YGL9 mediates LHC assembly by regulating LHCPs transport and chlorophyll synthesis in rice

作者：Tianquan Zhang, Tianquan Zhang, Wenwen Xiao, Zhongwei Wang, Jichao Zhang, Wenqiang Shen, Ranran Tu, Ruhui Wu, Kai Zhou, Xianchun Sang, Yinghua Ling, Guanghua He, Ting Zhang, Ting Zhang · 发表于：The Plant Journal · 年份：2025 · DOI：10.1111/tpj.17256 · 被引用次数：9 · 研究领域：Photosynthetic Processes and Mechanisms、Plant Stress Responses and Tolerance、Plant Molecular Biology Research

LHC assembly is a fundamental process in forming a peripheral antenna system, which has a significant impact on photosynthesis. However, the molecular mechanism of the LHC assembly still needs to be further investigated in monocotyledonous plants. Here, we identified a bifunctional protein YGL9 in rice, a homolog of cpSRP43 in Arabidopsis, mediates LHC assembly by simultaneously regulating LHCPs transport and chlorophyll synthesis. Mutation of YGL9 exhibits a yellow-green leaf phenotype, with reduced LHCPs contents, impaired photosystem activity and reduced chlorophyll content. YGL9 interacts with cpSRP54 forming the cpSRP complex that transport LHCPs, and YGL9 also interacts with and stabilizes OsGUN4, which is an activator of MgCh and participates in the regulation of chlorophyll synthesis, to synergistically participate in chlorophyll synthesis. Further, genetic evidence demonstrates that YGL9 functions in the same pathway as cpSRP54 and OsGUN4 to regulate LHCPs transport and chlorophyll synthesis. Thus, our study reveals a cross-relationship between LHCPs transport and chlorophyll synthesis, and provides new insights into the LHC assembly process in monocotyledonous plants.