Zinc and iron-mediated alleviation water deficiency of maize by modulating antioxidant metabolism

Abstract

Microelements are inorganic compounds involved in the synthesis of enzymes and biologically active substances. To evaluate the physiological responses of maize to ZnSO4 and FeSO4 under drought stress, a field experiment was conducted on maize plants grown under different soil moistures and treated with foliar ZnSO4 and FeSO4 applications. Drought stress especially at early seed growth stage significantly reduced grain yield and Fv/Fm ratio; however, the activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and glutathione reductase (GR) was enhanced under drought stress. Foliar applied ZnSO4 and FeSO4 boosted the grain yield under non irrigation at vegetative growth stage and at early seed growth stage, respectively.  Between grain yield and MDA concentration (r=­ -0.73), superoxide dismutase (r= -0.57), peroxidase (r= -0.49), H2O2 (r= -0.67) and catalase enzyme (r= -0.42) significant and negative correlation were observed. Combined application of ZnSO4 and FeSO4 resulted in alleviation of maize plant drought stress by Zn and Fe-mediated improvement in photosynthetic attributes. In addition, the foliar application of ZnSO4 and FeSO4 regulated physiological processes in maize plants and alleviated the adverse effects of water stress. According to the results, ZnSO4 and FeSO4 could be used for improving maize growth under drought stress.