Genome-wide sequence identification and expression analysis of N6-methyladenosine demethylase in sugar beet (Beta vulgaris L.) under salt stress

In eukaryotes, N-6-methyladenosine (m(6)A) is the most abundant and highly conserved RNA modification. In vivo, m(6)A demethylase dynamically regulates the m(6)A level by removing the m(6)A marker where it plays an important role in plant growth, development and response to abiotic stress. The confirmed m(6)A demethylases in Arabidopsis thaliana include ALKBH9B and ALKBH10B, both belonging to the ALKB family. In this study, BvALKB family members were identified in sugar beet genome-wide database, and their conserved domains, gene structures, chromosomal locations, phylogeny, conserved motifs and expression of BvALKB genes were analyzed. Almost all BvALKB proteins contained the conserved domain of 2OG-Fe II-Oxy. Phylogenetic analysis suggested that the ten proteins were clustered into five groups, each of which had similar motifs and gene structures. Three Arabidopsis m(6)A demethylase-homologous proteins (BvALKBH6B, BvALKBH8B and BvALKBH10B) were of particular interest in our study. Expression profile analysis showed that almost all genes were upregulated or down-regulated to varying degrees under salt stress. More specifically, BvALKBH10B homologous to AtALKBH10B was significantly up-regulated, suggesting that the transcriptional activity of this gene is responsive to salt stress. This study provides a theoretical basis for further screening of m(6)A demethylase in sugar beet, and also lays a foundation for studying the role of ALKB family proteins in growth, development and response to salinity stress.