight and white sugar yield was found at N230. The highest N rate (N280) caused a reduction in fresh root weight and white sugar yield in 2013 and 2014.

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EFFECT OF ORGANIC AND INORGANIC MIXTURE APPLICATIONS ON RICE PRODUCTION UNDER SALT AFFECTED SOIL CONDITIONS

Megahed Amer (1), Ahmed El-Henawy (2), Tarek Alshaal (2) and Hassan R. El-Ramady (2)

P

(1)PSoils, Water and Environment Research Institute (SWERI), ARC Egypt

P

(2)PSoil and Water Dept., Faculty of Agriculture, Kafrelsheikh Uni., Kafr El-Sheikh, Egypt

*Corresponding author: Hassan El-Ramady (4TUramady2000@gmail.com U4T) ABSTRACT

A field experiment was conducted at Sakha Agricultural Research Station Farm, North Delta, during two successive summer growing seasons (2014 and 2015) to study the application effect of organic and inorganic mixtures on rice yield (Oryza sativa L.) under salt affected soils in North Delta. The experiment was designed as split-split plot with three replicates. The main plots were occupied by control (cont.), mixture 1 (M1: amino acids 9.5%, fulvic acid 6.5% and humic acid 35% at the rate of 5 L haP

-1P) and mixture 2 (M2: 10% N, 20% K and

15.5% Ca at the rate of 5 L haP

-1P) as well as M1 + M2. Sub plots were devoted to zinc levels

(250, 500 and 1000 mg kgP

-1P). Sub –sub plot includes the application methods including foliar

(F), soil (S) and foliar + soil application. The results showed that organic treatment as soil application clearly improved the soil salinity (EC), sodium adsorption ratio (SAR) and exchangeable sodium percent (ESP). However, cation exchange capacity (CEC) was significant increased due to these mixtures comparing with the control in both growing seasons. Yield of rice was highly significant increase due to organic acids application during the two growing seasons. The grain and straw yields as well as content of protein and nutrients were highly significant increase due to the interaction among the organic, mineral and methods of application. Nitrogen uptake and its recovery by rice was highly significant increase due to interaction among different treatments during growing seasons. It is also found that, potassium and zinc alleviates salt stress and increased the yield of rice, whereas the organic acids (amino, fulvic and humic acids) improved physical, chemical and biological properties of soil as well as the uptake of macro- and micro-nutrients. Data clearly demonstrated the beneficial effects of mixtures of organic (amino, humic and fulvic acids), inorganic (N, K, Ca) mixture and/ or zinc on the yield of rice and soil properties under salt affected soils. It could be concluded that the alleviation of soil salinity stress of salt-affected soils can be achieved by foliar and/or soil application of previous mixtures as well as zinc under the experimentation condition. Key words: Rice yield, N-recovery, uptake, salt affected soil, amino, fulvic, humic acids and zinc. Acknowledgments Authors thank the outstanding contribution of STDF research teams (Science and Technology Development Fund, Egypt) and MBMF/DLR (the Federal Ministry of Education and Research of the Federal Republic of Germany), (Project ID 5310) for their help. Great support from this German-Egyptian Research Fund (GERF) is gratefully acknowledged.

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[1] FAO. "Erntemenge der führenden Anbauländer von Zuckerrohr weltweit im Jahr 2014 (in Tonnen)." Statista - Das Statistik-Portal. Statista. Dezember 2015a. Accessed 06.05.2016. Available from <http://de.statista.com/statistik/daten/studie/454425/umfrage/erntemenge-der-fuehrenden-anbaulaender-von-zuckerrohr-weltweit/>

[2] FAO."Sugarcane, soybean and maize production by Brazil vs. global production ", 2015b, Accessed 06.05.2016. Available from http://faostat3.fao.org/compare/E

[3] Goldemberg, J., Mello, F. F., Cerri, C. E., Davies, C. A., and Cerri, C. C.: Meeting the global demand for biofuels in 2021 through sustainable land use change policy, Energy Policy, 69, pp. 14–18, 2014.

[4] Goes, T., Marra. R., Araujo, M. d., Alves, E., Oliveira de Souza, M.: Sugarcane in Brazil: current technologic stage and perspectives. Revista de Politica Agricola, pp. 52–65, 2011.

[5] Endres, L.: Photosynthesis and Water Relations in Brazilian Sugarcane, TOASJ, 4, pp. 31–37, 2010. [6] George, O. P. A., Eras, J. J. C., Gutierrez, A. S., Hens, L., and Vandecasteele, C.: Residue from

Sugarcane Juice Filtration (Filter Cake): Energy Use at the Sugar Factory, Waste Biomass Valor, 1, pp. 407–413, 2010.

[7] Rocha, G. J. d. M., Nascimento, V. M., Gonçalves, A. R., Silva, V. F. N., and Martín, C.: Influence of mixed sugarcane bagasse samples evaluated by elemental and physical–chemical composition, Industrial Crops and Products, 64, pp. 52–58, 2015.

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The effect of light intensity on the root exudation pattern of sugar beet under phosphorus deficiency

Luojin Yang1, Bernd Steingrobe1, Katharina Pfohl2, Klaus Dittert1, Petr Karlovsky2

1 Department of Crop Sciences, Section of Plant Nutrition and Crop Physiology, Georg-August-University, Carl-Sprengel-Weg 1, 37075 Göttingen, Germany

2 Department of Crop Sciences, Section of Molecular Phytopathology and Mycotoxin Research, Georg-August-University Goettingen, Grisebachstrasse 6, 37077 Goettingen, Germany

email: bsteing@gwdg.de

INTRODUCTION Secretion of root exudates is one strategy of plants to cope with P deficiency (Vance et al.

2003). Besides this, root exudation pattern, i.e. the quantity and quality of exudates, is

influenced by several environmental factors (Hinsinger 2001). Increasing light intensity

greatly enhanced release of total amount of exudates (Samal 2007) as well as of specific

compounds, such as citrate for P-deficient white lupin (Cheng et al. 2014). However,

knowledge about the complete shift in exudate composition due to light intensity is scarce.

Previous studies on root exudation have mainly been conducted in growth chambers, with

large differences in light intensity between different authors (e.g. range between 200 to 500

µmol m-2 s-1; Neumann and Römheld 1999; Khorassani et al. 2011; Duffner et al. 2012). This

complicates the comparison of results and also their transferability to high light field

conditions. The aim of the present study was to assess the influence of light intensity on root

exudation pattern of sugar beet at P deficiency.

MATERIAL AND METHODS Sugar beet was grown hydroponically with either high light intensity (400 µmol m-2 s-1) or

low light intensity (100 µmol m-2 s-1) and a sufficient (500 µM P) or deficient (< 2 µM P) P

supply. Exudates were collected by the dipping method (Neumann and Römheld 2007) at 35

and 42 days after transplanting and the composition was analyzed by HPLC-ESI-MS. Signals

which occurred in at least 4 of 6 replicates were taken into account and compared in a non-

targeted metabolic profiling procedure.

RESULTS

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Light intensity positively influenced plant biomass production and root/shoot dry weight ratio,

particularly under P-deficient conditions. The exudation rate (µg m-1 root length h-1) was

increased by both low P supply and increasing light intensity, whereas the effect of light

intensity on root exudation was more pronounced under P deficiency. A comparison of

HPLC-ESI-MS signals showed a strong influence of light intensity on exudate composition.

Total number of signals was 100-200 depending on plant age and treatment. At a given P

supply level, only about 40% of signals occured at both light intensities, indicating that a large

number of exudate compounds were released solely either under low light or under high light

conditions.

CONCLUSIONS These observations suggest that light intensity is an important factor in root exudation

processes. It is suggested that in studies concerning root exudation a special attention should

be given to the light conditions.

LITERATURE Cheng L, Tang X, Vance CP, et al (2014) Interactions between light intensity and phosphorus nutrition affect the

phosphate-mining capacity of white lupin (Lupinus albus L.). J Exp Bot 65:2995–3003. Duffner A, Hoffland E, Temminghoff EJ (2012) Bioavailability of zinc and phosphorus in calcareous soils as

affected by citrate exudation. Plant Soil 361:165–175.

Hinsinger P (2001) Bioavailability of soil inorganic P in the rhizosphere as affected by root-induced chemical changes: a review. Plant Soil 237:173–195.

Khorassani R, Hettwer U, Ratzinger A, et al (2011) Citramalic acid and salicylic acid in sugar beet root exudates solubilize soil phosphorus. BMC Plant Biol 11:121.

Neumann G, Römheld V (1999) Root excretion of carboxylic acids and protons in phosphorus-deficient plants. Plant Soil 211:121–130.

Neumann G, Römheld V (2007) The release of root exudates as affected by the plant physiological status. Rhizosphere Biochem Org Subst Soil-Plant Interface 23–72.

Samal D (2007) Potassium uptake efficiency mechanisms and root exudates of different crop species. Dissertation, Uni Göttingen.

Vance CP, Uhde-Stone C, Allan DL (2003) Phosphorus acquisition and use: critical adaptations by plants for securing a nonrenewable resource. New Phytol 157:423–447.

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BioFectors

Resource Preservation by Application of BIOefFECTORs in European Crop Production – The BIOFECTOR Project

BIOFECTOR is an integrated project with the aim to reduce input of mineral fertilisers in European agriculture by development of specifically adapted bio-effectors (BEs) to improve the efficiency of alternative fertilisation strategies, such as organic and low-input farming, use of fertilisers based on waste recycling products and fertiliser placement technologies.

Bio-effectors addressed comprise fungal strains of Trichoderma, Penicillium and Sebacinales, as well as bacterial strains of Bacillus and Pseudomonades with well-characterized root growth promoting and nutrient-solubilising potential. Natural extraction products of seaweed, compost and plant extracts, as well as their purified active compounds with protective potential against biotic and abiotic stresses are also tested in various combinations. These features offer perspectives for a more efficient use of nutrients by strategic combination with the alternative fertilisation strategies. Maize, wheat and tomato are chosen as representative crops. Laboratory and European-wide field experiments assure product adaptation to the various geo-climatic conditions characteristic for European agriculture.

The final goal is the development of viable alternatives to the conventional practice of mineral fertilisation as contribution to a more efficient management of the non-renewable resources of mineral nutrients, energy and water, to preserve soil fertility and to counteract the adverse environmental impact of agricultural production. Research contributions of the Hohenheim working grouos will be presented.

The project has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 312117 (BIOFECTOR).

Postertitel

Hasan M M, Weinmann M, Nkebiwe PM, Weber N, Zaytseva O, Bradáčová K, Morad-talab N, Mpagana I, Müller T, Neumann G Application strategies for microbial bio-effectors: Comparison for rhizosphere colonization and improved plant growth in pot and field experiments

Moradtalab N, Weinmann M, , Bradáčová K, Weber NF, Imran M, Neumann G Interactions of silicone and micronutrients for the improvement of cold tolerance in maize Moradtalab N, Aneesh A,Weinmann M, Neumann G

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Silicone, micronutrients and microbial inoculants as cold stress protectants during early growth of maize under field conditions Moradtalab N, Weinmann M, Sharma S, Selby C, Neumann G Field performance of winter wheat after foliar application of selected plant extracts and micronutrients as cold stress protectants Weber NF, Khar S, Ludewig U, Neumann G Triggering plant responses to P limitation - A novel mode of action for microbial plant growth promotion ?

Weber NF, Herrmann I, Hochholdinger F, Ludewig U, Neumann G PGPR-induced stimulation of root growth and nutrient acquisition in maize. Do root hairs matter ?

