Beyond aflatoxin: four distinct expression patterns and functional roles associated withAspergillus flavussecondary metabolism gene clusters
Autor: | Natalie D. Fedorova, Jin Woo Bok, James L. Burroughs, Sigal Horowitz-Brown, Charles P. Woloshuk, D. Ryan Georgianna, Nancy P. Keller, Jiujiang Yu, Andrea L. Dolezal, Gary A. Payne |
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Rok vydání: | 2010 |
Předmět: |
Indoles
Transcription Genetic Genes Fungal Soil Science Aspergillus flavus Plant Science Secondary metabolite Zea mays Article Fungal Proteins chemistry.chemical_compound Aflatoxins Gene Expression Regulation Fungal Gene cluster medicine Cluster Analysis heterocyclic compounds Secondary metabolism Molecular Biology Gene Genetics Aspergillus Fungal protein biology Reverse Transcriptase Polymerase Chain Reaction Temperature food and beverages Hydrogen-Ion Concentration biology.organism_classification chemistry Multigene Family Cyclopiazonic acid Agronomy and Crop Science medicine.drug |
Zdroj: | Molecular Plant Pathology. 11:213-226 |
ISSN: | 1364-3703 1464-6722 |
Popis: | SUMMARY Species of Aspergillus produce a diverse array of secondary metabolites, and recent genomic analysis has predicted that these species have the capacity to synthesize many more compounds. It has been possible to infer the presence of 55 gene clusters associated with secondary metabolism in Aspergillus flavus; however, only three metabolic pathways—aflatoxin, cyclopiazonic acid (CPA) and aflatrem—have been assigned to these clusters. To gain an insight into the regulation of and to infer the ecological significance of the 55 secondary metabolite gene clusters predicted in A. flavus, we examined their expression over 28 diverse conditions. Variables included culture medium and temperature, fungal development, colonization of developing maize seeds and misexpression of laeA, a global regulator of secondary metabolism. Hierarchical clustering analysis of expression profiles allowed us to categorize the gene clusters into four distinct clades. Gene clusters for the production of aflatoxins, CPA and seven other unknown compound(s) were identified as belonging to one clade. To further explore the relationships found by gene expression analysis, aflatoxin and CPA production were quantified under five different cell culture environments known to be conducive or nonconducive for aflatoxin biosynthesis and during the colonization of developing maize seeds. Results from these studies showed that secondary metabolism gene clusters have distinctive gene expression profiles. Aflatoxin and CPA were found to have unique regulation, but are sufficiently similar that they would be expected to co-occur in substrates colonized with A. flavus. |
Databáze: | OpenAIRE |
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