PEG6000模拟干旱胁迫对大麦幼苗丙二醛含量及保护酶活性的影响

Effect of Drought Stress Simulated by PEG6000 on Malondialdehyde Content and Activities of Protective Enzymes in Barley Seedlings

【目的】模拟干旱胁迫下对不同大麦品种幼苗丙二醛(MDA)含量以及保护酶活性的影响。【方法】利用PEG6000溶液模拟干旱胁迫,测定了4个大麦品种地上部分及根系中丙二醛含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性变化。【结果】参试大麦品种地上部分及根系中丙二醛含量随干旱胁迫时间的延长均有不同程度增加,地上部分超氧化物歧化酶、过氧化物酶活性随胁迫时间的延长呈先升高后下降趋势,保护酶活性根系中与地上部分存在差异。品种间也存在差异,表现为抗旱品种Tevcel和矮秆早的超氧化物歧化酶和过氧化物酶活性升高较快,进一步胁迫中各酶活性均有不同程度下降,且不抗旱品种广麦7号和Cmebc下降幅度较大。【结论】干旱胁迫下,超氧化物歧化酶、过氧化物酶和过氧化氢酶活性及丙二醛含量变化可作为大麦抗旱筛选的依据。

[Objective] The aim of this paper was to study the effect of drought stress on malondialdehyde content and activities of protective enzymes in barley seedlings. [ Method ] Malondialdehyde contents and the activities of superoxide dismutase, peroxidase, and catalase in shoot and root of 4 barley varieties under drought stress simulated by PEG6000 were determined. [ Result]The malondialdehyde contents in shoot and root of 4 tested varieties increased with the prolongation of drought stress time. The superoxide dismutase and peroxidase activities in shoot rose up firstly and then declined with the prolongation of drought stress time. There were differences between root and shoot protective enzyme activities . The 4 varieties also differed in the activities of superoxide dismutase, peroxidase and catalase. The activities of superoxide dismutase and peroxidase in drought- resistant varieties （Tercel and Aiganzao） increased more quickly than that in drought- sensitive varieties （Guangmai 7 and Cmebe）. The activities of three enzymes decreased with the prolongation of drought stress time. Moreover, the activities of the three enzymes of the drought - sensitive varieties （Guangmai 7 and Cmebe ） decreased sharply. [Conclusion ] Under drought stress, the activities of superoxide dismutase, peroxidase and catalase and malondialdehyde content can be used as the screening indicator in barley drought resistance.