Genome-wide characterization and expression analysis of glycoside hydrolase family 1 in Morus alba

BACKGROUND: BGLUs (β-glucosidase) are members of the glycoside hydrolase family 1 (GH1) and play essential roles in plant growth, development, and responses to environmental stresses. Although extensive genome-wide studies of BGLU gene families have been conducted in numerous plant species, the BGLU gene family in Morus alba has not been systematically characterized. RESULTS: In this study, 41 MaBGLU genes were identified from the M. alba genome and their biological characteristics were analyzed using bioinformatics approaches. The MaBGLU proteins exhibited considerable variation in physicochemical properties and were classified into eight mulberry-specific subfamilies based on the Arabidopsis thaliana classification system. Sequence alignment revealed conserved core motifs among MaBGLU proteins, along with broadly similar exon-intron organization. Chromosomal mapping showed that the 41 MaBGLU genes were unevenly distributed across nine chromosomes, with six tandem duplication events involving 30 genes and one segmental duplication detected. Promoter analysis identified numerous cis-acting elements associated with stress and hormone responses. Expression analysis of nine MaBGLU genes under abiotic stress and hormone treatments revealed distinct expression patterns, underscoring the important roles of MaBGLU genes in abiotic stress adaptation and hormone signaling pathways. CONCLUSIONS: This study provides a comprehensive foundation for understanding the functions of β-glucosidases in woody plants and identifies promising candidate genes for stress-tolerance breeding in M. alba.