Antioxidative enzyme responses under single and combined effect of water and heavy metal stress in two Pigeon pea cultivars

Abstract

Heavy metal toxicity and water stress are the two frequently co-occurring abiotic stresses restraining the growth of crop plants as the metal contaminated sites are over alarmingly increasing due to industrial pollution. The present study is to evaluate the effect of heavy metals (Cadmium, Chromium), PEG induced water stress and their combination on antioxidative enzyme activities in two Pigeon pea cultivars LRG-41 and Yashoda-45. The activities of antioxidative enzymes Superoxide dismutase, Catalase, Ascorbate peroxidase, Polyphenol Oxidase and Glutathione Reductase registered higher values in both roots and shoots with all the single stress treatments when compared to their controls. The levels of antioxidative enzyme activities and lipid peroxidation were high in cv. Yashoda-45 than cv. LRG-41. Overall, cv Yashoda-45 has shown better tolerance to both heavy metal and water stress. These results may show the novel insight in to the responses associated with combined stress in the cultivars of economically important crop, Pigeon pea.