title: Phytohormone sensing in the biotrophic fungus Ustilago maydis - the dual role of the transcription factor Rss1.
abstract: The phenolic compound salicylic acid (SA) is a key signalling molecule regulating local and systemic plant defense responses, mainly against biotrophs. Many microbial organisms, including pathogens, share the ability to degrade SA. However, the mechanism by which they perceive SA is unknown. Here we show that Ustilago maydis, the causal agent of corn smut disease, employs a so far uncharacterized SA sensing mechanism. We identified and characterized the novel SA sensing regulator, Rss1, a binuclear zinc cluster protein with dual functions as putative SA receptor and transcriptional activator regulating genes important for SA and tryptophan degradation. Rss1 represents a major component in the identified SA sensing pathway during the fungus' saprophytic stage. However, Rss1 does not have a detectable impact on virulence. The data presented in this work indicate that alternative or redundant sensing cascades exist that regulate the expression of SA-responsive genes in U. maydis during its pathogenic development.
authors.affiliation: Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria.
authors.forename: Franziska
authors.initials: F
authors.lastname: Rabe
authors.affiliation: Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria.
authors.forename: Denise
authors.initials: D
authors.lastname: Seitner
authors.affiliation: Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria.
authors.forename: Lisa
authors.initials: L
authors.lastname: Bauer
authors.affiliation: Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria.
authors.forename: Fernando
authors.initials: F
authors.lastname: Navarrete
authors.affiliation: Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria.
authors.forename: Angelika
authors.initials: A
authors.lastname: Czedik-Eysenberg
authors.affiliation: Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria.
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Rabanal
authors.affiliation: Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria. armin.djamei@gmi.oeaw.ac.at.
authors.forename: Armin
authors.initials: A
authors.lastname: Djamei
mesh_terms: D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D010935:Plant Diseases / Q000382:microbiology; D010937:Plant Growth Regulators / Q000378:metabolism*; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014588:Ustilago / Q000235:genetics / Q000378:metabolism*; D003313:Zea mays / Q000382:microbiology
chemical_list: D005656:Fungal Proteins; D010937:Plant Growth Regulators; D014157:Transcription Factors; D020365:RNA Helicases; D020156:Salicylic Acid