| The effects of wastewater on the antioxidant system in leaf tissues of cucumber seedlings were studied by culturing with different solutions named waste solution 1(S1),waste solution 2(S2) and waste solution 3(S3),in which the solutes were the necessary nutriments of plants and the solvents were the wastewater from paper mill,the wastewater from chemical fertilizer factory and the mixture of both origins.It was found that after being cultured for 5 days,in the leaf tissues,the activities of APX in S1,APX and SOD in S2,CAT,SOD and APX in S3 were increased (P<0.01 or P<0.05),and the activity of GR in S3 was decreased (P<0.05). After being cultured for 13 days,in the leaf tissues,the activities of APX,SOD,CAT and GR and the content of GSH and ASA were decreased (P<0.01 or P<0.05) in these three kinds of waste solution.At the same time,the contents of H2O2,O·2 and MDA and electrolyte leakage rate in the leaf tissues were increased.The results showed that the three kinds of waste solution were all harmful to the antioxidant system in the leaf tissue of cucumber seedlings.In despite of being given all necessary nutriments,the growth of cucumber seedlings was remarkably inhibited by the waste solutions. |