Sulfur starvation reduces phytosiderophores release by iron-deficient barley plants

Abstract

The aim of the present study was to examine the effect of sulfur (S) supply on the response to iron (Fe) deficiency in graminaceous plants. Barley seedlings (Hordeum vulgare L. cv. Europa) were cultured hydroponically for 10 days at three S levels (0, 60 and 1200 μmol L-1 sulfate) with (+Fe) or without (-Fe) 100 μmol L-1 FeIII-ethylene diamine tetracetic acid. Lowering S supply resulted in a sharp decrease in the release of phytosiderophores by Fe-deficient barley plants. Furthermore, uptake of 59Fe from (59Fe)-hydroxide decreased by approximately 30% when S availability was lowered; Fe deficiency caused a sharp increase in 59Fe uptake that was as high as the level of S supply. The results support the view that S availability can influence either the release of phytosiderophores or the ability to take up Fe from an external solution. © 2006 Japanese Society of Soil Science and Plant Nutrition.