title: Regulation of flavonol content and composition in (Syrah×Pinot Noir) mature grapes: integration of transcriptional profiling and metabolic quantitative trait locus analyses.
abstract: Flavonols are a ubiquitous class of flavonoids that accumulate preferentially in flowers and mature berries. Besides their photo-protective function, they play a fundamental role during winemaking, stabilizing the colour by co-pigmentation with anthocyanins and contributing to organoleptic characteristics. Although the general flavonol pathway has been genetically and biochemically elucidated, the genetic control of flavonol content and composition at harvest is still not clear. To this purpose, the grapes of 170 segregating F1 individuals from a 'Syrah'×'Pinot Noir' population were evaluated at the mature stage for the content of six flavonol aglycons in four seasons. Metabolic data in combination with genetic data enabled the identification of 16 mQTLs (metabolic quantitative trait loci). For the first time, major genetic control by the linkage group 2 (LG 2)/MYBA region on flavonol variation, in particular of tri-hydroxylated flavonols, is demonstrated. Moreover, seven regions specifically associated with the fine control of flavonol biosynthesis are identified. Gene expression profiling of two groups of individuals significantly divergent for their skin flavonol content identified a large set of differentially modulated transcripts. Among these, the transcripts coding for MYB and bZIP transcription factors, methyltranferases, and glucosyltranferases specific for flavonols, proteins, and factors belonging to the UV-B signalling pathway and co-localizing with the QTL regions are proposed as candidate genes for the fine regulation of flavonol content and composition in mature grapes.
authors.affiliation: Genomics and Biology of Fruit Crops Department, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 S. Michele all'Adige, Trento, Italy giulia.malacarne@fmach.it.
authors.forename: Giulia
authors.initials: G
authors.lastname: Malacarne
authors.affiliation: Genomics and Biology of Fruit Crops Department, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 S. Michele all'Adige, Trento, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Costantini
authors.affiliation: Computational Biology Department, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 S. Michele all'Adige, Trento, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Coller
authors.affiliation: Genomics and Biology of Fruit Crops Department, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 S. Michele all'Adige, Trento, Italy.
authors.forename: Juri
authors.initials: J
authors.lastname: Battilana
authors.affiliation: Genomics and Biology of Fruit Crops Department, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 S. Michele all'Adige, Trento, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Velasco
authors.affiliation: Food Quality and Nutrition Department, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 S. Michele all'Adige, Trento, Italy.
authors.forename: Urska
authors.initials: U
authors.lastname: Vrhovsek
authors.affiliation: Genomics and Biology of Fruit Crops Department, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 S. Michele all'Adige, Trento, Italy.
authors.forename: Maria Stella
authors.initials: MS
authors.lastname: Grando
authors.affiliation: Genomics and Biology of Fruit Crops Department, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 S. Michele all'Adige, Trento, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Moser
mesh_terms: D044948:Flavonols / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010858:Pigmentation / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D040641:Quantitative Trait Loci; D017422:Sequence Analysis, DNA; D027843:Vitis / Q000235:genetics* / Q000378:metabolism
chemical_list: D044948:Flavonols; D010940:Plant Proteins
keywords: Berry; Vitis vinifera.; candidate gene; flavonols; metabolic profiling; microarray; quantitative trait loci; segregating population