Antioxidant Enzymes Activities of Medicago sativa L.Seedling under Salt Stress

To explore the responses of alfalfa(Medicago sativa L.'Golden Empress') to salt stress,provide the scientific evaluation of alfalfa salt tolerance,antioxidant defense mechanisms of alfalfa seedling were treated.The antioxidant enzymes activities(Superoxide,MDA,POD,SOD,CAT,Vc and T-AOC) in alfalfa leaves and roots under different NaCl stress(0,40,80,120 and 160 mmol·L-1) were measured.Results showed that both superoxide and Vc levels initially increased then decreased while MDA and POD increased but SOD,CAT and T-AOC decreased in alfalfa root.However,superoxide levels initially increased then decreased,MDA,Vc and SOD increased,POD,CAT and T-AOC decreased in leaves of alfalfa under different NaCl stress.Comprehensive analysis showed that the roots of alfalfa seedlings experienced more serious salt damage compared to aboveground parts.