Our current ignorance of most of the mechanisms involved in plant iron homeostasis is a major obstacle in devising approaches for biofortification of staple foods with iron. Biofortification refers to the genetic engineering of staple crops to accumulate additional bioavailable iron in edible parts, and is widely regarded as a sustainable means of improving the iron nutrition of the 2-3 billion people worldwide (World Health Organization) whose inadequate diet causes iron deficiency anemia. Understanding these transport mechanisms is the key to allowing enhanced seed iron accumulation through either engineering or through marker assisted breeding efforts.
Improving our understanding of plant iron homeostatic mechanisms is also critical if we wish to improve growth of crops in marginal soils, where iron deficiency frequently limits crop growth. This problem is of particular concern for growth of upland rice (i.e., non-paddy rice), which is an increasingly important crop in Asia as water resources become more limited. It is also a growing problem in the North American soybean crop, as soy production moves into less favorable northern latitudes. Plant's efficient use of iron within tissues is a promising target to address these issues, provided that additional information about such mechanisms becomes available. By carefully characterizing the Yellow Stripe-Like (YSL) transporter family in corn, we will gain much needed insight into the molecular mechanisms that this important crop species uses to maintain proper iron homeostasis. Even more importantly, the detailed molecular information that will be obtained will suggest strategies that can be used to alter the pattern of iron distribution in corn, and will thus aid in the development of novel strategies to achieve iron biofortification.
