title: Esa1, an Arabidopsis mutant with enhanced susceptibility to a range of necrotrophic fungal pathogens, shows a distorted induction of defense responses by reactive oxygen generating compounds.
abstract: An Arabidopsis thaliana mutant, esa1, that shows enhanced susceptibility to the necrotrophic pathogens Alternaria brassicicola, Botrytis cinerea and Plectosphaerella cucumerina, but has wild-type levels of resistance to the biotrophic pathogens Pseudomonas syringae pv. tomato and Peronospora parasitica. The enhanced susceptibility towards necrotrophic pathogens correlated with a delayed induction of phytoalexin accumulation and delayed induction of the plant defensin gene PDF1.2 upon inoculation with pathogens. Two reactive oxygen generating compounds, paraquat and acifluorfen, were found to cause induction of both phytoalexin accumulation and PDF1.2 expression in wild-type plants, but this induction was almost completely abolished in esa1. This finding suggests that esa1 may somehow be involved in transduction of signals generated by reactive oxygen species.
authors.affiliation: Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Belgium.
authors.forename: Koenraad F M J
authors.initials: KF
authors.lastname: Tierens
authors.forename: Bart P H J
authors.initials: BP
authors.lastname: Thomma
authors.forename: Rajendra P
authors.initials: RP
authors.lastname: Bari
authors.forename: Marie
authors.initials: M
authors.lastname: Garmier
authors.forename: Kristel
authors.initials: K
authors.lastname: Eggermont
authors.forename: Margreet
authors.initials: M
authors.lastname: Brouwer
authors.forename: Iris A M A
authors.initials: IA
authors.lastname: Penninckx
authors.forename: Willem F
authors.initials: WF
authors.lastname: Broekaert
authors.forename: Bruno P A
authors.initials: BP
authors.lastname: Cammue
mesh_terms: D000528:Alternaria / Q000472:pathogenicity*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D003517:Cyclopentanes / Q000494:pharmacology; D023082:Defensins; D005030:Ethylenes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007113:Immunity, Innate / Q000187:drug effects; D007211:Indoles / Q000494:pharmacology; D009154:Mutation; D009579:Nitrobenzoates / Q000494:pharmacology; D054883:Oxylipins; D010269:Paraquat / Q000494:pharmacology; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D010936:Plant Extracts / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012459:Salicylates / Q000494:pharmacology; D012717:Sesquiterpenes; D013729:Terpenes; D013844:Thiazoles / Q000494:pharmacology; D000094162:Phytoalexins
chemical_list: D003517:Cyclopentanes; D023082:Defensins; D005030:Ethylenes; D007211:Indoles; D009579:Nitrobenzoates; D054883:Oxylipins; D010936:Plant Extracts; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D012459:Salicylates; D012717:Sesquiterpenes; D013729:Terpenes; D013844:Thiazoles; C102405:camalexin; C011006:jasmonic acid; C036216:ethylene; C018425:acifluorfen; D010269:Paraquat; D000094162:Phytoalexins