Sfp-type 4'-phosphopantetheinyl transferase is required for lysine synthesis, tolerance to oxidative stress and virulence in the plant pathogenic fungus Cochliobolus sativus.

摘要: SUMMARY Polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs) are the major enzymes involved in biosynthesis of secondary metabolites, which have diverse activities, including roles as pathogenicity/virulence factors plant pathogenic fungi. These activated by 4′-phosphopantetheinylation at conserved serine residues, is catalysed 4′-phosphopantetheinyl transferase (PPTase). PPTase also required for primary metabolism (α-aminoadipate reductase, AAR). In genome sequence cereal fungal pathogen Cochliobolus sativus, we identified a gene (PPT1) orthologous to PPTase-encoding genes found other filamentous ascomycetes. The deletion PPT1 C. sativus generated mutants (Δppt1) that were auxotrophic lysine, unable synthesize melanin, hypersensitive oxidative stress significantly reduced virulence barley cv. Bowman. To analyse pleiotropic effects PPT1, characterized PKS1 (involved melanin synthesis), AAR1 (for AAR) NPS6 siderophore-mediated iron metabolism). melanin-deficient strain (Δpks1) showed no differences pathogenicity compared with wild-type strain. Lysine-auxotrophic (Δaar1) induced spot blotch symptoms, produced strain, when inoculated on wounded leaves or lysine was supplemented. Δnps6 slightly but exhibited higher than Δppt1 Our results suggest an unknown factor, presumably synthesized PKSs NRPSs PPTase, directly responsible high