PetM Is Essential for the Stabilization and Function of the Cytochrome b6f Complex in Arabidopsis
PetM Is Essential for the Stabilization and Function of the Cytochrome b6f Complex in Arabidopsis
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PetM 对于拟南芥细胞色素 b6f 复合物的稳定和功能至关重要
DOI：
10.1093/pcp/pcab116
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发表时间：
2021-07-26
影响因子：
4.9
通讯作者：
Mi, Hualing
中科院分区：
文献类型：
--
作者：
Lan, Yixin;Chen, Qi;Mi, Hualing
细胞色素B（6）f（cyt B（6）f）是光合作用中光系统I和光系统II之间电子传递的一个共同连接体。PetM是cyt B（6）f复合物的8个亚基之一，是一个位于外周的疏水性小亚基，其在高等植物中的作用机制尚不清楚。在这项工作中，我们发现，与集胞藻PCC 6803中的PetM突变体不同，拟南芥PetM突变体表现出与拟南芥PetC突变体相似的白化表型，具有淡黄色的叶片，光合电子传递受阻和光自养丧失。虽然PetM在高等植物和蓝藻之间相对保守，但集胞藻PetM不能拯救拟南芥中PetM敲除的表型。我们提供的证据表明，集胞藻PetM没有稳定地结合到拟南芥cyt B（6）f复合物。基于这些结果，我们认为PetM是拟南芥维持cyt B（6）f复合物功能所必需的，可能是通过其与核心亚基的紧密连接形成一个紧密的“栅栏”，稳定复合物的核心。
The cytochrome b(6)f (cyt b(6)f) acts as a common linker of electron transport between photosystems I and II in oxygenic photosynthesis. PetM, one of eight subunits of the cyt b(6)f complex, is a small hydrophobic subunit at the outside periphery, the functional mechanism of which remains to be elucidated in higher plants. In this work, we found that unlike the PetM mutant in Synechocystis sp. PCC 6803, the Arabidopsis thaliana PetM mutant showed a bleached phenotype with yellowish leaves, block of photosynthetic electron transport and loss of photo-autotrophy, similar to the Arabidopsis PetC mutant. Although PetM is relatively conserved between higher plants and cyanobacteria, Synechocystis PetM could not rescue the PetM-knockout phenotype in Arabidopsis. We provide evidence that the Synechocystis PetM did not stably bind to the Arabidopsis cyt b(6)f complex. Based on these results, we suggest that PetM is required by Arabidopsis to maintain the function of the cyt b(6)f complex, likely through its close link with core subunits to form a tight 'fence' that stabilizes the core of the complex.