Objective To systematically analyze the composition, structural characteristics of the UDP-glucosyltransferase (UGT) gene family in Polygonum cuspidatum, investigate its expression patterns across different root tissues, as well as its potential roles in the glycosylation of resveratrol and emodin, so as to provides a theoretical foundation for elucidating the biosynthetic mechanisms of active metabolites. Methods The UGT gene family of P. cuspidatum was identified at the genome-wide level based on transcriptome and genomic datasets. Analyses of physicochemical properties, chromosomal localization, gene structure, conserved motifs and cis-regulatory elements were then performed. The evolutionary characteristics were analyzed through phylogenetic reconstruction, gene duplication analysis and protein interaction network prediction. Correlation analysis integrating transcriptomic and metabolomic data was conducted, and six representative genes potentially involved in the glycosylation of resveratrol and emodin were selected for validation using qRT-PCR. Results A total of 178 UGT genes were identified and grouped into 14 subfamilies, exhibiting substantial structural and functional diversity. The gene family members were unevenly distributed in chromosomes, and several genes were likely generated through tandem or segmental duplication events. Promoter analysis revealed that cis-acting elements were predominantly associated with stress and hormone responses, as well as developmental regulation. Expression correlation heatmaps indicated that genes such as PcUGT065 and PcUGT130 showed strong correlation with resveratrol, emodin, and their glycosylated derivatives. The qRT-PCR results further confirmed the reliability of transcriptome-based expression patterns. Conclusion The UGT gene family in P. cuspidatum exhibits clear structural conservation along with distinct expression divergence. Several members may participate in the modification of resveratrol and emodin. This study provides a theoretical basis for future investigations into the biosynthetic mechanisms of active metabolites in P. cuspidatum and offers insights for its molecular breeding.

Polygonum cuspidatum Sieb. et Zucc.  /  UGT gene family  /  bioinformatics analysis  /  member identification  /  expression analysis  /  resveratrol  /  emodin