title: Sfp-type 4'-phosphopantetheinyl transferase is indispensable for fungal pathogenicity.
abstract: In filamentous fungi, Sfp-type 4'-phosphopantetheinyl transferases (PPTases) activate enzymes involved in primary (alpha-aminoadipate reductase [AAR]) and secondary (polyketide synthases and nonribosomal peptide synthetases) metabolism. We cloned the PPTase gene PPT1 of the maize anthracnose fungus Colletotrichum graminicola and generated PPTase-deficient mutants (Deltappt1). Deltappt1 strains were auxotrophic for Lys, unable to synthesize siderophores, hypersensitive to reactive oxygen species, and unable to synthesize polyketides (PKs). A differential analysis of secondary metabolites produced by wild-type and Deltappt1 strains led to the identification of six novel PKs. Infection-related morphogenesis was affected in Deltappt1 strains. Rarely formed appressoria of Deltappt1 strains were nonmelanized and ruptured on intact plant. The hyphae of Deltappt1 strains colonized wounded maize (Zea mays) leaves but failed to generate necrotic anthracnose disease symptoms and were defective in asexual sporulation. To analyze the pleiotropic pathogenicity phenotype, we generated AAR-deficient mutants (Deltaaar1) and employed a melanin-deficient mutant (M1.502). Results indicated that PPT1 activates enzymes required at defined stages of infection. Melanization is required for cell wall rigidity and appressorium function, and Lys supplied by the AAR1 pathway is essential for necrotrophic development. As PPTase-deficient mutants of Magnaporthe oryzea were also nonpathogenic, we conclude that PPTases represent a novel fungal pathogenicity factor.
authors.affiliation: Martin-Luther-Universität Halle-Wittenberg, Naturwissenschaftliche Fakultät III, Institut für Agrar und Ernährungswissenschaften, Phytopathologie und Pflanzenschutz, D-06099 Halle (Saale), Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Horbach
authors.forename: Alexander
authors.initials: A
authors.lastname: Graf
authors.forename: Fabian
authors.initials: F
authors.lastname: Weihmann
authors.forename: Luis
authors.initials: L
authors.lastname: Antelo
authors.forename: Sebastian
authors.initials: S
authors.lastname: Mathea
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Liermann
authors.forename: Till
authors.initials: T
authors.lastname: Opatz
authors.forename: Eckhard
authors.initials: E
authors.lastname: Thines
authors.forename: Jesús
authors.initials: J
authors.lastname: Aguirre
authors.forename: Holger B
authors.initials: HB
authors.lastname: Deising
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D020231:Colletotrichum / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology*; D020082:Magnaporthe / Q000201:enzymology / Q000235:genetics / Q000472:pathogenicity; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017855:Transferases (Other Substituted Phosphate Groups) / Q000235:genetics / Q000502:physiology*; D014774:Virulence / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D005656:Fungal Proteins; C082662:phosphopantetheinyl transferase; D017855:Transferases (Other Substituted Phosphate Groups)