Identifying potential sugar metabolism and drought tolerance regulator NtBglu13 by comprehensive analysis of tobacco glycosyl hydrolase family I members

β-glucosidases (Bglus), comprising a diverse group of enzymes abundant in plants and play essential roles in cell wall modification, phytohormone signaling, defense response, secondary metabolism, and resistance to herbivores. However, the function and molecular mechanisms of β-glucosidases belonging to Glycoside Hydrolase family 1 (GH1-Bglus) are still under investigation. Accessible genomic and expression information on the GH1-Bglu family in tobacco remains limited. In this study, 38 GH1- NtBglu s were identified in Nicotiana tabacum and classified into six categories based on evolutionary analysis. Furthermore, gene structure analysis of NtBglu s demonstrated a conserved evolutionary pattern. Ka/Ks analysis indicated that NtBglu s have undergone purifying selection during evolution, and collinearity analysis indicated 26 orthologous gene pairs between tobacco, Arabidopsis thaliana , and Oryza sativa . Additionally, the promoters of NtBglu s contained numerous cis-acting regulatory elements (CREs) associated with plant development, phytohormone signaling, defense and stress responses. Tissue-specific expression profiles and specific responses to cold, drought, cadmium (Cd), and lead (Pb) were also characterized. Notably, overexpression of NtBglu13 enhanced drought tolerance and increased glucose and lignin accumulation, whereas its knockout reduced glucose content and reduced drought resistance. Functional validation through exogenous glucose application confirmed that glucose supplementation helps maintain PSII activity and enhances ROS scavenging, thereby alleviating drought-induced damage. These results provide molecular insights for the targeted engineering of plant metabolic and drought tolerance improving. • Tobacco genome contains 38 NtBglu genes grouped into six subclades. • NtBglus show conserved structure and undergo purifying selection. • Most NtBglus are upregulated by cold/drought but downregulated by Cd/Pb. • NtBglu13 overexpression enhances glucose/lignin accumulation and drought tolerance. • NtBglu13-induced Glucose scavenges ROS to protect PSII.