The Roles of RNA Modifications in Regulating Chloroplast Performance and Photosynthesis Efficiency.

The regulation of gene expression is crucial for maintaining cellular activities and responding to environmental stimuli. RNA molecules are central to this regulatory network, influencing transcription, post-transcriptional processing, and translation. Recent advancements have expanded our understanding of RNA modifications beyond the nucleus, highlighting their impact on chloroplast function and photosynthesis efficiency. Chloroplasts, essential for photosynthesis, rely on precise genetic regulation to adapt to environmental changes. RNA modifications, such as methylation and pseudouridylation, are critical in regulating chloroplast RNA stability, processing, and translation. This review summarizes current knowledge of how RNA modifications affect chloroplast function and photosynthesis. It discusses the roles of specific RNA modifications occurring in chloroplast RNA, including N6-methyladenosine (mA), 5-methylcytosine (mC), and pseudouridylation, as well as the enzymes which are known to be involved in these processes. This review also explores extrachloroplastic RNA modifications that influence chloroplast function, emphasizing the importance of mA and mC modifications and their associated enzymes.