期刊
PHYTOCHEMISTRY
卷 95, 期 -, 页码 135-144出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.phytochem.2013.07.021
关键词
Grapevine; Monoterpenes; Diterpenes; 1-Deoxy-D-xylulose; Mevalonic acid; Head space; Solid phase-microextration; Gas Chromatography-Mass Spectrometry; Deuterium labeling
资金
- U.S. National Institutes of Health [1RC2GM092561-01]
- Emerging Research Issues for Washington Agriculture Initiative of the Agricultural Research Center at Washington State University
The participation of the mevalonic acid (MVA) and 1-deoxy-D-xylulose 5-phosphate/2-C-methyl-D-erythritol-4-phosphate (DOXP/MEP) pathways in sesquiterpene biosynthesis of grape berries was investigated. There is an increasing interest in this class of terpenoids, since the oxygenated sesquiterpene rotundone was identified as the peppery aroma impact compound in Australian Shiraz wines. To investigate precursor supply pathway utilization, in vivo feeding experiments were performed with the deuterium labeled, pathway specific, precursors [5,5-H-2(2)]-1-deoxy-D-xylulose and [5,5-H-2(2)]-mevalonic acid lactone. Head Space-Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS) analysis of the generated volatile metabolites demonstrated that de novo sesquiterpene biosynthesis is mainly located in the grape berry exocarp (skin), with no detectable activity in the mesocarp (flesh) of the Lemberger variety. Interestingly, precursors from both the (primarily) cytosolic MVA and plastidial DOXP/MEP pathways were incorporated into grape sesquiterpenes in the varieties Lemberger, Gewurztraminer and Syrah. Our labeling data provide evidence for a homogenous, cytosolic pool of precursors for sesquiterpene biosynthesis, indicating that a transport of precursors occurs mostly from plastids to the cytosol. The labeling patterns of the sesquiterpene germacrene D were in agreement with a cyclization mechanism analogous to that of a previously cloned enantioselective (R)-germacrene D synthase from Solidago canadensis. This observation was subsequently confirmed by enantioselective GC-MS analysis demonstrating the exclusive presence of (R)-germacrene D, and not the (S)-enantiomer, in grape berries. (C) 2013 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据