Distinct responses of the mitochondrial respiratory chain to long- and short-term high-light environments in Arabidopsis thaliana
Distinct responses of the mitochondrial respiratory chain to long- and short-term high-light environments in Arabidopsis thaliana
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DOI：
10.1111/j.1365-3040.2010.02267.x
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发表时间：
2011-04-01
影响因子：
7.3
通讯作者：
Noguchi, Ko
中科院分区：
文献类型：
--
作者：
Yoshida, Keisuke;Watanabe, Chihiro K.;Noguchi, Ko
为了保证与光合系统的合作功能，线粒体呼吸链需要灵活地适应波动的光环境。非磷酸化替代氧化酶（AOX）是一种显著的呼吸成分，可能在高光（HL）条件下支持细胞氧化还原稳态。在这里，我们报道了呼吸链对长期和短期HL条件的不同适应方式以及AOX在拟南芥叶片中的关键功能。在高光照条件下生长的植物（HL植物）比低光照条件下生长的植物（LL植物）具有更大的泛醌（UQ）库和更高的细胞色素c氧化酶量。这些反应在高低温植物中可能是有效的ATP生产和维持植物快速生长的功能。短期HL胁迫（sHL）下，LL植株的UQ还原水平瞬间升高。在野生型植物中，UQ池被再氧化，同时AOX上调。另一方面，缺乏aox的aox1a突变体的UQ降低水平仍然很高。此外，在这种条件下，aox1a突变体的质体醌池也减少得更多。这些结果表明，AOX在呼吸链对sHL的快速适应中起重要作用，这可能支持有效的光合性能。
In order to ensure the cooperative function with the photosynthetic system, the mitochondrial respiratory chain needs to flexibly acclimate to a fluctuating light environment. The non-phosphorylating alternative oxidase (AOX) is a notable respiratory component that may support a cellular redox homeostasis under high-light (HL) conditions. Here we report the distinct acclimatory manner of the respiratory chain to long- and short-term HL conditions and the crucial function of AOX in Arabidopsis thaliana leaves. Plants grown under HL conditions (HL plants) possessed a larger ubiquinone (UQ) pool and a higher amount of cytochrome c oxidase than plants grown under low light conditions (LL plants). These responses in HL plants may be functional for efficient ATP production and sustain the fast plant growth. When LL plants were exposed to short-term HL stress (sHL), the UQ reduction level was transiently elevated. In the wild-type plant, the UQ pool was re-oxidized concomitantly with an up-regulation of AOX. On the other hand, the UQ reduction level of the AOX-deficient aox1a mutant remained high. Furthermore, the plastoquinone pool was also more reduced in the aox1a mutant under such conditions. These results suggest that AOX plays an important role in rapid acclimation of the respiratory chain to sHL, which may support efficient photosynthetic performance.