Genome-Wide Identification, Expression Patterns, and Functional Analysis of UDP Glycosyltransferase Family in Peach (Prunus persica L. Batsch)

Abstract

Peach (<i>Prunus persica</i> L. Batsch) is a commercial grown fruit trees, important because of its essential nutrients and flavor promoting secondary metabolites. The glycosylation processes mediated by UDP-glycosyltransferases (UGTs) play an important role in regulating secondary metabolites availability. Identification and characterization of peach <i>UGTs</i> is therefore a research priority. A total of 168 peach <i>UGT</i> genes that distributed unevenly across chromosomes were identified based on their conserved PSPG motifs. Phylogenetic analysis of these genes with plant UGTs clustered them into 16 groups (A-P). Comparison of the patterns of intron-extron and their positions within genes revealed one highly conserved intron insertion event in peach <i>UGTs</i>. Tissue specificity, temporal expression patterns in peach fruit during development and ripening, and in response to abiotic stress UV-B irradiation was investigated using RNA-seq strategy. The relationship between <i>UGTs</i> transcript levels and concentrations of glycosylated volatiles was examined to select candidates for functional analysis. Heterologous expressing these candidate genes in <i>Escherichia coli</i> identified UGTs that were involved in the <i>in vitro</i> volatile glycosylation. Our results provide an important source for the identification of functional <i>UGT</i> genes to potential manipulate secondary biosynthesis in peach.