Effects of Se on Enzyme Activity and Chlorophyll Content of Brassica napus under Pb Stress

[Objective]The propose was to provided the reference for taking Brassica napus as the remediation plant in soil polluted by heavy metals.[Method]B.napus seedlings stressed in Pb solution at 500 mg/L were treated with sodium selenite solution at 0(CK),5,10,15,20,25 and 30 mg/L to study the effects of Se on enzyme activity and chlorophyll content of B.napus under Pb stress. [Result] When Se was below 15 mg/L,the root-shoot ratio of B.napus was increased.When Se was over15 mg/L,the root-shoot ratio was decreased along with the increment of Se concn.Se in some concn.range(below 10 mg/L) could increase relative activity of SOD,POD and CAT and the change of SOD activity was most obvious.Se at over 10 mg/L could reduce the enzyme activity.Se at below 10 mg/L could increase the chlorophyll content and Se at over 15 mg/L could aggravate the decrease of chlorophyll content.[Conclusion] When Se was below 10 mg/L,Se and Pb showed the antagonism;when Se was over10 mg/L,Se and Pb showed the cooperation action.