ZURICH—Scientists at ETH Zurich have developed rice plants that contain six times more iron in polished rice kernels by transferring two plant genes into an existing rice variety. In the future, the high-iron rice could help to combat iron deficiency, especially in developing countries in Africa and Asia.
The rice plants express the two genes to produce the enzyme nicotianamin synthase, which mobilizes iron, and the protein ferritin, which stores iron. Their synergistic action allows the rice plant to absorb more iron from the soil and store it in the rice kernel. The product of nicotianamine synthase, called nicotianamin, binds the iron temporarily and facilitates its transportation in the plant. Ferritin acts as a storage depot for iron in both plants and humans. The researchers controlled the genes introduced in such a way that nicotianamin synthase is expressed throughout the rice plant, but ferritin only in the rice kernel. Together, the expression of the genes has a positive impact on iron accumulation in the rice kernel and increases the iron content more than six-fold compared to the original variety.