N-acetyltransferase 10 catalyzes RNA N-acetylcytidine to regulate photosynthesis in rice.

N-acetylcytidine (acC) is a novel mRNA modification that enhances RNA stability and translation in mammals and plants. We previously identified acC in Arabidopsis, introduced by two homologs of human N-acetyltransferase 10 (NAT10). While acC influences leaf development in Arabidopsis, its role in rice is unclear. In this study, we identify OsNAT10 as the acC writer in rice. osnat10 mutants show developmental defects, including shorter roots, fewer tillers, and lower yield. Compared with wild type, acC-modified genes are less abundant in osnat10, particularly those related to photosynthesis. Additionally, osnat10 exhibits decreased photosynthetic capacity and reduced RNA stability and translation efficiency of acC target genes, like LIGHT-INDUCED RICE 1 (LIR1). Overexpressing OsLIR1 partially rescues osnat10 defects, underscoring OsNAT10's role in photosynthesis regulation. Our findings highlight acC's crucial function in photosynthesis and plant development, offering insights into epitranscriptomic modifications for crop improvement.