The transcription factor AflR is required for up-regulation of specific pathway genes involved in aflatoxin biosynthesis in the filamentous fungus Aspergillus. nor-1 encodes an early aflatoxin pathway enzyme; its promoter contains a consensus AflR binding site (AflR1). Proteins in Aspergillus parasiticus cell extracts and AflR expressed in Escherichia coli do not bind to A. parasiticus AflR1 in...

The filamentous fungus Aspergillus nidulans contains a cluster of 25 genes that encode enzymes required to synthesize a toxic and carcinogenic secondary metabolite called sterigmatocystin (ST), a precursor of the better known fungal toxin aflatoxin (AF). One ST Cluster (stc) gene, aflR, functions as a pathway-specific transcriptional regulator for activation of other genes in the ST pathway. Ho...

BACKGROUND The effect of curcumin as a natural safe compound with different biological activities was examined on fungal growth and aflatoxin production in Aspergillus parasiticus NRRL 2999. METHODS The fungus was cultured in presence of serial two-fold concentrations of curcumin (125-2000 μg/ml) in yeast extract sucrose broth for 3 days at 28°C. Mycelia dry weight was determined as an index ...

In this study, the production of aflatoxin B1 (AFB1) and cyclopiazonic acid (CPA) was investigated in toxigenic and non-toxigenic Aspergillus flavus with respect to expression of aflR, veA and laeA genes that are involved to toxins production. A. flavus strains were cultured in YES broth at 28 °C for 4 days and the presence of (AFB1) and (CPA) was confirmed and measured by TLC and HPLC. The exp...

Transformants of Aspergillus flavus containing the Aequorea victoria gfp gene fused to a viral promoter or the promoter region and 483 bp of the coding region of A. flavus aflR expressed green fluorescence detectable without a microscope or filters. Expression of green fluorescent protein fluorescence was correlated with resistance to aflatoxin accumulation in five corn genotypes inoculated wit...

objective: aflatoxin is important in the food industry, in animal husbandry and the medical area; there are enormous negative economic impacts due to this toxin. numerous studies have researched extracts and plant compounds with the intent to reduce the growth of aflatoxin-producing organisms, inhibit toxin production and suppress the major toxin encoded genes (i.e., aflr) in these organisms. l...

The aim was to decipher the temporal impact of key interacting climate change (CC) abiotic factors temperature (30 vs 37 °C), water activity (aw; 0.985 0.930) and CO2 exposure (400 1000 ppm) on (a) growth Aspergillus flavus effects (b) gene expression a structural (aflD) regulatory (aflR) involved in aflatoxin B1 (AFB1) biosynthesis (c) AFB1 production yeast extract sucrose medium over period 1...

Aflatoxins (AFs) are secondary metabolites produced mainly by Aspergillus parasiticus and A. flavus. To study AF regulation, previously isolated non-toxigenic A. parasiticus sec- (for secondary metabolism minus) variants were genetically analysed. In parasexual crossing, the sec- strains failed to form heterokaryons and diploids with other sec- strains. Heterokaryon test results suggested that ...

Phosducin or phosducin-like protein (PhLP) is a positive regulator of Gbetagamma activity. The Gbeta (SfaD) and Ggamma (GpgA) subunits function in vegetative growth and developmental control in the model filamentous fungus Aspergillus nidulans. To better understand the nature of Gbetagamma-mediated signaling, phnA, encoding an A. nidulans PhLP, has been studied. Deletion of phnA resulted in phe...