Nassal D, Marhan S, Kandeler E Pseudomonades also like it well-fertilized? A rhizobox experiment proving the plant growth promoting effect of Pseudomonas jessenii under varying P supplied soil conditions

Nassal D, Spohn M, Marhan S, Eltlbany N, Smalla K Kandeler E Short-term effects of Pseudomonas jessenii RU47 on C and P cycle in maize

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APPLICATION STRATEGIES FOR MICROBIAL BIO-EFFECTORS: COMPARISON FOR RHIZOSPHERE COLONIZATION AND IMPROVED PLANT GROWTH IN POT AND FIELD EXPERIMENTS.

Hasan M M1, Weinmann M1, Nkebiwe PM2, Weber N1, Olga Zaytseva1, Klára Bradáčová1, Narges Morad-Talab1, Isaac Kwadwo Mpagana1, Müller T2, Neumann G1

1 Institute of Crop Science, Nutritional Crop Physiology (340h), Universität Hohenheim, 70593 Stuttgart, Germany; 2 Institute of Crop Science, Fertilisation and Soil Matter Dynamics (340i), Universität Hohenheim, 70593 Stuttgart, Germany; markus.weinmann@uni-hohenheim.de

BioFector is a current research project funded by the European Union that aims to develop strategies for the applications of microbial bio-effectors in alternative plant nutrition strategies. For many microbial bio-effectors, such as strains of Bacillus spp., the ability to support the plant acquisition of mineral nutrients has been proven under controlled conditions. Direct mobilization of mineral nutrients, stimulation of root growth, and interactions with other microorganisms are among the possible modes of action. Yet, there is a lack of adequate formulation and application technologies to support the expression of these traits under field conditions. To ensure persistent rhizosphere colonization at sufficient population densities in competition with the autochthonous microflora and despite of adverse environmental conditions is thought to be a critical factor.

In this work, delivery strategies for microbial bio-effectors such as seed treatment, near to the seed placement, and broadcast with soil incorporation are compared for their effectiveness concerning root colonization, root and shoot growth promotion, and the plant acquisition of mineral nutrients. Advanced application strategies, such as the combination of bio-effector treatments with fertilizer placement are studied in maize crops.

Tracing analyses indicate that broadcast with soil incorporation is the most effective strategy to achieve a persistent establishment of introduced bacterial strains in the rhizosphere over several weeks after sowing. Low or no colonization of distant root segments could be detected in response to seed treatments. In pot experiments, however, even seed treatments increased the rooting density of maize in the proximity of fertilizer depots.

These findings indicate that adequate formulation and application technologies are of key importance for the success of bio-effector treatments in alternative plant nutrition strategies. The viability of different strategies is discussed with respect to technical and economic aspects.

Funding supplied by the BIOFECTOR project (Resource Preservation by Application of BIOefFECTORs in European Crop Production). Grant Agreement Number 312117 under the Seventh Framework Program (FP7), European Commission, Brussels, Belgium.

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PGPR-INDUCED STIMULATION OF ROOT GROWTH AND NUTRIENT ACQUISTION IN MAIZE: DO ROOT HAIRS MATTER?

Nino F. Weber1, Ilja. Herrmann1, Uwe Ludewig1, Günter Neumann1

1: Universität Hohenheim, Stuttgart, niweb@uni-hohenheim.de

Plant growth promotion by PGPRs is a well-known phenomenon intensively described in the literature. However, the characterization of the underlying mechanisms is frequently based on in vitro studies of PGPR properties on artificial growth media with questionable significance for real rhizosphere conditions.

Here we describe effects of the well-characterized, commercial PGPR strain Pseudomonas sp. DSMZ 13134 (Proradix ®) on plant growth and nutrient acquisition of a maize mutant (B73 rth2) with impaired root hair production as compared with the corresponding wild type line, to study the importance of root hairs for the interaction of the PGPR strain with the host plant. The study was conducted in a rhizobox-culture on a sand-soil mixture with moderate P supply.

Root hair development of the mutant was clearly impaired, reflected by slower growth and limited elongation as compared with the wildtype line. Obviously, this defect was compensated by more intense root growth and fine root production of the mutant and this effect was particularly expressed after inoculation with Proradix. By contrast, PGPR inoculation had no effect on root hair length. The finding that root growth stimulation was particularly expressed in the mutant line without any effects on root hair development suggests limited significance of root hairs in the PGPR/plant interaction.

The beneficial effects of Proradix on root growth were reflected in higher shoot contents of macronutrients, such as P and K, and lacking differences between mutant and wildtype underline the ability of Proradix to compensate defective root hair development by increased fine root production. However, despite improved root growth, surprisingly Proradix had negative effects on shoot accumulation of micronutrients such as Zn and Cu. This may reflect a competitive effect between the host plant and the PGPR strain, since many Pseudomonades are effective producers of metal chelators (siderophores), while maize is known to be comparatively ineffective in phytosiderophore production for metal acquisition.

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MICROBIAL BIO-EFFECTORS FOR IMPROVED PHOSPHORUS ACQUISITION FROM ROCK PHOSPHATES IN WHEAT.

Sara Bandari1, Markus Weinman1, Günter Neumann1

1: Nutritional Crop Physiology (340H), Institute of Crop Sciences, University of Hohenheim, Stuttgart, sara.bandari@gmail.com

Phosphorus (P) is the second most limiting element in soils for crop production after nitrogen (N) in arable soils. High economic and environmental costs of easily soluble P fertilizers and limited natural resources for their production necessitate the use of alternative P fertilizers in agriculture. In this regard, the use of microbial bio-effectors, such as plant growth promoting strains of Pseudomonas spp., is receiving increasing attention due to their ability to solubilize sparingly available P forms and to stimulate root growth.

In this study, pot experiments with soil material low in plant available P and a field experiment on a P deficient field near Horb am Neckar, Germany were conducted to test the commercial bio-effector product Proradix® WP (active ingredient: Pseudomonas sp. strain DSMZ 13134; Sourcon Padena, Tübingen) in combination with different P fertilizer forms for improved P nutrition of wheat. Thereby the use of sparingly soluble rock phosphates (Naturphosphat P26; Timac AGRO, Zwentendorf, Östereich; Granuphos, Landor, Birsfelden, Schweiz) was compared with control variants that were not fertilized with P or supplied with water soluble phosphate (super phosphate).

Measurement of mineral nutrient concentrations in flag leaves showed (Fig. 1a) no significant differences neither between fertilizer nor Proradix® treatments. However, the results of visual ratings (Figure 1b) indicted a significant difference between fertilizers and in the variants with Rock P from Landor (RPL) a significant improvement of plant performance in response to the application of Proradix®. Similar findings were made in the field experiment.

Fig.1: Phosphorus (P) concentrations in flag leaves at 69 days after sowing and plant performance evaluated by visual ratings for vigorous growth and P deficiency symptoms, such as anthocyanin coloration or paleness of leaves, at 79 days after sowing of wheat in the pot experiment with low P soil substrate. The soil substrate of different variants was supplied with only nitrogen fertilizers (Standard), nitrogen plus rock phosphate fertilizers from Timac (RPT) or Landor (RPL), nitrogen plus

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super phosphate (Positive Control), or not (Zero). In addition, Proradix® was applied to the soil twice, i.e. at sowing and at 37 days after sowing, or not (untreated). Data represent mean values ± standard errors (n = 5). Significant differences between mean values are indicated by columns not sharing same letters (one-way ANOVAs followed by Tukey’s test; p < 0.05).

Although further evaluations are in process, the present results suggest that strategies for the combined application of microbial P solubilizers and alternative P fertilizers need to be further developed to achieve significant improvements in wheat production.

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TOP 4: Molecular Mineral Nutrition / Sensing

Schönberger, Brigitte Site-dependent differences in DNA

methylation and their impact on plant establishment and phosphorus nutrition in Populus Trichocarpa

44

Mager, Svenja DNA methylation adaptation and the correlation to transcript abundance in maize as response to nutrient deficiencies

45

Schlindewein, Claudia Genome-wide identification of the CPK gene family in Medicago Truncatula and its expression in nodules

46

Frank, Julia Novel proteins regulating Ca2+ concentrations in the chloroplast

47

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SITE-DEPENDENT DIFFERENCES IN DNA METHYLATION AND THEIR IMPACT ON

PLANT ESTABLISHMENT AND PHOSPHORUS NUTRITION IN POPULUS

TRICHOCARPA

Brigitte Schönberger1 and Uwe Ludewig1

1 University of Hohenheim, Institution of Crop Science, Department of Nutritional Crop

Physiology, D-70599 Stuttgart, Germany, Brigitte_Schoenberger@uni-hohenheim.de

Abstract

Higher plants, like trees, have a repertoire of mechanisms to increase phosphorus (P) acquisition when

P supply is low. The genetic and physiological basis of these mechanisms has been studied

extensively. In addition, phosphorus starvation was recently suggested to transiently affect DNA

methylation in two annual plant species. However, the impact of differential DNA methylation and

microRNAs (miRNAs) on gene expression, as well as on P-related physiology, is largely unknown in

perennials.

In this study, clonal Populus trichocarpa (cv. Muhle Larson) starting material (cuttings) from

two different locations was grown in hydroponic culture with different P levels. These clones

established differently in common growth chambers, suggesting epigenetic site-dependent

memory. Using bisulfite sequencing, site-specific genome-wide methylomes were determined

and the gene and miRNA expression of differentially methylated regions (DMRs) was

quantified via qPCR. Methylation differences were nucleotide context-specific and a few

genes encoded in top-differentially methylated regions were differentially expressed.

Furthermore, miRNAs and their target genes in DMRs were extensively regulated in an

organ-specific way. A general site-dependent transcriptional repression by DNA methylation

was detected, but differential DNA methylation was not related to P nutritional genes,

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although recent studies described P-starvation induced DNA methylation changes. However,

a few differentially methylated miRNAs, together with their target genes, showed P-

dependent expression profiles, indicating miRNA expression differences as a P-related

epigenetic modification in poplar. Hence, it was shown that differences in DNA methylation

or differentially methylated miRNAs might influence plant establishment and partially

correlate with P acquisition, and thus be responsible for a site-dependent adaptation and

growth performance.

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DNA METHYLATION ADAPTATION AND THE CORRELATION TO TRANSCRIPT ABUNDANCE IN MAIZE AS RESPONSE TO NUTRIENT DEFICIENCIES Svenja Mager, Uwe Ludewig Institute of Crop Sciences, University of Hohenheim, 70599 Stuttgart, svenja.mager@uni-hohenheim.de DNA methylation occurs in organisms with a wide range of functions. In plants, it has an important influence on the expression rate of genes. How this works, which factors are involved and how it influences plant growth is not fully understood. Getting a deepened understanding on the mechanisms behind DNA methylation might create a variety of new possibilities for breeding useful crop plants. This work addresses the question whether DNA methylation in plants is adapted under nutrient deficiencies and how it relates to gene transcription. Additionally, a possible correlation between methylation amount and miRNA abundance is investigated. Maize plants are grown under controlled conditions with Nitrogen-, Phosphorus-, Iron-, Zinc- or Boron-deficiency. Additionally, plants supplied well with all necessary nutrients are grown as control. The DNA of these plants is used for reduced representation bisulfite sequencing (RRBS). In this method all unmethylated cytosines are converted to uracil before sequencing the DNA. After sequencing, the methylome of a sample is compiled by aligning the sequenced reads to the reference genome of Zea mays. The methylome of samples coming from nutrient deficient plants are compared to the methylome from control plants to find differentially methylated regions (DMRs). From the same plants, the miRNA is extracted and quantitated by usage of capillary electrophoresis. For measuring gene transcript abundance, RNA sequencing is used to evaluate the influence of DNA methylation on gene transcription. Evaluation of RRBS showed that there is a general loss of DNA methylation in nutrient deficient maize plants in comparison to well supplied plants. Additionally, many differentially methylated genes can be found between deficient and control plants, being especially abundant in nitrogen- and zinc-deficient plants. Though there is not a direct evidence of correlation between amount of methylation and number of miRNAs in the plants, there is a trend hinting in the direction of more miRNAs meaning more DNA methylation. The correlation between DNA methylation amount and transcript abundance remains to be evaluated with the receiving of the RNA-Sequencing data.

