短期干旱胁迫对黄瓜幼苗叶片抗氧化系统的影响

An antioxidant system in cucumber seedling leaves with short term drought stress

以黄瓜‘津优1号’Cucumis sativus‘Jinyou No.1’为试材,采用水培法,通过在营养液中添加不同比例聚乙二醇PEG 6000模拟干旱胁迫,研究短期干旱胁迫对黄瓜幼苗叶片抗氧化系统的影响。结果显示:在不同程度干旱胁迫下处理24 h后,超氧化物歧化酶(SOD),谷胱甘肽还原酶(GR),脱氢抗坏血酸还原酶(DHAR)和单脱氢抗坏血酸还原酶(MDHAR)活性以及抗坏血酸(ASA)和还原型谷胱甘肽(GSH)质量摩尔浓度均下降,其中超氧化物歧化酶和谷胱甘肽还原酶活性、抗坏血酸和还原性谷胱甘肽GSH质量摩尔浓度与对照比较有显著差异(P<0.05);而过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性、可溶性蛋白质量分数和丙二醛(MDA)质量摩尔浓度在胁迫条件下升高,其中可溶性蛋白和丙二醛质量摩尔浓度增加明显(P<0.05);过氧化物酶(POD)活性则呈现出中度胁迫下显著升高(P<0.05)和重度胁迫下略有下降的趋势。以上表明:短期干旱胁迫引起了黄瓜叶片膜脂过氧化加剧,酶促抗氧化系统比非酶促系统在抗氧化过程中起到了更积极的作用。

To determine the effect of short term drought stress on an antioxidant system in cucumber seedling leaves, the Cucumis sativus ＇Jinyou No. 1＇ seedlings were cultured in a shanqi nutrient solution under drought stress simulated by 5% and 10% PEG 6000. A control, 5% and 10% PEG 6000 with three replications was used to compare superoxide dismutase （SOD）, glutathione reductase （GR）, ascorbate （ASA）, glutathione （GSH）, soluble protein, malondialdehyde （MDA）. Results after 24 h of treatment showed that compared to the control, SOD and GR activities as well as ASA and GSH content significantly decreased （P〈0.05）. However, soluble protein and MDA content significantly increased （P〈0.05）. Thus, short term stress resulted in accel- eration of the membrane lipid peroxidation, and the enzymatic antioxidant system played a more active role in the process of antioxidant. [Ch, 3 fig. 21 ref.]