Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/17/2009
Publication Date: 6/17/2009
Citation: Wiemann, P., Brown, D.W., Humpf, H., Tudzynski, B. 2009. How does VeA Regulates some Secondary Metabolism in Fusarium fujikuroi? [abstract]. Mycotoxin-Workshop, Munster, Germany. Interpretive Summary:
Technical Abstract: Fusarium fujikuroi is best known as a pathogen of rice that causes hyper elongation of seedling stalks and leaves due to the production of gibberellic acids (GAs). Besides GAs, F. fujikuroi may also synthesize other toxins like fumonisins, fusarin C, and bikaverin as well as carotenoids. Although the clustered genes responsible for synthesis of these secondary metabolites are well characterized, our understanding of their regulatory mechanisms is incomplete. In this study, we identified and characterized the F. fujikuroi veA gene and examined its role as a global regulator of secondary metabolism. Comparison of wild type and veA deletion strains in pathogenicity assays revealed significant less hyper elongation of rice infected with the deletion mutant. To identify genes influenced by VeA in F. fujikuroi, we examined changes in gene expression of wild type and veA knock-out strains by use of a F. verticillioides oligo microarray. We found that among the down-regulated genes are those involved in sexual development as well as GA and fumonisin synthesis. Up-regulated genes included those involved in bikaverin synthesis. No changes in expression were observed for genes involved in fusarin C or carotenoid production. Northern blot analysis confirmed the microarray data. Examination of veA-regulated genes led to the tentative identification of a putative ortholog of laeA, a critical regulator of secondary metabolism in Aspergillus. The impact of this gene on Fusarium secondary metabolism is currently under investigation. Our results further prove the cross-species use of the F. verticillioides microarray to elucidate the diverse effects VeA has on secondary metabolism in F. fujikuroi.