Increased photosystem II translation efficiency as an important photoprotective mechanism in an Arabidopsis thaliana ecotype (Tibet-0) adapted to high light environments
Increased photosystem II translation efficiency as an important photoprotective mechanism in an Arabidopsis thaliana ecotype (Tibet-0) adapted to high light environments
复制标题
提高光系统 II 翻译效率，作为适应高光环境的拟南芥生态型 (Tibet-0) 的重要光保护机制
DOI：
10.1016/j.envexpbot.2020.104350
复制
发表时间：
2021-03-01
影响因子：
5.7
通讯作者：
Jin, Hong-Lei
中科院分区：
文献类型：
--
作者：
Zhang, Man;Zhao, Jing;Jin, Hong-Lei
青藏高原是世界上海拔最高、面积最大的年轻高原，具有多种多样的极端环境。由于空气密度低，大气透明度高，QTP阳光充足，光照强度高。光保护机制的进化对于QTP植物适应强光环境具有重要意义。拟南芥（Arabidopsis thaliana）是植物科学和分子生物学研究的重要模式生物。Tibet-0是青藏高原海拔4000 m以上的第一个拟南芥生态型。本文系统分析了西藏0号的光合作用对强光的响应。我们的研究结果表明，西藏-0有更有效的PSII光合活性在连续强光条件下（1000 μ mol光子m（-2）s（-1））相比，哥伦比亚（Col-0）。叶绿素荧光分析表明，西藏0号在强光条件下表现出较高的PSII量子效率（Phi PSII）、光化学猝灭（qP）和电子传递速率（ETR）。而西藏-0的花色苷积累量较低。蓝色Native-PAGE和免疫印迹分析表明，PSII复合物和亚基的丰度显着较高，在西藏-0与Col-0在标准和强光条件下。值得注意的是，PSII核心亚基mRNA psbA，psbB，psbC和psbD与叶绿体核糖体蛋白的关联在Tibet-0中显着更高，基于核糖体新生链复合物（RNC）-定量PCR。此外，强光处理后，西藏0号叶绿体核糖体蛋白相关基因的表达被激活。这些结果表明，增强的光保护能力的西藏-0出现通过组成型更高的翻译效率的PSII蛋白，由于激活的核糖体蛋白表达。因此，这项研究提供了深入了解在高海拔植物高光适应的机制。
The Qinghai-Tibet Plateau (QTP) is the highest and largest young plateau in the world, with a wide variety of extreme environments. Due to the low density of air and high transparency of the atmosphere, QTP has abundant sunshine and high light intensity. It is important for plants in QTP to evolve mechanism of photoprotection to adapt the high-light conditions. Arabidopsis thaliana is an important model organism in plant science and molecular biology. Tibet-0 was the first Arabidopsis thaliana ecotype collected in the QTP, at >4000 m above sea level. Here, we systematically analyzed the photosynthetic responses of Tibet-0 to high light. Our results show that Tibet-0 has more efficient PSII photosynthetic activity under continuous high-light conditions (1000 mu mol photons m(-2) s(-1)) compared to Columbia (Col-0). Chlorophyll fluorescence analysis showed that Tibet0 exhibited enhanced PSII quantum yield (Phi PSII), photochemical quenching (qP), and electron transport rate (ETR) under high-light conditions. However, anthocyanin accumulation was lower in Tibet-0. Blue Native-PAGE and immunoblot analyses showed that the abundances of PSII complexes and subunits were significantly higher in Tibet-0 vs. Col-0 under standard and high-light conditions. Notably, the associations of PSII core subunit mRNAs psbA, psbB, psbC and psbD with chloroplast ribosomal protein were significantly higher in Tibet-0, based on ribosome-nascent chain complex (RNC)-quantitative PCR. Moreover, the expression of amounts of chloroplast ribosomal protein-related genes was activated in Tibet-0 after high-light treatment. These results suggest that the enhanced photoprotection capability of Tibet-0 arises via constitutively higher translation efficiency for PSII proteins due to activated ribosomal protein expression. This study thus provides insight into the mechanism underlying high-light adaptation in plants at high altitudes.