Ziziphus jujuba var. spinosa Raw sequence reads
Chinese sour jujube (Ziziphus jujuba var. spinosa (Bunge) Hu ex H. F. Chow) is one of woody plant with the same origin of medicine and food. Flavonoid are mainly distributed in its fruits as active ingredient, but the composition and biosynthesis mechanism of flavonoid in different harvest times are still unclear. The accumulation of flavonoids in Chinese sour jujube from five development stages was investigated, using a combined metabolomics and transcriptomics approach in this study. And a total of 1539 differentially accumulated metabolites (DAMs) and 11592 differentially expressed genes (DEGs) were identified. The flavonoid, flavone, and flavonol biosynthtic pathways were significantly enriched in the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs). Furthermore, a comprehensive regulatory network was built for flavonoid biosynthesis and it was discovered that there is one FLS gene, and one NAC transcription factors (TFs) with a high connection with flavonoid biosynthesis by weighted gene co-expression network analysis (WGCNA). This finding was further verified by real-time quantitative polymerase chain reaction (PCR) experiments. This study offered candidate genes involved in flavonoid biosynthesis, information of flavonoid composition and characteristics of flavonoids accumulation, and provided references for the metabolic engineering of flavonoid biosynthesis in Chinese sour jujube.