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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 3/27/2014 Publication Date: 3/27/2014 Citation: Brown, D.W., Busman, M., Proctor, R. 2014. Fusarium verticillioides SGE1 is required for full virulence and regulates expression of protein effector and secondary metabolite biosynthetic genes. Meeting Abstract. Interpretive Summary: Technical Abstract: The transition from one lifestyle to another in some fungi is initiated by a single orthologous gene, SGE1, that regulates markedly different genes in different fungi. Despite these differences, many of the regulated genes encode effector proteins or proteins involved in the synthesis of secondary metabolites (SMs), both of which can contribute to pathogenicity. Fusarium verticillioides is both an endophyte and a pathogen of maize and can grow as a saprophyte on dead plant material. During growth on live maize plants, the fungus can synthesize a number of toxic SMs, including fumonisins, fusarins, and fusaric acid, that can contaminate kernels and kernel-based food and feed. In this study, the role of F. verticillioides SGE1 in pathogenicity and secondary metabolism was examined by gene deletion analysis and transcriptomics. SGE1 is not required for vegetative growth or conidiation but is required for wild-type pathogenicity and affects synthesis of multiple SMs including fumonisins and fusarins. Induced expression of SGE1 enhanced or reduced expression of hundreds of genes, including numerous putative effector genes that could contribute to growth in planta, genes encoding cell surface proteins, gene clusters required for synthesis of fusarins, bikaverin, and an unknown metabolite, as well as the gene encoding the fumonisin cluster transcriptional activator. Together, our results indicate that SGE1 has a role in global regulation of transcription in F. verticillioides, but that its role in regulation of pathogenicity and secondary metabolism is limited as is evident by partial reduction rather than elimination of virulence on maize and production of fumonisin |
