Genome-wide characterization, evolution and expression profiling of UDP-glycosyltransferase family in pomelo (Citrus grandis) fruit.

Background: Pomelo is one of the three major species of citrus. The fruit accumulates a variety of abundant secondary metabolites that affect the flavor. UDP-glycosyltransferases (UGTs) are involved in the glycosylation of secondary metabolites.

Results: In the present study, we performed a genome-wide analysis of pomelo UGT family, a total of 145 UGTs was identified based on the conserved plant secondary product glycosyltransferase (PSPG) motif. These UGT genes were clustered into 16 major groups through phylogenetic analysis of these genes with other plant UGTs (A-P). Pomelo UGTs were distributed unevenly among the chromosomes. At least 10 intron insertion events were observed in these UGT genome sequences, and I-5 was identified to be the highest conserved one. The expression profile analysis of pomelo UGT genes in different fruit tissues during development and ripening was carried out by RNA-seq.

Conclusions: We identified 145 UGTs in pomelo fruit through transcriptome data and citrus genome database. Our research provides available information on UGTs studies in pomelo, and provides an important research foundation for screening and identification of functional UGT genes.