外源腐胺对干旱胁迫下冬小麦幼苗叶片膜脂过氧化的调节效应

Effect of Exogenous Putrescine on Membrane Lipid Peroxidation in Winter Wheat Seedling Leaves under Drought Stress

为了研究外源物质对小麦抗旱性的诱导作用,水培条件下研究了外源腐胺对干旱胁迫(15%PEG-6000)条件下冬小麦幼苗叶片膜脂过氧化及抗氧化酶活性的影响。结果表明,干旱胁迫48 h后冬小麦幼苗叶片含水量下降了27.43%,O2的产生速率、丙二醛(MDA)和H2O2含量随时间的推移均呈增加的趋势,SOD、POD、CAT活性分别下降了23%、37%、70%。外源腐胺处理下叶片含水量仅下降了7.62%;叶片MDA含量降低80%左右,H2O2的含量下降50%左右,O2的产生速率降低了1/3,而叶片SOD、POD、CAT活性分别提高了41%、165.8%、246%。因此认为,外源腐胺可通过抑制活性氧(O2,H2O2)的产生,降低MDA含量,提高抗氧化酶(SOD、POD、CAT)的活性,缓解干旱胁迫造成的冬小麦幼苗叶片细胞膜脂过氧化损伤,提高冬小麦的抗旱性。

In the nutrient solution culture conditions, the effects of exogenous putrescine on membrane lipid peroxidation and antioxidant enzyme activity in wheat seedling leaves were investigated under 15% PEG- 6000 drought stress. The results indicated that at 48 h after drought stress, content of water in wheat seedling leaves decreased by 27. 430%, superoxide （O2-） production rate, MDA and H202 content increased, while the SOD, POD, CAT activities decreased by 23%, 37%, 70%, respectively. Compared with drought stress, content of water in wheat seedling leaves only decreased by 7. 620,/00 in the treatment of 100μmol·L ^-1 putrescine, accumulation of MDA declined about 80%, content of H2O2 declined about 50%,and 02- production rate reduced by 35%; however, SOD,CAT and POD activities increased by 41%, 165.80%, 246% in winter wheat seedling leaves. It indicated that exogenous putrescine alleviate membrane oxidative damage in winter wheat seedlings possible by inhibiting reactive oxygen species （O2- , H2O2） production, decreasing content of MDA and enhancing the antioxidant enzyme （SOD, POD, CAT） activity, to improve drought resistance of winter wheat.