The essential photoprotective role of proton gradient regulation 5 (PGR5)-dependent cyclic electron flow (CEF) has been reported in , rice, and algae. However, its functional assessment has not been performed in tomato yet. In this study, we focused on elucidate the function of and in tomato. We performed RNA interference and found that -suppressed transformants exhibited extremely low CO assimilation capacity, their photosystem I (PSI) and PSII were severely photoinhibited and chloroplasts were obviously damaged. The -suppressed plants almost completely inhibited CEF and Y(ND), and PSII photoinhibition may be directly related to the inability to produce sufficient proton motive force to induce NPQ. The transgenic plants overexpressing and driven by 35S promoter capable alleviate photoinhibition of plants under low night temperature. The transcriptomic and proteomic analyses suggested that the nuclear gene transcription and turnover of chloroplast proteins, including the plastoglobule-related proteins, were closely related to SlPGR5/SlPGRL1 pathway dependent CEF. The bridge relationship between CEF and chloroplast quality maintenance was a novel report to our knowledge. In conclusion, these results revealed the regulatory mechanism of the SlPGR5/SlPGRL1 pathway in photoprotection and maintenance of chloroplast function in tomato, which is crucial for reduce yield loss, especially under adverse environmental conditions.

中文翻译：

---

SlPGR5/SlPGRL1途径依赖性循环电子传递调节番茄植株的光保护和叶绿体质量


质子梯度调节 5 (PGR5) 依赖的循环电子流 (CEF) 在水稻和藻类中具有重要的光保护作用。然而，其功能评估尚未在番茄中进行。在这项研究中，我们重点阐明番茄的功能。我们进行RNA干扰，发现β-抑制的转化子表现出极低的CO同化能力，其光系统I（PSI）和PSII受到严重的光抑制，叶绿体明显受损。抑制的植物几乎完全抑制了CEF和Y(ND)，PSII光抑制可能与无法产生足够的质子动力来诱导NPQ直接相关。过表达35S启动子驱动的转基因植物能够减轻夜间低温下植物的光抑制。转录组和蛋白质组分析表明，叶绿体蛋白（包括质体球相关蛋白）的核基因转录和更新与SlPGR5/SlPGRL1通路依赖的CEF密切相关。据我们所知，CEF 和叶绿体质量维护之间的桥梁关系是一份新颖的报告。总之，这些结果揭示了SlPGR5/SlPGRL1途径在番茄光保护和维持叶绿体功能中的调节机制，这对于减少产量损失至关重要，特别是在不利的环境条件下。