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

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。

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

To reveal the response mechanism of antioxidant enzymes to drought and rewatering,drought stress was simulated by 10% PEG-6000,and the malondialdehyde(MDA),O-2·contents,antioxidant enzymes including superoxide dismutase(SOD),catalase(CAT),ascorbate peroxidase(APX),peroxidase(POD) were analyzed in Jinda 74(tolerant cultivar) and Jinda 75(non-tolerant cultivar) under drought stress and rewatering.The results indicated that MDA and O-2·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-2· contents to control in Jinda 74 after rewatering showed that rewatering caused compensation effect.Under drought stress,tolerant cultivar can reduce active oxygen damage by keeping the higher SOD activities and the lower decrease extent of APX and CAT.However,it can remove effectively reactive oxygen species and avoid membrane damage by the higher activities of SOD,APX and CAT enzymes and their collaboration.Tolerant soybean cultivar enhanced antioxidant protective ability under drought stress and rewatering.