title: Strigolactones interact with ethylene and auxin in regulating root-hair elongation in Arabidopsis.
abstract: Strigolactones (SLs) or derivatives thereof have been identified as phytohormones, and shown to act as long-distance shoot-branching inhibitors. In Arabidopsis roots, SLs have been suggested to have a positive effect on root-hair (RH) elongation, mediated via the MAX2 F-box. Two other phytohormones, auxin and ethylene, have been shown to have positive effects on RH elongation. Hence, in the present work, Arabidopsis RH elongation was used as a bioassay to determine epistatic relations between SLs, auxin, and ethylene. Analysis of the effect of hormonal treatments on RH elongation in the wild type and hormone-signalling mutants suggested that SLs and ethylene regulate RH elongation via a common regulatory pathway, in which ethylene is epistatic to SLs, whereas the effect of SLs on RH elongation requires ethylene synthesis. SL signalling was not needed for the auxin response, whereas auxin signalling was not necessary, but enhanced RH response to SLs, suggesting that the SL and auxin hormonal pathways converge for regulation of RH elongation. The ethylene pathway requirement for the RH response to SLs suggests that ethylene forms a cross-talk junction between the SL and auxin pathways.
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Kapulnik
authors.forename: Natalie
authors.initials: N
authors.lastname: Resnick
authors.forename: Einav
authors.initials: E
authors.lastname: Mayzlish-Gati
authors.forename: Yulia
authors.initials: Y
authors.lastname: Kaplan
authors.forename: Smadar
authors.initials: S
authors.lastname: Wininger
authors.forename: Joseph
authors.initials: J
authors.lastname: Hershenhorn
authors.forename: Hinanit
authors.initials: H
authors.lastname: Koltai
mesh_terms: D000598:Amino Acids, Cyclic / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism*; D044783:F-Box Proteins / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D007210:Indoleacetic Acids / Q000378:metabolism*; D007783:Lactones / Q000378:metabolism* / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development*; D011956:Receptors, Cell Surface / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D015398:Signal Transduction / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D000598:Amino Acids, Cyclic; D029681:Arabidopsis Proteins; D005030:Ethylenes; D044783:F-Box Proteins; C507382:GR24 compound; D007210:Indoleacetic Acids; D007783:Lactones; D011956:Receptors, Cell Surface; C501405:TIR1 protein, Arabidopsis; C023863:1-aminocyclopropane-1-carboxylic acid; C036216:ethylene; C088137:aminoethoxyvinylglycine; D005998:Glycine