Alpha-tocopherol alters endogenous oxidative defense system in mung bean plants under water-deficit conditions

Foliar spray of plant growth regulating compounds including antioxidants is an effective strategy to overcome the adverse effects of environmental constraints on different plants. a pot experiment was conducted to assess the influence of exogenously applied α-tocopherol (toc) in up-regulating the oxidative defense system in two mung bean cultivars (cyclone 7008 and cyclone 8009) grown under normal and water deficit conditions. after 30-day of water deficit treatment,four levels of toc [0 (non spray),100,200 and 300 mg l-1] were applied as a foliage application (at vegetative growth stage). a significant reduction was observed in plant height and total soluble proteins,while an increase was observed in the levels of hydrogen peroxide (h2o2),ascorbic acid,total phenolics,malondialdehyde (mda),total free amino acids and the activities of enzymatic (sod,pod and cat) antioxidants in both mung bean cultivars under drought conditions. foliar spray of toc was effective in improving plant height,asa,total soluble proteins,total free amino acids,and activities of pod and cat enzymes,but reduced mda under water stress conditions. however,no prominent change was observed on the concentrations of h2o2,phenolics,and sod enzyme due to foliar-applied toc in both mung bean cultivars under both water regimes. both mung bean cultivars were almost similar in all attributes measured except that cv. cyclone 7008 was higher in the levels of h2o2 and tsp while cv. cyclone 8009 in phenolics. so,from the results of this study we can suggest that exogenous application of toc is effective in improving growth and antioxidative potential of mung bean plants under dry arid environment. © 2016,pakistan botanical society. all rights reserved.