arbuscular mycorrhizal interactions – an important trait · pdf filearbuscular...

Arbuscular mycorrhizal interactions –

an important trait for biomass

production of bioenergy crops?

Heike Bücking

Symbiosis Conference, Cornell University

June 20, 2013

1. C4 photosynthesis

2. Long canopy duration

3. Capability to recycle nutrients

4. High water acquisition and use

efficiency

5. Non-invasive

6. High pathogen and pest resistance

7. Clean burning

Characteristics of an ‚ideal‘ bioenergy crop

Majority of these characteristics is

affected by beneficial plant-microbe

interactions, and here particularly by

arbuscular mycorrhizal interactions

JGI DOE

Why prairie cordgrass?

Why prairie cordgrass?

Native perennial grass

High biomass production

Suitable for growth on

marginal lands

Salt tolerant

Large carbon sequestration

capacity

Recycling of nutrients

Early spring growth

High genetic diversity and lack of

genome/transcriptome resources

hinders molecular breeding

Prairie cordgrass Switchgrass

What is the AM community composition of

prairie cordgrass?

0

20

40

60

80

100

Myco

rrh

iza

l co

lon

iza

tio

n i

n %

Collection sites

2011

Mycorrhizal communities of prairie cordgrass

1.1

1.2

2.1

2.2

3.1

3.2 3.3

3.4

3.5

4.1

4.2

4.3

5.1 6.1

6.2 6.3

7.1 8.1

8.2

8.3

9.1 9.2

9.3 9.4

10.1

10.2

11.1

11.2

12.1

12.2

12.3

Glomus intraradices, Glomus irregulare, Rhizophagus irregulare 1.1; 2.1; 3.1; 4.1; 6.1; 8.1; 9.2; 10.1; 12.1 2.2; 3.4; 10.2; 11.2 Glomus iranicum 3.2; 3.3; 3.4; 3.5; 4.2; 4.3; 6.2; 6.3, 9.3, 9.4; 12.2; 12.3 Glomus fasciculatum 11.1 Glomus hoi, Glomus macrocarpum 9.1 Unidentified AM fungus 5.1; 1.2; 8.2; 8.3;


What is the effect of arbuscular

mycorrhizal communities on biomass

development in prairie cordgrass?

Control G.i.1 G.i.2

Mycorrhizal responsiveness

0

20

40

60

80

0µg P,0µg N

0µg P,125µg

N

5µg P,125µg

N

25µg P,125µg

N

50µg P,125µg

N

50µg P,0µg N

50µg P,12.5µg

N

50µg P,62.5µg

N

Pe

rce

nta

ge

In

cre

ase

Shoot Biomass compared to control

0 P 0 N

50 P 125 N

50 P 0 N

50 P 12.5 N

50 P 62.5 N

0 P 125 N

5 P 125 N

25 P 125 N

P and N supply conditions in µg

G.i.1 G.i.2

Control G.i.1 G.i.2

Mycorrhizal responsiveness

0

20

40

60

80

0µg P,0µg N

0µg P,125µg

N

5µg P,125µg

N

25µg P,125µg

N

50µg P,125µg

N

50µg P,0µg N

50µg P,12.5µg

N

50µg P,62.5µg

N

Pe

rce

nta

ge

In

cre

ase

Fertilizer Treatment

Plant Total P content compared to control

0 P 0 N

50 P 125 N

50 P 0 N

50 P 12.5 N

50 P 62.5 N

0 P 125 N

5 P 125 N

25 P 125 N

P and N supply conditions in µg

G.i.1 G.i.2

How does fungal diversity affect

plant benefit?

Plant benefit and P uptake

y = 270.87x - 83.097 R² = 0.7962

y = 270.87x - 83.097 R² = 0.7962

0

100

200

300

400

500

0.4 0.9 1.4 1.9

Plant Biomass in g

Mensah, Koch, Bücking, unpublished

P c

on

ten

t in

mg

pla

nt

d.w

t.

