Genome-Wide Identification of the Glycosyl Hydrolase Family 1 Genes in Brassica napus L. and Functional Characterization of BnBGLU77

The β-glucosidases (BGLUs) of Glycoside Hydrolase Family 1 (GH1) exhibit essential functions in plant secondary metabolism and stress responses, mediated by their dual catalytic capabilities in hydrolysis and transglycosylation. This study identified 149 BGLU family members within B. napus (Brassica napus L.), which were systematically categorized into 10 distinct subgroups. Subsequent characterization encompassed detailed examination of their motif composition, chromosomal distribution, gene collinearity, selection pressure, and expression profiling. Transient overexpression of BnBGLU77 in N. benthamiana (Nicotiana benthamiana), combined with untargeted metabolomics analysis, revealed pronounced modulatory effects on the degradation and accumulation of β-glucosidic compounds, suggesting potential roles of the protein encoded by BnBGLU77 in metabolic homeostasis and stress response mechanisms. These experimental results first validated the bidirectional catalytic activity of a BGLU enzyme in B. napus, while simultaneously advancing fundamental understanding of BnBGLU gene functions and providing new insights for developing stress-resistant rapeseed cultivars through targeted genetic improvement.