title: The 1-deoxy-D: -xylulose 5-phosphate synthase gene co-localizes with a major QTL affecting monoterpene content in grapevine.
abstract: Muscat flavor is a relevant trait both in winemaking and in fresh grape consumption. From a chemical point of view, it is strongly related to the accumulation of monoterpenes in berries. However, knowledge of the genetic mechanisms underlying its regulation is still limited. The objective of this study was to dissect the genetic determinism of aroma in grapevine by applying the analysis of quantitative trait loci (QTL) and the candidate gene (CG) approach. Two F(1) segregating progenies were evaluated through high-resolution gas chromatography-mass spectrometry (HRGC-MS) for the amounts of individual monoterpenes over 3 and 2 years. In the Italia x Big Perlon cross 34 CGs, chosen according to gene ontology (GO) terms, were placed on a complete map and tested for linkage with QTLs for linalool, nerol and geraniol levels. Two CGs mapped within a QTL for linalool content on LG 10. A third one co-localized with a major QTL for the level of the three monoterpenes on LG 5; this gene encodes 1-deoxy-D: -xylulose 5-phosphate synthase (DXS), which is the first enzyme in the plastidial pathway of terpene biosynthesis. Depending on these findings, we report the first in silico analysis of grapevine DXS genes based on the whole genome sequence. Further research on the functional significance of these associations might help to understand the genetic control of Muscat flavor.
authors.affiliation: Department of Genetics and Molecular Biology, IASMA Research Center, Fondazione Edmund Mach, 38010 San Michele all'Adige, Italy.
authors.forename: Juri
authors.initials: J
authors.lastname: Battilana
authors.forename: Laura
authors.initials: L
authors.lastname: Costantini
authors.forename: Francesco
authors.initials: F
authors.lastname: Emanuelli
authors.forename: Federica
authors.initials: F
authors.lastname: Sevini
authors.forename: Cinzia
authors.initials: C
authors.lastname: Segala
authors.forename: Sergio
authors.initials: S
authors.lastname: Moser
authors.forename: Riccardo
authors.initials: R
authors.lastname: Velasco
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Versini
authors.forename: M
authors.initials: M
authors.lastname: Stella Grando
mesh_terms: D001483:Base Sequence; D002874:Chromosome Mapping; D019295:Computational Biology; D040461:Gene Components; D008969:Molecular Sequence Data; D039821:Monoterpenes / Q000032:analysis*; D018807:Polymorphism, Single-Stranded Conformational / Q000235:genetics; D040641:Quantitative Trait Loci / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014166:Transferases / Q000235:genetics*; D027843:Vitis / Q000737:chemistry / Q000235:genetics*
chemical_list: D039821:Monoterpenes; D014166:Transferases; C109461:deoxyxylulose-5-phosphate synthase