title: Molecular genetics of berry colour variation in table grape.
abstract: The genetics and biochemistry of anthocyanins and flavonol biosynthesis and their role in plant organ pigmentation is well established in model species. However, the genetic basis of colour variation is species specific and understanding this variation is very relevant in many fruit and flower crop species. Among grape cultivars, there is a wide genetic variation for berry colour ranging from yellow-green ("white" cultivars) to dark blue berries. Berry colour results from the synthesis and accumulation of anthocyanins in the berry skin, which in plants is commonly regulated by transcription factors belonging to the MYB and bHLH families. In this work, we aimed to identify the major genetic determinants of berry colour variation in a large collection of table grape cultivars and somatic variants. The genetic analyses of berry colour in a few grape segregating progenies had previously identified a single locus on linkage group 2 responsible for colour variation. Furthermore, somatic variation for berry skin colour in cultivar Italia had been associated with the presence of a Gret1 retrotransposon in the promoter region of VvmybA1, a Myb gene whose expression is associated to skin colouration. The results show that VvmybA1 is the gene underlying the mapped locus controlling berry colour in grape. Additionally, the molecular analyses indicate that genetic and somatic berry colour variation can be associated to molecular variation at VvmybA1 in more than 95% of the analyzed cultivars. Thus, VvmybA1 is a major determinant of berry colour variation in table grape and its instability is the major cause of somatic variation for this trait.
authors.affiliation: Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), C/ Darwin 3, 28049 Madrid, Spain. dlijavetzky@cnb.uam.es
authors.forename: Diego
authors.initials: D
authors.lastname: Lijavetzky
authors.forename: Leonor
authors.initials: L
authors.lastname: Ruiz-García
authors.forename: José A
authors.initials: JA
authors.lastname: Cabezas
authors.forename: María T
authors.initials: MT
authors.lastname: De Andrés
authors.forename: Gemma
authors.initials: G
authors.lastname: Bravo
authors.forename: Ana
authors.initials: A
authors.lastname: Ibáñez
authors.forename: Juan
authors.initials: J
authors.lastname: Carreño
authors.forename: Félix
authors.initials: F
authors.lastname: Cabello
authors.forename: Javier
authors.initials: J
authors.lastname: Ibáñez
authors.forename: José M
authors.initials: JM
authors.lastname: Martínez-Zapater
mesh_terms: D000872:Anthocyanins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D003116:Color; D017931:DNA Primers; D044948:Flavonols / Q000235:genetics / Q000378:metabolism; D005638:Fruit / Q000235:genetics* / Q000378:metabolism; D014644:Genetic Variation; D005838:Genotype; D008969:Molecular Sequence Data; D010641:Phenotype; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000872:Anthocyanins; D017931:DNA Primers; D044948:Flavonols