title: Effects of laeA deletion on Aspergillus flavus conidial development and hydrophobicity may contribute to loss of aflatoxin production.
abstract: LaeA of Aspergillus nidulans is a putative methyltransferase and a component of the velvet complex; it is thought to mainly affect expression of genes required for the production of secondary metabolites. We found that although Aspergillus flavus CA14 laeA deletion mutants showed no aflatoxin production, expression of some of the early genes involved in aflatoxin formation, but not the later genes, could still be detected. The mutants grown in minimal medium supplemented with simple sugars and on some complex media exhibited altered conidial development. On potato dextrose agar (PDA) medium the deletion mutants showed reduced conidial chain elongation, increased production of conidiophores, and decreased colony hydrophobicity when compared to the parental strain. The loss of hydrophobicity and the other developmental changes in the laeA deletion mutants could affect the ability of the fungus to produce aflatoxins.
authors.affiliation: Southern Regional Research Center, Agricultural Research Service, US Department of Agriculture, New Orleans, LA 70124, United States. perngkuang.chang@ars.usda.gov
authors.forename: Perng-Kuang
authors.initials: PK
authors.lastname: Chang
authors.forename: Leslie L
authors.initials: LL
authors.lastname: Scharfenstein
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Ehrlich
authors.forename: Qijian
authors.initials: Q
authors.lastname: Wei
authors.forename: Deepak
authors.initials: D
authors.lastname: Bhatnagar
authors.forename: Bruce F
authors.initials: BF
authors.lastname: Ingber
mesh_terms: D000348:Aflatoxins / Q000378:metabolism*; D001231:Aspergillus flavus / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development; D050260:Carbohydrate Metabolism; D003470:Culture Media / Q000737:chemistry; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D057927:Hydrophobic and Hydrophilic Interactions; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism*; D013172:Spores, Fungal / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development
chemical_list: D000348:Aflatoxins; D003470:Culture Media; D008780:Methyltransferases