低温胁迫下栾树幼苗衰老与膜脂质过氧化关系

The Relationship of Senescence and Membrane Lipid Peroxidation ofLeaves of Koelreuteria paniculata Under Low Temperatures

栾树幼苗在不同的低温处理下叶片均出现衰老生理反应，并随低温加深和持续时间延长而加速。轻度低温胁迫下植物的应激反应表现在ＳＯＤ，ＣＡＴ活性升高，膜脂过氧化作用下降，抗寒能力增强；深度低温胁迫下膜脂质过氧化产物ＭＤＡ含量升高，细胞膜系统结构和功能发生改变，细胞内电解质外渗量明显增大。结果表明，低温首先引起栾树幼苗衰老，随之增强的膜脂过氧化作用进一步加速了衰老过程。

Treated by different low temperatures leaves of Koelreuteria paniculata seedings appeared senescence reaction which was more quickly as the low temperature lasted longer. Underthe stress of slight low temperature the adapting reaction of the plant were: the activity of SODand CAT was increased; membrane lipid peroxidation was decreased, the ability of low temperature resistance was strengthened. Under serious stress of low temperature the reactions of theplant were; MDA (the product of membrane lipid peroxidation) was increased; the structure andfunction of cell membrane varied; the amount of electrolyte leakage increased obviously. Thisshowed that the senescence of K. paniculata seeding was caused by low temperature first andthen by the membrane lipid peroxidation finally. The process was accelerated by the low temperature further.