乙醇对葡萄果实成熟的调控效应及其生理与分子机制

This project aimed to understand the role and mechanism of ethanol which is a non phytohormone small molecules in regulating the grape fruits ripening. Two major grape Cultivars in Xinjiang (Vitis vinifera L. cv. ‘Redglobe’ and ‘Crimson Seedless’) fruits are selected as material, with applications of ethanol on different period including veraison, pre- veraison, and post-veraison. The effect of ethanol affecting the fruit quality including sugar content, organic acid content, total phenolic content, total tannin content and total anthocyanin content, as well as physiological activities and endogenous hormones content will be determined during the fruit ripening process. In addition, to investigate the signal pathways of ethanol in regulating the ripening of grape fruits, the expression level changes of major anthocyanin-related genes such as CHS and UFGT, ABA biosynthetic and ABA-degradation gene such as NCED1, BG1 and CYP707A, ETH biosynthetic related gene, sucrose and acid metabolism related gene during the fruit ripening process will be compared, with and without the application of ethanol. Combined with fruit physiological maturity analysis and ripening related gene expression analysis, this project reveals the relationship with abscisic acid of ethanol during the fruit ripening process. The proposed project will provide direct evidence for understanding the mechanism of physiology and molecule of ethanol in regulating grape ripening process.

为了研究非激素类小分子物质乙醇调控果实成熟进程的机制，本项目以‘红地球’葡萄（Vitis vinifera L. cv. Muscat Hamburg）和‘克瑞森无核’葡萄（Vitis vinifera L. cv. ‘Crimson Seedless’）为试材，在果实转色期前后进行乙醇处理，对处理后果实生长发育期间相关品质如糖、酸、花色苷、单宁、多酚等物质的累积进程进行系统分析，并探索其对处理后果实成熟相关生理特性及与成熟相关的内源激素水平的影响。此外，通过分析乙醇处理对果实成熟进程中ABA积累关键酶基因VvNCED1、VvBG1，ABA降解酶基因VvCYP707A，乙烯合成关键酶基因、糖酸代谢相关基因以及色素代谢相关基因 CHS、UFGT 的表达水平的影响，进一步揭示其调控葡萄果实成熟进程的信号通道和生理与分子机制。

为了研究非激素类小分子物质调控果实成熟进程的机理，本项目以‘红地球’葡萄和‘克瑞森无核’葡萄为试材，在果实转色期进行乙醇喷施处理，分析果实成熟期间品质特性和成熟相关生理特性及内源激素水平的变化。同时，测定其对ABA积累关键酶基因VvNCED1、VvBG1，ABA降解酶基因VvCYP707A以及色素代谢相关基因 VvCHS、VvUFGT 的表达水平的影响，进面揭示乙醇调控葡萄果实成熟进程的信号通道和作用机制。主要研究结果如下：.1. 15%乙醇中溶入1%氯化钙显著抑制‘红地球’葡萄可溶性固形物含量以及葡萄果皮总酚含量的累积，同时延缓了花青素含量的积累以及叶绿素含量的降低，保持了较高的果皮亮度，显著延缓葡萄果实的成熟和着色进程。.2. 15%乙醇中溶入1%氯化钙显著抑制了‘克瑞森无核’葡萄可滴定酸含量的下降及采收期叶绿素含量的降解和花色苷含量的积累，对果实色泽和可溶性固形物含量无明显影响，延缓了果皮总酚含量的积累；显著增加了果实纵、横径，提高了单果重，保持了果实硬度，提高了果实品质。.3. 乙醇处理延迟了果实ABA含量的峰值期，对照提前启动果实的成熟；各处理种子BR含量与对照比延迟了成熟后期峰值期以及果皮ZR的峰值期，延缓了果实成熟与脱落。GA和ZR含量变化趋势一致，在采收期各激素含量呈下降趋势，直至采收。各处理组显著降低了果肉GA的含量。与对照比，15%乙醇处理提高了种子和果肉内源IAA含量和果皮内源ABA含量，推迟果实的成熟。.4. 高效液相色谱法分析葡萄成熟过程中果皮中花色苷组分及含量的结果表明：‘红地球’葡萄果皮检测出飞燕草素3-O-葡萄糖苷、矢车菊素3-O-葡萄糖苷、牵牛花素3-O-葡萄糖苷、芍药素3-O-葡萄糖苷和锦葵素3-O-葡萄糖苷5种花色苷，其中，锦葵素3-O-葡萄糖苷含量最高，其次是芍药素3-O-葡萄糖苷，乙醇处理有效延缓了果皮花色苷含量的积累。 .5. 基因表达分析表明：在成熟过程中，15%EtOH中溶入1%CaCl2对‘红地球’葡萄果实成熟与着色相关基因VvNCED1、VvBG1、VvCYP707A、VvCHS和VvUFGT基因下调表达，有效延缓了了ABA的合成与花色甘的累积。