Crosstalk between RNA mA modification and epigenetic factors in plant gene regulation.

N-methyladenosine (mA) is the most abundant modification observed in eukaryotic mRNAs. Advances in transcriptome-wide mA mapping and sequencing technologies have enabled the identification of several conserved motifs in plants, including the RRACH (R = A/G and H = A/C/U) and UGUAW (W = U or A) motifs. However, the mechanisms underlying deposition of mA marks at specific positions in the conserved motifs of individual transcripts remain to be clarified. Evidence from plant and animal studies suggests that mA writer or eraser components are recruited to specific genomic loci through interactions with particular transcription factors, 5-methylcytosine DNA methylation marks, and histone marks. In addition, recent studies in animal cells have shown that microRNAs play a role in depositing mA marks at specific sites in transcripts through a base-pairing mechanism. mA also affects the biogenesis and function of chromatin-associated regulatory RNAs and long noncoding RNAs. Although we have less of an understanding of the link between mA modification and epigenetic factors in plants than in animals, recent progress in identifying the proteins that interact with mA writer or eraser components has provided insights into the crosstalk between mA modification and epigenetic factors, which plays a crucial role in transcript-specific methylation and regulation of mA in plants.