Genome-Wide Identification of m 6 A Writers, Erasers and Readers in Poplar 84K.

N 6 -methyladenosine (m 6 A) RNA modification is a conserved mechanism to regulate gene expression that plays vital roles in the development of plants. However, the m 6 A RNA modification in forest trees remains limited. Here, we performed a complete analysis of m 6 A writers, erasers and readers in Poplar 84K, including gene location, gene structures, conserved motifs, phylogenetic relationships, promoter analysis, expression profiles and the homology modeling. We have identified 61 m 6 A pathway genes in Poplar 84K ( Populus alba × Populus glandulosa ), including 14 m 6 A writers, 14 m 6 A erasers and 33 m 6 A readers. Phylogenetic analysis indicated that the m 6 A writers and erasers were clustered into four groups and m 6 A readers were clustered into two groups. Promoter analysis showed that m 6 A pathway genes were mainly responsive to low oxygen followed by ABA and ethylene. The expression of the identified m 6 A pathway genes showed tissue-specific expression patterns in leaves, xylem, phloem and roots. Moreover, 17 genes were significantly up-regulated and 13 genes were significantly down-regulated in poplar overexpressing the transcription factor LBD15 . Homology modeling and molecular docking results suggested that PagFIP37b was most likely to be regulated by LBD15 , and the qPCRshowed that PagFIP37b were up-regulated in the LBD15-oe plants. The results provide insights that aid in the future elucidation of the functions of these m 6 A pathway genes and the epigenetic regulation mechanism of these genes in Poplar 84K.