Functional characterization, sequence comparisons and distribution of a polyketide synthase gene required for perithecial pigmentation in some Fusarium species

• Published in: Food additives and contaminants 2007-10, Vol.24 (10), p.1076-1087
• Main Authors: Proctor, R.H, Butchko, R.A.E, Brown, D.W, Moretti, A
• Format: Article
• Language: English
• Subjects: acetogenins; anamorphs; biochemical pathways; Biological and medical sciences; biosynthesis; Edible Grain - microbiology; food contamination; Food industries; food pathogens; Fundamental and applied biological sciences. Psychology; fungus physiology; Fusarium; Fusarium - genetics; Fusarium graminearum; Fusarium solani f. sp. pisi; Fusarium verticillioides; Gene Expression Profiling; gene expression regulation; Gene Expression Regulation, Fungal - genetics; General aspects; Genes, Fungal - genetics; genomics; Gibberella; Gibberella - genetics; Gibberella fujikuroi; Gibberella zeae; Hordeum - microbiology; Hygiene and safety; introns; microbial genetics; molecular sequence data; Mycotoxins - biosynthesis; Nectria haematococca; perithecium; phytotoxins; Pigments, Biological - biosynthesis; Pigments, Biological - genetics; Plant Diseases - genetics; plant pigments; polyketide synthase; Polyketide Synthases - genetics; Polymerase Chain Reaction; sequence analysis; Species Specificity; tetracyclines; toxigenic strains; Triticum - microbiology; wild relatives; wild type progenitor; Zea mays - microbiology
• ISSN: 0265-203X; 1464-5122
• DOI: 10.1080/02652030701546495

Polyketides are a structurally diverse class of secondary metabolites produced by bacteria, fungi, plants and animals. The fungal genus Fusarium includes agronomically important plant pathogenic and mycotoxin-producing species and produces numerous polyketides. The study further characterized a polyketide synthase-encoding gene (PKS3 = PGL1) that was previously identified in F. graminearum and F. verticillioides. Disruption of the F. verticillioides PGL1 indicated that it is required for the production of the dark pigment in perithecial walls, as previously shown in F. graminearum. A third PGL1 orthologue was identified in the genomic sequence of N. haematococca (anamorph F. solani f. sp. pisi). Analysis of the carboxy-terminal end of the deduced PGL1 protein indicated that it had a functional domain related to dehydrogenases/reductases that is sometimes present in non-ribosomal peptide synthetases. Comparison of the genomic regions flanking PGL1 in F. graminearum, F. verticillioides and N. haematococca revealed that the extent of gene synteny in this region was greater between F. graminearum and F. verticillioides than between either of these species and N. haematococca. Southern blot analysis indicated that PGL1 occurs widely within the genus Fusarium including species with no known sexual stage.