EFFECT OF LA~(3+) ON THE ACTIVITIES OF ANTIOXIDANT ENZYMES IN WHEAT SEEDLINGS UNDER LEAD STRESS

The effects of 0.05mg·l -1La(NO 3) 3 on the activities of catalase(CAT),superoxide dismutase(SOD),the level of malondialdehyde(MDA)under lead stress and its effects on plant growth,chlorophyll content in wheat seedlings were studied after administration at 0,50,100 mg·l -1Pb(NO 3) 3 for 12 days.The plants were grown in nutrient solution in strictly controlled climate growth room.A significant effects of La compare with check groups was evident:the activities of SOD and CAT in root were enhanced 0.45-1.65 times and 32.20-77.77% respectively and MDA content was reduced in root 11.05-27.49% from the 2 nd day after treatments till the end of experiment.The activities of SOD,CAT could be increased slightly but significantly(P0.05)and MDA content be decreased in shoot and root of wheat seedlings by La 3+ under lead stress during 0-5d after treatments compare with check groups.The increased antioxidant enzymes by La(NO 3) 3 enhance the antioxidant potential of the wheat seedlings to reduce lead stress.It can be suggested that La 3+ could remedy lead stress,especially the beginning stress period and the stress was not serius.