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GENOME-WIDE IDENTIFICATION OF THE CPK GENE FAMILY IN MEDICAGO TRUNCATULA AND ITS EXPRESSION IN NODULES

Lisa Bischoff1, Claudia Schlindwein1, Joachim Schulze2, Edgar Peiter1

1 Plant Nutrition Laboratory, Institute of Agriculture and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany, 2 Department of Crop Science, Faculty of Agriculture, University of Göttingen, Germany

Symbiotic nitrogen fixation is an effective strategy for enhancing the nitrogen availability used by various plant families. Legumes which engage in a symbiosis with rhizobia form characteristic root nodules. In the climatic temperate region indeterminate nodules composed of distinct zones representing successive developmental stages are prevalent. Starting with the apical area those de novo organs are segmented into a meristematic zone, an infection zone, a fixation zone containing infected cells with special organelles called symbiosomes, and a senescence zone, present only in mature nodules. In differentiated bacteroids incorporated into the symbiosomes the enzyme Nitrogenase converts N2 to ammonia (NH3). In this mutual relationship the plant supplies the bacteroid with reduced carbon in return for fixed nitrogen. The flux of nutrients across the symbiosome membrane, as well as other processes in nodules associated with the symbiotic interaction, need to be strictly regulated in response to a varying demand. In plants, signals that trigger changes in physiological functions are often transduced by the calcium signalling network. In nodules, essential metabolic enzymes and transport proteins, such as Glutamine Synthetase GS2a and Nodulin 26 (a NH3-permeable channel in the symbiosome membrane) are known to be regulated by Ca2+-dependent protein kinases (CDPKs) (Weaver et al., 1991; Lima et al., 2006). The combined capabilities to bind Ca2+ and to modify downstream components enable CDPKs to act as plant-specific sensors and decoders for Ca2+ signals. While the CPK gene family has characterized in several plant species, little is known about CDPKs in the model plant for legume/rhizobium symbiosis, Medicago truncatula. In our work we identified a total of 24 CPK genes in the genome of M. truncatula, located on six different chromosomes. The protein products of these genes clustered in four distinct groups, equivalent to CDPKs in various other plant species. An in silico analysis of the protein structures revealed the presence of domains specific for CDPKs. A highly conserved catalytic Ser/Thr kinase domain was detected along with four EF hands in each protein sequence. The N-terminal domains varied in length and sequence, as formerly shown in Arabidopsis thaliana (Hrabak et al., 2003). By analysing publically available and unpublished expression profiles, we investigated the expression of CPKs in nodules. No nodule-specific genes could be detected, but several were strongly expressed in nodules. Our analyses provide a foundation for further functional studies concerning the role of CDPKs in the regulation of symbiotic interactions and signal transduction in legume nodules. Hrabak EM, Chan CWM, Gribskov M, Harper JF, Choi JH, Halford N, Kudla J, Luan S, Nimmo

HG, Sussman MR, Thomas M, Walker-Simmons K, Zhu J-K, Harmon AC (2003) The Arabidopsis CDPK-SnRK superfamily of protein kinases. Plant Physiol. 132: 666-680

Lima L, Seabra A, Melo P, Cullimore J, Carvalho H (2006) Phosphorylation and subsequent interaction with 14-3-3 proteins regulate plastid glutamine synthetase in Medicago truncatula. Planta 223: 558-567

Weaver CD, Crombie B, Stacey G, Roberts DM (1991) Calcium-dependent phosphorylation of symbiosome membrane proteins from nitrogen-fixing soybean nodules. Evidence for phosphorylation of Nodulin-26. Plant Physiol. 95: 222-227

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NOVEL PROTEINS REGULATING CA2+ CONCENTRATIONS IN THE CHLOROPLAST

Julia Frank1, Haidong Ding2, Ricardo Happeck2, Edgar Peiter2, and Sacha Baginsky1

1 Institute of Biochemistry, Martin Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany

2 Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany

julia.frank@biochemtech.uni-halle.de

Calcium (Ca2+) is a ubiquitous signalling agent in plant cells, involved in a plethora of responses to external stimuli and internal cues. While its role in signal transduction is well-established for the cytosolic and nuclear compartments, little is known about the integration of plastids in the cellular Ca2+ signalling network, albeit numerous processes in the chloroplast are known to be regulated by Ca2+ (Stael et al., 2012). This project thus aims to elucidate the plastidic Ca2+ signalling machinery. The Ca2+-binding photoprotein aequorin, fused to specifically targeted peptide sequences, provides a tool to detect Ca2+ signals in subcellular compartments in a non-invasive way. We have developed a fast and powerful method based on transient expression of aequorin in (mutant) protoplasts. This enabled us to identify two mutants with altered [Ca2+] responses in the chloroplast stroma. Those mutants showed higher or lower Ca2+ signal intensity than the wild type after a light-to-dark shift, a response first described by Johnson et al. (1995). The disturbance of plastidic signalling and/or ion loading and distribution in those mutants is associated with a strongly retarded development and with defects in photosynthetic performance. GFP fusions of those proteins are localized to the envelope and thylakoid membranes. Radioisotope transport studies on isolated chloroplasts and thylakoids, as well as heterologous expression in yeast indicate that the newly identified proteins are bona fide Ca2+ transporters that regulate chloroplast Ca2+ homeostasis.

Johnson CM, Knight MR, Kondo T, Masson P, Sedbrook J, Haley A, Trewavas A (1995) Circadian oscillations of cytosolic and chloroplastic free calcium in plants. Science 269: 1863-1865

Stael S, Wurzinger B, Mair A, Mehlmer N, Vothknecht UC, Teige M (2012) Plant organellar calcium signalling: an emerging field. J. Exp. Bot. 63: 1525-1542

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TOP 5: Nutrient Cycles

Westerschulte, Matthias Soil mineral nitrogen dynamics after slurry

injection compared to broadcast application in maize

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Dombinov, Vitalij Sugarcane bagasse ash as alternative nutrient sources for plant nutrition

49

Seiz, Perik Effect of different N-management measures to reduce N-surpluses on N2O emissions from vegetable production

50

Göbel, Leonie Soil nitrogen cycling in conventional versus agroforestry systems

51

Puig, Alice Effect of legume share of cover crop seed mixtures and plant removal on N2O emissions during winter period

52

Kesenheimer, Katharina N2O emission after oilseed rape residue incorporation as affected by soil tillage

53

Häfner, Franziska Effect of feedstocks on digestate composition and subsequent short-term nitrous oxide emissions after field application

54

Haitao, Wang Einfluss der N- und C-Verfügbarkeit auf die N2O-Emissionen nach Raps im Winter

55

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SUGARCANE BAGASSE ASH AS ALTERNATIVE NUTRIENT SOURCES FOR PLANT NUTRITION

Vitalij Dombinov, Silvia D. Schrey, Hendrik Poorter, Nicolai D. Jablonowski

Institute of Bio- and Geosciences (IBG-2), Plant Sciences, Forschungszentrum Jülich, v.dombinov@fz-juelich.de

Brazil is the largest sugarcane producer worldwide.1 In the marketing year 2014/15, Brazilian farmers produced around 39 % of the global harvest.2 Sugarcane is of a great relevance for Brazilian economy, because the cane juice is used for sugar and ethanol production. To meet the projected demand of fuel-ethanol (61.1 BL) by 2021, the ethanol production needs to increase by 65% compared to the marketing year 2014/15.3 One of the strategies to cover growing demand of fuel-ethanol is to expand the sugarcane cultures4 by occupying new agricultural areas including regions with unfavourable agro-climatic conditions.5 As a consequence, the Brazilian farmers will rely more on mineral fertiliser for maximising the yields as they do already nowadays.

Sugar is stored in the sugarcane stalks. To extract it, the canes are crushed and the solid by-product remaining after juice extraction is the bagasse.6 Bagasse is burned and the resulting energy in form of electricity and heat cover the energy demand of the sugarcane industries7 located in remote regions. Consequently, the power plants produce high amounts of bagasse ash. In 2014 the production is estimated to have reached 5 Mt/year. Since the sugarcane cultivation is continuously expanding, larger amounts of bagasse ash production can be expected in near future. The bagasse ashes are considered as waste and pollute the environment but the ashes contain varying amounts of minerals essential for plant-nutrition and can be used as fertiliser. Due to the limited availability of phosphorus (P) in Brazilian soils and the high dependency on rock P, the project “ASHES” aims at reducing the dependency on mineral P sources by using the bagasse ashes. Since the plant-nutrient availabilities depend on incineration conditions, the aim of the project “ASHES” is to find optimal burning conditions for maximising the P availability for plants.

The study presented here focuses on P-availabilities for plants. (i) Pre-germinated maize (Zea mays) and soybean (Glycine max) seedlings were transplanted in nutrient-poor substrates containing no nutrient-additions, four doses of bagasse ash (5, 15, 30, 45t/ha) and P-amounts equivalent to ash treatments. The seedling growth increased with applied ash dose. At applied amount of 30t/ha the seedling sizes were comparable to the positive controls growing in substrates with equivalent amounts of P. (ii) High amounts of bagasse ash inhibited the germination rate of soybeans planted in sand. Consequently, the focus will be expanded from plant growth additionally to the ash effects on soil quality.

[1] FAO. "Erntemenge der führenden Anbauländer von Zuckerrohr weltweit im Jahr 2014 (in Tonnen)." Statista - Das Statistik-Portal. Statista. Dezember 2015a. Accessed 06.05.2016. Available from <http://de.statista.com/statistik/daten/studie/454425/umfrage/erntemenge-der-fuehrenden-anbaulaender-von-zuckerrohr-weltweit/>

[2] FAO."Sugarcane, soybean and maize production by Brazil vs. global production ", 2015b, Accessed 06.05.2016. Available from http://faostat3.fao.org/compare/E

[3] Goldemberg, J., Mello, F. F., Cerri, C. E., Davies, C. A., and Cerri, C. C.: Meeting the global demand for biofuels in 2021 through sustainable land use change policy, Energy Policy, 69, pp. 14–18, 2014.

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[4] Goes, T., Marra. R., Araujo, M. d., Alves, E., Oliveira de Souza, M.: Sugarcane in Brazil: current technologic stage and perspectives. Revista de Politica Agricola, pp. 52–65, 2011.

[5] Endres, L.: Photosynthesis and Water Relations in Brazilian Sugarcane, TOASJ, 4, pp. 31–37, 2010. [6] George, O. P. A., Eras, J. J. C., Gutierrez, A. S., Hens, L., and Vandecasteele, C.: Residue from

Sugarcane Juice Filtration (Filter Cake): Energy Use at the Sugar Factory, Waste Biomass Valor, 1, pp. 407–413, 2010.

[7] Rocha, G. J. d. M., Nascimento, V. M., Gonçalves, A. R., Silva, V. F. N., and Martín, C.: Influence of mixed sugarcane bagasse samples evaluated by elemental and physical–chemical composition, Industrial Crops and Products, 64, pp. 52–58, 2015.