How does fungal diversity affect benefit?

Ent col NB104

Glo mos NB114

Ent col CL356

Ent col GA101

Acau mor FB219B

How does plant diversity affect

plant benefit?

UPGMA

Nei & Li's Coefficient

RR1

RR2

SP26.2

SP3.2

RR20

SP2.1B

SP35.1A

SP4.1A

RR10

RR16

RR11

RR7

RR5

SP13.3B

SP46.1

RR3

SP23.1B

SP78.2A

SP9.1D

SP34.1

SP42.2A

SP53.1

SP57.1

SP59.1

SDPCG11

SP33.1

SP55.1C

SP40.1

SP1.1C

SP13.5

SP13.2C

SP6.1A

SP14.2A

SP10.1C

SP11.1B

SP8.2

SP15.2E

SP9.1A

SP12.1

SP1.3

SP3.1B

SP7.3

SP5.1

SP7.1A

SP13.4B

SP14.1B

SP5.3A

SP80.2

SP15.1A

SP77.2

SP78.3

SP81.2A

SP49.2

SP52.1

SP71.1

SP78.1B

SP80.1

SP72.3B

SP43.1

SP74.2A

SP74.3

SP75.1

SP77.1

SP13.6B

SP14.3

SP4.1B

SP56.2

SP66.1C

SP70.1

SP16.1A

SP7.4C

SP8.1

SP21.3

SP22.1D

SP48.1

SP72.1B

SP82.1B

SP20.3

SP7.2B

SP20.1B

SP60.1

SP73.1D

SP74.1C

SP30.2B

SP31.3A

SP63.1

SP56.1

SP67.1B

SP31.4

SP72.2

SP32.1

SP42.1A

SP33.2A

SP44.1

SP79.1B

SP51.1

SP46.2

SP49.1

SP52.2B

SP71.2A

SP15.2C

SP47.1

SP24.1

SP31.2B

SP21.2

SP27.1A

SP31.1A

SP41.2

SP28.1

SP29.6D

SP29.3

SP32.2D

SP101

SP120

SP110

SP118

SP103

SP105

SP106

SP114

SP113B

SP119

SP108

SP107

SP111

SP115

SP116

SP121

SP13.3A

SP14.4C

SP14.5C

SP21.4B

SP41.1B

SP44.2

SP40.2A

SP58.1A

SP20.2

SP29.1B

SP29.2

SP29.5C

SP29.7C

SP81.1

SP21.1B

SP22.1B

SP25.1

SP26.1A

SP1.2C

SP13.1A

SP29.4

SP5.2

SP62.1

SP61.1

SP16.1C

SP6.2

SP28.2A

SP8.3

SP65.1A

SP43.2A

SP64.1

SP54.1

SP54.2

SP30.1

SP45.1B

-0.2 0 0.2 0.4 0.6 0.8 1

SP21.1D

RR2

SP21.2

How does plant diversity affect benefit?

Genotypic differences in mycorrhizal responsiveness

0

500

1000

1500

2000

RR2 SP21.2 SP21.1D

Control Gi

Biomass in g at 0 P 0 N


-50

0

50

100

150

200

250

300

RR2 SP21.2 SP21.1D

0P 0N 0P 100N

Growth response in %


-50

0

50

100

150

200

250

RR2 SP21.2 SP21.1D

Increase in P oontent in %

Mycorrhizal pathway Plant pathway

Depletion zone

Depletion zone

P

P

P

P Level P Level

P

P

P

P

P

P

P ERM

P

V

V

A

V

A

V

S

A

Potential reasons for differences

in nutrient efficieny

Carbon costs of the

symbiosis for the host

Reduction in plant P

uptake that is not

compensated for by AM

fungal P uptake

Inefficient nutrient

exchange across the

mycorrhizal interface

C

How does resource exchange

affect plant benefit?

