title: Strigolactone inhibition of shoot branching.
abstract: A carotenoid-derived hormonal signal that inhibits shoot branching in plants has long escaped identification. Strigolactones are compounds thought to be derived from carotenoids and are known to trigger the germination of parasitic plant seeds and stimulate symbiotic fungi. Here we present evidence that carotenoid cleavage dioxygenase 8 shoot branching mutants of pea are strigolactone deficient and that strigolactone application restores the wild-type branching phenotype to ccd8 mutants. Moreover, we show that other branching mutants previously characterized as lacking a response to the branching inhibition signal also lack strigolactone response, and are not deficient in strigolactones. These responses are conserved in Arabidopsis. In agreement with the expected properties of the hormonal signal, exogenous strigolactone can be transported in shoots and act at low concentrations. We suggest that endogenous strigolactones or related compounds inhibit shoot branching in plants. Furthermore, ccd8 mutants demonstrate the diverse effects of strigolactones in shoot branching, mycorrhizal symbiosis and parasitic weed interaction.
authors.affiliation: Université de Toulouse, UPS, CNRS, Surface Cellulaire et Signalisation chez les Végétaux, 24 chemin de Borde Rouge, F-31326 Castanet-Tolosan, France.
authors.forename: Victoria
authors.initials: V
authors.lastname: Gomez-Roldan
authors.forename: Soraya
authors.initials: S
authors.lastname: Fermas
authors.forename: Philip B
authors.initials: PB
authors.lastname: Brewer
authors.forename: Virginie
authors.initials: V
authors.lastname: Puech-Pagès
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Dun
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Pillot
authors.forename: Fabien
authors.initials: F
authors.lastname: Letisse
authors.forename: Radoslava
authors.initials: R
authors.lastname: Matusova
authors.forename: Saida
authors.initials: S
authors.lastname: Danoun
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Portais
authors.forename: Harro
authors.initials: H
authors.lastname: Bouwmeester
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bécard
authors.forename: Christine A
authors.initials: CA
authors.lastname: Beveridge
authors.forename: Catherine
authors.initials: C
authors.lastname: Rameau
authors.forename: Soizic F
authors.initials: SF
authors.lastname: Rochange
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D049308:Dioxygenases; D017343:Genes, Plant / Q000235:genetics; D007783:Lactones / Q000032:analysis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D009154:Mutation; D038821:Mycorrhizae / Q000502:physiology; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism; D018532:Pisum sativum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism* / Q000469:parasitology; D010641:Phenotype; D010937:Plant Growth Regulators / Q000032:analysis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism* / Q000469:parasitology; D013559:Symbiosis; D013729:Terpenes / Q000032:analysis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology
chemical_list: D029681:Arabidopsis Proteins; C507382:GR24 compound; D007783:Lactones; D010937:Plant Growth Regulators; D010940:Plant Proteins; D013729:Terpenes; D010105:Oxygenases; C494442:CCD8 protein, Arabidopsis; D049308:Dioxygenases