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EFFECT OF DIFFERENT N-MANAGEMENT MEASURES TO REDUCE N-SURPLUSES ON N2O EMISSIONS FROM VEGETABLE PRODUCTION Seiz, P.1, Schulz, R.1, Müller, T.1, Ruser, R.1

1 Institute of Crop Science, Dp. Fertilization and Soil Matter Dynamics (340i), University of Hohenheim, 70599 Stuttgart; Email: perik.seiz@uni-hohenheim.de

German vegetable production is commonly associated with elevated N inputs to assure full marketable yield and product quality. However, this often results in considerable N surpluses. Different N-management measures to reduce these N surpluses have been proposed, but their effect on N2O emissions is rarely investigated. The experiment was carried out at the Heidfeldhof (University of Hohenheim). Soil type was a silty haplic Luvisol. Crops were iceberg lettuce and broccoli (first year), and cauliflower followed by broccoli (second year). The following treatments were included (1) unfertilized control, (2) ‘High N’, (3) ‘KNS’ with optimized N rates, (4) ‘Red N’ with reduced N fertilization compared to KNS, (5) ‘NI’ with addition of a nitrification inhibitor (3,4-Dimethylpyrazole phosphate), (6) ‘CC’ with cover crop during winter, (7) ‘+S’ with straw addition before winter, and (8) –CR with post-harvest removal of crop residues. Trace gas fluxes were measured at least weekly over the entire experimental phase with the “closed chamber”-method [1]. Simple N balances were calculated for each treatment as N input (N fertilization + straw) – N removal (N in marketable yield + N in removed residues). Increased N2O fluxes were measured after N applications and rainfall with highest flux rates after incorporation of the crop residues before winter. Strong correlations between N2O and CO2 fluxes, high soil moisture and soil nitrate contents suggested denitrification as major N2O source. Cumulative N2O emissions varied between 12.8 and 81.5 kg N2O-N ha-1 2 yr-1 in ‘Zero N’ and ‘High-N’. Adaption of applied N according to KNS significantly reduced the emitted N2O by 37% without any effect on yield and commodity. In the ‘Red N’ treatment, 36% lower N fertilizer input resulted in 51% lower N2O emission (slightly reduced plant growth). The highest reduction of 74% was measured in the treatment -CR. We found a strong positive correlation between N-balances and N2O emissions over the entire experimental period of two years. Based on this strong correlation, the most important conclusion of our results is that every measure which reduces N surpluses, though not always statistically significant, also reduces N2O emissions from vegetable production. Reference: [1] Flessa, H. et al. (1995) J. Geophys. Res. 100, 23115 – 23124

Acknowledgement: This study was founded by the German Federal Office for Agriculture and Food (BLE).

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SOIL NITROGEN CYCLING IN CONVENTIONAL VERSUS AGROFORESTRY SYSTEMS

Leonie Göbel1, Lin Chen2, Edzo Veldkamp1, Marife Corre1

1: Büsgen-Institute – Soil Science of Tropical and Subtropical Ecosystems, Georg-August-University Göttingen, Germany 2: Guangxi University Nanning, China leonie.goebel@forst.uni-goettingen.de

Conventional agricultural systems are very productive and profitable but not efficient in using soil nutrients, which may cause serious environmental problems such as high nutrient losses to the atmosphere and groundwater. Agroforestry systems (i.e. combination of crops and trees) are innovative agricultural systems in that they take advantage of beneficial ecological functions of their components, which are crucial to attain high productivity with possibly less environmental effects. This study is part of the BMBF-funded project BONARES-SIGNAL, which is investigating a sustainable intensification of agriculture through agroforestry. Central aim of this project is to evaluate whether and under which site conditions agroforestry in Germany can be a land-use alternative that is ecologically, economically and socially more sustainable than conventional agriculture. Our present study within SIGNAL is focusing on soil nutrient cycling and nutrient retention efficiency in six paired sites of conventional and agroforestry systems (with grassland or cropland alley cropping) located in northern and eastern Germany. Our hypothesis is that agroforestry systems are more efficient in producing yield and retaining nutrients in the soil than conventional systems.

Nutrient response efficiency (ratio of biomass production to soil available nutrients), nutrient retention efficiency (1- leaching losses/ soil available nutrient) and asymbiotic N2 fixation in soil are measured in 2016 and 2017 on all sites. A higher nutrient response and retention efficiency are expected in agroforestry systems compared to conventional systems.

Our first results on soil N cycling from conventional and grassland agroforestry systems in Reiffenhausen, Lower Saxony will be presented. Gross and net N mineralization, gross and net nitrification, microbial N immobilization, dissimilatory nitrate reduction to ammonium (DNRA) as well as microbial biomass were measured in summer 2015. These measurements were taken within willow tree strips as well as at 1 m and 4 m distance from the tree strip within the grass strips and in adjacent plots of conventional grassland (N = 4). Microbial N was higher in the conventional than agroforestry system (P ≤ 0.05). However, there were no significant differences in both gross (index of soil N availability) and net rates (index of plant-N availability) of mineral N production, microbial N immobilization and DNRA between conventional and agroforestry systems.

As complementary information and influencing soil controlling factors, soil organic C, total N, plant-available phosphorus, soil exchangeable calcium, potassium, magnesium, nutrient leaching losses and plant biomass production are measured in 2016. These results will be integrated to calculate nutrient response and retention efficiency and to test our above-mentioned hypothesis.

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EFFECT OF LEGUME SHARE OF COVER CROP SEED MIXTURES AND PLANT REMOVAL ON N2O EMISSIONS DURING WINTER PERIOD

Alice Puig1, Ivan Guzman-Bustamante1, Perik Seiz1, Sabine Zarnik2,Andreas Butz2, Reiner Ruser1

1 University of Hohenheim, Institute of Crop Science, Fertilization and Soil Matter Dynamics (340i), Stuttgart, Email: alice.puigrodriguez@gmx.de

2 Landwirtschaftliches Technologiezentrum Augustenberg, Allgemeine Produktionstechnik, Karlsruhe

The implementation of the common agricultural policy (CAP) on European scale includes compulsory ecological conservation areas, as one of the so called "Greening" measures. The surrender of these “greening measures” lowers the farmers claim for direct payments. Many seed mixtures are commercially available to realize this measure. These seed mixtures often contain nitrogen fixing legumes which often do not survive pronounced frost events. By the decomposition of such cover crops in winter, suitable conditions for denitrification can occur. Hence, the risk for elevated nitrous oxide (N2O) emissions is very high. Increasing contribution of legumes in the seed mixture, results in increased amount of fixed N released into soil and thereby enhances the risk of additional N2O losses.

A promising mitigation strategy, however not allowed by the CAP, is the biomass removal before the winter period.

The aim of our work was to assess the N2O losses from soil sown with seed mixtures differing in legume shares, and to evaluate the removal of above ground biomass as a mitigation tool.

In a field split-plot experiment in Ettlingen, near Karlsruhe, gas and soil samples were taken weekly from October 2015 until May 2016, in order to determine N2O fluxes and its covariables (soil mineral nitrogen, dissolved organic carbon, soil temperature and moisture). Greenhouse gas measurements were carried out with “closed chambers” [1]. The investigated treatments comprised: (1) bare soil, (2) white mustard, (3) a mixture with legume share of 55% and (4) of 95%, while for the three treatments with cover crops an additional removal of biomass treatment before winter (5,6,7) was investigated.

First results show a positive relationship between share of legumes and cumulative N2O losses, with the highest emissions in the 95% legume treatment (1.8 kg N2O-N ha-1, 185 days-1). Thus, the pronounced application of frost-sensitive legumes for winter greenings could be a concern in terms of N2O mitigation. Removal of biomass markedly reduced N2O emissions in 95% legumes, and by tendency in 55% legumes and in white mustard as well. With approximately 1 kg N2O-N ha-1 185 days-1 no differences among the three “removal”-treatments were observed. This corresponded to a reduction of up to 44%. Due to this pronounced N2O reduction potential reconsideration of the utilization of aboveground biomass seems reasonable.

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Reference: [1] Flessa, H., Dörsch, P., Beese, F. 1995. J. Geophys. Res. 100, 23115 – 23124

This study was founded by the Thünen Institute, Institute of Climate-Smart Agriculture, Braunschweig, Germany.

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N2O EMISSION AFTER OILSEED RAPE RESIDUE

INCORPORATION AS AFFECTED BY SOIL TILLAGE Kesenheimer, K.1, Pandeya, H.1, Müller, T.1, Buegger, F.2, Ruser, R.1 1Institute of Crop Science 340i, University of Hohenheim, Stuttgart, Germany 2Institute of Biochemical Plant Pathology, Helmholtz Zentrum, Munich, Germany

Contact: k.kesenheimer@uni-hohenheim.de

Oilseed rape (Brassica napus L.) is a prominent oilseed crop in the northern part of

Europe. Production of oilseed rape has increased in Germany during the last decades

due to its economic and ecological importance towards biodiesel production. Winter

oilseed rape is known for its elevated nitrogen demand during early growth stages and a

low nitrogen use efficiency resulting in high N surpluses and possible gaseous or

leaching losses [1]. Furthermore, the crop residues of oilseed rape are suspected to

cause high N2O emissions in the following crop. In this experiment, the fate of 15N

labelled rape residue was studied under field conditions. The main objective of this

study was to quantify the effect of post-harvest rape residue incorporation at two tillage

depths on N2O emissions and on the direct contribution of the residue bound N to the

N2O fluxes. The study was conducted on a Luvisol at the research station Ihinger Hof,

South Germany as part of a consisting experiment (split-plot-design, n = 4). Crop

residues (CR) with a 15N abundance of 14.4 atom % were exchanged with the unlabeled

residues in field. The C-to-N-ratio of the residues was 52, in total 135 kg N ha-1 were

applied. Four treatments were investigated: (1) shallow tillage with CR (15 cm), (2)

shallow tillage without CR, (3) conventional tillage with CR (30 cm), and (4)

conventional tillage without CR. Trace gas fluxes of N2O, 15N-N2O, and CO2 were

measured at least once a week with additional event driven samplings. Closed chambers

were used for flux measurements [2]. The cumulative N2O emissions fluctuated between

1.7 (shallow tillage without CR) and 2.4 kg N-N2O ha-1 300 days-1 (shallow tillage with

CR), without statistically significant difference. The share of crop residues with 3.7 %

(conventional) and 4.6 % (shallow) to the N2O emissions was low, probably due to the

low soil moisture during the whole experimental period. Increase in greenhouse gas

fluxes are often observed after crop residue application during incubation or field trials.

However, in this field study postharvest N2O emission from winter rape crop residues

was low and not significant higher than treatments without crop residues. Due to the

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high C-to-N ratio of the crop residues, there was possibly an immobilization of mineral

N. Therefore, the N losses through postharvest crop residue application play just a minor

role in the losses of reactive N during rapeseed cultivation.

[1] Rathke et al., 2006. Agriculture, Ecosystems & Environment, 117, 80–108.

[2] Flessa et al., 1995. Journal of Geophysical Research, 100, 23115–23124.

The project is funded by the Agency for Renewable Resources (FNR) due to a decision of the German Federal Parliament with funds of the Federal Ministry of Food and Agriculture.

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EFFECT OF FEEDSTOCKS ON DIGESTATE COMPOSITION AND SUBSEQUENT SHORT-TERM NITROUS OXIDE EMISSIONS AFTER FIELD APPLICATION

Franziska Häfner, Kurt Möller

Institute of Crop Science (340i), University of Hohenheim, Stuttgart,

Biogas production offers a valuable opportunity for producing renewable energy by anaerobic digestion from a broad range of organic materials. Biogas feedstocks such as energy crops, animal slurry or urban organic waste lead to digestates differing in nutrient and organic matter composition. It was assumed that the amount and availability of nitrogen and organic carbon applied by organic fertilizers determine to some extent nitrification and denitrification in the soil, hence nitrous oxide (N2O) emissions. Therefore, it can be expected that differences in NH4

+/Nt ratio and organic matter degradability between the digestates will affect the amount of N2O emissions. For this purpose, a field experiment was conducted, assessing digestates from different feedstocks regarding short-term N2O emissions after application to the soil. The experimental set-up included four repetitions, seven digestate treatments and one unfertilized control. The soil type was a Haplic Luvisol with a silty loam texture. Digestates were applied at a rate of 170 kg N ha-1 and incorporated into the upper soil within a soil embedded base ring (706.5 cm2 area). Gas sampling was carried out on 20 days within eight weeks after fertilization (May-July), using the closed chamber method. Separate gas samples were collected for N2O and 15N2O. On each sampling day volumetric water content was determined by TDR (Time Domain Reflectometry). Soil samples at beginning and end were taken for mineral nitrogen analysis. Four of seven digestates (maize, grass, sugar beet, sugar beet leaves) were derived by 15N-labeled plant material, digested in a 2 l fed-batch system (State Institute of Agricultural Engineering and Bioenergy, Hohenheim), thus showing a 6-12 atom% 15N signature in mineral and organic nitrogen. The remaining three digestates (cattle slurry, food waste and source-seperated organic household waste) originated from commercial biogas plants in Baden-Württemberg and were enriched to 5 atom% 15N after digestion, by adding ammonium-15N2 sulfate. Consequently, those three digestates only showed a 15N signature for the ammonium fraction. N2O concentration was measured by an automated gas chromatographic system and 15N2O signature by a PreCon-GC-C-IRMS coupling. N2O flux rate of the different digestates during the sampling period will be determined. Digestate and soil borne N2O emissions will be distinguished by isotopic 15N signature of the digestates.

