Genome-Wide Identification of the UGT Family Based on the Panax ginseng T2T Genome and Expression Analysis of Glycosylation Modification of Active Ingredients-Related Genes

UDP-glycosyltransferases (UGT) family enzymes are core genes for glycosylation of ginseng active ingredients (including polysaccharides and ginsenosides), transferring activated sugar moieties from nucleotide sugar donors to acceptors of secondary metabolites and polysaccharide intermediates. These active ingredients are widely used for replenishing vital energy and treating tumors but rely on traditional cultivation and extraction, limited by narrow suitable planting areas, long growth cycles, and low resource utilization. Based on the Panax ginseng telomere-to-telomere (T2T) genome, this study identified 167 UGT members via bioinformatics. Most localize to the cell membrane and chloroplasts, with only 4 containing a transmembrane domain. Phylogenetic analysis first revealed the ginseng-specific P-W subgroup; all members harbor 5 conserved motifs and the GT1_Gtf-like conserved domain, distributing unevenly across 24 chromosomes. Thirty-four types of promoter cis-acting elements were predicted, with light-responsive elements being the most abundant. Candidate genes related to polysaccharide synthesis showed regulated expression under salt, low-temperature, heavy metal, and PEG-induced osmotic stress. This study provides key genetic resources for elucidating ginseng polysaccharide biosynthesis, facilitating sustainable resource utilization and modernization of traditional Chinese medicine.