Table_1_Exogenous Abscisic Acid Mediates Berry Quality Improvement by Altered Endogenous Plant Hormones Level in “Ruiduhongyu” Grapevine.docx

Abscisic acid (ABA) plays a key role in fruit development and ripening in non-climacteric fruit. A variety of metabolites such as sugars, anthocyanins, fatty acids, and several antioxidants, which are regulated by various phytohormones, are important components of fruit quality in grape. Here, grape cultivar “Ruiduhongyu” was used to investigate the relationship between endogenous phytohormones and metabolites associated to grape berry quality under exogenous ABA treatment. 500 mg/L ABA significantly improved the appearance parameters and the content of many metabolites including sugar, anthocyanin, and other compounds. Exogenous ABA also increased the contents of ABA, auxin (IAA), and cytokinins (CTKs), and transcription level of ABA biosynthesis and signaling related genes in fruit. Furthermore, a series of genes involved in biosynthesis and the metabolite pathway of sugars, anthocyanins, and fatty acids were shown to be significantly up-regulated under 500 mg/L ABA treatment. In addition, Pearson correlation analysis demonstrated that there existed relatively strong cooperativities in the ABA/kinetin (KT)-appearance parameters, ABA/IAA/KT-sugars, ABA/indolepopionic acid (IPA)/zeatin riboside (ZR)-anthocyanins, and gibberellin 3 (GA3)/methyl jasmonate (MeJA)-fatty acids, indicating that 13 kinds of endogenous phytohormones induced by ABA had different contributions to the accumulation of quality-related metabolites, while all of them were involved in regulating the overall improvement of grape fruit quality. These results laid a primary foundation for better understanding that exogenous ABA improves fruit quality by mediating the endogenous phytohormones level in grape.

脱落酸（Abscisic acid, ABA）在非呼吸跃变型果实的发育与成熟过程中发挥关键调控作用。糖类、花青素、脂肪酸及多种抗氧化物质等各类代谢物是葡萄果实品质的重要组成成分，其积累受多种植物激素的调控。本研究以葡萄品种‘瑞都红玉’为试材，探究外源脱落酸处理下，葡萄内源植物激素与果实品质相关代谢物之间的关联机制。500 mg/L的外源脱落酸处理可显著改善葡萄果实的外观品质参数，并提升糖类、花青素等多种代谢物的积累含量。外源脱落酸处理还可提升果实内源脱落酸、生长素（auxin, IAA）及细胞分裂素（cytokinins, CTKs）的含量，并上调ABA生物合成与信号通路相关基因的转录水平。此外，500 mg/L脱落酸处理下，参与糖类、花青素及脂肪酸生物合成与代谢通路的一系列基因均显著上调表达。进一步的皮尔逊相关分析显示，脱落酸/激动素（kinetin, KT）与外观品质参数、脱落酸/生长素/激动素与糖类、脱落酸/吲哚丙酸（indolepopionic acid, IPA）/玉米素核苷（zeatin riboside, ZR）与花青素、赤霉素3（GA3）/茉莉酸甲酯（methyl jasmonate, MeJA）与脂肪酸之间均存在较强的协同调控关系，这表明脱落酸诱导产生的13种内源植物激素对品质相关代谢物的积累具有不同的调控贡献，且所有内源激素均参与调控葡萄果实整体品质的提升。本研究结果为深入解析外源脱落酸通过介导葡萄内源植物激素水平提升果实品质的分子机制奠定了重要基础。