Identification and regulation of fusA, The polyketide synthase gene responsible for fusarin production in Fusarium fujikuroi

Fusarins are a class of mycotoxins of the polyketide family produced by different Fusarium species, including the gibberellin- producing fungus Fusarium fujikuroi. Based on sequence comparisons between polyketide synthase (PKS) enzymes for fusarin production in other Fusarium strains, we have identi...

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Detalles Bibliográficos
Autores: Ávalos Cordero, Francisco Javier, Limón Mirón, María del Carmen, Díaz Sánchez, Violeta
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/36412
Acceso en línea:http://hdl.handle.net/11441/36412
https://doi.org/10.1128/AEM.01552-12
Access Level:acceso abierto
Palabra clave:Agar culture
Conidiation
Fusarium
Fusarium oxysporums
Fusarium species
High sensitivity
MRNA level
Nitrogen availability
Plant tissues
Polyketide synthase genes
Polyketide synthases
Polyketides
Sequence comparisons
Wild types
Descripción
Sumario:Fusarins are a class of mycotoxins of the polyketide family produced by different Fusarium species, including the gibberellin- producing fungus Fusarium fujikuroi. Based on sequence comparisons between polyketide synthase (PKS) enzymes for fusarin production in other Fusarium strains, we have identified the F. fujikuroi orthologue, called fusA. The participation of fusA in fusarin biosynthesis was demonstrated by targeted mutagenesis. Fusarin production is transiently stimulated by nitrogen avail- ability in this fungus, a regulation paralleled by the fusA mRNA levels in the cell. Illumination of the cultures results in a reduc- tion of the fusarin content, an effect partially explained by a high sensitivity of these compounds to light. Mutants of the fusA gene exhibit no external phenotypic alterations, including morphology and conidiation, except for a lack of the characteristic yellow and/or orange pigmentation of fusarins. Moreover, the fusA mutants are less efficient than the wild type at degrading cel- lophane on agar cultures, a trait associated with pathogenesis functions in Fusarium oxysporum. The fusA mutants, however, are not affected in their capacities to grow on plant tissues.