title: Increase in tomato locule number is controlled by two single-nucleotide polymorphisms located near WUSCHEL.
abstract: In tomato (Solanum lycopersicum) fruit, the number of locules (cavities containing seeds that are derived from carpels) varies from two to up to 10 or more. Locule number affects fruit shape and size and is controlled by several quantitative trait loci (QTLs). The large majority of the phenotypic variation is explained by two of these QTLs, fasciated (fas) and locule number (lc), that interact epistatically with one another. FAS has been cloned, and mutations in the gene are described as key factors leading to the increase in fruit size in modern varieties. Here, we report the map-based cloning of lc. The lc QTL includes a 1,600-bp region that is located 1,080 bp from the 3' end of WUSCHEL, which encodes a homeodomain protein that regulates stem cell fate in plants. The molecular evolution of lc showed a reduction of diversity in cultivated accessions with the exception of two single-nucleotide polymorphisms. These two single-nucleotide polymorphisms were shown to be responsible for the increase in locule number. An evolutionary model of locule number is proposed herein, suggesting that the fas mutation appeared after the mutation in the lc locus to confer the extreme high-locule-number phenotype.
authors.affiliation: INRA, UR1052 Génétique et Amélioration des Fruits et Légumes, Domaine Saint-Maurice, 84143 Montfavet Cedex, France. stephane.munos@toulouse.inra.fr
authors.forename: Stéphane
authors.initials: S
authors.lastname: Muños
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ranc
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Botton
authors.forename: Aurélie
authors.initials: A
authors.lastname: Bérard
authors.forename: Sophie
authors.initials: S
authors.lastname: Rolland
authors.forename: Philippe
authors.initials: P
authors.lastname: Duffé
authors.forename: Yolande
authors.initials: Y
authors.lastname: Carretero
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Le Paslier
authors.forename: Corinne
authors.initials: C
authors.lastname: Delalande
authors.forename: Mondher
authors.initials: M
authors.lastname: Bouzayen
authors.forename: Dominique
authors.initials: D
authors.lastname: Brunel
authors.forename: Mathilde
authors.initials: M
authors.lastname: Causse
mesh_terms: D000383:Agriculture; D001483:Base Sequence; D019143:Evolution, Molecular; D035264:Flowers / Q000033:anatomy & histology / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D056726:Genetic Association Studies; D018551:Solanum lycopersicum / Q000033:anatomy & histology* / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009929:Organ Size; D010641:Phenotype; D020161:Physical Chromosome Mapping; D010940:Plant Proteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D015203:Reproducibility of Results; D012639:Seeds / Q000235:genetics*
chemical_list: D010940:Plant Proteins