盐胁迫及La^(3+)对不同耐盐性水稻根中抗氧化酶及质膜H^+-ATPase的影响  

Effects of Salt Stress and La^(3+) on Antioxidative Enzymes and Plasma Membrane H^+-ATPase in Roots of Two Rice Cultivars with Different Salt Tolerance

作　　者：陈海燕[1] 崔香菊[1] 陈熙[1] 李建友[1] 张炜[1] 

机构地区：[1]南京农业大学生命科学学院生物化学与分子生物学系,江苏南京210095

出　　处：《作物学报》2007年第7期1086-1093,共8页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(30400030);江苏省基础研究计划创新人才项目(BK2004416)

摘　　要：用盐敏感的武运粳8号和强耐盐的韭菜青两个粳稻品种,比较了盐胁迫条件下根中抗氧化酶类和质膜H+-ATPase活性的变化以及La3+对其变化的影响。结果表明,两个品种根中SOD和APX活性无显著区别,但耐盐品种的CAT和POD活性强于盐敏感品种。盐胁迫不同程度地提高了两者抗氧化酶活性。La3+对其影响最显著的差异出现在高盐条件下(200~300mmolL-1NaCl),对耐盐品种添加La3+可以提高上述4种酶的活力,而对盐敏感品种,La3+的作用不明显。对盐敏感品种,盐胁迫导致其质膜H+-ATPase活性持续下降,添加La3+明显提高其H+-ATPase活性,而对耐盐品种,盐胁迫导致其质膜H+-ATPase活性呈现先降后升的趋势,La3+对其活性影响不大。进一步分析表明,上述H+-ATPase活性变化及La3+对其影响均发生在转录水平上。据此推测,以上2个品种可能具有完全不同的盐胁迫响应机制。Plant tolerance to salinity is genetically and physiologically complex. Many mechanisms, such as ion compartmentalization, osmotic regulation and scavenging of reactive oxygen species, have been demonstrated. Among them, anti-oxidative enzymes play an important role in salt tolerant characteristic in plants. In addition, the plasma membrane P-type H^＋-ATPase （EC 3.6.1.3） also involved in the plant response to salinity by regulating the ion homeostasis and so on. Although the relationship between salt stress and anti-oxidative enzymes or PM H^＋ -ATPase has been studied widely, the results varied with the different experimental materials. An interesting shortcut is to comparatively study plants naturally adapted to salt versus their more salt-sensitive relatives. In this report, changes in the activities of antioxidative enzymes and plasma membrane H^＋ -ATPase from root tips are compared between salt-sensitive and salt-tolerant rice cuhivars under NaCl stress, in the presence or absence of La^3＋ . The results indicated that CAT and POD activities, but not SOD and APX activities, were higher in salt-tolerant cultivar than in salt-sensitive one. Under NaCl stress, especially in the range of 200-300 mmol L^- 1 NaCl, external La^3＋ increased the activities of CAT, SOD, APX, and POD in salt-tolerant rice, but not in salt-sensitive cultivar, which suggests that external La^3＋ can lighten the oxidative damage of rice seedling roots, mainly at high salt concentration range. Plasma membrane H^＋ -ATPase activities were suppressed by 30% under NaCl stress in salt-sensitive cultivar, and La^3＋ effectively alleviated such suppression. On the contrary, in salt tolerant cultivar, H^＋ -ATPase activity increased by 32% under NaCl treatment, and La^3＋ had little effect on the activities. Semi-quantitative RT-PCR analysis demonstrated that the changes in PM H^＋ -ATPase activities and La3^＋ effect under salt stress might occur at transcriptional level. Taken together, the data suggested that in salt-sensiti

关 键 词：水稻 盐胁迫 三价镧离子 抗氧化酶 质膜H^+-ATPASE 

分 类 号：S511[农业科学—作物学]