title: A natural frameshift mutation in Campanula EIL2 correlates with ethylene insensitivity in flowers.
abstract: The phytohormone ethylene plays a central role in development and senescence of climacteric flowers. In ornamental plant production, ethylene sensitive plants are usually protected against negative effects of ethylene by application of chemical inhibitors. In Campanula, flowers are sensitive to even minute concentrations of ethylene.
  
  
  
  Monitoring flower longevity in three Campanula species revealed C. portenschlagiana (Cp) as ethylene sensitive, C. formanekiana (Cf) with intermediate sensitivity and C. medium (Cm) as ethylene insensitive. We identified key elements in ethylene signal transduction, specifically in Ethylene Response Sensor 2 (ERS2), Constitutive Triple Response 1 (CTR1) and Ethylene Insensitive 3- Like 1 and 2 (EIL1 and EIL2) homologous. Transcripts of ERS2, CTR1 and EIL1 were constitutively expressed in all species both throughout flower development and in response to ethylene. In contrast, EIL2 was found only in Cf and Cm. We identified a natural mutation in Cmeil2 causing a frameshift which resulted in difference in expression levels of EIL2, with more than 100-fold change between Cf and Cm in young flowers.
  
  
  
  This study shows that the naturally occurring 7 bp frameshift discovered in Cmeil2, a key gene in the ethylene signaling pathway, correlates with ethylene insensitivity in flowers. We suggest that transfer of the eil2 mutation to other plant species will provide a novel tool to engineer ethylene insensitive flowers.
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Højbakkegård Allé 9-13, 2630, Taastrup, Denmark.
authors.forename: Line
authors.initials: L
authors.lastname: Jensen
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Højbakkegård Allé 9-13, 2630, Taastrup, Denmark. jnh@plen.ku.dk.
authors.forename: Josefine Nymark
authors.initials: JN
authors.lastname: Hegelund
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Højbakkegård Allé 9-13, 2630, Taastrup, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Olsen
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Højbakkegård Allé 9-13, 2630, Taastrup, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Lütken
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Højbakkegård Allé 9-13, 2630, Taastrup, Denmark.
authors.forename: Renate
authors.initials: R
authors.lastname: Müller
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D029422:Campanulaceae / Q000235:genetics* / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism*; D016368:Frameshift Mutation; D018506:Gene Expression Regulation, Plant; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D013045:Species Specificity; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D005030:Ethylenes; D010937:Plant Growth Regulators; D010940:Plant Proteins; D014157:Transcription Factors; C036216:ethylene
keywords: Campanula; Deletion; EIL; EIN; Ethylene; Ethylene insensitive; Flower development