Evaluation of oxidative stress in Vigna radiata L. in response to chlorpyrifos

This study aims to evaluate the effect of chlorpyrifos on several metabolic and stress related parameters of Vigna radiata L. Twenty-day-old plants were exposed to several concentrations of chlorpyrifos, ranging from 0 to 1.5 mM through foliar spray in the field condition. Analyses were done at pre-flowering (Day 5), flowering (Day 10), and post-flowering (Day 20) stages after the treatment. Lipid peroxidation rate, proline, dehydroascorbate, oxidized and total glutathione were all ascended. Chlorpyrifos enhanced lipid peroxidation rate and proline content with 1.5 mM at Day 20 whereas dehydroascorbate, oxidized and total glutathione were increased in 1.5 mM at Day 10. However, dose dependence significantly declined in content of ascorbate and reduced glutathione levels were observed at all growth stages. Among the enzymatic antioxidants, activities of superoxide dismutase, ascorbate peroxidase and glutathione reductase enhanced significantly in all the concentrations at Day 10. Maximum catalase activity was observed at Day 10 in control and it declined thereafter. The above results clearly depicted the provoked state of oxidative stress under chlorpyrifos exposure in Vigna radiata L. and therefore can be used to evaluate the degree of insecticide contamination to plant, which may be serving as biomarker in Vigna radiata L.