Transgenic multivitamin corn through biofortification of endosperm with three vitamins representing three distinct metabolic pathways

TLDR

Vitamin deficiency affects up to 50 % of the world’s population, especially in developing countries reliant on cereal‑rich diets, and although transgenic plants can boost vitamin content, only single vitamins have been enhanced to date. The study aimed to produce elite South African transgenic corn with elevated levels of three distinct vitamins in the endosperm. This was achieved by simultaneously modifying three separate metabolic pathways in the endosperm of inbred lines. The resulting kernels exhibited 169‑fold higher beta‑carotene, 6‑fold higher ascorbate, and twice the folate of normal corn, with these levels remaining stable through the T3 generation and surpassing conventional breeding, thereby paving the way for nutritionally complete cereals.

Abstract

Vitamin deficiency affects up to 50% of the world's population, disproportionately impacting on developing countries where populations endure monotonous, cereal-rich diets. Transgenic plants offer an effective way to increase the vitamin content of staple crops, but thus far it has only been possible to enhance individual vitamins. We created elite inbred South African transgenic corn plants in which the levels of 3 vitamins were increased specifically in the endosperm through the simultaneous modification of 3 separate metabolic pathways. The transgenic kernels contained 169-fold the normal amount of beta-carotene, 6-fold the normal amount of ascorbate, and double the normal amount of folate. Levels of engineered vitamins remained stable at least through to the T3 homozygous generation. This achievement, which vastly exceeds any realized thus far by conventional breeding alone, opens the way for the development of nutritionally complete cereals to benefit the world's poorest people.