Genome-Wide Identification of the Soybean AlkB Homologue Gene Family and Functional Characterization of GmALKBH10Bs as RNA m6A Demethylases and Expression Patterns under Abiotic Stress

Soybean (<i>Glycine max</i> (L.) Merr) is one of the most important crops worldwide, but its yield is vulnerable to abiotic stresses. In Arabidopsis, the AlkB homologue (ALKBH) family genes plays a crucial role in plant development and stress response. However, the identification and functions of its homologous genes in soybean remain obscured. Here, we identified a total of 22 <i>ALKBH</i> genes in soybean and classified them into seven subfamilies according to phylogenetic analysis. Gene duplication events among the family members and gene structure, conserved domains, and motifs of all candidate genes were analyzed. By comparing the changes in the m⁶A levels on mRNA from hair roots between soybean seedlings harboring the empty vector and those harboring the GmALKBH10B protein, we demonstrated that all four GmALKBH10B proteins are <i>bona fide</i> m⁶A RNA demethylases in vivo. Subcellular localization and expression patterns of the GmALKBH10B revealed that they might be functionally redundant. Furthermore, an analysis of <i>cis</i>-elements coupled with gene expression data demonstrated that <i>GmALKBH10B</i> subfamily genes, including <i>GmALKBH10B1</i>, <i>GmALKBH10B2</i>, <i>GmALKBH10B3</i>, and <i>GmALKBH10B4</i>, are likely involved in the <i>cis</i>-elements' response to various environmental stimuli. In summary, our study is the first to report the genome-wide identification of <i>GmALKBH</i> family genes in soybean and to determine the function of GmALKBH10B proteins as m⁶A RNA demethylases, providing insights into <i>GmALKBH10B</i> genes in response to abiotic stresses.