title: Segregation of secondary metabolite biosynthesis in hybrids of Fusarium fujikuroi and Fusarium proliferatum.
abstract: Fusarium fujikuroi and Fusarium proliferatum are two phylogenetically closely related species of the Gibberella fujikuroi species complex (GFC). In some cases, strains of these species can cross and produce a few ascospores. In this study, we analyzed 26 single ascospore isolates of an interspecific cross between F. fujikuroi C1995 and F. proliferatum D4854 for their ability to produce four secondary metabolites: gibberellins (GAs), the mycotoxins fusarin C and fumonisin B(1), and a family of red polyketides, the fusarubins. Both parental strains contain the biosynthetic genes for all four metabolites, but differ in their ability to produce these metabolites under certain conditions. F. fujikuroi C1995 produces GAs and fusarins, while F. proliferatum D4854 produces fumonisins and fusarubins. The segregation amongst the progeny of these traits is not the expected 1:1 Mendelian ratio. Only eight, six, three and three progeny, respectively, produce GAs, fusarins, fumonisin B(1) and fusarubins in amounts similar to those synthesized by the producing parental strain. Beside the eight highly GA(3)-producing progeny, some of the progeny produce small amounts of GAs, predominantly GA(1), although these strains contain the GA gene cluster of the non-GA-producing F. proliferatum parental strain. Some progeny had recombinant secondary metabolite profiles under the conditions examined indicating that interspecific crosses can yield secondary metabolite production profiles that are atypical of the parent species.
authors.affiliation: Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität, Hindenburgplatz 55, 48143 Münster, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Studt
authors.forename: C
authors.initials: C
authors.lastname: Troncoso
authors.forename: F
authors.initials: F
authors.lastname: Gong
authors.forename: P
authors.initials: P
authors.lastname: Hedden
authors.forename: C
authors.initials: C
authors.lastname: Toomajian
authors.forename: J F
authors.initials: JF
authors.lastname: Leslie
authors.forename: H-U
authors.initials: HU
authors.lastname: Humpf
authors.forename: M C
authors.initials: MC
authors.lastname: Rojas
authors.forename: B
authors.initials: B
authors.lastname: Tudzynski
mesh_terms: D003433:Crosses, Genetic; D005670:Fusarium / Q000235:genetics*; D005800:Genes, Fungal; D005875:Gibberellins / Q000235:genetics / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D009183:Mycotoxins / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D061065:Polyketides / Q000378:metabolism; D011995:Recombination, Genetic
chemical_list: D005875:Gibberellins; D009183:Mycotoxins; D061065:Polyketides