Skin Browning and Expression of PPO, STS, and CHS Genes in the Grape Berries of ‘Shine Muscat’
Skin Browning and Expression of PPO, STS, and CHS Genes in the Grape Berries of ‘Shine Muscat’
复制标题
‘阳光麝香’葡萄浆果的皮肤褐变和 PPO、STS 和 CHS 基因的表达
DOI：
--
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
T. Esumi
中科院分区：
文献类型：
--
作者：
Yuka Suehiro;K. Mochida;H. Itamura;T. Esumi
最近在日本流行的黄绿皮鲜食葡萄，'闪耀麝香'（葡萄属labruscana Bailey × V. vinifera L.），存在浆果表皮布朗宁的问题，褐变发生在收获前的成熟阶段。微小的红棕色斑点出现在浆果的表面，大大降低了葡萄的市场价值。虽然布朗宁的机制和因素是未知的，我们假设多酚化合物和它们的氧化反应的参与。本研究分析了果实成熟过程中多酚氧化酶（PPO）、二苯乙烯合成酶（STS）和查尔酮合成酶（CHS）等多酚代谢关键酶基因的表达，探讨了布朗宁的分子基础。一串玫瑰香果实从盛花后80 d开始出现果皮布朗宁，之后果皮布朗宁变的果实数量增多，褐变区域随着成熟向果实表面扩展。VvPPO 2、VvSTS B型和VvCHS 1表达的增加与布朗宁相关，反式白藜芦醇含量在布朗宁皮肤中也增加，表明酚类化合物的生物合成和代谢途径在布朗宁时被激活。在VvPPO基因方面，与VvPPO 1基因相比，观察到VvPPO 2表达的特异性上调。VvPPO 2的启动子序列比VvPPO 1含有更多的Myb结合基序和W-box基序。VvPPO 2基因表达的特异性上调将在理解和控制“玫瑰红”葡萄果实的果皮褐变机制中发挥关键作用。
A recently popular Japanese yellow-green-skin table grape, ‘Shine Muscat’ (Vitis labruscana Bailey × V. vinifera L.), has the problem of berry skin browning, which occurs at the maturation stage just before harvest. Tiny reddish-brown blotches appear on the surface of berries and considerably decrease the grape’s market value. Although the mechanisms and factors for browning are unknown, we hypothesized the involvement of polyphenol compounds and their oxidation reactions. In this study, the gene expressions of polyphenol oxidase (PPO), stilbene synthase (STS), and chalcone synthase (CHS), which are key enzymatic genes related to the metabolic pathway for polyphenols, were analyzed during berry maturation to examine the molecular basis for browning. Skin browning occurred on several berries in a bunch of ‘Shine Muscat’ from 80 days after full bloom (DAFB), after which the number of berries with skin browning increased, and the browned area spread on the berry surfaces with maturation. Increases in the expression of VvPPO2, VvSTS type B, and VvCHS1 were associated with skin browning, and the trans-resveratrol content also increased in the browning skin, suggesting that biosynthesis and metabolic pathways for phenolic compounds were activated at the time of browning. In terms of VvPPO genes, specific up-regulation of VvPPO2 expression was observed compared with the VvPPO1 gene. The promoter sequence of VvPPO2 contains more Myb binding motifs and W-box motifs than does VvPPO1. The specific up-regulation of VvPPO2 gene expression will play a crucial role in understanding and managing the skin-browning mechanism in the grape berries of ‘Shine Muscat’.