title: Ethylene is involved in pistil fate by modulating the onset of ovule senescence and the GA-mediated fruit set in Arabidopsis.
abstract: BACKGROUND
  Ovule lifespan is an important factor in determining the ability to set fruits and produce seeds. Once ovule senescence is established, fruit set capacity in response to gibberellins (GAs) is lost. We aimed to elucidate whether ethylene plays a role in controlling ovule senescence and the fruit set response in Arabidopsis.
  
  
  RESULTS
  Ethylene response inhibitors, silver thiosulphate (STS) and 1-methylcyclopropene (1-MCP), were able to delay the loss of pistil response to GA(3). In addition, ethylene insensitive mutants ein2-5 and ein3-1 showed delayed loss of pistil response, as in plants treated with STS and 1-MCP, while constitutive mutant ctr1-1 displayed premature loss of response. The analysis of the expression of ethylene biosynthesis genes suggests that ethylene is synthesised in ovules at the onset of ovule senescence, while a transcriptional meta-analysis also supports an activated ethylene-dependent senescence upon the establishment of ovule senescence. Finally, a SAG12:GUS reporter line proved useful to monitor ovule senescence and to directly demonstrate that ethylene specifically modulates ovule senescence.
  
  
  CONCLUSIONS
  We have shown that ethylene is involved in both the control of the ovule lifespan and the determination of the pistil/fruit fate. Our data support a role of the ovule in modulating the GA response during fruit set in Arabidopsis. A possible mechanism that links the ethylene modulation of the ovule senescence and the GA3-induced fruit set response is discussed.
authors.affiliation: Centro Nacional de Biotecnología (CNB), Consejo Superior de Investigaciones Científicas (CSIC), Cantoblanco, 28049 Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Carbonell-Bejerano
authors.forename: Cristina
authors.initials: C
authors.lastname: Urbez
authors.forename: Antonio
authors.initials: A
authors.lastname: Granell
authors.forename: Juan
authors.initials: J
authors.lastname: Carbonell
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Perez-Amador
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003521:Cyclopropanes / Q000494:pharmacology; D005030:Ethylenes / Q000096:biosynthesis*; D035264:Flowers / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D005638:Fruit / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000494:pharmacology*; D056771:Ovule / Q000254:growth & development* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013885:Thiosulfates / Q000494:pharmacology; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; D003521:Cyclopropanes; C119963:EIN2 protein, Arabidopsis; D005030:Ethylenes; D005875:Gibberellins; D011956:Receptors, Cell Surface; D013885:Thiosulfates; C095213:silver thiosulfate; C036216:ethylene; C412563:1-methylcyclopropene