Physiological impact of mitochondrial alternative oxidase on photosynthesis and growth in Arabidopsis thaliana.
Physiological impact of mitochondrial alternative oxidase on photosynthesis and growth in Arabidopsis thaliana.
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DOI：
10.1111/j.1365-3040.2011.02384.x
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发表时间：
2011-11
期刊：
影响因子：
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通讯作者：
Keisuke Yoshida;C. Watanabe;I. Terashima;K. Noguchi
中科院分区：
文献类型：
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作者：
Keisuke Yoshida;C. Watanabe;I. Terashima;K. Noguchi
线粒体交替氧化酶（AOX）已被认为在光照叶片中具有有益的作用，但其功能尚未完全阐明。在这项研究中，我们研究了AOX 1a基因敲除对拟南芥光合作用和生长在几种光照条件下的影响。AOX缺陷的aox 1a突变体表现出降低的光系统II的运作效率和光系统I周围的循环电子传递（CET-PSI）在高辐射增强的活动。为了进一步解决AOX与CET-PSI的生理关联，我们将aox 1a与CET-PSI活性受损的pgr 5突变体杂交。在pgr 5突变体背景下，AOX缺陷并不影响表观光合效率，表明AOX对光合作用的直接贡献不如CET-PSI那么大。然而，aox 1a pgr 5双突变体的生长显著受损，这取决于生长条件下的光强度。AOX与CET-PSI在支持植物生长方面的协同作用的可能性进行了讨论。
The mitochondrial alternative oxidase (AOX) has been suggested to have a beneficial role in illuminated leaves, but its function has not yet been fully elucidated. In this study, we investigated the effects of a knockout of the AOX1a gene on photosynthesis and growth under several light conditions in Arabidopsis thaliana. The AOX-deficient aox1a mutant showed a lowered operating efficiency of photosystem II and an enhanced activity of cyclic electron transport around photosystem I (CET-PSI) at high irradiance. To further address the physiological association of AOX with CET-PSI, we crossed aox1a with the pgr5 mutant, which is impaired in CET-PSI activity. In the pgr5 mutant background, AOX deficiency did not affect the apparent photosynthetic efficiency, indicating that the direct contribution of AOX to photosynthesis is not so large compared with CET-PSI. Nevertheless, the growth of the aox1a pgr5 double mutant was significantly impaired depending on the light intensity under growth conditions. The possibility of a synergistic function of AOX with CET-PSI in supporting plant growth is discussed.