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Einfluss der N- und C-Verfügbarkeit auf die N2O-Emissionen nach Raps im Winter Haitao Wang1, Sarah Köbke1 and Klaus Dittert1 1: Department of Crop Sciences, Section of Plant Nutrition and Crop Physiology, Georg-Augugst-University, Carl-Sprengel-Weg 1, 37075 Göttingen, Germany, haitao.wang@agr.uni-goettingen.de Einleitung

Obwohl die Konkurrenz zur Nahrungsmittelproduktion noch umstritten ist, werden die Energiepflanzen wegen der starken Nachfrage nach Energie eine wichtiger Substituent der fossilen Energien. Zudem wird bei den Energiepflanzen oft über die Auswirkungen auf den Klimawandel diskutiert, insbesondere über die Emissionen der klimarelevanten Spurengase Kohlendioxid (CO2), Methan (CH4) und Lachgas (N2O) während die Nutzung der Energie und angesichts der sich ausweitenden landwirtschaftliche Produktion.

Häufig werden N2O-Emissionen in Zusammenhang mit verschiedenen Düngemaßnahmen untersucht. In dieser Arbeit wird die Interaktion von N und C-Quelle im Winter auf die N2O-Emissionen untersucht. Diese Arbeit will einen Beitrag zur Untersuchung der Ursache für die höheren N2O-Emissionen im Winter leisten.

Material und Methoden

Diese Untersuchung erforscht die Interaktion zwischen verschiedenen Niveaus von N-Düngungen und verschiedenen C-Quellen. Deshalb wurden drei NO3-N (KNO3, 0 kg ha-1, 30 kg ha-1, 60 kg ha-1) Düngestufen und drei C-Quellen (ohne C-Quelle, Stroh und Glucose) kombiniert. Jeder Block hat 9 Varianten und die Varianten in jedem Block sind randomisiert.

In diesem Versuch wurden von jedem Plot in den Tiefen 0- 15 cm, 15- 30 cm und 30- 45 cm Bodenproben genommen. Die Gasprobenahme wurden insgesamt 15-mal durchgeführt. Eine Woche vor dem Düngetermin (12.2.2014) waren die erste Gasprobenahmen. Am Tag des Düngetermins wurden die zweite Gasproben genommen, und in die folgende Woche wurden einmal pro Tag und später alle 2-3 Tage Gasproben genommen.

Ergebnisse und Diskussion

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Kohlenhydrate sind die wichtigste Energiequelle der Mikroorganismen, sie können die Aktivität der Mikroorganismen oder extrazellulären Enzyme deutlich erhöhen. Im Boden ist die Mineralisierung von organischer Substanz die wichtigste Quelle der Kohlenhydrate. Die CO2-Emissionen werden nur wenig von der mineralischen N-Düngung verändert, wenn die C-Verfügbarkeit im Boden limitierend ist.

Die N-Verfügbarkeit kann die Mikroorganismengruppen beeinflussen und unter N limitierenden Bedingungen sind die K-Strategen leistungsfähiger als die r-Strategen, aber eine höhere N-Verfügbarkeit kann das Wachstum der r-Strategen stimulieren. Außerdem werden die Einzelheiten der Enzymen arten von der N-Verfügbarkeit beeinflusst.

Auf der Fläche mit 60 kg N Düngung und Zuckergabe gab es die höchsten N2O-Emissionen, da C und N gut verfügbar sind. Die N2O-Emissionen haben einen hohen Anteil von Denitrifikation. Bei der limitierenden C-Quelle wurde die Aktivität der Mikroorganismen, die zu Denitrifikation führen konnte, beschränkt. Und bei der limitierenden N-Quelle wurden die Rohstoffe für die Denitrifikation beschränkt. Deswegen zeigt die Kombination von Nitratdüngung und Zuckergabe die höchsten N2O-Emissionen.

Zusammenfassend sind sowohl N als auch C an diesem Versuchsstandort im Winter beschränkt, da man bei Raps nach der Ernte die höchsten N2O-Emissionspotentiale erhält. Im Winter hat man auf einem natürlichen Rapsfeld nur sehr niedrige N2O-Emissionen erhalten. In der Praxis können die N2O-Emissionen durch reduzierenden organischen Dünger im Winter einigermaßen kontrolliert werden.

Literatur

Baggs E. M., et al., (2012), N2O Emissions and Inorganic N Release Following Incorporation of Crop Residue and/or Inorganic N Fertiliser into Soil, West African Journal of Applied Ecology, Vol. 20 (1), 75-87.

Blagodatskaya E. V., Blagodatsky S. A., Dorodnikov M., Kuzyakov Y. (2010), Elevated atmospheric CO2 increases microbial growth rates in soil: results of three CO2 enrichment experiments. Global Change Biology, 16, 836-848.

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Bouwman A. F., (1998), Environmental science: Nitrogen oxides and tropical agriculture. Nature, 392, 866-867.

Ju, X. T., Xing, G. X., Chen, X. P., Zhang, S. L., Zhang, L. J., Liu, X. J., Cui, Z. L., Yin, B., Christie, P., Zhu, Z. L., and Zhang, F. S., (2009), Reducing environmental risk by improving N management in intensive Chinese agricultural systems, Proc. Natl. Acad. Sci. USA, 106, 3041-3046.

Köster J. R., Cardenas L., Senbayram M., et al. (2011), Rapid shift from denitrification to nitrification in soil after biogas residue application as indicated by nitrous oxide isotopomers. Soil Biology & Biochemistry, 43, 1671-1677.

Kuzyakov, Y., 2006. Sources of CO2 efflux from soil and review of partitioning methods. Soil Biology and Biochemistry 38, 425-448.

Zumft W. G., Coyle C. L., Frunzke K., (1985), The effect of oxygen on chromatographic behavior and properties of nitrous oxide reductase. FEBS Letters, 183, 240–244.

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TOP 6: Free Topics

Lucas, Maik Effect of apple replant diseases on root-growth, root-function and soil microbial community

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Beschow, Heidrun Cyanobacterial lyophilisates as biofertilizers – manufacturing process and effects on plants

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Heck, Christian Neonicotinoids can improve abiotic stress tolerance and increase ascorbate level in rice

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Zinsmeister, Daniel Management of leaf wetness by Taiwan yellow cypress (Chamaecyparis Obtusa Var. Formosana) in a perhumid cloud forest

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Abdalla, Neama A. Review on plant nanobiotechnology

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Bischoff, Lisa Calcium as regulator of the N2-fixing legume nodule

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Steckenmesser, Daniel Effects of various thermochemical treatments on phosphorus specification solubility and bioavailability of sewage sludge ashes and carbonizates

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Fellmann, Sebastian Acute effects of engineered nanoparticles on the germination, growth and gas exchange of Zea Mays.

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EFFECT OF APPLE REPLANT DISEASES ON ROOT-GROWTH, ROOT-FUNKTION AND SOIL MICROBIAL COMMUNITY

Maik Lucas1, Doris Vetterlein1, Kornelia Smalla2, Alicia Babín-Suárez2 and Ina-Maria Zickenrott1

Department of Soil Physics, Helmholtz Centre for Enviromental Research –UFZ, Halle (Saale), Germany 2Julius Kühn-Institut, Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, Braunschweig, Germany; e-mail address: maik.lucas@ufz.de,

Apple replant disease (ARD) occurs after repeated replanting of apple trees on the same site and results in a reduction and delay of tree growth and in brown, necrotic roots.

We here explore this phenomenon by conducting a split-root experiment with rhizoboxes consisting out of plexiglas on the front site. Therefore the roots of apple trees (M26) were embedded in ARD soil from Ellerhoop (Germany), healthy soil from the same site with no previous apple growth (Control) and gamma treated ARD soil (-ARD). The experimental design is shown in figure one. By labelling the soil in one compartment of the split-root boxes with 15N we later can relate root growth to root function. For this C,N- and 15N-analyses of the rhizosphere soil, bulk soil and all parts of the plant will be conducted. Differences in root growth were investigated by scanning the boxes with a fled bed scanner and analysing the images with WhinRhizo every third day. After five weeks of growing in a climate chamber the plants were harvested. Samples were taken from bulk and rhizosphere soil. The latter one was taken by using a toothbrush to remove adhering soil. After this we washed the roots and centrifuged the washing suspension, to get samples of the rhizoplane. Subsamples of the roots were used for further analyses with WhinRhizo, to estimate the “hidden” part of the roots in the split-root boxes. The DNA from bulk soil, rhizosphere and rhizoplane was extracted and purified. Polymerase chain reaction (PCR) amplified 16S rRNA gene and ITS fragments were analysed by denaturing gradient gel electrophoresis (DGGE) to obtain fingerprints of the bacterial and fungal communities. The quantification of 16S rRNA genes was done by real-time quantitative PCR (qPCR).

First results showed that the ARD soil led to significant decrease in growth of shoot and root in comparison to the -ARD and the control soil. The DGGEs showed differences in the fungal and bacterial community structure between the three soils, resulting in separate clustering of the different soils in cluster analysis based on similarities of DGGE fingerprints. These findings were seen in the DGGEs fingerprints of the bacterial and fungal communities, and also in DGGEs of the groups of beta-proteobacteria, alpha-proteobacteria and actinobacteria in bulk soil, rhizosphere and rhizoplane.

Figure 3: Experimental design. +ARD, Soil with apple replant disease; -ARD, gamma treated ARD; CONTROL, Soil from the same site, but without ARD; 14N, without 15N label, 15N, with 15N label.

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CYANOBACTERIAL LYOPHILISATES AS BIOFERTILIZERS - MANUFACTURING PROCESS AND EFFECTS ON PLANTS Mathias Rupf1, Lisa Sawade2, Edgar Peiter2, Klaus Krüger1, Heidrun Beschow2

1: Gesellschaft zur Förderung von Medizin-, Bio- und Umwelttechnologie e.V. (GMBU), Halle (Saale), Germany, 2: Plant Nutrition Laboratory, Institute of Agriculture and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany Heidrun.Beschow@landw.uni-halle.de Introduction Auxins have a great impact on cell elongation, formation of roots and shoots, induction of vascular tissue, apical dominance, and gravitropism. An indole-3-acetic acid (IAA)-containing cyanobacterial lyophilisate (CBL) was developed, which can be used as biofertilizer to change the root architecture in order to improve water and nutrient uptake, especially in organic farming and horticulture. In initial experiments, the effects of CBL on Arabidopsis and barley were investigated.

Manufacturing process The axenic strain Synechocystis sp. PCC 6714 (Pasteur Institute, Paris) forms IAA after addition of tryptophane. After optimization of biomass concentration, illumination, CO2 supply, and process strategy, a lyophilisate with 10 µg IAA mg-1 was obtained.

