Institute of Basic Biological Problems RAS, Institutskaya st. 2, Pushchino, 142290, Moscow region, Russian Federation; and Corresponding author. Email:
Institute of Basic Biological Problems RAS, Institutskaya st. 2, Pushchino, 142290, Moscow region, Russian Federation.
Funct Plant Biol. 2020 Oct;47(11):959-969. doi: 10.1071/FP19362.
We investigated acclimatory responses of Arabidopsis plants to drought and salinity conditions before the appearance of obvious signs of damage caused by these factors. We detected changes indicating an increase in the reduction level of the chloroplast plastoquinone pool (PQ pool) 5-7 days after introduction of the stress factors. After 10-14 days, a decrease in the size of PSII light harvesting antenna was observed in plants under conditions of drought and salinity. This was confirmed by a decrease in content of PSII antenna proteins and by downregulation of gene expression levels of these proteins under the stress conditions. No changes in values of performance index and maximum quantum yield of PSII were detected. Under drought and salinity, the content of hydrogen peroxide in leaves was higher than in control leaves. Thus, we propose that reduction of the size of PSII antenna represents one of the universal mechanisms of acclimation of higher plants to stress factors and the downsizing already begins to manifest under mild stress conditions. Both the PQ pool reduction state and the hydrogen peroxide content are important factors needed for the observed rearrangement.
我们研究了拟南芥植物在出现明显干旱和盐胁迫损伤迹象之前，对这些因素的适应反应。我们发现，在引入胁迫因素 5-7 天后，指示叶绿体质体醌库（PQ 库）还原水平增加的变化。10-14 天后，在干旱和盐胁迫条件下，观察到 PSII 光捕获天线的大小减小。这通过 PSII 天线蛋白含量的降低以及这些蛋白在胁迫条件下的基因表达水平下调得到证实。未检测到 PSII 性能指数和最大量子产量值的变化。在干旱和盐胁迫下，叶片中的过氧化氢含量高于对照叶片。因此，我们提出 PSII 天线大小的减小代表高等植物对胁迫因子适应的普遍机制之一，在轻度胁迫条件下已经开始表现出这种减小。PQ 库还原状态和过氧化氢含量都是观察到的重排所必需的重要因素。
