RNA-seq profiles of Arabidopsis thaliana wild-type and trm4b-4

Methylation of carbon 5 in cytosine (5-methylcytosine; m5C) is a well-characterized DNA modification, and is also predominantly reported in highly abundant noncoding RNAs, such as rRNA and tRNA, in both prokaryotes and eukaryotes. However, the distribution and biological functions of m5C in plant mRNAs remain largely unknown. Here we develop an m5C RNA immunoprecipitation followed by deep sequencing approach (m5C-RIP-seq) to achieve transcriptome-wide profiling of RNA m5C in Arabidopsis thaliana. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and dot blot analyses reveal a dynamic pattern of m5C mRNA modification in various tissues and at different developmental stages. m5C-RIP-seq analysis identifies 6,045 putative m5C peaks in 4,465 expressed genes in young seedlings. m5C is enriched in coding sequences with two peaks located immediately after start codons and before stop codons, and is associated with mRNAs with low translation activity. We further show that a RNA (cytosine-5)-methyltransferase, tRNA specific methyltransferase 4B (TRM4B), exhibits the m5C mRNA methyltransferase activity. Mutations in TRM4B display defects in root development and decreased m5C levels in root mRNA. Furthermore, TRM4B affects transcript levels of the genes involved in root development, which is positively correlated with their mRNA stability and m5C levels. Our results suggest that m5C in mRNA is a new epitranscriptome marker widely distributed in plant genes, and that regulation of this modification is an integral part of gene regulatory networks underlying plant development. Overall design: RNA-seq in Arabidopsis thaliana (Col-0) wild-type and trm4b-4, two replicates for each sample

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Cui X, Liang Z, Shen L, Zhang Q, Bao S, Geng Y, Zhang B, Leo V, Vardy LA, Lu T, Gu X, Yu H