Identification of genetic defects in the atoxigenic biocontrol strain Aspergillus flavus K49 reveals the presence of a competitive recombinant group in field populations.
Int J Food Microbiol
; 154(3): 192-6, 2012 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-22285533
ABSTRACT
Contamination of corn, cotton, peanuts and tree nuts by aflatoxins is a severe economic burden for growers. A current biocontrol strategy is to use non-aflatoxigenic Aspergillus flavus strains to competitively exclude field toxigenic Aspergillus species. A. flavus K49 does not produce aflatoxins and cyclopiazonic acid (CPA) and is currently being tested in corn-growing fields in Mississippi. We found that its lack of production of aflatoxins and CPA resulted from single nucleotide mutations in the polyketide synthase gene and hybrid polyketide-nonribosomal peptide synthase gene, respectively. Furthermore, based on single nucleotide polymorphisms of the aflatoxin biosynthesis omtA gene and the CPA biosynthesis dmaT gene, we conclude that K49, AF36 and previously characterized TX9-8 form a biocontrol group. These isolates appear to be derived from recombinants of typical large and small sclerotial morphotype strains. This finding provides an easy way to select future biocontrol strains from the reservoir of non-aflatoxigenic populations in agricultural fields.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peptídeo Sintases
/
Aspergillus flavus
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Aflatoxinas
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Policetídeo Sintases
/
Indóis
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article