title: Transcriptional and hormonal regulation of petal and stamen development by STAMENLESS, the tomato (Solanum lycopersicum L.) orthologue to the B-class APETALA3 gene.
abstract: Four B-class MADS box genes specify petal and stamen organ identities in tomato. Several homeotic mutants affected in petal and stamen development were described in this model species, although the causal mutations have not been identified for most of them. In this study we characterized a strong stamenless mutant in the tomato Primabel cultivar (sl-Pr), which exhibited homeotic conversion of petals into sepals and stamens into carpels and we compared it with the stamenless mutant in the LA0269 accession (sl-LA0269). Genetic complementation analysis proved that both sl mutants were allelic. Sequencing revealed point mutations in the coding sequence of the Tomato APETALA3 (TAP3) gene of the sl-Pr genome, which lead to a truncated protein, whereas a chromosomal rearrangement in the TAP3 promoter was detected in the sl-LA0269 allele. Moreover, the floral phenotype of TAP3 antisense plants exhibited identical homeotic changes to sl mutants. These results demonstrate that SL is the tomato AP3 orthologue and that the mutant phenotype correlated to the SL silencing level. Expression analyses showed that the sl-Pr mutation does not affect the expression of other tomato B-class genes, although SL may repress the A-class gene MACROCALYX. A partial reversion of the sl phenotype by gibberellins, gene expression analysis, and hormone quantification in sl flowers revealed a role of phytohormones in flower development downstream of the SL gene. Together, our results indicated that petal and stamen identity in tomato depends on gene-hormone interactions, as mediated by the SL gene.
authors.affiliation: Groupe de Recherche en Physiologie végétale, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 4-5 bte L7.07.13, B-1348 Louvain-la-Neuve, Belgium muriel.quinet@uclouvain.be.
authors.forename: Muriel
authors.initials: M
authors.lastname: Quinet
authors.affiliation: Groupe de Recherche en Physiologie végétale, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 4-5 bte L7.07.13, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Gwennaël
authors.initials: G
authors.lastname: Bataille
authors.affiliation: Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, Prague 6, 16502, Czech Republic.
authors.forename: Petre I
authors.initials: PI
authors.lastname: Dobrev
authors.affiliation: Centro de Investigación en Biotecnología Agroalimentaria (BITAL), Universidad de Almería, 04120 Almería, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Capel
authors.affiliation: Centro de Investigación en Biotecnología Agroalimentaria (BITAL), Universidad de Almería, 04120 Almería, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Gómez
authors.affiliation: Centro de Investigación en Biotecnología Agroalimentaria (BITAL), Universidad de Almería, 04120 Almería, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Capel
authors.affiliation: Groupe de Recherche en Physiologie végétale, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 4-5 bte L7.07.13, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Stanley
authors.initials: S
authors.lastname: Lutts
authors.affiliation: Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, Prague 6, 16502, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Motyka
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.
authors.forename: Rafael
authors.initials: R
authors.lastname: Lozano
mesh_terms: D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D018551:Solanum lycopersicum / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D026161:MADS Domain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D014158:Transcription, Genetic
chemical_list: C101342:APETALA 3 protein, Arabidopsis; D029681:Arabidopsis Proteins; D026161:MADS Domain Proteins; D010937:Plant Growth Regulators; D010940:Plant Proteins
keywords: APETALA3; B-class gene; STAMENLESS; Solanum lycopersicum; flower morphogenesis; hormone regulation; tomato.