Richer in diglucosides without acylation: a metabolite-transcriptome dissection of the anthocyanin chemotype in Vitis amurensis and its hybrids with V. vinifera.

Vitis amurensis Rupr. is a wild grape species of the East Asian Vitis populations with remarkable cold tolerance and disease resistance, demonstrating promising potential for application. In the study, anthocyanins and flavonols were analyzed in five V. amurensis cultivars and three interspecific hybrids with V. vinifera across different developmental stages. Additionally, transcriptome analyses were performed on V. amurensis 'Shuangfeng' and the hybrid 'Beibinghong' to explore the transcriptional regulatory mechanisms underlying anthocyanin biosynthesis. Compared with the interspecific hybrids, V. amurensis accumulated higher total anthocyanin levels and a greater proportion of diglucoside anthocyanins (accounting for more than 75% of total anthocyanins), but lacked acylated anthocyanins. Transcriptomic analysis identified a shared regulatory network associated with anthocyanin accumulation in both of the two cultivars, involving structural genes and transcription factors, including VviUFGT1, VviLAR2, VviMYB14, etc. Additionally, differentially expressed genes associated with cultivar-specific anthocyanin accumulation were identified, and their coordinated regulation contributed to the differences in anthocyanin accumulation between the two cultivars. This study revealed anthocyanin diversity and regulatory networks in V. amurensis grapes, providing insights for grape quality improvement, molecular breeding, and germplasm utilization.