Hunseung Kang

CONFLICT OF INTEREST The authors declare no conflict of interest. DATA AVAILABILITY STATEMENT The data that support the findings of this study are available in the supplementary material of this article. Supporting Information Filename Description tpj70637-sup-0001-FigureS1-S8-TableS1-S2.pdfPDF document, 995.1 KB Figure S1. Conserved amino acid sequences and purification of recombinant ECT10 protein. Figure S2. EMSA analysis showing the lack of ECT10 binding to m5C-modified RNA. Figure S3.

CONFLICT OF INTEREST STATEMENT The authors declare no conflict of interest. Supporting Information Filename Description ppl70135-sup-0001-supinfo.pdfPDF document, 809.7 KB Data S1: Supporting Information. REFERENCES , , , & (2009) Arabidopsis MSI1 is required for negative regulation of the response to drought stress. Molecular Plant, 2, 675–687. , , & (2023) FLK is an mRNA m6A reader that regulates floral transition by modulating the stability and splicing of FLC in Arabidopsis.

INTRODUCTION Chemical modifications in RNAs, including mRNA, rRNA, tRNA, microRNA, and long noncoding RNA, have recently been recognized as a potent gene regulatory mechanism in living organisms (Boccaletto et al., 2022; reviewed by Hu et al., 2022; Tang et al., 2023). More than 170 chemical modifications have been identified in RNAs, with N6-methyladenosine (m6A) being the most abundant modification in eukaryotic mRNAs (Boccaletto et al., 2022).