Dr. Elsbeth Walker

Professor of Biology
Plant Biology Graduate Program Director
ewalker at bio.umass.edu
Lab website

Iron Homeostasis in Plants

Iron is one of the most important and most problematic of all the micronutrients used by living organisms. Iron is an essential cofactor for many cellular redox reactions, yet the same high reactivity that makes it so useful can cause cellular damage if iron is not carefully controlled. Add to this problem that iron is also only sparingly soluble in aqueous solution, and it is easy to see why plants have evolved multifaceted iron homeostatic mechanisms. These mechanisms include control of uptake, translocation from organ to organ and cell to cell, re-mobilization of stored iron, as well as poorly understood sensing and signaling systems by which the plant communicates its iron status between tissues. Many of the mechanisms involved in plant iron homeostasis are not well understood, and this is a major obstacle to 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; it is widely regarded as a sustainable means of improving the iron nutrition of the 2-3 billion people worldwide whose inadequate diet causes iron deficiency anemia.

My group has a strong interest in the processes by which plants move iron and other transition metals within their above ground parts. We have recently shown that members of the Yellow Stripe Like (YSL) family of transporters are required for normal iron, zinc, and copper loading into both vegetative and reproductive tissues. In future, my group will continue to perform experiments that will elucidate the mechanisms that plants use to achieve correct distribution of iron and other metals into above ground organs and seeds. We will also pursue experiments that will elucidate the function(s) of additional YSL family members both at the biochemical and whole plant physiological levels.