Submitted to: Fungal Genetics and Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/10/2012
Publication Date: 6/17/2012
Citation: Butchko, R.A., Brown, D.W., Busman, M., Tudzynski, B., Wiemann, P. 2012. LAE1 regulates expression of multiple secondary metabolite gene clusters in Fusarium verticillioides. Fungal Genetics and Biology. 49(2012)602-612. Interpretive Summary: This research discovered that the fungus Fusarium verticillioides has a gene called LAE1 that is involved in production of mycotoxins. One of the fungi that infects corn is called Fusarium verticillioides. This fungus can cause ear and stalk rot on corn, but it is also capable of producing toxins, called mycotoxins, that have been shown to cause cancer and birth defects in humans and also cause diseases in horses and swine. In this paper we investigated a gene called LAE1, which has previously been shown in other related fungi to function as a “global” regulator of mycotoxin production. In this research we have shown that LAE1 also regulates genes for mycotoxin production in F. verticillioides. This knowledge will be useful for designing novel methods for the control of mycotoxin contamination of corn by Fusarium.
Technical Abstract: The filamentous fungus Fusarium verticillioides can cause disease of maize and is capable of producing the polyketide derived mycotoxins called fumonisins. Fumonisin contamination of maize kernels is a food safety concern. Fumonisins have been implicated in human esophageal cancer as well as in causing neural tube defects. Fumonisins also pose a threat to livestock, causing lung edema in swine and leukoencephalomalacia in equines. The expression of genes required for fumonisin production (FUM gene cluster) is influenced by a number of environmental factors and a number of specific transcription factors have been implicated in the regulation of FUM gene expression. Here we describe an ortholog of the global regulatory factor LaeA from Aspergillus nidulans. LAEA is proposed to function in A. nidulans by modifying heterochomatin structure thus affecting expression of specific DNA regions. It is known that LaeA is part of a velvet complex in Aspergillus species and is involved in the regulation of multiple secondary metabolite gene clusters as well as in development. The F. verticillioides LAE1 ortholog was identified in a screen of genes expressed in a F. fujikuroi Vel1 deletion strain. Deletion of LAE1 in F. verticillioides results in the repression of expression of a number of secondary metabolite gene clusters. Biosynthesis of known secondary metabolites is also affected.