【作者】 曹慧； 兰彦平； 刘会超； 王孝威； 王中英；

【Author】 CaoHui, Lan Yanping, Liu Huichao, Wang Xiaowei,Wang Zhongying (Dept. of Hort.. ShanXi Agri.Univ..TaiGu030801)

【机构】 山西农业大学园艺系； 河南职业技术师范学院；

【摘要】 以短枝型新红星幼树盆栽苗为试材,研究了水分胁迫对短枝型果树叶片活性氧代谢的影响。结果表明:(1)不同程度水分胁迫均使叶片内O2-.产生速率增加,细胞质膜相对透性增大,膜脂过氧化产物MDA含量增多。且增加幅度:重度>中度胁迫>轻度胁迫。经方差分析表明:轻度水分胁迫与对照之间的差异不显著;中度、重度胁迫与对照之间的差异达显著水平。(2)不同程度水分胁迫使叶片内SOD、CAT活性在水分胁迫前期比对照均有不同程度的提高,且增加幅度:重度胁迫>中度胁迫>轻度胁迫。这表明水分胁迫前期SOD、CAT活性的增加,是适应水分胁迫条件下O2-.、H2O2等增多,保护体内活性氧积累与清除系统平衡的一种适应性调节,以减轻O2-.增加所引起的细胞伤害。随着胁迫时间的延长, SOD、CAT活性大幅度下降,且下降幅度:重度胁迫>中度胁迫>轻度胁迫。轻度、中度胁迫虽下降, 但仍高于对照水平;而重度胁迫低于对照水平。因此水分胁迫下造成O2-.的过量生成超过了防御系统的清除能力,从而造成O2-.累积,膜脂过氧化加剧, 导致膜系统损伤。(3)水分胁迫下苹果叶片O2-.产生速率与细胞质膜相对透性增大、MDA含量之间呈显著正相关。这说明随着O2-.产生的增多,质膜相对透性增大,膜脂过氧化加剧, MDA含量增多, 这就意味着水分胁迫引起的膜伤害可能是由于活性氧的累积所造成的。更多还原

【Abstract】 Effects of water stress in soil on active oxygen metabolism of spur-apple young leaves were studied under pot cultivation in 1996-1998. The results showed that: under different water stress conditions, generation rate of the superoxide free radical, the malondialdehyde content, the membrane permeability increased. The range was mild water stress, moderate water stress, severe water stress. Meanwhile, there was no significant difference between mild water stress and CK; there was significant difference between moderate, severe water stress and CK. The superoxide dismutase activity, the catalase activity increased during the early period, the range was mild, moderate, severe, water stress. The protective enzyme system (SOD. CAT) can inhibit the accumulation of active oxygen and lessen membrane damage, the activity levels of SOD and CAT corresponded to the change in O2-. with the duration of water stress, the activity of SOD, CAT decreased, the excessive accumulation of O2-. is due to the reduced SOD, CAT activity. There was a positive correlation between increment of MDA content, the membrane permeability and the generation rate of O2-.. The present findings suggest that membrane lipid peroxidation is due to the excessive accumulation of the O2-..更多还原