Relationship between H2O2 and Changes of Glutathione Reductase Activity and Isoenzyme Pattern Induced by Stress
The changes of H2O2 content,GR activity and isoenzyme pattern were studied by using wild type (Oryza sativa L.cv‘Zhonghua 11',W) and the gain-of-function mutant (M) of rice (co-expressing glutathione-S-transferase (GST,EC.2.5.1.18) and catalase1 (CAT1,EC.1.11.1.6)) treated with multiple abiotic stress.The results showed that the content of H2O2 in W is significantly higher than that in M under all stresses.Three isoenzymes of GR were observed both in W and M under non-stressed conditions,and there was no significant difference between W and M.An extra isoenzyme was induced by cadmium (Cd),PEG-6000 and exogenous H2O2 in W,respectively.However,this band canot be induced in W by combined H2O2 and ascorbate.When subjected to the combined Cd and 3-amino-1,2,4-triazole (a CAT inhibitor),the activities of GR isoenzymes decreased in both W and M,but no GR isoforms were observed in W following Cd together with N,N′-dimethylthiourea (a scavenger of H2O2) application.Moreover,the GR isoenzyme patterns and/or activities with other applied stresses were also significantly different (salt,zinc,heat,heat+salt or Cd or PEG,zinc+Cd) in W and M.The total GR activity consisted with the increased/decreased expression of GR isoenzymes in W and M under all treatments.These results indicated that the variations of GR activity and isoenzymes under single and combined abiotic stresses in rice may be related to the level of H2O2.
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万方数据
维普
