A Candidate-Gene Association Study for Berry Colour and Anthocyanin Content in Vitis vinifera L.

Anthocyanin content is a trait of major interest in Vitis vinifera L. These compounds affect grape and wine quality, and have beneficial effects on human health. A candidate-gene approach was used to identify genetic variants associated with anthocyanin content in grape berries. A total of 445 polymorphisms were identified in 5 genes encoding transcription factors and 10 genes involved in either the biosynthetic pathway or transport of anthocyanins. A total of 124 SNPs were selected to examine association with a wide range of phenotypes based on RP-HPLC analysis and visual characterization. The phenotypes were total skin anthocyanin (TSA) concentration but also specific types of anthocyanins and relative abundance. The visual assessment was based on OIV (Organisation Internationale de la Vigne et du Vin) descriptors for berry and skin colour. The genes encoding the transcription factors MYB11, MYBCC and MYCB were significantly associated with TSA concentration. UFGT and MRP were associated with several different types of anthocyanins. Skin and pulp colour were associated with nine genes (MYB11, MYBCC, MYCB, UFGT, MRP, DFR, LDOX, CHI and GST). Pulp colour was associated with a similar group of 11 genes (MYB11, MYBCC, MYCB, MYCA, UFGT, MRP, GST, DFR, LDOX, CHI and CHSA). Statistical interactions were observed between SNPs within the transcription factors MYB11, MYBCC and MYCB. SNPs within LDOX interacted with MYB11 and MYCB, while SNPs within CHI interacted with MYB11 only. Together, these findings suggest the involvement of these genes in anthocyanin content and on the regulation of anthocyanin biosynthesis. This work forms a benchmark for replication and functional studies.

花青素含量是欧洲葡萄（Vitis vinifera L.）的核心性状之一。该类化合物不仅直接影响葡萄与葡萄酒的品质，还对人体健康具有诸多益处。本研究采用候选基因法（candidate-gene approach），旨在筛选与葡萄浆果花青素含量相关的遗传变异。研究人员在5个编码转录因子的基因，以及10个参与花青素生物合成或转运过程的基因中，共鉴定出445处多态性位点。基于反相高效液相色谱（RP-HPLC）分析与色泽视觉表征，研究人员筛选出124个单核苷酸多态性位点（SNPs），以探究其与多种表型的关联。所涉表型指标包括果皮总花青素（Total Skin Anthocyanin，TSA）浓度、特定类型花青素及其相对占比；色泽视觉表征则依据国际葡萄与葡萄酒组织（Organisation Internationale de la Vigne et du Vin，OIV）制定的浆果与果皮色泽描述规范。分析结果显示，编码转录因子MYB11、MYBCC与MYCB的基因与果皮总花青素浓度显著相关；UFGT与MRP基因则与多种不同类型的花青素存在显著关联。果皮与果肉色泽分别与9个基因（MYB11、MYBCC、MYCB、UFGT、MRP、DFR、LDOX、CHI及GST）相关；果肉色泽则与另外11个基因（MYB11、MYBCC、MYCB、MYCA、UFGT、MRP、GST、DFR、LDOX、CHI及CHSA）存在关联。研究还观测到转录因子MYB11、MYBCC与MYCB内部的SNPs之间存在统计学互作效应；LDOX内部的SNPs可与MYB11、MYCB产生互作，而CHI内部的SNPs仅与MYB11存在互作。上述结果表明，这些基因共同参与了花青素含量调控及花青素生物合成途径。本研究可为后续重复验证实验与功能研究提供重要基准参考。