Sulfur regulates iron uptake and iron use efficiency in bread and durum wheat

Abstract

Present study elucidates the role and physiological basis of sulfur (S) mediated iron (Fe) regulation, uptake and use efficiency under deficient availability of soil Fe (4–6 ppm) at different level of applied S [0 (S0), 30 (S30) and 60 (S60) kg ha−1] in bread and durum wheat. Sulfur supply at S30 and S60 greatly improved the Fe and S uptake of the wheat cultivars over S0. Bread wheat recorded a greater agronomic SUE than the durum wheat but it declined with S application in a dose dependent manner in both the wheat cultivars. Further, the increase in grain yield and grain Fe under S application than without it in both the cultivars may also be related to phytosiderophore mediated higher root Fe uptake, and root to shoot and to grain translocation of Fe and subsequent induction of Fe deficiency tolerance response, more so in bread wheat than the durum wheat. It is suggested that the effect of S on Fe uptake under Fe deficient condition may be mediated via an increase in S supply regulated biosynthesis of phytosiderophore and their consequent release in rhizosphere. Results indicate two way interaction between Fe and S, at the rhizosphere and at the plant level.