Effects of Exogenous Nitric Oxide on Seed Germination and Physiological Characteristics of Wheat Seedlings under Lead Stress

By the method of solution culture,wheat was used to investigate the effects of exogenous NO donor SNP on seed germination and seedlings physiological characteristics under Pb2+ stress.The results showed that Pb2+ treatment resulted in significant decreases in seed germination and seedling growth of wheat,and notable reduction in the levels of chlorophyll a,chlorophyll b and chlorophyll fluorescence,25 μmol·L-1 SNP could alleviate the inhibition of Pb2+ on these indexes.No significant changes in the activities of CAT and POD were observed in comparison with the control under Pb2+ stress.However,the application of SNP induced increases of CAT activity and soluble protein content in wheat seedlings under Pb2+ treatment.Therefore,exogenous NO could alleviate the poison of Pb2+ and enhance the adaptation of wheat seedlings to Pb2+ stress.