Identification of BGLC gene family in watermelon and analysis of its expression pattern under abiotic stresses

β-glucosidase, a key enzyme in plant sugar metabolism, belongs to the glycoside hydrolase family and plays a crucial role in plant defense against abiotic stresses. We conducted a comprehensive genome-wide analysis of the watermelon BGLC gene family, identifying eight ClBGLC genes. The molecular weights of these ClBGLCs ranged from 58.17 to 79.53 kDa, and were classified into three subfamilies. Members within the same subfamily exhibited similar gene structures, with these genes being located across five watermelon chromosomes. Collinearity analysis revealed five homologous gene pairs between watermelon and melon, and two with Arabidopsis. Promoter analysis identified several cis-regulatory elements related to plant growth, hormone responses, and abiotic stress responses in the ClBGLC genes. Expression pattern analysis demonstrated that ClBGLCs were expressed across various watermelon tissues. Furthermore, ClBGLC expression was upregulated under salt, drought, and low-temperature stresses, although expression levels varied markedly among genes in response to different stressors. These findings suggest that BGLC genes play a pivotal regulatory role in plant abiotic stress responses. This study provides a foundational basis for future research on the BGLC gene family's functional roles and response mechanisms under abiotic stress conditions.