Biofortification of staple food crops: Engineering the metabolic pathways

ABSTRACT:Over three billions of the world people are affected by micronutrient malnutrition and nearly two-thirds of all child deaths are linked to malnutrition’s specifically micronutrients deficiencies. “Biofortification” is a word coined to refer to increasing the bioavailable micronutrient content of food crops via plant breeding. Developing micronutrient-enriched staple plant foods, either through traditional plant breeding or via molecular techniques, is a powerful intervention tool that targets the most vulnerable people. A significant portion of people in developing countries relies largely on one or more of the staple crops such as rice, maize, wheat, potato and cassava for their nutrition. These crops are the main subjects of biofortification projects. In staple grains such as rice, improvement of some complex traits such as vitamin A is not possible using conventional breeding strategies, as there are no natural rice varieties rich in this vitamin. Conventional breeding is also very difficult in vegetative propagated varieties (such as cassava and potatoes), due to the scarcity of genetically well-defined breeding lines. In addition, conventional breeding can change important traits of the crops desired by consumers, such as taste. Agricultural biotechnology methods, and in specific genetic engineering through Genetically Modified Organism (GMO) production represent therefore a very valuable and complementary strategy for developing more nutritious crops through engineered metabolic pathways such as Golden rice. Half the daily recommended allowance of vitamin A for a 1-3 year old child would be provided for in 72g of Golden Rice 2.