Engineering the provitamin A (beta-carotene) biosynthetic pathway into (carotenoid-free) rice endosperm

Rice (Oryza sativa), a major staple food, is usually milled to remove the o il-rich aleurone layer that turns rancid upon storage, especially in tropic al areas. The remaining edible part of rice grains, the endosperm, Lacks se veral essential nutrients, such as provitamin A. Thus, predominant rice con sumption promotes vitamin A deficiency, a serious public health problem in at least 26 countries, including highly populated areas of Asia, Africa, an d Latin America. Recombinant DNA technology was used to improve its nutriti onal value in this respect. A combination of transgenes enabled biosynthesi s of provitamin A in the endosperm.