biofortification of staple crops: provitamin a cassava as a case study
DESCRIPTION
Biofortification refers to micronutrient enrichment of staple crops through plant breeding, to address the negative economic and health consequences of vitamin and mineral deficiencies in humans. It is the process of increasing the bioavailable micronutrient density of staple crops through conventional plant breeding and modern biotechnology to achieve a measurable and positive impact on human health.. Currently, agronomic, conventional, and transgenic biofortification are three common approaches. Progress has been made in breeding orange sweetpotato, provitamin A maize, provitamin A cassava, high zinc rice and high zinc wheat, and high iron beans and high iron pearl millet via conventional breeding. Transgenic biofortification is used when genetic variability for vitamin and mineral targets is too low to meet the desired target levels, or for crops that are very difficult to breed, such as banana. The biofortification of cassava with Provitamin A (beta-carotene) was achieved through pure line and hybrid seed technology as well as genetic engineering. The provitamin A carotenoid in biofortified cassava is primarily β-carotene. In white cassava, there may be trace amounts of β-carotene, which may be present in concentrations as low as 1 mg/g fresh weigh or 3 mg/g dry weigh. Due to the instability of beta-carotene, cooking and processing methods can affect the retention of β-carotene in cassava leading to decrease bioavailability and bioefficacy.TRANSCRIPT
Biofortification of Staple Crops : Pro-vitamin A Cassava as a case
study.A Seminar (BCM 417) Presented
ByONYIBA, Cosmos Ifeanyi
MOUAU/10/15593
Department of BiochemistryCollege of Natural Sciences (COLNAS)
Micheal Okpara University of Agriculture, Umudike July, 2014
[email protected] +2348062633518
Outline
Introduction The concept of Biofortification Latest Biofortified crops on market Methods of Biofortification Conventional breeding of Provitamin A cassava Genetic Modification/Trangenic Provitamin A cassava development Integration of genetic modification and conventional breeding Conventional Breeding versus Genetic Modification Biochemical Relevance of Provitamin A cassava Conclusion
Deficiencies in vitamins and minerals in our diets causes malnutrition and is popularly known as “hidden hunger”. Conventional responses (such as diet diversification, supplementation, fortification of manufactured foods) have had limited impact
Vitamin A and zinc deficiencies are estimated to cause 600,000 and 400,000 deaths annually, respectively (Black et al., 2008)
Cassava contains little zinc, iron, and β-carotene, yet it is the primary staple crop of over 250 million Africans thus, Children Consuming Cassava as a Staple Food are at risk for Inadequate Zinc, Iron, and Vitamin A Intake (Gegios et al., 2010)
Biofortifying staple crops (such as cassava) that feed the world's poor can significantly improve the amount of these nutrients consumed by target populations (Welch et al., 2004).
Introduction
The Concept of Biofortification
Greek word “bios” means “life”
Latin word “fortificare” means “make strong”
• Rice• Wheat• Maize• Cassava• Sweet Potato• Beans• Millet• Yam
• Potato• Barley• Cowpeas• Groundnuts• Lentils• Plantain• Sorghum• Pigeon Peas
MAKE LIFE STRONG!!!
Targeted Crops
Latest Biofortified Crops in the market
2007
2011
CassavaProvitamin ADR Congo, Nigeria
2012
BeansIron DR Congo, Rwanda
2012
MaizeProvitamin AZambia, Nigeria*
Sweet PotatoProvitamin AMozambique, Uganda
2013
RiceZinc Bangladesh, India
2013
WheatZincIndia, Pakistan
2012
Pearl MilletIron India
Methods of Biofortification
Biofortification
Fertilizer application
Conventional breeding
Genetic modification
Conventional breedingConventional Development of Provitamin A Cassava
“The use of biotechnological tools, such as molecular marker-assisted selection, will significantly increase the pace and prospects of success for breeding to improve the nutritional value of staple food crops” Gregorio 2002
Genetic modificationEngineering the beta-carotene pathway in cassava
Genetic ModificationTrangenic Provitamin A development procedures
Nucleic acid extraction
Gene cloning
Gene Design and Packaging
Detection of Inserted Genes
Backcross Breeding (if needed)
Polymerase chain reaction
Integration of Genetic Modification and Conventional Breeding
Conventional Breeding vs. Genetic Modification
Biofortified Crops
Dioxygenase
Beta-carotene
Retinol (vitamin A)
Retinal
Reductase
Biochemical relevance of Pro-vitamin A cassava(intestinal conversion, absorption and transport)
2
2Liver
Blood
Tissues
Biochemical relevance of Pro-vitamin A cassava(metabolism)
Biofortification has the potential to complement the existing micronutrient interventions, in particular by targeting the rural poor who eat large quantities of staple crops and often have little access to commercially processed food – i.e. among whom the impact of industrial fortification is limited (Tanumihardjo et al. 2008)
Biofortification of cassava with the provitamin A carotenoid beta-carotene is a potential mechanism for alleviating vitamin A deficiences
Conclusion
