光调控广西毛葡萄酚类物质代谢机理研究

Vitis quinquangularis Rehd. grape is the most important wine grape resource in Guangxi province. The red wine made from Vitis quinquangularis Rehd. grape showed prominent characteristics. However, the wine color of Vitis quinquangularis Rehd. faded quickly in the aging process, and the wine body was sour and hard. The composition and content of phenolic substances in grape berries is an important index to measure the color and taste of wine. The lack of light would significantly inhibit the synthesis and accumulation of phenolic compounds. The insufficient sunlight in growing season was one of the main factors, which lead to the poor quality of Vitis quinquangularis Rehd. wine. At present, there is no study about phenolic metabolism of Vitis quinquangularis Rehd. grapes modulated by sunlight in Guangxi, and improving the wine quality by change of light conditions. The present project will apply diverse light modulated measures to control the light conditions of grapevines: removing leaves around the clusters and laying reflective material. Phenolic variation of Vitis quinquangularis Rehd. grape and wine will be compared by means of RNA-Seq and HPLC-MS, from transcription and metabolite levels respectively, so as to reveal the regulation mechanism of the light on phenolic metabolism of Vitis quinquangularis Rehd. Grape. This study can provide a theoretical basis for the improvement of Vitis quinquangularis Rehd. grape cultivation technology, and has potential application value, which is of great significance to the development of the wine industry in Guangxi.

毛葡萄（Vitis quinquangularis Rehd.）是广西最重要的酿酒葡萄资源，以毛葡萄为原料酿造的红葡萄酒风格特征突出，但酒体酸涩、粗硬，陈酿过程中颜色消退快。葡萄果实的酚类物质决定着葡萄酒的颜色和口感，光照不足会严重抑制酚类化合物合成及累积。而广西毛葡萄的生长季光照严重不足，这是导致毛葡萄酒品质不佳的重要原因之一。目前，运用光调控毛葡萄酚类物质代谢、提升毛葡萄酒品质的研究还未见报道。本项目通过对不同发育期的毛葡萄施行摘除果穗周围叶片和铺设反光材料的方法改变其生长光照条件，利用转录组测序（RNA-Seq）和液相色谱-质谱联用（HPLC-MS）技术分别从转录水平和代谢水平对毛葡萄果实及葡萄酒中酚类物质变化规律进行研究，揭示光照对毛葡萄酚类物质代谢的调控机理。本研究能够为广西毛葡萄栽培技术改进提供理论依据，具有潜在的应用价值，对广西酿酒产业的发展具有重要意义。

毛葡萄（Vitis quinquangularis Rehd.）是广西最重要的酿酒葡萄资源。毛葡萄酒虽然花色苷含量高，但陈酿过程中颜色消退较快，严重影响外观品质，成为制约广西地区高档、优质葡萄酒生产的主要因素。酚类物质是葡萄酒中影响感官品质、决定其风格特征的重要组分。光照不足会严重抑制酚类化合物合成及累积。而广西毛葡萄的生长季光照严重不足对葡萄酒品质产生不利影响。目前，运用光调控毛葡萄酚类物质代谢、提升毛葡萄酒品质的研究鲜有报道。本项目通过对毛葡萄施行摘除果穗周围叶片和铺设反光膜的方法改变其生长光照条件，利用转录组测序（RNA-Seq）和超高性能液相色谱-三重四极杆质谱联用（UPLC-QQQ-MS）技术分别从转录水平和代谢水平对毛葡萄果实中酚类物质变化规律进行研究。研究结果发现，摘叶与铺设反光膜处理均可增强野酿2号果际光照强度，且摘叶处理的效果更明显，其果际的光合有效辐射日均值是对照的6～13倍，太阳总辐射日均值是对照的2～4倍。两种光调控处理均可不同程度降低野酿2号果际的昼夜温差、日最高温度、昼夜湿度差和日最高湿度，同时增加日最低温度和湿度; 降低采收期果实鲜重和可滴定酸含量，增加可溶性固形物含量及果皮色度和红色色调值。铺设反光膜对野酿2号葡萄果实酚类物质代谢路径结构基因表达模式的影响比摘叶处理更大。铺设反光膜处理可能通过上调STS，DFR和UFGT等基因的表达量，促进芪类化合物和花色苷类物质的合成。野酿2号葡萄浆果中的大多数酚酸含量较高，尤其是咖啡酸、水杨酸、阿魏酸和香豆酸。芪类化合物的含量也高于欧亚种和毛欧杂种。对于类黄酮中的黄酮醇，野酿2号的山奈酚和杨梅酮类化合物高于其它品种。本项目的实施揭示了光照对毛葡萄酚类物质代谢的调控机理。为解决广西地方特色葡萄酒颜色稳定性差的难题提供新思路、新方法，同时为进一步充分开发和利用我国东亚种葡萄资源奠定理论基础。