Radiochemical evidence for the contribution of iron (using ${}^{59}$Fe) remobilization efficiency towards nitrogen (N) and Fe deficiency tolerance in wheat

Widespread deficiency of soil macro (N) and micro nutrient (Fe) limit crop productivity and nutritional quality of the produce worldwide. Iron is relatively immobile in plants however, its retranslocation can be facilitated by naturally produced chelator in the leaves. Synthesis of these metal-chelators depends on N nutrition of crops. The present study uses ${}^{59}$Fe tracer to measure the contribution of in-plant remobilization (from fully developed 2${}^{nd}$ older leaf (OL) to a younger developing 3${}^{rd}$ leaf (YL)) of relatively immobile iron towards N and Fe deficiency stress tolerance in Fe efficient bread and Fe inefficient durum wheat. Dual nutrient deficiency of nitrogen and iron induced senescence and hastened the process of chlorophyll degradation and induced a higher ${}^{59}$Fe remobilization from OL to YL. Further, ${}^{59}$Fe retranslocation was also highest under dual nutrient deficiency (N−Fe−). Percent ${}^{59}$Fe retranslocated into the YL of bread and durum wheat, respectively was higher in Fe deficient (N+Fe− and N−Fe−) than Fe sufficient (N+Fe+ and N+Fe−) treatments. Results clearly reveal that Fe deficiency tolerance response under N and Fe deficiency is chiefly determined an efficient Fe uptake and Fe retranslocation, respectively in the bread and the durum wheat.