Effect of hydrogen peroxide on protein content and catalase activity in cajanus cajan (l.) millsp. leaves

In this report protein content and catalase (CAT) activity were used to study the effect of hydrogen peroxide (H2O2) on leaf senescence in detached Pigeon pea leaves. A decrease in protein content measured as an indicator of leaf senescence, and a drop in CAT activity was observed following treatment with H2O2 in Pigeon pea detached leaves compared with control leaves. However after longer incubations CAT activity significantly increased in comparison with day 1 treatment. Protein content and CAT activity were also studied in the leaves treated by 0.025, 0.05, 0.075 and 0.1 mM H2O2. The optimal concentration of H2O2 in reducing protein content seems to be 0.075 mM, whereas concentration of 0.025, 0.05, 0.075 mM increase the CAT activity while lower and higher concentrations shown the opposite effect. The observed changes revealed that H2O2 induces oxidative stress and oxidative damage thereby leaf senescence in the detached leaves of Pigeon pea.