Transcriptomic analysis of berry development and a corresponding analysis of anthocyanin biosynthesis in teinturier grape

Teinturier cultivars of grape (Vitis vinifera) accumulate anthocyanins in both the skin and pulp of grape berries. RNA-seq and HPLC/MS were used to elucidate the mechanism of anthocyanin biosynthesis in whole grape berries of a new source of teinturier germplasm, ZhongShan-HongYu (ZS-HY). Berries were sampled at 3 days after anthesis (3 DAA, green-pulp), 6 days after anthesis (6 DAA, pulp-veraison), 22 days after anthesis (22 DAA, pulp-half-colored), and at maturity (77 DAA). Results indicated that total anthocyanin levels increased with berry development. The relative content of anthocyanins was different in the pulp vs. skin. Besides, Pelargonidin-3-O-monoglucoside, which unable to be produced in most varieties of Vitis vinifera, was detected in ZS-HY. RNA-seq analysis result that a total of 56 candidate genes, including 30 structural and 26 regulatory genes, were identified that putatively participate in biosynthesis pathway of anthocyanins in ZS-HY. A KEGG analysis indicated that photosynthesis - antenna proteins and photosynthesis, which is significantly enriched in response to light, is proposed to be responsible for the regulation of anthocyanin production in teinturier grapes by light. The present study provides the first transcriptomic analysis of teinturier grapes and provides a foundation for further studies that will assist in the breeding of high-quality teinturier grapes.