高温胁迫对黄瓜幼苗叶片质膜透性及保护酶活性的影响

Influences of High Temperature Stress on Membrane Permeability and Activity of Cell Defence Enzymes in Leaves of Cucumber Seedlings

用耐热性不同的两个黄瓜品种为试材,以昼28℃/夜13℃为对照,研究其在高温胁迫下(昼35℃/夜20℃)细胞膜透性与保护酶活性的变化情况。结果表明,高温胁迫使黄瓜幼苗叶片脯氨酸(Pro)含量积累量、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、电解质渗漏率(EL)、丙二醛(MDA)含量均上升。耐热品种脯氨酸含量积累量、保护酶POD、CAT活性上升幅度大于不耐热品种,而电解质渗漏率、丙二醛含量增幅小于不耐热品种;而保护酶超氧化物歧化酶(SOD)活性呈下降趋势,耐热品种下降程度小于不耐热品种。解除逆境胁迫正常温度恢复2天,两品种各项指标值均有所恢复,且耐热品种恢复程度大于不耐热品种。

Seedlings of two cucumber cultivars were treated with high temperature （CK： day 28℃/night 13℃ ;High temperature stress：day 35℃/night 20℃;）.The results indicated that after being treated with high temperature, Pro content, Peroxidase（POD）activity, Catalase （CAT）activity,contents of Electrolytic leakage and Malondialdehyde （MDA） increased, and the increased degrees of Pro content,POD activity,CAT activity in cuhivar tolerant to high temperature were greater than that of cultivar sensitive to high temperature （Zhongnong No.12）,while increased range of electrolytic leakage and MDA in Jinchun No.4 were lower than that in Zhongnong No.12. At the same time,the superoxide （SOD） activities decreased in leaves of cucumber seedlings with time of high temperature stress,and the decreased degree in Jingchun No.4 is lower. All indexes at high temperature stress could recover to some extent after the plants had been resumed for two days,and the recovering ability in cultivar tolerant to high temperature is stronger than that in cultivarsensitive to high temperature.