Genome-wide identification and characterization of UDP-glycosyltransferases gene family in sour jujube (Ziziphus jujuba var. Spinosa)

Semen Ziziphi Spinosa (SZS), the dried mature seed of Ziziphus jujuba var. Spinosa (Bunge) Hu ex H.F. Chou, is a classic traditional Chinese medicine. Flavonoids constitute the predominant secondary metabolites in SZS, demonstrating potent sedative, anxiolytic, and antidepressant activities. UDP- glycosyltransferases (UGTs), the largest glycosyltransferase family in the plants, regulate many metabolic processes including flavonoids by transferring sugar moieties onto various small molecules. However, the UGT family in sour jujube, particularly regarding their response to low-temperature stress and Methyl Jasmonate (MeJA) treatment on a genome-wide scale, remains largely unexplored. The study performed a genome-wide identification of ZjUGT gene family and comprehensively analyzed their physicochemical properties, the phylogenetic relationships, gene structures, chromosomal distributions, syntenic relationships, and tissue-specific expression patterns. A total of 201 members of ZjUGTs gene family were identified in the sour jujube genome. Phylogenetic analysis classified ZjUGTs proteins into 16 subfamilies. The closely linked subfamilies exhibited more similarity in motifs and intron/exon numbers. Numerous cis -elements associated with defense stress and hormone responses were detecded in their promoter regions. Expression analysis revealed distinct expression patterns of ZjUGTs in different organs. Four ZjUGTs were potentially involved in the biosynthesis of active flavonoid in SZS, spinosin. Additionally, ZjUGTs displayed distinct expression patterns following low-temperature and MeJA treatments. This study provides important insights into potential functions of ZjUGTs in sour jujube, advancing our understanding of their role in the regulation of the flavonoid compounds biosynthesis pathway and stress resistance in sour jujube.