Chen Hua, Zhang Dongyuan, Guo Jinkui, Wu Hao, Jin Meifang, Lu Qingtao, Lu Congming, Zhang Lixin
Key Laboratory of Arid and Grassland Ecology, School of Life Sciences, Lanzhou University, 730000 Lanzhou, China.
Plant Mol Biol. 2006 Jul;61(4-5):567-75. doi: 10.1007/s11103-006-0031-x.
Psb27 has been identified as a lumenal protein associated with photosystem II (PSII). To gain insight into the function of Psb27, we isolated a mutant Arabidopsis plant with a loss of psb27 function. The quantity of PSII complexes and electron transfer within PSII remained largely unaffected in the psb27 mutant. Our results also showed that under high-light-illumination, PSII activity and the content of the PSII reaction center protein D1 decreased more significantly in the psb27 mutant than in wild-type (WT) plant. Treatment of leaves with a chloroplast protein synthesis inhibitor resulted in similar light-induced PSII inactivation levels and D1 protein degradation rates in the WT and psb27 mutant plants. Recovery of PSII activity after photoinhibition was delayed in the psb27 mutant, suggesting that Psb27 is required for efficient recovery of the photodamaged PSII complex. Overall, these results demonstrated that Psb27 in Arabidopsis is not essential for oxygenic photosynthesis and PSII formation. Instead, our results provide evidence for the involvement of this lumenal protein in the recovery process of PSII.
Psb27已被鉴定为一种与光系统II（PSII）相关的类囊体腔蛋白。为深入了解Psb27的功能，我们分离出了一株psb27功能缺失的拟南芥突变体植株。在psb27突变体中，PSII复合物的数量以及PSII内的电子传递基本未受影响。我们的结果还表明，在高光照射下，psb27突变体中PSII活性和PSII反应中心蛋白D1的含量比野生型（WT）植株下降得更显著。用叶绿体蛋白合成抑制剂处理叶片后，WT和psb27突变体植株中光诱导的PSII失活水平和D1蛋白降解速率相似。psb27突变体在光抑制后PSII活性的恢复延迟，这表明Psb27是光损伤的PSII复合物有效恢复所必需的。总体而言，这些结果表明拟南芥中的Psb27对于放氧光合作用和PSII形成并非必不可少。相反，我们的结果为这种类囊体腔蛋白参与PSII的恢复过程提供了证据。
