title: Siderophore synthesis in Magnaporthe grisea is essential for vegetative growth, conidiation and resistance to oxidative stress.
abstract: The plant pathogenic fungus Magnaporthe grisea excretes siderophores of the coprogen-type for iron acquisition and uses ferricrocin for intracellular iron storage. In the present report we characterize mutants with defects in extracellular siderophore biosynthesis. Deletion of the M. grisea SSM2 gene, which encodes a non-ribosomal peptide synthetase, resulted in a loss of the production of all coprogens. The mutant strains had a reduced growth rate, produced fewer conidia and were more sensitive to oxidative stress. Ferricrocin production was not affected. Upon deletion of M. grisea OMO1, a gene predicted to encode an L-ornithine-N(5)-monooxygenase, no siderophores of any type were detected, the strain was aconidial, growth rate was reduced and sensitivity to oxidative stress was increased. Abundance of several proteins was affected in the mutants. The Deltassm2 and Deltaomo1 mutant phenotypes were complemented by supplementation of the medium with siderophores or reintroduction of the respective genes.
authors.affiliation: Institut für Biotechnologie und Wirkstoff-Forschung e.V., Kaiserslautern, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Hof
authors.forename: Katrin
authors.initials: K
authors.lastname: Eisfeld
authors.forename: Luis
authors.initials: L
authors.lastname: Antelo
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Foster
authors.forename: Heidrun
authors.initials: H
authors.lastname: Anke
mesh_terms: D005656:Fungal Proteins / Q000235:genetics; D017353:Gene Deletion; D005816:Genetic Complementation Test; D020082:Magnaporthe / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D006899:Mixed Function Oxygenases / Q000235:genetics; D018384:Oxidative Stress; D010453:Peptide Synthases / Q000235:genetics; D017262:Siderophores / Q000096:biosynthesis*; D013172:Spores, Fungal / Q000254:growth & development*; D013312:Stress, Physiological
chemical_list: D005656:Fungal Proteins; D017262:Siderophores; D006899:Mixed Function Oxygenases; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase