N6-methyladenosine RNA modification regulates photosynthesis during photodamage in plants

Abstract N 6 -methyladenosine (m 6 A) modification of mRNAs affects many biological processes. However, the function of m 6 A in plant photosynthesis remains unknown. Here, we demonstrate that m 6 A modification is crucial for photosynthesis during photodamage caused by high light stress in plants. The m 6 A modification levels of numerous photosynthesis-related transcripts are changed after high light stress. We determine that the Arabidopsis m 6 A writer VIRILIZER (VIR) positively regulates photosynthesis, as its genetic inactivation drastically lowers photosynthetic activity and photosystem protein abundance under high light conditions. The m 6 A levels of numerous photosynthesis-related transcripts decrease in vir mutants, extensively reducing their transcript and translation levels, as revealed by multi-omics analyses. We demonstrate that VIR associates with the transcripts of genes encoding proteins with functions related to photoprotection (such as HHL1 , MPH1 , and STN8 ) and their regulatory proteins (such as regulators of transcript stability and translation), promoting their m 6 A modification and maintaining their stability and translation efficiency. This study thus reveals an important mechanism for m 6 A-dependent maintenance of photosynthetic efficiency in plants under high light stress conditions.