Identification of the UGT Family and Functional Validation of MwUGT2 in Meconopsis wilsonii

Flower color is one of the most ornamental values of <i>Meconopsis wilsonii</i>, but very limited studies have been reported on its flower color formation. The UDP-glycosyltransferase (UGT) gene family plays a crucial role in plant flower color formation. In this study, the full-length transcriptome data of <i>M. wilsonii</i> was used to identify MwUGTs, focusing on protein physicochemical properties' subcellular localization, and phylogenetic relationships. In addition, sequence analysis, expression pattern analysis, subcellular localization, and functional validation of <i>MwUGT2</i> were also performed. A total of 26 MwUGTs were identified in full-length transcriptome and clustered into eight subgroups. Phylogenetic analysis and KEGG database annotation showed that <i>MwUGT2</i> is associated with anthocyanin synthesis and accumulation. Subsequently, based on the expression of <i>MwUGT2</i> during flower development and in different tissues, it was preliminarily determined that MwUGT2 plays a role in the flower bud stage. Subcellular localization assays suggested that <i>MwUGT2</i> is present in the nucleus and cytoplasm. Overexpression in <i>Nicotiana tabacum</i> showed that <i>MwUGT2</i> significantly increased the content of Cyanidin-3-O-glucoside and resulted in dark pink flowers in transgenic plants. In summary, our findings suggest that <i>MwUGT2</i> plays a crucial role in the biosynthesis of anthocyanin and will also contribute to understanding the mechanisms of flower color formation in <i>M. wilsonii</i>.