title: From lateral root density to nodule number, the strigolactone analogue GR24 shapes the root architecture of Medicago truncatula.
abstract: In the rhizosphere, strigolactones not only act as crucial signalling molecules in the communication of plants with parasitic weeds and arbuscular mycorrhiza, but they also play a key role in regulating different aspects of the root system. Here we investigated how strigolactones influence the root architecture of Medicago truncatula. We provide evidence that addition of the synthetic strigolactone analogue GR24 has an inhibitory effect on the lateral root density. Moreover, treatment with GR24 of Sinorhizobium meliloti-inoculated M. truncatula plants affects the nodule number both positively and negatively, depending on the concentration. Plants treated with 0.1 µM GR24 had a slightly increased number of nodules, whereas concentrations of 2 and 5 µM strongly reduced it. This effect was independent of the autoregulation of nodulation mechanism that is controlled by SUPER NUMERIC NODULE. Furthermore, we demonstrate that GR24 controls the nodule number through crosstalk with SICKLE-dependent ethylene signalling. Additionally, because the expression of the nodulation marker EARLY NODULATION11 was strongly reduced in GR24-treated plants, we concluded that strigolactones influence nodulation at a very early stage of the symbiotic interaction.
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium.
authors.forename: Carolien
authors.initials: C
authors.lastname: De Cuyper
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 441, Institut National de la Recherche Agronomique, F-31326 Castanet-Tolosan, France Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 2594, Centre National de la Recherche Scientifique, F-31326 Castanet-Tolosan, France.
authors.forename: Justine
authors.initials: J
authors.lastname: Fromentin
authors.affiliation: Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 441, Institut National de la Recherche Agronomique, F-31326 Castanet-Tolosan, France.
authors.forename: Rosita Endah
authors.initials: RE
authors.lastname: Yocgo
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium.
authors.forename: Annick
authors.initials: A
authors.lastname: De Keyser
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium.
authors.forename: Bruno
authors.initials: B
authors.lastname: Guillotin
authors.affiliation: Plant Science Department, Forestry and Agricultural Biotechnology Institute, University of Pretoria, 0083 Pretoria, South Africa.
authors.forename: Karl
authors.initials: K
authors.lastname: Kunert
authors.affiliation: Institut National de la Recherche Agronomique, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Equipe de Recherche Labellisée Centre National de la Recherche Scientifique 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Equipe de Recherche Labellisée Centre National de la Recherche Scientifique 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles, Unité Propre de Recherche 2301, Centre National de la Recherche Scientifique, F-91198 Gif-sur-Yvette, France.
authors.forename: François-Didier
authors.initials: FD
authors.lastname: Boyer
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium sofie.goormachtig@psb.vib-ugent.be.
authors.forename: Sofie
authors.initials: S
authors.lastname: Goormachtig
mesh_terms: D006575:Heterocyclic Compounds, 3-Ring / Q000378:metabolism*; D007783:Lactones / Q000378:metabolism*; D046913:Medicago truncatula / Q000254:growth & development / Q000502:physiology*; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
chemical_list: C000591191:GR24 strigolactone; D006575:Heterocyclic Compounds, 3-Ring; D007783:Lactones
keywords: ENOD11; GR24; Medicago truncatula; ethylene; nodulation; root architecture.