DROUGHT INDUCES OXIDATIVE STRESS IN PEA-PLANTS
DROUGHT INDUCES OXIDATIVE STRESS IN PEA-PLANTS
复制标题
DOI：
10.1007/bf00197534
复制
发表时间：
1994-08-01
期刊：
影响因子：
4.3
通讯作者：
APARICIOTEJO, P
中科院分区：
文献类型：
--
作者：
MORAN, JF;BECANA, M;APARICIOTEJO, P
豌豆(Pisum sativum L.cv.)在干旱(叶水势约为-1.3 Mpa)下，植株的光合作用(78%)、蒸腾作用(83%)和乙醇酸氧化酶(EC1.1.3.1)活性显著降低(44%)，叶绿素a、类胡萝卜素和可溶性蛋白质含量略有降低(约18%)。水分胁迫还导致过氧化氢酶(EC 1.11.1.6)、脱氢抗坏血酸还原酶(EC 1.8.5.1)和谷胱甘肽还原酶(EC 1.6.4.2)活性显著下降(72~85%)，而非特异性过氧化物酶(EC 1.11.1.7)和超氧化物歧化酶(EC 1.15.1.1)活性增加(32~42%)。抗坏血酸过氧化物酶(EC 1.11.1.11)和单脱氢抗坏血酸还原酶(EC 1.6.5.4)活性仅下降15%，且这两种酶循环清除过氧化氢，而过氧化氢在胁迫下不积累。干旱对叶片中抗坏血酸和氧化谷胱甘肽的含量没有影响，但使还原型谷胱甘肽的含量下降了25%，维生素E的含量增加了67%。叶片中催化铁(即能够催化氧化还原循环产生自由基的铁)的平均浓度估计为0.7~7亩M(水分充足的植物，取决于年龄)和16亩M(水分胁迫植物)，催化铜的平均浓度分别约为4.5亩M和18亩M。在胁迫条件下，叶片中的脂肪和蛋白质的氧化增加了两到三倍，而且这两个过程高度相关。Fenton系统由叶片中据称浓度的抗坏血酸、过氧化氢和催化金属离子组成，产生羟基自由基、过氧化的膜脂和氧化的叶片蛋白质。在体内观察到的氧化损伤是由于水分胁迫期间催化金属水平的增加和分解所致。
Pea (Pisum sativum L. cv. Frilene) plants subjected to drought (leaf water potential of approximate to -1.3 MPa) showed major reductions in photosynthesis (78%), transpiration (83%), and glycolate oxidase (EC 1.1.3.1) activity (44%), and minor reductions (approximate to 18%) in the contents of chlorophyll a, carotenoids, and soluble protein. Water stress also led to pronounced decreases (72-85%) in the activities of catalase (EC 1.11.1.6), dehydroascorbate reductase (EC 1.8.5.1), and glutathione reductase (EC 1.6.4.2), but resulted in the increase (32-42%) of nonspecific peroxidase (EC 1.11.1.7) and superoxide dismutase (EC 1.15.1.1). Ascorbate peroxidase (EC 1.11.1.11) and monodehydroascorbate reductase (EC 1.6.5.4) activities decreased only by 15% and the two enzymes acted in a cyclic manner to remove H2O2, which did not accumulate in stressed leaves. Drought had no effect on the levels of ascorbate and oxidized glutathione in leaves, but caused a 25% decrease in the content of reduced glutathione and a 67% increase in that of vitamin E. In leaves, average concentrations of catalytic Fe, i.e. Fe capable of catalyzing free-radical generation by redox cycling, were estimated as 0.7 to 7 mu M (well-watered plants, depending on age) and 16 mu M (water-stressed plants); those of catalytic Cu were approximate to 4.5 mu M and 18 mu M, respectively. Oxidation of lipids and proteins from leaves was enhanced two- to threefold under stress conditions and both processes were highly correlated. Fenton systems composed of the purported concentrations of ascorbate, H2O2, and catalytic metal ions in leaves produced hydroxyl radicals, peroxidized membrane lipids, and oxidized leaf proteins. It is proposed that augmented levels and decompartmentation of catalytic metals occurring during water stress are responsible for the oxidative damage observed in vivo.