Arabidopsis thaliana has been recognized as a chilling tolerant species based on analysis of resistance to low temperature stress, however, the mechanisms involved in this tolerance are not yet clarified. The low temperature-induced effects are exacerbated when plants are exposed to low temperatures in the presence of high light irradiance but the experimental data on the impact of light intensity during cold stress and its influence during recovery from stress are rather limited. The main objective of this study was to re-examine the photosynthetic responses of Arabidopsis thaliana plants to short term (6 days) low temperature stress (12/10°C) under optimal (150 μmol m-2 s-1 ) and high light (500 μmol m-2 s-1 ) intensity and the subsequent recovery from the stress. Simultaneous measurements of the in vivo and in vitro functional performance of both photosystem II (PSII) and photosystem I (PSI), as well as, net photosynthesis, low temperature (77 K) chlorophyll fluorescence and immunoblot analysis of the relative abundance of PSII and PSI reaction center proteins were used to evaluate the role of light in the development of possible protective mechanisms during low temperature stress and the consequent recovery from exposure to low temperature and different light intensities. The results presented clearly suggest that Arabidopsis plants can employ a number of highly dynamic photoprotective strategies depending on the light intensity. These strategies include one based on LHCII quenching and two other quenching mechanisms localised within the PSII and PSI reaction centers, which are all expressed to different extent depending on the severity of the photoinhibitory treatments under low temperature stress conditions. This article is protected by copyright. All rights reserved.

中文翻译：

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拟南芥低温高光动态光保护策略

基于对低温胁迫的抗性分析，拟南芥已被认为是一种耐寒物种，但是，这种耐受性所涉及的机制尚未阐明。当植物在高光辐照度下暴露于低温时，低温诱导的影响会加剧，但关于冷胁迫期间光强度影响及其在胁迫恢复期间影响的实验数据相当有限。本研究的主要目的是重新研究拟南芥植物在最佳（150 μmol m-2 s-1 ）和强光下对短期（6 天）低温胁迫（12/10°C）的光合反应。 (500 μmol m-2 s-1 ) 强度和随后的应力恢复。同时测量光系统 II (PSII) 和光系统 I (PSI) 的体内和体外功能性能，以及净光合作用、低温 (77 K) 叶绿素荧光和 PSII 相对丰度的免疫印迹分析PSI 反应中心蛋白用于评估光在低温胁迫期间可能的保护机制的发展以及随后从暴露于低温和不同光强度中恢复的作用。所呈现的结果清楚地表明，拟南芥植物可以根据光强度采用多种高度动态的光保护策略。这些策略包括一种基于 LHCII 猝灭的策略和另两种位于 PSII 和 PSI 反应中心内的猝灭机制，根据低温胁迫条件下光抑制处理的严重程度，它们都有不同程度的表达。本文受版权保护。版权所有。