干旱胁迫对不同衰老型小麦抗氧化酶活性的影响

目的]探讨大田干旱胁迫对小麦抗氧化酶活性的影响。方法]在大田自然干旱条件下以2类衰老型6个小麦品种(系)为试验材料,在小麦灌浆的4个时段测量了旗叶中3种抗氧化酶活力的变化以及MDA含量的变化。结果]在大田自然干旱胁迫影响下,SOD活性会有大幅度的持续升高,到干旱末期,酶活性降低,CAT活性变化对干旱胁迫响应最快,在干旱前期活性即达到最大,之后开始持续下降,在干旱胁迫诱导下,POD活性在干旱胁迫前期活性降低,而在干旱中期活性开始升高,在干旱末期又下降,MDA含量的变化在干旱胁迫下先升高后降低,在干旱末期升高。抗衰老类型的2号、4号小麦及其姊妹系3号小麦与非抗衰老小麦相比,旗叶抗氧化酶活力较高,而旗叶MDA含量较低或持续下降。结论]在大田自然干旱条件下,与其他模拟干旱试验结果不同,抗氧化酶和MDA的变化规律均呈S型变化曲线。

Effects of Drought Stress on the Antioxidant Enzyme Activity of Wheat Varieties with Different Senescence Types

Objective] The aim of this paper was to discuss the effects of drought stress on antioxidant enzyme activity of wheat varieties with different senescence types in field.Method] Six wheat varieties of two senescence types under nature field drought stress were used to study the change tendency of three antioxidant enzymes activities and the MDA contents at four stages during grain filling period.Results] During the field drought stress,the activities of SOD increased continuously and decreased at stage 3 or stage 4;the CAT activities raised fastest,then decreased;POD activities first dropped with the induction of drought stress,then enhanced at stage 3,and dropped to initial level at the end.The change tendency of MDA contents were contrary to the change of the antioxidant enzymes.The enzymes activities of anti-senescence wheat No.2,No.4 and its sister line wheat No.3 were higher than those of normal types,while the MDA contents were lower.Conclusion] The three antioxidant enzymes activities and the MDA contents changed as S type curves under filed drought stress,which was different with the results from other simulated drought stress experiments.