外源24-表油菜素内酯对低氧胁迫下黄瓜幼苗抗氧化系统及蛋白含量的影响

采用营养液水培,研究了根际低氧胁迫下外源24-表油菜素内酯(24-ep iBR)对2个抗低氧能力不同的黄瓜品种(“绿霸春四号”和“中农八号”)叶和根组织中抗氧化系统及根系中可溶性蛋白和热稳定蛋白含量的影响。结果表明,营养液添加1×10-3m g/L 24-ep iBR能显著提高黄瓜植株叶和根组织抗氧化酶SOD、POD活性,对CAT活性无明显影响,降低了O.2-和M DA含量,同时,根系可溶性蛋白和热稳定蛋白含量显著提高;与抗低氧性较弱的品种“中农八号”相比,24-ep iBR处理对抗低氧性强的品种“绿霸春四号”效果更明显,表明外源24-ep iBR处理通过促进抗氧化酶活性和蛋白含量的提高,降低低氧胁迫下植株体内RO S含量,增强植株低氧逆境的适应能力。

Effect of exogenous 24-epibrassinolide on antioxidant system and protein content in cucumber seedlings under nutrient solution hypoxia stress

The effects of exogenous 24-epibrassinolide(24-epiBR) on time dependent changes of activities of major antioxidant enzymes(superoxide dimutase,SOD;peroxidase,POD;catalase,CAT),lipid peroxidation,soluble protein and heat shock protein(HSP) contents of cucumber Seedlings in hypoxia-resistant cultivar were studied in this paper.Compared to seedlings treated with "hypoxia stress",the activities of SOD and POD increased in both cultivars treated with "hypoxia 24-epiBR".There was no significant difference in CAT activity between the("hypoxia) stress" treatment and "hypoxia 24-epiBR" treatment.Lipid peroxidation level was significantly(increased) in seedlings exposed to hypoxia stress but decreased with exogenous 24-epiBR application.In contrary to seedlings treated with "hypoxia stress",soluble protein and HSP contents were enhanced in seedlings treated with "hypoxia 24-epiBR",and soluble protein contents were higher than those of the control.The results(suggest) oxidative damage that occurs in seedlings under hypoxia-stress conditions is considerably alleviated by (24-epiBR) treatment.