Requirement of LaeA for Secondary Metabolism and Sclerotial Production in Aspergillus flavus

Funding Source

United States Agency for International Development, National Institutes of Health, National Science Foundation

Grant Number

LAG-G-00-96-90013-00, 5SO6GM08008, MCB-0236393, 2002-35201-12562,R01 AI065728-01A1


Department of Biology

Document Type


Publication Date



The nuclear regulator LaeA has been shown to govern production of multiple secondary metabolites in A. nidulans and A. fumigatus. Herein we examine the role of this protein in Aspergillus flavus. Similarly as in other Aspergilli, LaeA had a major effect on A. flavus secondary metabolism where ΔlaeA and over-expression laeA (OE::laeA) strains yielded opposite phenotypes resulting in decreased (increased) secondary metabolite production. The two mutant strains also exhibited striking morphological phenotypes in the loss (increase) of sclerotial production in comparison to wildtype. Growth on seed was marked by decreased (increased) conidial and aflatoxin production of the respective mutants; this was accompanied by decreased lipase activity in ΔlaeA, an enzymatic process correlated with seed maceration. Transcriptional examination of the mutants showed LaeA negatively regulates expression of its recently identified nuclear partner VeA, another global regulator of A. flavus secondary metabolites and sclerotia.


DOI: 10.1016/j.fgb.2008.06.009

PubMed ID: 18667168

Funding text

Our thanks to Dr. Gary A. Payne for access to A. flavus genome data and for providing us with strains. This research was funded by NIH (MBRS) Grant 5SO6GM08008 to S.P.K., and in part by NSF MCB-0236393, USAID Peanut Collaborative Research Support Program Grant LAG-G-00-96-90013-00 and USDA/NRI Competitive Grant 2002-35201-12562 to N.P.K. and NIH R01 AI065728-01A1 to N.P.K. and J.C.F. J.C.F. also thanks the Danish Research Agency for financial support (Center for Microbial Biotechnology).