5-azaC处理对低温弱光胁迫下黄瓜幼苗抗氧化酶活性的影响

为了研究5-azaC处理与植物耐冷性机理之间的关系,本实验以黄瓜幼苗为试材,研究了不同浓度5-azaC处理对低温弱光(10℃/6℃,300(μmol/m~2)/s)胁迫下黄瓜幼苗抗氧化酶活性的影响。结果表明:与对照相比,喷施500~800μmol/L的5-azaC处理可以显著降低幼苗叶片内MDA含量(P0.05),在低温24 h时分别降低了19.45%、19.83%,低温48 h时分别降低了12.19%、16.20%;提高SOD、CAT、APX和GR抗氧化酶活性,有效降低了黄瓜幼苗在低温弱光胁迫下活性氧(H_2O_2和O_2~-)的产生和积累;但随着浓度的升高,1000~5000μmol/L的5-azaC处理导致黄瓜叶片膜脂过氧化产生,使抗氧化酶活性显著降低,导致植物产生氧化损伤。

Effect of 5-azacytidine on Antioxidant Systems of Leaves in Cucumber under Low Temperature and Light Intensity

In order to investigate the relationship between cold resistance mechanism of plants and 5-azacytidine treatments,we investigated the activities of antioxidant enzymes in cucumber leaves under low temperature and light intensity （10 ℃/6 ℃,300 （μmol/m2）/s） treated with different concentration of 5-azacytidine.The results showed that MDA contents of cucumber leaves were reduced 19.45%,19.83% treated with 5-azaC of 500 and 800 μmol/L for 24 h,and 12.19%,16.20% at 48 h,respectively, compared with the control.The activities of antioxidant enzymes such as SOD,CAT,APX and GR were increased than control, and production and accumulation of the reactive oxygen （H202 and 02-） were reduced effectively.Whereas,with the increase of coucentration,5-azaC at the content of 1000-5000 μmol/L will led to production of membrane lipid peroxidation in cucumber leaves and reduced the activity of antioxidant enzymes,which resulting in oxidative damage to cucumbers.