The responses of red clover ( Trifolium pratense L.) to iron deficiency: a root Fe(III) chelate reductase

Abstract

Red clover ( Trifolium pratense L. cv. Kenland) was found to be an Iron (Fe)-efficient plant while it was sensitive to deficiencies of Cu, Zn and Mn or toxicities of Cu and Mn. Under Fe deficiency, the activity of Fe(III) chelate reductase in roots displayed two distinct peaks during 24 days of treatment. The root Fe(III) chelate reductase was induced within 1 day, during which no proton extrusion was observed. Both roots and shoots are involved in the reductase induction. The roots alone were able to rapidly induce reductase activity, while the shoots were necessary for the later enhancement of reductase activity. It is proposed that the rapidly-induced root reductase plays an important role in overcoming Fe deficiency in calcareous soils. The relationships between reductase induction, proton extrusion, and the role of shoots and roots are also discussed.