干旱胁迫下小麦叶片微粒体活性氧自由基的产生及其对膜的伤害

从不同干旱胁迫时间下的小麦(Triticum aestivum L.)叶片中提取微粒体膜,测定活性氧自由基变化和膜伤害程度。结果表明,随着干旱胁迫时间的延长发生以下变化:(1)O_2~-和H_2O_2的产生速率在一定时间内逐渐加快然后下降;(2)膜脂过氧化产物丙二醛(MDA)的含量逐渐增加;(3)微粒体膜上的SOD活性逐渐下降;(4)—SH基的含量在一定时间内逐渐增多以后下降;(5)与膜伤害程度有关的生理指标如根系电导率、叶片水势及其含水量等均有变化。

GENERATION OF ACTIVE OXYGEN FREE RADICALS AND ITS INJURY TO MICROSOME MEMBRANES IN WHEAT LEAVES UNDER DROUGHT STRESS

The microsome membrane of wheat ( Tritkum aestivum L.) leaves under different time of drought stress was purified to detennine the active oxygen free radicals generated and their severity of injury to the membrane. During the drought stress the rate of O2- and H2O2 generation increased for a certain time and then decreased. The concentration of MDA increased continuously. The activity of SOD decreased gradually. The concentration of --SH group and MDA increased from the beginning until the 36th hour under drought stress, thereafter MDA content continued to increase while the --SH content decreased. Several physiological indexes related to membrane injury, such as root electroconductivity,leaf water potential and water content were all affected accordingly.