title: Jasmonates act positively in adventitious root formation in petunia cuttings.
abstract: BACKGROUND
  Petunia is a model to study the process of adventitious root (AR) formation on leafy cuttings. Excision of cuttings leads to a transient increase in jasmonates, which is regarded as an early, transient and critical event for rooting. Here, the role of jasmonates in AR formation on petunia cuttings has been studied by a reverse genetic approach.
  
  
  RESULTS
  To reduce the endogenous levels of jasmonates, transgenic plants were generated expressing a Petunia hybrida ALLENE OXIDE CYCLASE (PhAOC)-RNAi construct. The transgenic plants exhibited strongly reduced PhAOC transcript and protein levels as well as diminished accumulation of cis-12-oxo-phytodienoic acid, jasmonic acid and jasmonoyl-isoleucine after wounding in comparison to wild type and empty vector expressing plants. Reduced levels of endogenous jasmonates resulted in formation of lower numbers of ARs. However, this effect was not accompanied by altered levels of auxin and aminocyclopropane carboxylate (ACC, precursor of ethylene) or by impaired auxin and ethylene-induced gene expression. Neither activity of cell-wall invertases nor accumulation of soluble sugars was altered by jasmonate deficiency.
  
  
  CONCLUSIONS
  Diminished numbers of AR in JA-deficient cuttings suggest that jasmonates act as positive regulators of AR formation in petunia wild type. However, wound-induced rise in jasmonate levels in petunia wild type cuttings seems not to be causal for increased auxin and ethylene levels and for sink establishment.
authors.affiliation: Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, D06120, Halle/Salle, Germany. Frau.Lee@gmx.de.|Present address: Interdisziplinäres Stoffwechsel-Centrum, Charité, Augustenburger Platz 1, D13353, Berlin, Germany. Frau.Lee@gmx.de.
authors.forename: Sandra
authors.initials: S
authors.lastname: Lischweski
authors.affiliation: Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, D06120, Halle/Salle, Germany. Anne.Muchow@t-online.de.|Present address: IDT Biologika GmbH, Am Pharmapark, D06861, Dessau-Roßlau, Germany. Anne.Muchow@t-online.de.
authors.forename: Anne
authors.initials: A
authors.lastname: Muchow
authors.affiliation: Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, D06120, Halle/Salle, Germany. daniela.guthoerl@uzh.ch.|Present address: Institute of Plant Biology, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland. daniela.guthoerl@uzh.ch.
authors.forename: Daniela
authors.initials: D
authors.lastname: Guthörl
authors.affiliation: Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, D06120, Halle/Salle, Germany. bhause@ipb-halle.de.
authors.forename: Bettina
authors.initials: B
authors.lastname: Hause
mesh_terms: D003517:Cyclopentanes / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D019746:Intramolecular Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism*; D032306:Petunia / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D034622:RNA Interference
chemical_list: D003517:Cyclopentanes; D018076:DNA, Complementary; D007210:Indoleacetic Acids; D054883:Oxylipins; D010940:Plant Proteins; C011006:jasmonic acid; C030737:indoleacetic acid; D019746:Intramolecular Oxidoreductases; C021377:hydroperoxide isomerase