Enhanced photo- and antioxidative protection, and hydrogen peroxide accumulation in drought-stressed Cistus clusii and Cistus albidus plants.
Enhanced photo- and antioxidative protection, and hydrogen peroxide accumulation in drought-stressed Cistus clusii and Cistus albidus plants.
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DOI：
10.1093/treephys/23.1.1
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发表时间：
2003
期刊：
影响因子：
4
通讯作者：
S. Munné‐Bosch;T. Jubany-Marí;L. Alegre
中科院分区：
文献类型：
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作者：
S. Munné‐Bosch;T. Jubany-Marí;L. Alegre
研究了岩蔷薇 (Cistus clusii Dunal) 和岩蔷薇 (Cistus albidus L.) 的抗旱机制，这两种原生地中海灌木能够抵御严重的夏季干旱。虽然田间水分亏缺、太阳辐射和温度从冬季到夏季增加，但 C. clusii 和 C. albidus 减少了叶面积，增加了每叶面积的根质量，并且气孔导度表现出昼夜变化，以最大限度地减少水分损失。在这两个物种中，随之而来的二氧化碳同化的减少伴随着光系统II光化学效率的降低，并且通过增强叶黄素循环中紫黄质的脱环氧化以及α-生育酚和β-胡萝卜素的增加来提供对抗应激的保护。此外，在干旱的第一阶段，在两个物种的叶肉细胞壁中都观察到过氧化氢（H2O2）的积累，尽管在研究期间没有在叶绿体或其他细胞器中观察到H2O2的积累。尽管有这些共同的反应，但 C. albidus 和 C. clusii 的光保护和抗氧化保护程度有所不同。为了应对干旱，C. clusii 表现出比 C. albidus 更高的叶黄素循环脱环氧化状态以及更高的 α-生育酚和 β-胡萝卜素浓度。我们得出结论，几种结构和生化机制是 C. clusii 和 C. albidus 抗逆性的基础，并且表明这些灌木具有不同程度的抗逆性。
Mechanisms of drought stress resistance were studied in Cistus clusii Dunal and Cistus albidus L., two native Mediterranean shrubs that can withstand severe summer drought. While water deficit, solar radiation and temperature increased from winter to summer in the field, C. clusii and C. albidus reduced leaf area, increased root mass per leaf area, and showed diurnal changes in stomatal conductance to minimize water loss. In both species, the consequent reductions in CO2 assimilation were accompanied by reduced efficiency of photosystem II photochemistry, and protection against stress was afforded by enhanced de-epoxidation of violaxanthin in the xanthophyll cycle and increases in alpha-tocopherol and beta-carotene. In addition, hydrogen peroxide (H2O2) accumulation was observed in mesophyll cell walls of both species during the first stages of drought, although no accumulation of H2O2 was observed in chloroplasts or other organelles during the study. Despite these common responses, C. albidus and C. clusii differed in the extent of photo- and antioxidative protection. In response to drought, C. clusii showed a higher de-epoxidation state of the xanthophyll cycle and higher alpha-tocopherol and beta-carotene concentrations than C. albidus. We conclude that several structural and biochemical mechanisms underlie stress resistance in C. clusii and C. albidus, and are indicative of the different degrees of stress resistance of these shrubs.