Genome-Wide Identification and Analysis of BAHD Acyltransferases Involved in Anthocyanin Biosynthesis in Perilla frutescens.

Perilla frutescens (L.) Britt., a medicinal and edible herb, is valued for its diverse leaf coloration, attributed to varying levels of anthocyanin accumulation. The primary anthocyanins in P. frutescens are acylated cyanidin glycosides; however, the enzymes facilitating the acylation process have yet to be characterized. BAHD acyltransferases, known to catalyze such modifications, remain uncharacterized in P. frutescens. To systematically identify potential genes that may be associated with this function, we performed a comprehensive genome-wide analysis of the BAHD acyltransferase family in P. frutescens. Our study identified 134 PfBAHD genes, which were subsequently analyzed for their physicochemical properties, phylogenetic relationships, conserved domains, motif compositions, and promoter cis-elements. Phylogenetic analysis categorized the PfBAHD genes into six clades, with Clade I being the primary candidate for anthocyanin-related activity due to its enrichment with members known to acylate flavonoids in other species. Promoter analysis indicated a significant presence of cis-elements associated with light, phytohormones, and stress responses. By integrating tissue-specific metabolomic and transcriptomic data, we established correlations between anthocyanin accumulation patterns and PfBAHD gene expression. Through the integration of multi-omics data, six candidate genes were prioritized, with PfBAHD05, PfBAHD77, and PfBAHD112 emerging as the most promising candidates. These genes demonstrated predominant expression in leaves, were induced under conditions of high light exposure, and were predicted to be localized in the cytoplasm. To further explore their potential functions, molecular docking analyses were conducted, suggesting that PfBAHD77 may have a preference for highly glycosylated anthocyanins, whereas PfBAHD05 and PfBAHD112 may favor substrates with lower levels of glycosylation. Collectively, these findings provide a preliminary foundation for understanding anthocyanin acylation in P. frutescens and identify several BAHD candidate genes that could be potentially targeted in future metabolic engineering efforts pending further biochemical and genetic validation.