Requirement of LaeA for secondary metabolism and sclerotial production in Aspergillus flavus.
The nuclear regulator LaeA has been shown to govern production of multiple secondary metabolites in Aspergillus nidulans and Aspergillus 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 DeltalaeA 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 DeltalaeA, 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.
Kale
Shubha P
SP
Department of Biology, Xavier University of Louisiana, New Orleans, LA 70125, USA. skale@xula.edu
Milde
Lane
L
Trapp
Marisa K
MK
Frisvad
Jens C
JC
Keller
Nancy P
NP
Bok
Jin Woo
JW
D000348:Aflatoxins / Q000096:biosynthesis; D010367:Arachis / Q000382:microbiology; D001231:Aspergillus flavus / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D048690:Fruiting Bodies, Fungal / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology; D012639:Seeds / Q000382:microbiology; D013172:Spores, Fungal / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
D000348:Aflatoxins; D005656:Fungal Proteins