Iron deficiency induces sulfate uptake and modulates redistribution of reduced sulfur pool in barley plants.

We studied the possibility that the sulfur (S) assimilatory pathway might be modulated by iron (Fe) starvation in barley, as a consequence of plant requirement for an adequate amount of reduced S to maintain methionine and, in turn, phytosiderophore biosynthesis. Barley seedlings were grown with or without 100 µm Fe-EDTA, at three S levels in the nutrient solution (S = 1200, S = 60, and S = 0 µm sulfate) in order to reproduce conditions of optimal supply, latent and severe deficiency, respectively. Fe deprivation increased root cysteine content irrespective of the S supply.