【摘要】 干旱胁迫导致番茄叶片ＲＷＣ、Ｃｈｌ和可溶性蛋白质含量下降，质膜透性和ＡＴＰａｓｅ活性提高．短期干旱胁迫可提高叶片ＳＯＤ和ＣＡＴ活性．４ｄ以内的干旱胁迫后复水，ＲＷＣ、Ｃｈｌ和可溶性蛋白质含量升高，清除活性氧保护酶ＳＯＤ、ＰＯＤ和ＣＡＴ的活性显著提高，抗氧化物质ＡｓＡ和ＧＳＨ的水平得到恢复，ＭＤＡ得到清除，自动氧化速率降低，重新建立了活性氧产生与清除的平衡系统，ＡＴＰａｓｅ活性降低，膜系统的损伤得到修复，透性降低，恢复了原有正常的生理代谢机能．长期干旱胁迫导致叶片清除活性氧的平衡体系受到破坏，ＳＯＤ、ＰＯＤ和ＣＡＴ活性以及ＡｓＡ和ＧＳＨ的含量下降，膜脂过氧化加剧，自动氧化速率提高，ＭＤＡ积累，影响番茄正常代谢，从而加速衰老进程更多还原

【Abstract】 Relative water content (RWC) and the content of chlorophll (Chl) and soluble protein were reduced, and the rate of membrane permeability and ATPase activity increased in leaves of tomato, caused by drought stress. It was found that the activities of superoxide dismutase (SOD) and catalase (CAT) were increased under slight stress of drought. The results indicated that the contents of Chl and soluble protein, RWC and activities of 3 protective enzymes (SOD, CAT and POD) were increased significantly, the contents of AsA and GSH were increased too when watering was recommenced after less than 4 day drought stress, MDA was scavenged and the rate of tissue autoxidation was decreased, i.e. the balance system of activated oxygen being produced and scavenged was re established, the rate of permeability and ATPase activity was reduced, the damage to membrane system was repaired, and normal physiological metabolism was recovered. And the activities of SOD, CAT and peroxidase (POD) and the contents of ascorbic acid (AsA) and glutathione (GSH) were decreased, lipid peroxidation increased, the rate of tissue autoxidation, an indicator of the protective mechanism of tissue, increased greatly and the content of malonaldehyde (MDA) accumulated under severe stress of drought, i.e. the ability to scavenge activated oxygen was decreased significantly, which affected the normal metabolism and accelerated leaf senescence.更多还原