Experiments with a DR5:GUS auxin reporter strain of Arabidopsis thaliana Two experiments are presented to compare the effect of synthetic IAA and CBL on IAA distribution and plant growth. In the first experiment 8-days-old seedlings were transferred to agar plates with 0.2 µM synthetic IAA or CBL. After 24 h, increased IAA levels were reported over the entire root length, and root tip swelling and strong root hair formation (differentiation zone) were initiated. In the second experiment, 7-days-old seedlings were further cultivated on agar plates containing synthetic IAA or CBL. After 8 days, primary root length was strongly reduced and lateral root formation was promoted by both forms of exogenous IAA. In contrast to the first experiment, IAA was mainly found in the root tip and vascular

tissue, indicating that exogenous IAA was metabolized or degraded by light. Overall, the effects of synthetic IAA and CBL were similar. Pot experiment with spring barley cv. Barke Plants were cultivated in a greenhouse with optimal water and nutrient supply. Foliar and soil application of IAA (synthetic compound and CBL) was performed at the end of stem elongation. At heading, a trend to reduced dry mass was found in variants with application of IAA and CBL.

Conclusion Further experiments with a higher number of plants, varied dosage, different application periods, and varying growth conditions (including stress treatments) are required to validate potential benefits of CBL.

a) b) c)

DR5:GUS activity of 9-days-old seedlings, cultured for 8 days on ½ MS medium+sucrose and 24 h on treatment medium. a) control, b) 0,2 µM synthetic IAA, c) CBL containing 0,2 µM IAA

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Neonicotinoids can improve abiotic stress tolerance and increase ascorbate level in rice

Heck C, Höller S, Rösmann H, Goldbach HE, Eichert T

Institute of Crop Science and Resource Conservation, Dept. of Plant Nutrition, University of Bonn, Karlrobert-Kreiten-Str. 13, 53115 Bonn, Check@uni-bonn.de

Neonicotinoids (neonics), a class of insecticides chemically similar to nicotine, are registered in more than 120 countries and frequently used as seed treatments against a broad range of sucking and chewing insects. It has been reported that neonics may have positive effects on plant health, especially under stressful environmental conditions. We studied the effects of Thiamethoxam (TMX) on the biomass development, growth and tolerance against abiotic stresses of Oryza sativa (Nipponbare). In our first experimental design plants were kept in Yoshida solution under tropic conditions with added 100 µM TMX vs. untreated control, the experiment ran 35 days until harvest of plant material. There was no special abiotic stress treatment in this experiment. This experimental design was conducted two times. We found out that root length, root dry matter and the ascorbate (AsA) content in leaves in the TMX treated plants were significantly higher. Expectedly, the content of malondialdehyde (MDA) as an indicator for oxidative stress tended to decrease in leaves under TMX treatment, although the effect was not significant. In consequence to these results we conducted two more experiments with special abiotic stress treatments. In one experiment rice was grown in Yoshida solution in 100 ppb ozone flooded cabinets, in the other experiment rice was cultivated in soil under open land conditions in Bonn, Germany (cold stress). Under ozone stress application we observed significantly lower bronzing symptoms of leaves in the TMX-group. MDA content in leaves tended to be lower in TMX treated plants while AsA content tended to be higher. However, the differences in MDA and AsA were not significantly different to the control group. The results of the open land rice cultivation showed that TMX treated plants developed significantly higher shoots, less leaf bronzing, less MDA content and tended to a higher AsA content in leaves. Although we do not know the optimum of stress -level, -type and -timing yet, we conclude that a treatment with TMX might induce a stress tolerance in plants which leads to less stress symptoms and accordingly higher biomass development.

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MANAGEMENT OF LEAF WETNESS BY TAIWAN YELLOW CYPRESS (CHAMAECYPARIS OBTUSA VAR. FORMOSANA) IN A PERHUMID CLOUD

FOREST Shyam Pariyar1, Shih-Chieh Chang2, Daniel Zinsmeister1 Juergen Burkhardt1 1Institute of Crop Science and Resource Conservation, University of Bonn, Germany; 2Department of Natural Resources and Environmental Studies, National Dong Hwa University, 974 Hualien, Taiwan; s7dazins@uni-bonn.de

Continuous leaf wetness may impede CO2 uptake and photosynthesis. Adaptations to leaf wetness of Chamaecyparis obtusa var. formosana, an endemic tree species in the perhumid cloud forest of northeastern Taiwan, were investigated. Leaf traits affecting water repellency were studied along with the amount, distribution, and composition of moisture accumulated on leaf surfaces. Minimum epidermal conductance (gmin) and effects of vapor pressure deficit (VPD) on stomatal conductance were measured. Dynamics of condensation to leaf surfaces were captured using an environmental scanning electron microscope (ESEM).

Xeromorphism of Chamaecyparis obtusa var. formosana was suggested by high leaf mass per area (284 g m-2) and from stomatal encryption in clefts formed by the imbricate leaves, and by Florin rings of raised cuticle around the stomata. Despite the absence of visible droplets on leaf blades, a water layer thickness of 80 µm on adaxial and 40 µm on abaxial surfaces was detected. Condensation to clean waxes occurred under super-saturating conditions, but was promoted at lower RH by pollutants on older leaves. Anion concentrations in leaf surface moisture of sun leaves exceeded concentrations in local fog water. gmin of Chamaecyparis obtusa increased when leaves were sprayed with a salt solution containing surfactant.

Microscopic roughness and the surface tension of leaf surface solutions prevented water from occluding the stomata and likely enabled CO2 uptake via leaf gas films. Xeromorphic adaptations of Chamaecyparis enable successful leaf water management and effective photosynthetic performance in a perhumid environment. This functionality is threatened by climate change and air pollution.

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REVIEW ON PLANT NANOBIOTECHNOLOGY Neama A. Abdalla (1) , Hassan R. El-Ramady (2) , Éva Domokos-Szabolcsy (3)

and Hussein S. Taha (1) (1) Plant Biotechnology Dept., Genetic Engineering Division, National Research Center, Giza,

Egypt (2) Soil and Water Sciences Dept., Faculty of Agriculture, Kafrelsheikh Uni., Kafr El-Sheikh,

Egypt (3) Agricultural Botany, Plant Physiology and Biotechnology Dept., Debrecen Univ.,

Debrecen, Hungary *Corresponding author: Hassan El-Ramady (ramady2000@gmail.com)

Nanobiotechnology is a promising area that combines nanofabrication and biosystems to the benefit of both, for all applications of genomics, including mammalian, microbials and plants (Robinson et al. 2009). Nanobiotechnology being studied since several years is still in the early stages of advancement however, the development is multi-directional and spreading rapidly. Moreover, the increasing interest in nanobiotechnology has attracted enormous attention which led to the rapid development of commercial applications involving utilization of manufactured nanomaterials for crop improvement. Nowadays, a lot of attention is being given to the effect of different nanoparticles on plant growth and their metabolic functions (Ahmed et al. 2013). Different methods have been used in preparing the nanoparticles including physical, chemical and biological methods (El-Ramady et al. 2014, 2015, 2016). Using of nanoparticles in plant tissue culture has been confirmed as a promising tool in plant nanobiotechnology. Several studies carried out in vitro using metal/metalloid nanoparticles such as selenium (El-Ramady et al. 2014, 2015, 2016), silver oxide (Raman et al. 2015; Tomankova et al. 2015; Cox et al. 2016), titanium dioxide (Mandeh et al. 2012; Safavi 2014; Cox et al. 2016), zinc oxide (Javed et al. 2016) etc. Several distinguished effects of in vitro nanoparticles have been reported including eliminate the contamination, improving multiplication rate, rooting induction of hard rooting plants, enhancing plant growth under low concentrations of nanoparticles (Capaldi Arruda et al. 2015) and ameliorating stresses (e.g. drought and salinity). So, it could be used for in vitro propagation of economic plants and producing salt/drought tolerant traits.

Therefore, further in vitro researches should be done to focus on (1) the interaction between nanoparticles and plant responses including element uptake, transportation, localization, (2) understanding nanonutrient/elementally deficiency/toxicity symptoms, adequate/toxic concentrations and producing biofortified crops, (3) using of nanoparticles in remediation of multi-pollutants and (4) safety of plant nanobiotechnology i.e., evaluation the risks associated with the transfer of nanoparticles through the food chain.

Key words: Nanoparticles, in vitro, biofortification, nanoremediation Acknowledgments Authors thank the outstanding contribution of STDF research teams (Science and Technology Development Fund, Egypt) and MBMF/DLR (the Federal Ministry of Education and Research of the

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Federal Republic of Germany), (Project ID 5310) for their help. Great support from this German-Egyptian Research Fund (GERF) is gratefully acknowledged.

Fig. : In vitro multiplication of Jerusalem artichoke, tobacco, tobacco & giant reed and giant reed on MS medium supplemented with nanoselenium photo 1, photo 2, photo 3, photos 5 to 8 respectively. In vitro rooting of tobacco and giant reed on MS medium fortified with nanoselenium photo 4 and 8 respectively (Photos by El-Ramady) References: Ahmed F., N. Arshi, S. Kumar, S. S. Gill, R. Gill, N. Tuteja and B H. Koo (2013). Nanobiotechnology:

Scope and Potential for Crop Improvement. In: N. Tuteja, S. S. Gill (eds.), Crop Improvement Under Adverse Conditions. Pp: 245 – 269. DOI: 10.1007/978-1-4614-4633-0_11, Springer Science + Business Media New York

Capaldi Arruda S C., A L. D Silva, R M Galazzi, R A Azevedo and M A Z Arruda (2015). Review Nanoparticles applied to plant science: A review. Talanta 131: 693–705. http://dx.doi.org/10.1016/j.talanta.2014.08.050

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Cox A., P. Venkatachalam, S. Sahi, N. Sharma (2016). Silver and titanium dioxide nanoparticle toxicity in plants: A review of current research, Plant Physiology et Biochemistry, doi: 10.1016/j.plaphy.2016.05.022.

El-Ramady H, Domokos-Szabolcsy É, Abdalla NA, Alshaal TA, Shalaby TA, Sztrik A, Prokisch J, Fári M (2014a) Selenium and nano-selenium in agroecosystems. Environmental Chemistry Letters, 12 (4): 495-510. DOI 10.1007/s10311-014-0476-0

El-Ramady, H., T. Alshaal, S. A. Shehata, É. Domokos-Szabolcsy, N. Elhawat, J. Prokisch M. Fári and L. Marton (2014b). Plant nutrition: from liquid medium to micro-farm. In: E. Lichtfouse (ed.), Sustainable Agriculture Reviews Vol. 14, DOI 10.1007/978-3-319-06016-3_12, pp: 449-508. Springer International Publishing Switzerland

El-Ramady H. R., N. A. Abdalla, T. A. Alshaal, N. Elhawat, É. Domokos-Szabolcsy, J. Prokisch, A. Sztrik and M. Fári (2014). The presentation entitled: Nano-selenium: from in vitro to micro farm experiments. The international Conference "Biogeochemical Processes at Air-Soil-Water Interfaces and Environmental Protection" for the European Society for Soil Conservation, Imola–Ravenna, Italy 23-26 June 2014. DOI: 10.13140/2.1.2260.4481.

