Moving micronutrients from the soil to the seeds: Genes and physiological processes from a biofortification perspective

The micronutrients iron (Fe), zinc (Zn), and copper (Cu) are essential for plants and the humans and animals that consume plants. Increasing the micronutrient density of staple crops, or biofortification, will greatly improve human nutrition on a global scale. This review discusses the processes and genes needed to translocate micronutrients through the plant to the developing seeds, and potential strategies for developing biofortified crops.

Research highlights
► Whole-plant tracer studies are described to indicate which tissues supply micronutrients to seeds.
► Known genes that transport micronutrients from roots, from xylem to symplast, and into phloem are discussed.
► Potential methodology to discover new genes is discussed.
► Previous and potential transgenic strategies for biofortification of seeds are discussed.