钙对盐胁迫下黄瓜幼苗抗氧化系统的影响

以黄瓜（Cucumis sativus L.）品种‘津春2号’为材料，采用Hogland营养液栽培研究了Ca2+对盐（NaCl）胁迫下黄瓜幼苗体内可溶性蛋白和丙二醛（MDA）含量、超氧阴离子（）产生速率以及超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性的影响。结果表明：盐胁迫处理下，黄瓜幼苗体内可溶性蛋白和MDA含量、产生速率以及抗氧化酶SOD、POD、CAT活性均高于对照；营养液中加入Ca2+（8 mmol • L-1）后，幼苗体内可溶性蛋白含量和SOD、POD、CAT抗氧化酶活性进一步提高，而MDA含量和的产生速率降低；而营养液缺钙处理下幼苗体内MDA和产生速率进一步提高，可溶性蛋白含量和抗氧化酶活性较盐胁迫降低。可见外源Ca2+可通过促进盐胁迫下黄瓜幼苗植株体内抗氧化酶活性的提高，降低膜脂过氧化水平，减缓盐胁迫对植株的伤害，从而增强对盐胁迫的适应性。

Effects of Calcium on Antioxidant Enzymes Activities of Cucumber Seedlings Under Salt Stress

The effects of Ca2+ on the changes of soluble protein，malondialdehyde（MDA）contents，superoxideanion（）production rate，superoxide dismutase（SOD），peroxidase（POD）and catalase（CAT）activities in cucumber（Cucumis sativus L.‘Jinchun 2’）seedlings under 50 mmol &;#8226; L-1 NaCl salt treament was studied. The results showed that the contents of soluble proteins and MDA， production rate，antioxidant enzyme activities were higher in salt stress than control；In salt + Ca2+ treatment，soluble proteins content，SOD，POD and CAT activities increased，while MDA content and  production rate decreased. Under salt stress and salt + Ca2+，the MDA content， production rate raised，while soluble proteins content，SOD，POD and CAT activities declined. The results indicated that Ca2+ could raise the activities of antioxidant enzymes and decrease the membrane lipid peroxidation for cucumber seedlings，which could alleviate the damage of salt stress and improve the salt stress adaptability of cucumber seedlings.