Effect of Cadmium Stress on Seed Germination,Seedling Growth and the Activities of Antioxidant Enzymes of Wheat

Cadmium(Cd)was a highly toxic and persistent environmental poison,its increasing level in soil environment exerted a wild range of adverse effects on plants and even the healthy of human beings by food chains.In the study,the effects of Cd at different concentrations on wheat seeds germination,seedlings growth and the activities of antioxidant enzymes were studied.The results showed the germination percentage,germination potential and shoot growth were not significantly inhibited by cadmium,especially at low Cd concentrations.However,germination index,vigor index,root growth were restrained evidently with the increase of Cd stress.The content of MDA and activities of G-POD in root and shoot increased significantly with the increasing of Cd concentration.The activities of SOD first increased and then decreased as the Cd concentration increased and it was slight lower than that of control in root under 1 000 μmol/L Cd stress.However,the activities of CAT and APX were decreased with concentration-dependent manner,ie,the higher concentration of cadmium,the greater changes the enzyme activities,suggesting oxidative damage and membrane lipid peroxidation occurred in seedlings,and it might be the important reason for the growth inhibition of roots subjected to cadmium stress.