title: TOMATO AGAMOUS1 and ARLEQUIN/TOMATO AGAMOUS-LIKE1 MADS-box genes have redundant and divergent functions required for tomato reproductive development.
abstract: Within the tomato MADS-box gene family, TOMATO AGAMOUS1 (TAG1) and ARLEQUIN/TOMATO AGAMOUS LIKE1 (hereafter referred to as TAGL1) are, respectively, members of the euAG and PLE lineages of the AGAMOUS clade. They perform crucial functions specifying stamen and carpel development in the flower and controlling late fruit development. To gain insight into the roles of TAG1 and TAGL1 genes and to better understand their functional redundancy and diversification, we characterized single and double RNAi silencing lines of these genes and analyzed expression profiles of regulatory genes involved in reproductive development. Double RNAi lines did show cell abnormalities in stamens and carpels and produced extremely small fruit-like organs displaying some sepaloid features. Expression analyses indicated that TAG1 and TAGL1 act together to repress fourth whorl sepal development, most likely through the MACROCALYX gene. Results also proved that TAG1 and TAGL1 have diversified their functions in fruit development: while TAG1 controls placenta and seed formation, TAGL1 participates in cuticle development and lignin biosynthesis inhibition. It is noteworthy that both TAG1 and double RNAi plants lacked seed development due to abnormalities in pollen formation. This seedless phenotype was not associated with changes in the expression of B-class stamen identity genes Tomato MADS-box 6 and Tomato PISTILLATA observed in silencing lines, suggesting that other regulatory factors should participate in pollen formation. Taken together, results here reported support the idea that both redundant and divergent functions of TAG1 and TAGL1 genes are needed to control tomato reproductive development.
authors.affiliation: Centro de Investigación en Biotecnología Agroalimentaria (BITAL), Universidad de Almería, 04120, Almería, Spain.
authors.forename: Estela
authors.initials: E
authors.lastname: Gimenez
authors.affiliation: Centro de Investigación en Biotecnología Agroalimentaria (BITAL), Universidad de Almería, 04120, Almería, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Castañeda
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, 46022, Valencia, Spain.
authors.forename: Benito
authors.initials: B
authors.lastname: Pineda
authors.affiliation: Department of Biology, Stonehill College, 320 Washington Street, Easton, MA, 02357, USA.
authors.forename: Irvin L
authors.initials: IL
authors.lastname: Pan
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, 46022, Valencia, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Moreno
authors.affiliation: Centro de Investigación en Biotecnología Agroalimentaria (BITAL), Universidad de Almería, 04120, Almería, Spain.
authors.forename: Trinidad
authors.initials: T
authors.lastname: Angosto
authors.affiliation: Centro de Investigación en Biotecnología Agroalimentaria (BITAL), Universidad de Almería, 04120, Almería, Spain. rlozano@ual.es.
authors.forename: Rafael
authors.initials: R
authors.lastname: Lozano
mesh_terms: D035264:Flowers / Q000235:genetics / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D018551:Solanum lycopersicum / Q000235:genetics* / Q000502:physiology*; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D019441:Plant Epidermis / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D012098:Reproduction / Q000235:genetics
chemical_list: D026161:MADS Domain Proteins; D010940:Plant Proteins
keywords: Functional diversification; Redundancy; Reproductive development; Solanum lycopersicum; TAG1; TAGL1