El-Ramady, H., É. Domokos-Szabolcsy, T. A. Shalaby, J. Prokisch and M. Fári (2015). Selenium in agriculture: water, air, soil, plants, food, animals and nanoselenium. In: E. Lichtfouse (ed.), Environmental Chemistry for a Sustainable World Vol. 5 (CO2 sequestration, biofuels and depollution), pp: 153 – 232. DOI 10.1007/978-3-319-11906-9_5. Springer Berlin

El-Ramady, H., N. Abdalla, H. S. Taha, T. Alshaal, A. El-Henawy, S. E.-D. A. Faizy, M. S. Shams, S. M. Youssef, T. Shalaby, Y. Bayoumi, N. Elhawat, S. Shehata, A. Sztrik, J. Prokisch, M. Fári, É. Domokos-Szabolcsy, E. A. Pilon‑Smits, D. Selmar, S. Haneklaus and E. Schnug (2016). Selenium and nano-selenium in plant nutrition. Environ Chem Lett, 14 (1):123–147. DOI: 10.1007/s10311-015-0535-1

El-Ramady H., T. Alshaal, N. Abdalla, J. Prokisch, A. Sztrik, M. Fári and É. Domokos-Szabolcsy (2016). Selenium and nano-selenium biofortified sprouts using micro-farm systems. Proceedings of the 4th International Conference on Selenium in the Environment and human health, Sao Paulo, BRAZIL, 18–21 October 2015, pp: 189 – 190. (Eds.) G. S. Bañuelos, Z.-Q. Lin, L. R. G. Guilherme and A. R. dos Reis. CRC, Taylor & Francis Group, London, UK, DOI: 10.13140/RG.2.1.1065.9925

Javed R., M Usman, B Yücesan, M Zia and E Gürel (2016). Effect of zinc oxide (ZnO) nanoparticles on physiology and steviol glycosides production in micropropagated shoots of Stevia rebaudiana Bertoni. Plant Physiology and Biochemistry (In Press)

Mandeh M., M. Omidi and M. Rahaie (2012). In Vitro Influences of TiO2 Nanoparticles on Barley (Hordeum vulgare L.) Tissue Culture. Biol Trace Elem Res, 150(1-3):376-80. DOI: 10.1007/s12011-012-9480-z

Prasad R. (2014). Synthesis of silver nanoparticles in photosynthetic plants. Hindawi Publishing Corporation Journal of Nanoparticles Volume 2014, Article ID 963961, 8 pages http://dx.doi.org/10.1155/2014/963961

Raman P. P., S Parthiban, B. Srinithya, V. V Kumar, S P Anthony, A Sivasubramanian and M S Muthuraman (2015). Biogenic silver nanoparticles synthesis using the extract of the medicinal plant Clerodendron serratum and its in-vitro antiproliferative activity. Materials Letters, 160: 400-403.

Robinson DKR, Morrison M et al (2009). Nanotechnology developments for the agri-food sector report of the observatory NANO. Institute of Nanotechnol, UK; [http://observatorynano.eu/]

Safavi K. (2014). Effect of Titanium Dioxide Nanoparticles in Plant Tissue Culture Media for Enhance Resistance to Bacterial Activity. Bulletin of Environment, Pharmacology and Life Sciences Bull. Env. Pharmacol. Life Sci., 3 [Special Issue V] 2014: 163-166.

Tomankova K., J Horakova, M Harvanova, L Malina, J Soukupova, S Hradilova, K Kejlova, J Malohlava, L Licman, M Dvorakova, D Jirova and H Kolarova (2015). Reprint of: Cytotoxicity, cell uptake and microscopic analysis of titanium dioxide and silver nanoparticles in vitro. Food and Chemical Toxicology, 85: 20-30.

Wang P., E. Lombi, F.-J. Zhao and P. M. Kopittke (2016). Nanotechnology: A New Opportunity in Plant Sciences. Trends in Plant Science, http://dx.doi.org/10.1016/j.tplants.2016.04.005

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CALCIUM AS REGULATOR OF THE N2-FIXING LEGUME NODULE

Lisa Bischoff1, Claudia Schlindwein1, Bettina Hause2, Joachim Schulze3, Edgar Peiter1

1 Plant Nutrition Laboratory, Institute of Agriculture and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany, 2 Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Halle (Saale), Germany, 3 Department of Crop Science, Faculty of Agriculture, University of Göttingen, Germany

Lisa.Bischoff@landw.uni-halle.de

In root nodules of legumes, rhizobia convert atmospheric dinitrogen (N2) into ammonia - a process which is known as biological nitrogen fixation. In exchange for organic acids, the plant receives the fixed nitrogen as ammonia or ammonium. However, legumes are able to down-regulate N2 fixation if nitrogen is available from soil or if the nitrogen demand of the plant is reduced. There is evidence for the involvement of calcium in such regulatory processes. In infected nodule cells, calcium is accumulated in the symbiosome space, which is surrounded by the symbiosome membrane separating rhizobia from the plant cytosol. High calcium concentrations in the symbiosome space have been demonstrated to inhibit an ammonium channel (Tyerman et al., 1995). Additionally, calcium is involved in the regulation of Nodulin 26, an aquaporin which is able to transport ammonia (Hwang et al., 2010). While there is evidence for an involvement of calcium in the regulation of nitrogen transport across the symbiosome membrane, nothing is known about the calcium signalling pathways involved in this regulation process. In general, calcium signals are generated by the action of channels [glutamate receptors (GLR), cyclic nucleotide-gated channels (CNGC), two pore channel 1 (TPC1), annexins (Ann)], transporters [cation exchangers (CAX), GDT1-like proteins], and pumps (Ca2+-ATPase). Subsequently, calcium-binding proteins, like calcium-dependent protein kinases (CDPK), calcineurin B-like proteins (CBL), calmodulin (CaM), and CaM-like proteins (CML) decode the calcium signal. To investigate the role of calcium in the regulation of nitrogen transport and metabolism in root nodules of Medicago truncatula, we searched its genome sequence for members of protein families that may generate or decode calcium signals. For this objective, the JCVI Medicago database was searched. The expression profiles of the identified genes were investigated in silico using publically available and unpublished GeneChip and RNAseq expression data. Theses analyses served as a basis for the selection of candidate genes. Beside the characterization of the candidate genes by reporter gene assays (GUS and GFP) and the investigation of their function by mutant analyses, measurements of cytosolic free calcium in nodules are planned.

Hwang JH, Ellingson SR, Roberts DM (2010) Ammonia permeability of the soybean nodulin 26 channel. FEBS Lett. 584: 4339-4343

Tyerman SD, Whitehead LF, Day DA (1995) A channel-like transporter for NH4+ on

the symbiotic interface of N2-fixing plants. Nature 378: 629-632

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EFFECT OF VARIOUS THERMOCHEMICAL TREATMENTS ON PHOSPHORUS SPECIFICATION, SOLUBILITY AND BIOAVAILABILITY OF SEWAGE SLUDGE ASHES AND CARBONIZATES Daniel Steckenmesser1, Christian Vogel2, Christian Adam2, Diedrich Steffens1 1 Institute of Pant Nutrition (iFZ), Justus Liebig University, Heinrich-Buff-Ring 26-32, 35393 Giessen, Germany, daniel.steckenmesser@ernaehrung.uni-giessen.de 2 Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, 12205 Berlin, Germany Sewage sludge has one of the highest phosphorus (P) potentials of all waste materials. Therefore, P has to be recycled from sewage sludge to close the P cycle. To recycle P from sewage sludge, different processes have been developed, but most of them seem to fail due to their poor economic feasibility. The current trend in Germany is the mono-incineration, to handle the great amounts of sewage sludge. The resulting ashes from mono-incineration are deposited, but can be mined if a demand for P will occur in future. However, these ashes are often reported to have a very low P-bioavailability and are often still contaminated with heavy metals. Thus, a further treatment is needed to give consideration to the German Fertilizer Legislation. In the present study, two common methods (low-temperature conversion at 400 and 500°C and thermochemical treatment at 950°C) were combined and investigated with regard to gaining knowledge of how different sewage sludges (chemical and biological waste water treatment) and their disposal products can be treated to recycle P efficiently. In addition, Na2CO3, Na2SO4, and MgCl2 as common additives to enhance P-bioavailability were investigated as well. The results of P-fractionation, x-ray diffraction analysis and pot experiments with maize showed that biologically treated sludges and sludges with low Ca/P ratio can be treated with low temperatures (400°C). Furthermore, the chemically treated sludges have to be treated at higher temperatures mainly under reductive conditions by raising the Na/P ratio with Na2SO4. Besides the Na/P ratio, the Ca/P ratio has to be considered as well to guarantee an adequate forming of buchwaldite (CaNaPO4), which has a high plant availability.

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ACUTE EFFECTS OF ENGINEERED NANOPARTICLES ON THE GERMINATION, GROWTH AND GAS EXCHANGE OF ZEA MAYS.

Sebastian Fellmann and Thomas Eichert

Institute of Crop Science and Resource Conservation – Plant Nutrition, University of Bonn, sfellman@uni-bonn.de

The rapid growth of nanotechnology and the increasing applications of nanoparticles (nps) in industry and consumer products are rising concerns about their environmental fate, along with potential risks to ecosystems and toxicity to organisms. An increasing release of nps into the environment through waste streams and subsequently an exposure of biological systems to nps can be supposed. There is evidence that nps can cause damages on a cellular level to bacteria and also to higher organisms. However, there is only little known about effects of nps on the growth of plants and the potential reasons for already demonstrated toxic or beneficial effects in other studies. The goal of this work is to contribute to the risk assessment of nps and their effects on higher plants. Therefore, different commercially available nps (ZnO (30-40 nm), TiO2 (5-15 nm) and Ag (15 nm)) were applied at different doses (0.0-2.0 g/l) to Zea mays grown in petri dishes or a hydroponic system. For the analysis different parameters, such as germination rate, root and shoot growth, dry matter, photosynthesis and assimilation rate, were used. Positive effects of ZnO np treatments on the growth at low doses (0.02; 0.2 g/l) were found, while conventional ZnO (bulk material) had negative effects. The TiO2 nps were affecting the plant growth adversely in a dose dependent manner. However TiO2 bulk toxicity occurred in a similar way. The application of Ag nps showed a clear dose dependence of the adverse effects on plant growth, while the corresponding Ag bulk material didn´t show any effects. Related to Ag nps it was shown that the release of Ag ions from Ag nps is mostly, but not exclusively, responsible for the adverse effects. The results suggest that in addition the Ag nps themselves contribute to the toxic effects. However further investigations, with a detailed analysis of np behavior, are necessary to better understand the mechanisms causing the effects on the growth of plants. One other important aspect is the potential uptake of nps into plants. This point will be in the focus of our future research.

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List of participants

Name Vorname Institution/Land email

1 Aarts Mark Wageningen University (NL) mark.aarts@wur.nl

2 Abdalla Neama Abdelmoneim Dokki, Giza (Egypt) neama_ncr@yahoo.com

3 Afzal Afzal University Hohenheim 340h phyto_pak@yahoo.co.uk

4 Aguirre Alejandro IPK Gatersleben aguirrea@ipk-gatersleben.de

5 Araujo de Franca Amanda TU München franca@wzw.tum.de

6 Arkoun Mustapha AGRO, Saint-Malo (F) mustapha.arkoun@roullier.com

7 Bach Inga-Mareike University Hohenheim 340i Mareike.Bach@uni-hohenheim.de

8 Bandari Sara University Hohenheim 340h sara.bandari@gmail.com

9 Basharat Ali INRES, University Bonn basharat2018@yahoo.com

10 Becker Elisabeth TU München ebecker@wzw.tum.de

11 Becker Mathias Rheinische Friedrich-Wilhelms-University, Bonn mathias.becker@uni-bonn.de

12 Behr Jan University Hohenheim 340e jan.behr@uni-hohenheim.de

13 Berger Nils EuroChem Agro GmbH nils.berger@eurochemgroup.com

14 Beschow Heidrun Martin-Luther-University, Halle heidrun.beschow@landw.uni-halle.de

15 Bienert Gerd Patrick IPK Gatersleben bienert@ipk-gatersleben.de

16 Bischoff Lisa Martin-Luther-University, Halle lisa.bischoff@landw.uni-halle.de

17 Blaser Sebastian Helmholtz-Zentrum Halle sebstian.blaser@ufz.de

18 Bradacova Klara University Hohenheim 340h kfrady@centrum.cz

19 Braun Henrik FZ Jülich henrik.braun@uni-hohenheim.de

20 Burkhardt Jürgen Rheinische Friedrich-Wilhelms-University, Bonn j.burkhardt@uni-bonn.de

21 Cakmak Ismail Sabanci University, Istanbul cakmak@sabanciuniv.edu

22 Chen Xiaochao University Hohenheim 340i xiaochao.chen@uni-hohenheim.de

23 Dietrich Charlotte FZ Jülich c.dietrich@fz-juelich.de

24 Dombinov Vitalij FZ Jülich v.dombinov@fz-juelich.de

25 Dreyer Michael University Kiel m.dreyer@plantnutrition.uni-kiel.de

26 Eggert Kai IPK Gatersleben eggert@ipk-gatersleben.de

27 Eichert Thomas Rheinische Friedrich-Wilhelms-University, Bonn t.eichert@uni-bonn.de

28 El-Henawy Ahmed Saad Kafrelsheikh University (Egypt) aelhenawy@yahoo.com

29 El-Ramady Hassan Kafrelsheikh University (Egypt) ramady2000@gmail.com

30 Eticha Dejene Yara GmbH&CoKG, Dülmen dejene.eticha@yara.com

31 Faust Franziska IFZ University Giessen Franziska.Faust@ernaehrung.uni-giessen.de

32 Fellman Sebastian Rheinische Friedrich-Wilhelms-University, Bonn sfellman@uni-bonn.de

33 Frank Julia Martin-Luther-University, Halle julia.frank@biochemtech.uni-halle.de

34 Frei Michael INRES University Bonn mfrei@uni-bonn.de

35 Gans Wolfgang MLU Halle-Wittenberg wolfgang.gans@landw.uni-halle.de

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36 Gierth Diana IPK Gatersleben gierth@ipk-gatersleben.de

