title: Folic acid induces salicylic acid-dependent immunity in Arabidopsis and enhances susceptibility to Alternaria brassicicola.
abstract: Folates are essential for one-carbon transfer reactions in all organisms and contribute, for example, to de novo DNA synthesis. Here, we detected the folate precursors 7,8-dihydropteroate (DHP) and 4-amino-4-deoxychorismate (ADC) in extracts from Arabidopsis thaliana plants by Fourier transform ion cyclotron resonance-mass spectrometry. The accumulation of DHP, but not ADC, was induced after infection of plants with Pseudomonas syringae delivering the effector protein AvrRpm1. Application of folic acid or the DHP precursor 7,8-dihydroneopterin (DHN) enhanced resistance in Arabidopsis to P. syringae and elevated the transcript accumulation of the salicylic acid (SA) marker gene pathogenesis-related1 in both the treated and systemic untreated leaves. DHN- and folic acid-induced systemic resistance was dependent on SA biosynthesis and signalling. Similar to SA, folic acid application locally enhanced Arabidopsis susceptibility to the necrotrophic fungus Alternaria brassicicola. Together, the data associate the folic acid pathway with innate immunity in Arabidopsis, simultaneously activating local and systemic SA-dependent resistance to P. syringae and suppressing local resistance to A. brassicicola.
authors.affiliation: Department of Environmental Sciences, Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany.
authors.forename: Finni
authors.initials: F
authors.lastname: Wittek
authors.affiliation: Department of Environmental Sciences, Research Unit Analytical Biogeochemistry, Helmholtz Zentrum Muenchen, Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany.
authors.forename: Basem
authors.initials: B
authors.lastname: Kanawati
authors.affiliation: Department of Environmental Sciences, Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Wenig
authors.affiliation: Biotechnology of Natural Products, Technische Universitaet Muenchen, Liesel-Beckmann-Str. 1, 85354, Freising, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoffmann
authors.affiliation: Biotechnology of Natural Products, Technische Universitaet Muenchen, Liesel-Beckmann-Str. 1, 85354, Freising, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Franz-Oberdorf
authors.affiliation: Biotechnology of Natural Products, Technische Universitaet Muenchen, Liesel-Beckmann-Str. 1, 85354, Freising, Germany.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Schwab
authors.affiliation: Department of Environmental Sciences, Research Unit Analytical Biogeochemistry, Helmholtz Zentrum Muenchen, Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany.|Analytical Food Chemistry, Technische Universitaet Muenchen, Alte Akademie 10, 85354, Freising, Germany.
authors.forename: Philippe
authors.initials: P
authors.lastname: Schmitt-Kopplin
authors.affiliation: Department of Environmental Sciences, Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany.
authors.forename: A Corina
authors.initials: AC
authors.lastname: Vlot
mesh_terms: D000528:Alternaria / Q000472:pathogenicity*; D017360:Arabidopsis / Q000276:immunology* / Q000382:microbiology; D005492:Folic Acid / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism*
chemical_list: D005492:Folic Acid; D020156:Salicylic Acid
keywords: 7; 8-dihydropteroate; Arabidopsis thaliana; cross-talk; folic acid; innate immunity; salicylic acid; systemic acquired resistance