Photoprotection processes under water stress and recovery in Mediterranean plants with different growth forms and leaf habits
Photoprotection processes under water stress and recovery in Mediterranean plants with different growth forms and leaf habits
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DOI：
10.1111/j.1399-3054.2007.00919.x
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发表时间：
2007-08-01
影响因子：
6.4
通讯作者：
Flexas, Jaume
中科院分区：
文献类型：
--
作者：
Galmes, Jeroni;Abadia, Anunciacion;Flexas, Jaume
光保护机制的响应，以短期的水分胁迫期间，然后复水，模拟常见的情节水胁迫期间发生在地中海地区，进行了研究，在10个盆栽植物代表不同的生长形式和叶的习惯。在水分胁迫和恢复过程中，测定了相对含水量、气孔导度、叶片色素组成、电子传递速率、PSII光化学最大量子效率（F-v/F-m）、热能耗散和光呼吸速率（P-r）。所有分析的物种被证明是强烈的抵抗PSII的光失活下施加的水分胁迫条件下。分析参数的响应没有很大的不同物种之间，这表明地中海植物有类似的需要和能力，无论他们的生长形式和叶的习惯，在情节水胁迫期间的光保护。一般模式的光保护出现，包括在维持或增加的P-r在温和的压力和增加的热能耗散在更严重的压力。色素池大小的调整是不是一个重要的短期响应水分胁迫。由于水分胁迫的热能耗散的增加主要取决于叶黄素的脱环氧化状态，尽管这种关系的斜率和动力学在物种之间存在很大差异，这表明脱环氧化叶黄素的物种依赖性的额外作用。此外，在黎明前在水分胁迫过程中，F-V/F-M的小幅度下降与维持脱环氧化的叶黄素循环密切相关，这表明一种形式的叶黄素依赖的持续光保护开发在短期水分胁迫不仅在万年青，但也在半落叶和一年生植物。
The response of photoprotection mechanisms to a short-term water stress period followed by rewatering, to simulate common episodic water stress periods occurring in Mediterranean areas, was studied in 10 potted plants representative of different growth forms and leaf habits. During water stress and recovery, relative water content, stomatal conductance, leaf pigment composition, electron transport rates, maximum quantum efficiency of PSII photochemistry (F-v/F-m), thermal energy dissipation and photorespiration rates (P-r) were determined. All the species analyzed proved to be strongly resistant to photoinactivation of PSII under the imposed water stress conditions. The responses of the analyzed parameters did not differ largely among species, suggesting that Mediterranean plants have similar needs and capacity for photoprotection under episodic water stress periods regardless of their growth form and leaf habit. A general pattern of photoprotection emerged, consisting in maintenance or increase of P-r at mild stress and the increase of the thermal energy dissipation at more severe stress. Adjustments in pigment pool sizes were not an important short-term response to water stress. The increase of thermal energy dissipation because of water stress depended mostly on the de-epoxidation state of xanthophylls, although the slope and kinetics of such relationship strongly differed among species, suggesting species-dependent additional roles of de-epoxidated xanthophylls. Also, small decreases in F-v/F-m at predawn during water stress were strongly correlated with maintained de-epoxidation of the xanthophylls cycle, suggesting that a form of xanthophyll-dependent sustained photoprotection was developed during short-term water stress not only in evergreen but also in semideciduous and annual species.