Genome-wide Analysis of Soybean Demethylase Genes

Background DNA methylation is a key epigenetic modification in plants that regulates gene expression, silences transposable elements, and is a contributor to genome stability. Removal of DNA methylation marks by DNA demethylase (dMTase) is critical for transcriptional reprogramming and gene expression activation. Studies on dMTase genes indicate they are important in a variety of processes, including seed development, fruit maturation, and stress response. While dMTase genes have been studied in other plants, few studies have examined the evolutionary relationships and roles of soybean dMTase genes in plant immunity. Results In this study, five dMTase genes were identified in soybean. Phylogenetic analysis of dMTase genes from 20 plant species grouped soybean genes into two of five clades, comprising more than 89 protein sequences. Further examination, with a dN/dS analysis of the soybean paralogs, indicated that one gene was under strong purifying selection. All soybean dMTase genes shared a DNA glycosylase domain, as well as other conserved motifs and structures typical of these genes. In the promoter and UTR region of the genes, identified bound transcriptional factors were associated with development and stress response.