Identification of ANS gene regulating fruit color in jujube (Ziziphus jujuba Mill. cv. Lingwuchangzao) and analysis of its expression under elevated temperature and drought stress.

Background: The anthocyanin synthase (ANS) gene is pivotal in plant anthocyanin biosynthesis, significantly influencing fruit coloration. Despite extensive on various studies, there remains a notable absence of research on the regulatory functions of the ANS gene in the 'Lingwuchangzao' variety under elevated temperature and drought stress.

Results: In this study, 107 ZjANS genes were identified. Analyses of their physicochemical properties and gene structures revealed that most are localized in the cytosol and nucleus, with only seven ZjANS genes exhibiting basic characteristics. All genes contained the conserved domains 2OG-FeII_Oxy and DIOX-N. Chromosomal localization and Ka/Ks analysis indicated that these genes are distributed across 12 chromosomes, with 22 tandem gene pairs, suggesting purifying selection. Phylogenetic and synteny analysis demonstrated that ZjANS genes are evolutionarily conserved, forming collinear gene pairs with four species. Cis-acting element analysis identified elements related to anthocyanin synthesis and environmental stress, such as LTR and MBS. Predictions of protein interaction indicated that certain ZjANS proteins interact with MYB, CHI, and GA proteins, potentially involved in the anthocyanin synthesis pathway. Transcriptome and qRT-PCR analysis revealed that thirteen ZjANS genes positively respond to coloring in jujube under elevated temperature and drought stress, with ZjANS17 identified as particularly significant.

Conclusion: This study identified 107 ZjANS genes and systematically analyzed their evolutionary conservation. Thirteen ZjANS genes were found to positively influence fruit coloring in 'Lingwuchangzao' under elevated temperature and drought stress. These findings provide a foundation for further investigations into ZjANS genes and the breeding new jujube varieties.