Effects of sulfur and cadmium interactions on antioxidant enzyme activity in hyperaccumulator-Sedum alfredii Hance were investigated in hydroponic culture.The contents of MDA in leaf were decreased with sulfur application under three cadmium levels,significantly decreased by 12.4% in Cd0 and S2 treatment.On the contrary,the contents of MDA were significantly increased from 18.4% to 137.7% with increasing cadmium level.There were significant effects of sulfur and cadmium interactions on antioxidant enzyme ac...