【摘要】 用20%聚乙二醇(PEG 6000)研究了渗透胁迫对黑麦(Secale cereale L.)幼苗活性氧(reactive oxygen species,ROS)和主要抗氧化酶——超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、抗坏血酸过氧化物酶(ascorbate peroxidase,APX)和谷胱甘肽还原酶(glutathione reductase,GR)活性的影响。结果表明,与对照相比,PEG处理明显提高了叶子和根中丙二醛(malondialdehyde,MDA)的含量、ROS的水平和以上4种抗氧化酶的活性。渗透胁迫下,叶子和根中MDA和ROS水平变化的规律基本相似,但抗氧化酶活性在2种器官中表现不完全相同,叶子中CAT的活性在对照和处理中无显著差异,但在根中差异明显,表明叶子中SOD、APX和GR在植物应答渗透胁迫中起重要作用,而根中这4种抗氧化酶都参与植物对胁迫的反应。GR活性随PEG处理变化幅度显著高于其它抗氧化酶,表明GR在黑麦应答渗透胁迫中所起作用可能强于其它抗氧化酶。更多还原

【Abstract】 Effects of osmotic stress on the production of reactive oxygen species (ROS) and change in activities of the main antioxidant enzymes, inchuding superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and glutathione reduc- tase (GR), in seedlings of Secale cereale L. were investigated with 20% PEG 6000 treatment. Compared with controls, PEG-treated seedlings showed significantly increased level of membrane lipid peroxidation, contents of H2O2 and O2.- , and activities of SOD, APX, CAT and GR. The change pattern of MDA content and ROS level in leaves was similar to that in roots, but the change in antioxidant enzyme activity induced by PEG treatment in leaves and roots differed. CAT activity in roots but not leaves of PEG-treated and control seedlings differed significantly. These results showed that SOD, APX and GR in leaves and in roots may play important roles in S. cereale in response to osmotic stress. In addition, the change in magnitude of GR activity in PEG-treated seedlings was markedly higher than that of other antioxidant enzymes, which suggests that GR may play a more important role in removing ROS than other enzymes in S. cereale.更多还原