title: Mis-expression of a PISTILLATA-like MADS box gene prevents fruit development in grapevine.
abstract: The FLESHLESS BERRY (Flb) somatic variant identified in the grapevine cultivar Ugni Blanc develops grape berries without flesh, suggesting a role for the altered gene in differentiation of flesh cells. Here we describe identification of the molecular defect responsible for this phenotype. Using a combination of genetic and transcriptomic approaches, we detected the insertion of a miniature inverted-repeat transposable element in the promoter region of the PISTILLATA-like (VvPI) gene, the grapevine homologue of Arabidopsis PISTILLATA. The transposon insertion causes specific ectopic expression of the corresponding VvPI allele during early fruit development, causing expression of genes specific for petal and stamen development within the fruit. A causal relationship between the insertion and the phenotype was demonstrated by phenotypic and molecular analyses of somatic revertants showing that ectopic expression and mutant phenotype were always linked to the presence of the transposon insertion. The various phenotypic effects of the flb mutation on ovary morphology, fruit set and fruit development, depending on the cell lineage affected, are presented for each phenotype, offering new insights into floral and fleshly fruit development. The results highlight the importance of VvPI repression after fertilization to achieve normal fleshy fruit development, and the complex genetic, genomic and cellular interactions required for the flower to fruit transition in grapevine.
authors.affiliation: Instituto de Ciencias de la Vid y del Vino (Consejo Superior de Investigaciones Cientificas, Universitad de la Rioja, Gobierno de La Rioja), Calle Madre de Dios 51, 26006, Logroño, Spain.
authors.forename: Lucie
authors.initials: L
authors.lastname: Fernandez
authors.forename: Jamila
authors.initials: J
authors.lastname: Chaïb
authors.forename: José-Miguel
authors.initials: JM
authors.lastname: Martinez-Zapater
authors.forename: Mark R
authors.initials: MR
authors.lastname: Thomas
authors.forename: Laurent
authors.initials: L
authors.lastname: Torregrosa
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics; D004251:DNA Transposable Elements; D005638:Fruit / Q000235:genetics / Q000254:growth & development*; D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D027843:Vitis / Q000235:genetics* / Q000254:growth & development*
chemical_list: D029681:Arabidopsis Proteins; D004251:DNA Transposable Elements; D026161:MADS Domain Proteins; C090225:PISTILLATA protein, Arabidopsis; D010940:Plant Proteins