Technical Abstract: The genus Aspergillus produces a number of mycotoxins that pose adverse economic and health impacts on humans and animals. These include the toxic and carcinogenic polyketide-derived mycotoxins, sterigmatocystin and aflatoxins, produced by Aspergillus nidulans and Aspergillus flavus, respectively. Studies have identified the gene clusters that are responsible for the synthesis of these toxins however there is still much to be elucidated regarding the signal transduction pathways and globally-acting regulators that control production of these toxins during fungal contamination of crops. In many cases, the mechanisms by which the fungus responds to environmental and plant-based factors have been found to not only control toxin production but also fungal growth and development.