【摘要】 枳幼苗ＳＯＤ活性在细胞内的分布以细胞溶质部分最高，占总活性的８６％左右，而对高温最敏感的则是叶绿体部分的ＳＯＤ。用３０～５５℃一系列温度处理枳幼苗，随着处理温度的提高，先是叶绿体中的ＳＯＤ的活性下降，膜脂过氧化产物ＭＤＡ含量和细胞电解质泄漏率随之大幅度增加，枳幼苗出现热伤害症状。枳幼苗热伤害的相关原因是由于高温胁迫抑制了ＳＯＤ的活性，削弱了对自由基清洗能力和对细胞膜的保护作用，从而加剧了膜脂过氧化作用，导致膜伤害，电解质大量泄漏，最终使枳幼苗表现热伤害症状。更多还原

【Abstract】 The SOD activity in various organelles of P. trifoliata was studied. Approximately 86% of the total SOD activity was present in the cytosol. However, the most sensitive SOD to high temperature stress was found in the chloroplast. After treating by various temperature (30～55℃), the decrease of SOD activity in chloroplast and the rapid enhancement of MDA contents and leakage of electrolytes in cell were observed as temperature increasing. Subsequently, the injury symptoms of P. trifoliata seedlings gradually appeared. The results suggested that the decrease of SOD activity and its scavenging ability of free radicals did participate in the course of high temperature stress on P. trifoliata seedlings, the membrane lipids peroxidation and leakage of electrolytes result from high temperature stress and finally cansed injury sympotome on poncirus seedlings.更多还原