Transgenic technologies in cassava for nutritional improvement and viral disease resistance: a key strategy for food security in Africa

As a major staple food source in Africa and other tropical developing countries, cassava(Manihot esculenta) provides basic sustenance for many subsistence farmers. However, cassava roots mainly accumulate starch with limited contribution of other nutrients such as proteins and vitamins. Also, two viral diseases, cassava mosaic disease(CMD) and cassava brown streak disease(CBSD), cause great losses in cassava production in subSaharan Africa and the Indian sub-continent. Genetic engineering provides promising approaches to improve nutritional value and increase resistance to viral diseases in cassava. This report presents several successful case studies on engineering protein content by overexpression of nutritious storage proteins and improving cassava resistance to viral diseases by RNA interference. Perspectives on the sustainable acquisition of new knowledge and development of biotechnology to solve these bottlenecks are discussed.