37 Gnädinger Friederike TU München Friederike.Gnaedinger@wzw.tum.de

38 Göbel Leonie University Göttingen leonie.goebel@forst.uni-goettingen.de

39 Häfner Franziska University Hohenheim 340i f_haefner@uni-hohenheim.de

40 Hahn Heike SWK Piesteritz GmbH ivonne.mende@skwp.de

41 Hartmann Tobias University Hohenheim 340i tobias.hartmann@uni-hohenheim.de

42 Hasan Mohammed Mehedi University Hohenheim mehhasan@uni-hohenheim.de

43 Hawkesford Malcolm Rothhamsted Research, Harpenden(UK) malcolm.hawkesford@rothamsted.ac.uk

44 Heck Christian University Bonn check@uni-bonn.de

45 Herr Christina University Hohenheim 340i christinaherr@live.de

46 Hinrichs Martin University Hannover hinrichs@pflern.uni-hannover.de

47 Höller Stefanie University Bonn shoeller@uni-bonn.de

48 Horst Walter University Hannover horst@pflern.uni-hannover.de

49 Hosseini Sayed Abdollah AGRO, Saint-Malo (F) seyedabdollah.hosseini@roullier.com

50 Hütsch Birgit IFZ, University Gießen Birgit.W.Huetsch@ernaehrung.uni-giessen.de

51 Hunsche Mauricio COMPO EXPERT GmbH Mauricio.Hunsche@compo-expert.com

52 Jung Stephan IFZ University Gießen Stephan.Jung@agrar.uni-giessen.de

53 Kar Shikata Rani University Hohenheim shiktakar@yahoo.com

54 Kassem A.S. Mohammed National Research Centre Cairo (Egypt) kassem.mohammed@alumni.hu-berlin.de

55 Kesenheimer Katharina University Hohenheim 340h k.kesenheimer@uni-hohenheim.de

56 Khan Nufaid University Halle nufaidkhan16@hotmail.com

57 Kirchner Thomas W. University Hannover kirchner@pflern.uni-hannover.de

58 Kopka Joachim MPI Golm Kopka@mpimp-golm.mpg.de

59 Kopriva Stanislav University Köln skopriva@uni-koeln.de

60 Krippner Johanna University Gießen johanna.krippner@ernaehrung.uni-giessen.de

61 Kumar Ashwani University of Rajastahn,Jaipur(India) ashwanikumar214@gmail.com

62 Lang Carina Paola University Hohenheim 340e langca@uni-hohenheim.de

63 Lang Friederike University Freiburg fritzi.lang@bodenkunde.uni-freiburg.de

64 Lingner Annika University Göttingen DNPW alingne@agr.uni-goettingen.de

65 Liu Yuan University Hohenheim 340h liuyuanhn@hotmail.com

66 Lucas Maik Helmholtz Centre, Halle maik.lucas@ufz.de

67 Ludewig Uwe University Hohenheim u.ludewig@uni-hohenheim.de

68 Mager Svenja University Hohenheim 340i svenja.mager@uni-hohenheim.de

69 Mahmood Asim University Hohenheim 340i A.Mahmood@uni-hohenheim.de

70 Mancarella Silvia University Hohenheim(340h) silvia.mancarella@uni-hohenheim.de

71 Mannheim Thomas EuroChem Agro, Mannheim thomas.mannheim@eurochembgroup.com

72 Megahed Mohamed Amer SWERI (Egypt) dr_megahed120@yahoo.com

73 Meier Bastian Martin-Luther-University, Halle Bastian.Meier@landw.uni-halle.de

74 Möller Kurt University Hohenheim 340i kurt.moeller@uni-hohenheim.de

75 Moradtalab Narges University Hohenheim 340h n.moradtalab@uni-hohenheim.de

76 Mpanga Isaac University Hohenheim 340h isaac.mpanga@uni-hohenheim.de

77 Mühling Karl Hermann Christian-Albrechts-University, Kiel khmuehling@plantnutrition.uni-kiel.de

78 Müller Torsten University Hohenheim 340i Torsten.Mueller@uni-hohenheim.de

79 Nabel Moritz FZ Jülich m.nabel@fz-juelich.de

80 Neuhäuser Benjamin University Hohenheim 340h benjamin.neuhaeuser@uni-hohenheim.de

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81 Neumann Günter University Hohenheim 340h guenter.neumann@uni-hohenheim.de

82 Nkebiwe Mehdi University Hohenheim 340i Mehdi.Nkebiwe@uni-hohenheim.de

83 Olfs Hans-Werner University Osnabrück h-w.olfs@hs-osnabrueck.de

84 Pacholski Andreas EuroChem Agro, Mannheim andreas.pacholski@eurochemagro.com

85 Peiter Edgar Martin-Luther-University, Halle edgar.peiter@landw. uni-halle.de

86 Perez Romo Maria Luisa University Hohenheim (340e) m.romoperez@uni-hohenheim.de

87 Pitann Britta Christian-Albrechts-University, Kiel bpitann@plantnutrition.uni-kiel.de

88 Prey Lukas TU München prey@wzw.tum.de

89 Prigge Max maxprigge@gmail.com

90 Richter Julia Annika University Hohenheim 340e juliaannika_richter@uni-hohenheim.de

91 Robles Aguilar Ana Alejandra FZ Jülich a.robles.aguilar@fz-juelich.de

92 Rodriguez Puig Alice University Hohenheim 340i alice.rodriguez@gmx.de

93 Rubilar Valeska IPK Gatersleben rubilar@ipk-gatersleben.de

94 Ruser Reiner University Hohenheim 340i Reiner.Ruser@uni-hohenheim.de

95 Sanaullah Muhammad University Göttingen sanasial@gmail.com

96 Saqib Muhammad Justus-Liebig-University, Gießen drhmsab@yahoo.com;

97 Schaaf Gabriel ZMBP University Tübingen gabriel.schaaf@zmbp.uni-tuebingen.de

98 Schlindwein Claudia Martin-Luther-University, Halle claudia-schlindwein@web.de

99 Schmidthalter Urs TU München schmidhalter@wzw.tum.de

100 Schönberger Brigitte University Hohenheim 340h brigitte_schoenberger@uni-hohenheim.de

101 Schubert Sven Justus-Liebig-University, Gießen sven.schubert@ernährung.uni-giessen.de

102 Schultze Nico Helmholtz Centre, Halle nico.schultze@ufz.de

103 Schuster Konrad Martin-Luther-University, Halle konrad.schuster@gmx.de

104 Seiz Perik University Hohenheim 340i perik_seiz@uni-hohenheim.de

105 Smalla Kornelia Julius-Kühn-Institut, Braunschweig kornelia.smalla@julius-kuehn.de

106 Steckenmesser Daniel Justus-Liebig-University, Giessen daniel.steckenmesser@ernaehrung.uni-giessen.de

107 Steingrobe Bernd University Göttingen bsteing@gwdg.de

108 Ulas Firdes Erciyes Unviersity, Kayseri (Turkey) firdescetin84@hotmail.com

109 Ulas Abdullah Erciyes Unviersity, Kayseri (Turkey) agrulas@erciyes.edu.tr.

110 Vetterlein Doris Helmholtz Centre, Halle doris.vetterlein@ufz.de

111 Völkner Amrei EuroChem Agro, Mannheim amrei.voelkner@eurochemgroup.com

112 von Tucher Sabine TU München tucher@wzw.tum.de

113 von Wirén Nicolaus IPK Gattersleben vonwiren@ipk-gattersleben.de

114 Wang Haitao Justus-Liebig-University, Giessen haitao.wang@agr.uni-goettingen.de

115 Weber Nino University Hohenheim 340h NinoFrederik.Weber@uni-hohenheim.de

116 Weinmann Markus University Hohenheim 340h markus.weinmann@uni-hohenheim.de

117 Wei Gao Helmholtz Centre, Halle gao.wei@ufz.de

118 Wendel Anna FZ, Jülich annawendel@gmx.de

119 Westerschulte Matthias University Osnabrück M.Westerschulte@hs-osnabrueck.de

120 Wichern Florian Rhein-Waal-University, Kleve florian.wichern@hsrw.eu

121 Wimmer Monika Rheinische Friedrich-Wilhelms-University, Bonn m.wimmer@uni-bonn.de

122 Wissemeier Alexander BASF Agrarzentrum Limburgerhof alexander.wissemeier@basf.com

123 Wollmann Iris Uni Hohenheim 340h i.wollmann@uni-hohenheim.de

124 Wu Jiawen Christian-Albrechts-University, Kiel jwwu@plantnutrition.uni-kiel.de

125 Wu Lin-Bo Rheinische Friedrich-Wilhelms-University, Bonn linbowu@uni-bonn.de

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126 Yuan Lixing China Agricultural University, Beijing, (China) yuanlixing@cau.edu.cn

127 Zaytseva Olga University Hohenheim 340h olga.zaytseva@uni-hohenheim.de

128 Zeng Cheng KWS SAAT SE, Einbeck cheng.zeng@kws.com

129 Zhao Wenting Justus-Liebig-University, Gießen wenting.zhao@ernaehrung.uni-giessen.de

130 Zhou Yaping University Hohenheim 340h Yaping.Zhou@uni-hohenheim.de

131 Zickenrott Ina-Maria Helmholtz Centre UFZ, Halle ina-maria.zickenrott@ufz.de

132 Zinsmeister Daniel Rheinische Friedrich-Wilhelms-University, Bonn s7dazins@uni-bonn.de

133 Zörb Christian University Hohenheim 340e christian.zoerb@uni-hohenheim.de

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Location

The conference will take place on the campus of the University of Hohenheim in Stuttgart. The Plant Nutrition at Hohenheim has a long tradition and was founded by Margarethe von Wrangell, the first full female professor at a German University. Plant nutrition at the University is also famous for Horst Marschner (and colleagues) whose textbook is still an outstanding reference and basis for teaching.

Hohenheim is on the outskirts of Stuttgart, has good transport links with public transport and proximity to the airport.

https://www.uni-hohenheim.de/en/directions

Address

Euroforum Katharinasaal

Kirchnerstr. 3

University of Hohenheim

70593 Stuttgart