Protective Effect of La~(3+) on Radish Seedlings under Cd~(2+) Stress

[Objective] The study was to provide the reference for ecological defense of plants polluted by heavy metals.[Method]The radish seedlings were treated by CdCl2 with different concn.(0,1×10-4,5×10-4,1×10-3,5×10-3 mol/L),and the whole plant in each treatment was treated by foliage spray of La(NO3)3 with the same amount(with the treatment spraying the same amount of distilled water as CK),the protective effect of La3+on radish seedlings under Cd2+ stress was studied.[Result] Under Cd2+ stress,the plant height,main root length,root activity,chlorophyll content and nitrate reductase activity of radish seedlings were all decreased somewhat,and their membrane permeability,proline content and activities of catalase(CAT) and peroxidase(POD) were all increased somewhat.After spraying of La(NO3)3 with a certain dose(15 mg/L),the root activity,chlorophyll content and nitrate reductase activity of radish seedlings were all increased somewhat,and their membrane permeability,proline content were all decreased somewhat.[Conclusion]Rare earth element La with proper dose could reduce the damage of heavy metal Cd on radish seedlings.