title: The role of strigolactones during plant interactions with the pathogenic fungus Fusarium oxysporum.
abstract: Strigolactones (SLs) do not influence spore germination or hyphal growth of Fusarium oxysporum. Mutant studies revealed no role for SLs but a role for ethylene signalling in defence against this pathogen in pea. Strigolactones (SLs) play important roles both inside the plant as a hormone and outside the plant as a rhizosphere signal in interactions with mycorrhizal fungi and parasitic weeds. What is less well understood is any potential role SLs may play in interactions with disease causing microbes such as pathogenic fungi. In this paper we investigate the influence of SLs on the hemibiotrophic pathogen Fusarium oxysporum f.sp. pisi both directly via their effects on fungal growth and inside the plant through the use of a mutant deficient in SL. Given that various stereoisomers of synthetic and naturally occuring SLs can display different biological activities, we used (+)-GR24, (-)-GR24 and the naturally occurring SL, (+)-strigol, as well as a racemic mixture of 5-deoxystrigol. As a positive control, we examined the influence of a plant mutant with altered ethylene signalling, ein2, on disease development. We found no evidence that SLs influence spore germination or hyphal growth of Fusarium oxysporum and that, while ethylene signalling influences pea susceptibility to this pathogen, SLs do not.
authors.affiliation: School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7001, Australia. eloise.foo@utas.edu.au.
authors.forename: Eloise
authors.initials: E
authors.lastname: Foo
authors.affiliation: School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7001, Australia.
authors.forename: Sara N
authors.initials: SN
authors.lastname: Blake
authors.affiliation: School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, TAS, 7001, Australia.
authors.forename: Brendan J
authors.initials: BJ
authors.lastname: Fisher
authors.affiliation: School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, TAS, 7001, Australia.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Smith
authors.affiliation: School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7001, Australia.
authors.forename: James B
authors.initials: JB
authors.lastname: Reid
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics; D004198:Disease Susceptibility; D005030:Ethylenes / Q000378:metabolism / Q000494:pharmacology; D005670:Fusarium / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D018525:Germination / Q000187:drug effects; D007783:Lactones / Q000378:metabolism / Q000494:pharmacology*; D009154:Mutation; D018532:Pisum sativum / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D010937:Plant Growth Regulators / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology
chemical_list: D005030:Ethylenes; D007783:Lactones; D010937:Plant Growth Regulators; C036216:ethylene
keywords: Ethylene; Fusarium; Pea; Root pathogen; Strigolactones