title: Metabolite diversity in the plant pathogen Alternaria brassicicola: factors affecting production of brassicicolin A, depudecin, phomapyrone A and other metabolites.
abstract: A systematic investigation of the metabolites of Alternaria brassicicola produced under various culture conditions is reported. The phytotoxin brassicicolin A is produced in significantly larger amounts in potato dextrose broth than in minimal medium cultures. In general an increase in the incubation temperature of cultures 23-30 C increases the production of brassicicolin A but decreases depudecin production. Reducing or eliminating nitrate from culture media or adding ammonium chloride increases the production of brassicicolin A at 30 C, depudecin at 23 C and α-acetylorcinol at either temperature, suggesting that nitrogen represses their biosynthesis. Siderophores are detected in cultures of A. brassicicola containing low and high ferric ion concentrations. The metabolites α-acetylorcinol and tyrosol are isolated for the first time from cultures of A. brassicicola, and α-acetylorcinol is synthesized in four steps and 36% overall yield. Only brassicicolin A and no other isolated metabolites, including depudecin and phomapyrone A, display phytotoxicity on leaves of Brassica species (up to 5.0 mM). Epigenetic modifiers, 5-azacitidin (5-AZA), suberoylanilide hydroxamic acid (SAHA) and suberoyl bis-hydroxamic acid (SBHA) do not affect the metabolite profiles of liquid cultures of this fungal pathogen.
authors: Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, S7N 5C9 Canada s.pedras@usask.ca.
authors: M Soledade C
authors: MS
authors: Pedras
authors: Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, S7N 5C9 Canada.
authors: Myung Ryeol
authors: MR
authors: Park
mesh_terms: D000466:Alkadienes / Q000737:chemistry / Q000378:metabolism*; D000528:Alternaria / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D001937:Brassica / Q000382:microbiology; D004852:Epoxy Compounds / Q000737:chemistry / Q000378:metabolism*; D005233:Fatty Alcohols / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D009183:Mycotoxins / Q000737:chemistry / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology
chemical_list: D000466:Alkadienes; D004852:Epoxy Compounds; D005233:Fatty Alcohols; D009183:Mycotoxins; C072251:depudecin
keywords: HDAC inhibitors; host-selective; phytotoxin; siderophores; tyrosol; α-acetylorcinol