Antioxidative responses to short term waterlogging stress in pigeon pea

Waterlogging stress is a major abiotic stress having detrimental effects on crop production. Pigeon pea (Cajanus cajan (L.) Millsp.) is a waterlogging sensitive legume crop. Effect of short term waterlogging stress was studied on the activity of antioxidant enzymes in two pigeon pea genotypes, viz., ICPL-84023 (waterlogging resistant) and MAL-18 (waterlogging susceptible). The objective of the present experiment was to study the changes in antioxidant enzyme system in response to waterlogging. Waterlogging stress was imposed for 12 h at early vegetative stage (20 days after sowing), and activities of superoxide dismutase, ascorbate peroxidase, catalase, peroxidase and polyphenol oxidase were recorded in the root tissues at 0, 3, 6, 9 and 12 h after imposing waterlogging stress. Enzyme activities were higher in ICPL-84023 as compared to MAL-18. Activities of peroxidase and polyphenol oxidase increased immediately (3 h) after imposing waterlogging stress, indicating the activation of antioxidant enzyme system at very early stages. Changes in superoxide dismutase activity were variable at different stages of observation. Catalase activity increased significantly at 9 h and then decreased. Ascorbate peroxidase activities did not change significantly under waterlogging.