title: Malayamycin, a new streptomycete antifungal compound, specifically inhibits sporulation of Stagonospora nodorum (Berk) Castell and Germano, the cause of wheat glume blotch disease.
abstract: BACKGROUND
  Malayamycin is a novel perhydrofuropyran C-nucleoside isolated from Streptomyces malaysiensis that shows promising antifungal activity, fully controlling a range of diseases when applied to plants at 100 microg mL(-1). The goal of this study was to determine the mode of action.
  
  
  RESULTS
  Malayamycin exhibited in vitro antifungal activity against Stagonospora nodorum (Berk) Castell & Germano, the cause of stagonospora nodorum blotch of wheat. Growth in liquid minimum medium was merely delayed at 50 microg mL(-1), but sporulation was suppressed by more than 50% by 10 microg mL(-1) of malayamycin. When applied to wheat seedlings 36 h prior to infection, 10 microg mL(-1) of malayamycin reduced lesion size and significantly reduced pycnidiation to only 5% of the non-treated level. A transcription factor gene, Mrg1 (malayamycin response gene) whose expression was upregulated by application of malayamycin, was identified. Both Mrg1 knockout and overexpression strains were created. These strains were fully pathogenic, suggesting that the expression of Mrg1 did not affect pathogenicity. Interestingly, a strain that expressed Mrg1 50 times more than wild type showed a significant reduction in sporulation. However, all the tested knockout and overexpression strains retained sensitivity to malayamycin.
  
  
  CONCLUSIONS
  Malayamycin is a new type of antifungal compound that acts primarily by inhibiting sporulation. Although Mrg1 may be involved in the sporulation process, it is not the major contributor for sporulation inhibition caused by malayamycin treatment.
authors.affiliation: Australian Centre for Necrotrophic Fungal Pathogens, SABC, School of Veterinary and Biomedical Sciences, Murdoch University, Perth, WA, Australia.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Li
authors.forename: Michael
authors.initials: M
authors.lastname: Csukai
authors.forename: Andrew
authors.initials: A
authors.lastname: Corran
authors.forename: Patrick
authors.initials: P
authors.lastname: Crowley
authors.forename: Peter S
authors.initials: PS
authors.lastname: Solomon
authors.forename: Richard P
authors.initials: RP
authors.lastname: Oliver
mesh_terms: D001203:Ascomycota / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology*; D005659:Fungicides, Industrial / Q000494:pharmacology; D015966:Gene Expression Regulation, Fungal; D009705:Nucleosides / Q000494:pharmacology*; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014908:Triticum / Q000378:metabolism / Q000382:microbiology*
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D005659:Fungicides, Industrial; D009705:Nucleosides; D014157:Transcription Factors; C493874:malayamycin A