Agricultural Microbes Genome 2 Conference Agricultural Microbes Genome 2 Conference
Poster: Cellular Processes, Regulatory Networks
P07_01.html
Fungi of the genus Aspergillus section Flavi are known to have both a positive and negative economic impact on international commerce. Aflatoxins, produced by the fungi Aspergillus flavus and A. parasiticus, occur in food and feed crops before harvest and are known to be toxic and extremely carcinogenic when introduced into animal systems. A cluster of at least 27 genes has been identified within about 80 kilobases DNA fragment in both A. flavus and A. parasiticusupon which reside almost all the genes involved in aflatoxin biosynthesis. The molecular regulation of this gene cluster has been characterized in significant detail, including the identification of a regulatory gene and a common regulatory relationship between fungal development and toxin synthesis. Our results also indicate that industrially significant fungi of section Flavi (A. oryzae, A. sojae) contain aflatoxin pathway genes but do not produce aflatoxins at least partly due to mutations in the regulatory mechanism. Understanding the molecular basis of the toxigenicity in Aspergillus species could lead to development of genetic engineering strategies to disrupt aflatoxin genes in the creation of atoxigenic fungal strains. These strains could be used as biocompetitive fungi for use in outcompeting toxigenic strains in the field or in storage.