大豆(Glycine max(L.) Merr.)叶片抗氧化酶对干旱及复水的响应机制

The Response Mechanism of Antioxidant Enzymes to Drought and Rewatering in Soybean(Glycine max (L.) Merr.) Leaves

采用10%PEG-6000模拟干旱胁迫,研究了抗旱品种晋大74与不抗旱品种晋大75两种大豆幼苗在水分胁迫及复水后叶片MDA含量、O2-·含量、SOD、CAT、APX及POD等的活性变化,旨在揭示抗氧化酶对干旱及复水的响应机制。结果表明,在干旱胁迫下,两种大豆叶片MDA及O2-·,含量都高于对照,且晋大75增加幅度显著大于晋大74;复水后晋大74中MDA及O2-·接近于对照水平,表明旱后复水产生了补偿效应。干旱胁迫下,晋大74通过保持较高的SOD活性或较低的APX、CAT降幅以减弱活性氧伤害,而旱后复水过程中晋大74通过维持较高的SOD、APX、CAT酶活性,利用其协同作用有效清除活性氧,避免膜伤害。总之,耐旱品种在干旱及复水过程中具有更强的抗氧化修复能力。

To reveal the response mechanism of antioxidant enzymes to drought and rewatering, drought stress was simulated by 10% PEG-6000, and the malondialdehyde （MDA）, 02 ~ contents, antioxidant enzymes including superoxide dismutase （SOD）, catalase （CAT）, ascorbate peroxidase （APX）, peroxidase （POD） were analyzed in Jinda 74 （toler- ant cultivar） and Jinda 75 （non-tolerant cultivar） under drought stress and rewatering. The results indicated that MDA and 02 ~ contents were higher than the control, and the increase extent of Jinda 75 was higher than that of Jinda 74 under drought stress. Approaching of MDA and O~ ~ contents to control in Jinda 74 after rewatering showed that re- watering caused compensation effect. Under drought stress, tolerant cultivar can reduce active oxygen damage by keep- ing the higher SOD activities and the lower decrease extent of APX and CAT. However, it can remove effectively reac- tive oxygen species and avoid membrane damage by the higher activities of SOD, APX and CAT enzymes and their col- laboration. Tolerant soybean cultivar enhanced antioxidant protective ability under drought stress and rewatering.