title: CYP83A1 is required for metabolic compatibility of Arabidopsis with the adapted powdery mildew fungus Erysiphe cruciferarum.
abstract: Aliphatic glucosinolates function in the chemical defense of Capparales. The cytochrome P450 83A1 monooxygenase (CYP83A1) catalyzes the initial conversion of methionine-derived aldoximes to thiohydroximates in the biosynthesis of glucosinolates, and thus cyp83a1 mutants have reduced levels of aliphatic glucosinolates. Loss of CYP83A1 function leads to dramatically reduced parasitic growth of the biotrophic powdery mildew fungus Erysiphe cruciferarum on Arabidopsis thaliana. The cyp83a1 mutants support less well the germination and appressorium formation of E. cruciferarum on the leaf surface and post-penetration conidiophore formation by the fungus. By contrast, a myb28-1 myb29-1 double mutant, which totally lacks aliphatic glucosinolates, shows a wild-type level of susceptibility to E. cruciferarum. The cyp83a1 mutants also lack very-long-chain aldehydes on their leaf surface. Such aldehydes support appressorium formation by E. cruciferarum in vitro. In addition, when chemically complemented with the C26 aldehyde n-hexacosanal, cyp83a1 mutants can again support appressorium formation. The mutants further accumulate 5-methylthiopentanaldoxime, the potentially toxic substrate of CYP83A1. Loss of powdery mildew susceptibility by cyp83a1 may be explained by a reduced supply of the fungus with inductive signals from the host and an accumulation of potentially fungitoxic metabolites.
authors.affiliation: Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann-Straße 2, 85354, Freising, Germany.
authors.forename: Corina
authors.initials: C
authors.lastname: Weis
authors.affiliation: Julius-von-Sachs-Institut für Biowissenschaften, Lehrstuhl für Botanik II, Universität Würzburg, Julius-von-Sachs-Platz 3, 97082, Würzburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Hildebrandt
authors.affiliation: Biotechnologie der Naturstoffe, Technische Universität München, Liesel-Beckmann-Str. 1, 85354, Freising, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoffmann
authors.affiliation: Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann-Straße 2, 85354, Freising, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hemetsberger
authors.affiliation: Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann-Straße 2, 85354, Freising, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Pfeilmeier
authors.affiliation: Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann-Straße 2, 85354, Freising, Germany.
authors.forename: Constanze
authors.initials: C
authors.lastname: König
authors.affiliation: Biotechnologie der Naturstoffe, Technische Universität München, Liesel-Beckmann-Str. 1, 85354, Freising, Germany.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Schwab
authors.affiliation: Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann-Straße 2, 85354, Freising, Germany.
authors.forename: Ruth
authors.initials: R
authors.lastname: Eichmann
authors.affiliation: Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann-Straße 2, 85354, Freising, Germany.
authors.forename: Ralph
authors.initials: R
authors.lastname: Hückelhoven
mesh_terms: D000447:Aldehydes / Q000494:pharmacology; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001203:Ascomycota / Q000187:drug effects / Q000502:physiology*; D002734:Chlorophyll / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D005961:Glucosinolates / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D009154:Mutation; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D013172:Spores, Fungal
chemical_list: D000447:Aldehydes; D029681:Arabidopsis Proteins; D005961:Glucosinolates; D002734:Chlorophyll; D003577:Cytochrome P-450 Enzyme System; C094565:CYP83A1 protein, Arabidopsis
keywords: BAX INHIBITOR-1; aldoximes; aliphatic glucosinolates; cytochrome P450 monooxygenase; metabolon; powdery mildew; susceptibility; very-long-chain aldehydes