Genome-wide characterization of Solanum tuberosum UGT gene family and functional analysis of StUGT178 in salt tolerance

UDP-glycosyltransferases (UGTs) widely exists in plants and plays an essential role in catalyzing the glycosylation reaction associated with metabolic processes. UGT gene family have been identified in many species to date. However, the comprehensive identification and systematic analysis has not been documented yet in the latest potato genome. In this study, a total of 295 UGT members (StUGT) were identified and unevenly distributed on twelve chromosomes in potato. All StUGT genes were classified into 17 groups (A-P, R) and the UGT genes within same groups have similar structural characterization. Tandem duplication was the major driving force for the StUGT gene expansion. The prediction of cis -acting elements showed that development process, light, phytohormone, and abiotic stress responsive elements generally existed in StUGT promoter regions. Analysis of spatial and temporal expression pattern demonstrated that StUGT genes were widely and differentially expressed in various tissues. Additionally, to investigate the salt stress response genes, we analyzed the expression profiles of StUGT genes under salt treatment. A total of 50 and 20 StUGT genes were continuously up- and down-regulated, respectively, implicating that these genes involved in the regulation of salt resistance. The heterologous expression of StUGT178 promoter and protein in Arabidopsis further demonstrated that StUGT178 gene significantly response to salt treatment, and enhanced salinity resistance by regulating antioxidant enzyme activity and H ₂ O ₂ accumulation. These results provide comprehensive information for better understanding StUGT genes, and offer a foundation for uncovering their function associated with salt stress in potato.