高温胁迫对不同黄瓜品种幼苗中抗坏血酸代谢的影响

对高温胁迫条件下黄瓜幼苗叶片中的抗坏血酸以及与之代谢相关物质的含量和酶活性变化进行了研究。结果表明,高温处理1 d,津春4号和农城3号的抗坏血酸总含量均急剧下降,降幅分别为50.8%和37.1%,处理2 d时总谷胱甘肽含量降至最低,降幅分别为36.9%和39.5%,之后逐渐上升,抗坏血酸过氧化物酶（Ascorbic peroxidase,AAP）活性经1 d胁迫后分别增加67.4%和39.6%,抗坏血酸氧化酶（Ascorbic ox-idase,AAO）活性胁迫4 d时分别降低44.0%和35.0%,另外,脱氢抗坏血酸还原酶（DHAR）和单脱氢抗坏血酸还原酶（MDAR）活性也有所增加。抗坏血酸含量与谷胱甘肽含量间呈显著的正相关关系,与AAP及AAO活性之间均呈显著负相关关系。耐高温品种抗坏血酸和谷胱甘肽含量的变化幅度较小,AAP,AAO,MDAR和DHAR等酶活性变化幅度较大。

Effect of High Temperature Stress on the Metabolism of Ascorbic Acid in Cucumber Seedlings

Study on effect of high temperature stress on the content of ascorbic acid and other material and the activity of some enzymes being related to the metabolism of ascorbic acid in cucumber seed- lings. The results showed that the total content of ascorbic acid decreased rapidly in the Jinchun No. 4 and Nongcheng No. 3 seedlings after being handled ld,the range of changing are 50.8% and 37.1%, and the total content of glutathione droped to minimum, the range of reduction is 36.9% and 39.5%, then gradually increased . The range of increasing of AAP activiy is 67.4% and 39.6% after stressing 1 d the range of decreasing of AAO activity is 44.0% and 35.0% after stressing 4 d. Additionally, the activity of DHAR and MDAR also increased. A significant positive correlation was found between the content of ascorbic acid and glutathine,and showed a significant negative correlation between the content of ascorbic acid and the activity of AAP and AAO. For the cultival standing high temperature, the content of ascorbic acid and glutathione decreased less, the activity of AAP, AAO, DHAR and MDAR increase more.