Effects of exogenous melatonin on antioxidant system in leaves of kiwifruit seedlings under cadmium stress

Using one-year-old wild Actinidia deliciosa as the experimental material, effect of melatonin (MT) on the antioxidant system under heavy metal Cd stress was studied. The results showed that after Cd stress treatment, the relative electrical conductivity, MDA content, proline content, soluble protein content, H2O2 content and protection enzyme activity of kiwifruit seedlings leaves increased first and then decreased than those of control (CK). However, pretreatment with MT irrigatiing root effectively alleviated the kiwi membrane lipid peroxidation, reduced the relative level of membrane permeability, MDA content, H2O2 content, at the same time significantly increased the proline content, soluble protein content, improved the activity of protective enzyme, suggesting that MT can availably reduce the harm of Cd stress, improve the tolerance to Cd stress of kiwifruit seedling.