Integrative Analysis of Transcriptome and Metabolome Reveals the Regulatory Network Governing Aroma Formation in Grape

The aroma metabolites in grape berries have received attention in recent years, but a global analysis of gene-regulated metabolites is still lacking. In this study, three grape cultivars, "Kyoho", "Adenauer Rose", and "Mei Xiangbao", were used to determine the differential accumulation of metabolites and identify candidate genes related to grape berry aroma. A total of 27,228 genes were detected from the transcriptome, and 128 differentially accumulated metabolites (DAMs) were identified. Terpenoids and ester were the major substances in these three cultivars. KEGG enrichment showed that 12, 8, and 5 compounds were significantly enriched during the maturation process of these three grape cultivars, with most being terpenoids. A combined transcriptome and metabolome analysis found that the associated genes and metabolites were enriched in the following pathways: "Glycine, serine, and threonine metabolism", "Cysteine and methionine metabolism", "Tyrosine metabolism", "Phenylalanine metabolism", and "Phenylalanine, tyrosine, and tryptophan biosynthesis". Seven structural genes (VvOMR1, VvGLYK, VvLPD2, VvAK2, VvSHM7, VvASP3, and VvASP1) and four transcription factors (VvERF053, VvERF4, VvMYB46, and VvMYB340) related to grape berry aroma accumulation were discovered. Our findings provide new insights into grape aroma formation and regulatory mechanism research, and the results will be beneficial for grape aroma breeding in the future.