Experimental Design

ERM Ac Plant Plant ERM Ac

Glomus intraradices

Glomus

aggregatum

15N (14 d) 33P (5 d)

15N (14 d) 33P (5 d)

Host photosynthesis affects

fungal N transport in CMN

0

20

40

60

80

100

Non-shaded Shaded

G. intraradices

0

20

40

60

80

100

Non-shaded Shaded

Fungal N

tra

nsp

ort

in %

G. aggregatum

0

20

40

60

80

100

0% shade 50% shade

0

20

40

60

80

100

0% shade 50% shade

Fu

ng

al P

tra

nsp

ort

in

%

G. intraradices G. aggregatum

Host photosynthesis affects

fungal P transport in CMN

Fellbaum et al., PNAS, 2012

0.01

0.10

1.00

10.00

100.00

AL ASS CPS GluS GS1 GS2 CAR1 NT OAT1 OAT2 ODC URE

ERM Fo

ld in

du

ctio

n c

om

pa

red

to

co

ntr

ol

0.1

1.0

10.0


IRM

Fo

ld in

du

ctio

n c

om

pa

red

to

co

ntr

ol

Carbon acts as trigger for N uptake and transport

Arg biosynthesis Arg breakdown N assimilation

AM fungi are ubiquitous in soils and the mycorrhizal

conditions better reflects the natural stage

AM fungi lead to qualitative and quantitative changes in the

plant transcriptome

AM fungi change the nutrient uptake strategy of their host,

and molecular markers in the mycorrhizal stage better

represent the nutrient efficiency under field conditions

Integration of mycorrhizal fungi into breeding could represent

a new strategy for the development of nutrient efficient and

stress resistant cultivars

Implications and significance

What is the basis of fungal or plant

diversity in plant benefit?

Are these differences based on

presymbiotic or postsymbiotic

events?

How can the host plant maximize its

symbiotic benefit from one fungal

partner or from AM fungal

communities?

Transcriptome analysis of prairie

cordgrass, switchgrass, and

Brachypodium

Research Gaps

Acknowledgements

Jose Gonzalez

Arvid Boe

Carl Fellbaum

Jerry Mensah

Elliot Liepold

Brandon Monier

Toby Kiers Gautam Sarath

Thank you! Questions?

556,421 reads (average size=223bp) Assembly resulted in

the formation of 26,302 contigs (average length of 394bp)

454 Transcriptome

Fellbaum et al. 2012.

PNAS

0.01

0.10

1.00

10.00

100.00


Fo

ld in

du

ctio

n c

om

pa

red

to

co

ntr

ol

0.1

1.0

10.0


The host regulates with its carbon supply

fungal gene expression

Extraradical mycelium

Intraradical mycelium

Salinity in the Northern Plains


2010 2011 DGGE 2010 DGGE 2011

Mycorrhizal pathway Plant pathway

Depletion zone

Depletion zone

P

P

P

P Level P Level

P

P

P

P

P

P

P ERM

P

V

V

A

V

A

V

S

A

Mycorrhizal nutrient uptake

Increase in the nutrient

absorbing surface area

beyond the depletion zone of

the root

Highly efficient nutrient uptake

systems

Better P storage capabilities

Utilization of organic nutrient

resources

Connects the plant with

diverse microbial communities

in the soil

IRM/HN ERM

INTERFACIAL

APOPLAST

SOIL

PolyP

HOST

C

Pool

PolyP

Arg

Gln Orn

Urea

NH4

Glu

Arg

C

Pool

Pi Pi Pi

Hexose

Hexose

Pi

Pi

NO3

NO3

NH4

NH4

NH4 NH4

Sucrose

Sucrose

Photos.

Resource exchange in the AM symbiosis

Cordgrass

Switchgrass

Big

bluestem Indian

grass

Little

blue-

stem

Biomass potential of prairie cordgrass

arbuscular mycorrhizal interactions – an important trait · pdf filearbuscular...

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