Effects of Lanthanum on the Protective Enzyme System in Radish Seedlings under Low Temperature Stress

[Objective] The research aimed to study the effects of low temperature damage on the activated oxygen metabolism protective enzyme system and the induction of plant cold-tolerance by rare earth lanthanum(La).[Method] With the seedlings of early radish variety Baisgaduanye 13-6 as tested materials,based on determining the content changes of SOD,POD,CAT and common MDA in antioxidation protective enzyme system by the test method of simulated low temperature damage,the alleviating effect of La on radish seedlings were studied under low temperature stress.[Result] With the relative conductivity as index,LaCl3 was screened out,with the optimum concn.of 10 mg/L.Under the low temperature(10 and 5 ℃),MDA content obviously increased,and SOD content first increased and then decreased.With the decrease of stress temperature,the activities of POD and CAT also showed the trend of first increasing and then decreasing.In the process of low temperature stress,it was found that the enzyme activities of SOD,POD and CAT showed the decreasing trend and MDA content was obviously decreased after treatment of adding rare earth La.[Conclusion] Treatments with suitable concn.of rare earth La could induce the radish seedlings to produce resistance to low temperature stress and alleviate the damage of low temperature to radish seedlings.