title: Genetic and physiological characterization of the arlequin insertional mutant reveals a key regulator of reproductive development in tomato.
abstract: The genetic and phenotypic characterization of a new tomato (Solanum lycopersicum) insertional mutant, Arlequin (Alq) is reported. Alq mutant plants were affected in reproductive development and their sepals were homeotically converted into fleshy fruit-like organs. Molecular analysis demonstrated that a single copy of T-DNA was present in the mutant genome while genetic analysis confirmed that the mutant phenotype co-segregated with the T-DNA insertion and was inherited as a monogenic semi-dominant trait. The histological and scanning electron microscope analyses revealed cell identity changes in both external and internal tissues of Alq sepals. Flowers developed by Alq homozygous plants showed a severe mutant phenotype, since after fruit set, not only did the sepals become succulent but they also followed a ripening pattern similar to that of normal fruits. From a metabolic viewpoint, Alq sepals also behaved like a fruit, as they acquired the properties of a sink that acted alternatively and independently to the fruit. In fact, expression of regulatory genes controlling tomato fruit ripening was detected in Alq sepals at similar levels to those observed in mature fruits. Furthermore, the Alq mutation inhibited the development of the abscission zone in tomato flowers indicating that the JOINTLESS gene is regulated by ALQ. Results from the genetic and developmental characterization of the Alq tomato mutant suggest that the ALQ gene participates in the regulatory pathway controlling fruit ripening of tomato.
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, Avda de los Naranjos s/n, 46022 Valencia, Spain.
authors.forename: Benito
authors.initials: B
authors.lastname: Pineda
authors.forename: Estela
authors.initials: E
authors.lastname: Giménez-Caminero
authors.forename: Begoña
authors.initials: B
authors.lastname: García-Sogo
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Antón
authors.forename: Alejandro
authors.initials: A
authors.lastname: Atarés
authors.forename: Juan
authors.initials: J
authors.lastname: Capel
authors.forename: Rafael
authors.initials: R
authors.lastname: Lozano
authors.forename: Trinidad
authors.initials: T
authors.lastname: Angosto
authors.forename: Vicente
authors.initials: V
authors.lastname: Moreno
mesh_terms: D004269:DNA, Bacterial / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D035264:Flowers / Q000254:growth & development*; D005638:Fruit / Q000254:growth & development*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D040582:Inheritance Patterns; D018551:Solanum lycopersicum / Q000235:genetics* / Q000254:growth & development; D008855:Microscopy, Electron, Scanning; D016254:Mutagenesis, Insertional; D009154:Mutation; D010641:Phenotype
chemical_list: D004269:DNA, Bacterial; D018744:DNA, Plant; C036483:T-DNA