低温胁迫下喜旱莲子草幼苗膜脂过氧化及保护酶活性的变化  

Changes in membrane lipid peroxidation and activities of cell protective enzyme in leaves of Alternanthera philoxeroides seedling under low temperature stress

作　　者：许凯扬[1] 叶万辉[2] 沈浩[2] 李静[2] 

机构地区：[1]长沙理工大学生物食品工程学院,长沙410076 [2]中国科学院华南植物园,广州510650

出　　处：《生态科学》2006年第2期139-142,共4页Ecological Science

基　　金：国家重点基础研究发展规划项目(G2000046803)

摘　　要：分别在2℃和8℃低温胁迫下,对入侵种喜旱莲子草幼苗抗氧化酶活性进行了研究。与常温28℃的结果相比较,MDA含量、细胞膜透性在8℃条件下变化不明显,2℃处理36h后均显著上升。2℃时SOD、CAT和POD活性在较短时间内(12h)显著升高,随后逐渐下降,CAT活性在48h后受到低温胁迫的严重抑制。8℃处理条件下3种保护酶活性在48h内均有显著升高,但升幅明显小于2℃处理的升幅。8℃低温处理不是抑制而是促进了3种保护酶活性的提高。复温结果显示,8℃低温胁迫的喜旱莲子草幼苗和对照无生长差异,2℃低温胁迫下幼苗表现出形态特征差异。The antioxidant enzyme activities in the leaves of Alternanthera philoxeroides seedlings, an alien invasive species, were investigated under 2℃ and 8℃ low temperatures compared with the normal temperature 28℃. The results were as follows As for malondialdehyde （MDA） and membrane permeability, there were only a little changes under 8℃, but they showed significant increases after 36h under 2℃. The activities of cell protective enzymes-superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POD） increased significantly in 12h and then decreased gradually under 2℃. Moreover, CAT activity was inhibited more severely than those of SOD and POD activity after 48h by 2℃ low temperature stress. 3 cell protective enzymes SOD, CAT and POD activity all increased significantly in 48h under 8℃, but they changed less than those under 2℃. It gave us a hint that 8℃ low temperature stress probably could not inhibit, but promote cell protective enzymes activity in 48h for leaves ofA. philoxeroides seedlings. When the seedlings stressed by low temperature were subjected to normal temperature, there were little difference between the seedlings under 8℃ and the seedlings under normal temperature after 10d; however, some morphological differences of the seedlings appeared under 2℃.

关 键 词：喜旱莲子草 低温胁迫 膜脂过氧化 保护酶 

分 类 号：S68[农业科学—观赏园艺]