(Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China).
J Integr Plant Biol. 2008 Dec;50(12):1549-56. doi: 10.1111/j.1744-7909.2008.00723.x.
The relationships among desiccation sensitivities of Antiaris toxicaria seeds and axes, changes in activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR) and dehydroascorbate reductase, (DHAR), production rate of superoxide radical (.O(2) (-)), and the contents of hydrogen peroxide (H(2)O(2)) and thiobarbituric acid (TBA)-reactive substance were studied. Desiccation tolerance of seeds and axes decreased with dehydration. Desiccation tolerance of axes was higher than that of seeds, and that of epicotyls was higher than radicles. Activities of SOD, CAT and DHAR of seeds increased during the initial phase of dehydration, and then decreased with further dehydration, whereas activities of APX and GR decreased with dehydration. These five enzyme activities of axes, however, increased during the initial phase of dehydration, and then decreased with further dehydration. The rate of superoxide radical production, and the contents of H(2)O(2) and TBA-reactive products of seeds and axes gradually increased with dehydration. These results show that the A. toxicaria seed is a typical recalcitrant seed. Loss of desiccation tolerance in seeds and axes was correlated with the increase in .O(2) (-) production rate, content of H(2)O(2) and TBA-reactive products, and the decline of antioxidant enzyme activities of seeds and axes.
研究了相思树种子和轴的干燥敏感性之间的关系、超氧化物歧化酶（SOD）、抗坏血酸过氧化物酶（APX）、过氧化氢酶（CAT）、谷胱甘肽还原酶（GR）和脱氢抗坏血酸还原酶（DHAR）活性的变化、超氧自由基（.O(2) (-)）的产生速率以及过氧化氢（H(2)O(2)）和硫代巴比妥酸（TBA）反应物质的含量。种子和轴的干燥耐受性随脱水而降低。轴的干燥耐受性高于种子，上胚轴的干燥耐受性高于胚根。种子 SOD、CAT 和 DHAR 的活性在初始脱水阶段增加，然后随着进一步脱水而降低，而 APX 和 GR 的活性随着脱水而降低。然而，这些五个酶的活性在轴的初始脱水阶段增加，然后随着进一步脱水而降低。种子和轴的超氧自由基产生速率、H(2)O(2)含量和 TBA 反应产物的含量随着脱水逐渐增加。这些结果表明，相思树种子是一种典型的顽拗性种子。种子和轴的干燥耐受性丧失与.O(2) (-)产生速率、H(2)O(2)含量和 TBA 反应产物的增加以及种子和轴抗氧化酶活性的下降有关。
