摘要
应用砂培和水培法研究了盐渍对两个水稻品种80-85(耐盐)和83-51(不耐盐)幼苗地上部两个内源保护酶的影响。超氧物歧化酶和过氧化氢酶活性均因介质中盐浓度增高及处理时间延长不断下降。但品种间有明显的差异。耐盐品种在0.2％NaCl浓度下影响甚微,0.5％和0.8％浓度下酶活性受抑程度以及丙二醛的积累量都显著低于不耐盐品种。结果表明,水稻地上部Na^+的积累,明显削弱体内某些酶性防护系统,致使体内由活性氧引发的膜脂过氧化作用加剧。水稻品种的耐盐性可能与这类内源保护酶系统受抑程度较小有关。
The effect of salinity on the activities of superoxide dismutase (SOD) and catalase which are known to have a protective role against active oxygen toxicity in plant cells was investigated with two rice varieties, 80-85 (salt-tolerant) and 83-51 (intolerant). The seedlings were cultured with Espino solution containing 0.5% NaCl ( sand culture) and 0.2%, 0.5% or 0.8% NaCl (hydroponic culture) for 0, 5, 10 or 15 days. It was found that both the activities of SOD and catalase decreased markedly with the increase in NaCl concentration in the mediums and the prolonged duration of salinity treatments. A very significant correlation between enzyme activities and malondialdehyde (MDA), a product of membrane lipid peroxidation, was obtained. Similar relationships were observed in the two varieties. However, varietal differences in response to different levels of NaCl were shown by changes in enzyme activities and MDA content. The activities of SOD and catalase in the tolerant variety were affected slightly at 0.2% NaCl. At higher NaCl concentrations (0.5% and 0.8%), the inhibition of the activities of the two protective enzymes and the accompanying increase of MDA in the tolerant variety were less affected than those in the intolerant one. Studies also indicated that lower Na^+ content and higher K^+:Na^+ ratio may play an important role in the difference of tolerance. It is suggested that Na^+ accumulation in the shoot could lead to the decreased SOD and catalase activities, thus lowering the protective role against the active oxygen toxicity which may be regenerated in the plants under saline condition. Presumably, the salt tolerance of rice varieties is related to the inhibitory degree of the enzyme activities responsible for the protective and scavenging system to detoxify the active oxygen.
出处
《江苏农业学报》
CSCD
1990年第2期1-6,共6页
Jiangsu Journal of Agricultural Sciences
基金
国家自然科学基金资助项目
关键词
水稻
耐盐性
超氧物歧化酶
酶活性
Rice
Salt tolerance
Superoxide dismutase
Catalase
Membrane lipid peroxidation
