|Kistler, H - Corby|
Submitted to: Molecular Plant-Microbe Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/21/2010
Publication Date: 1/1/2011
Publication URL: http://hdl.handle.net/10113/48515
Citation: Lysoe, E., Pasquali, M., Breakspear, A., Kistler, H.C. 2011. The transcription factor FgStuAp influences spore development, pathogenicity, and secondary metabolism in Fusarium graminearum. Molecular Plant-Microbe Interactions. 24(1):54-67. Interpretive Summary: Fusarium graminearum is a fungus responsible for billions of dollars in agricultural losses to wheat and barley. We have conducted research aimed at understanding how genes in this harmful pathogen are turned on and off, especially if this regulation controls the ability of the fungus to cause disease or to allow toxins to contaminate grain. Using a genomics approach, we identified a new gene in the fungus that allows for toxin accumulation and disease causing ability. Factors which regulate this gene also control expression of important traits that potentially could be exploited for disease control measures. These disease management strategies may involve disruption of vital fungal developmental pathways. The primary users of the research in this publication will be other scientists engaged in research to improve disease management on small grain crops.
Technical Abstract: Fusarium graminearum is an important plant-pathogenic fungus and the major cause of cereal head blight. Here, we report the functional analysis of FgStuA, the gene for a transcription factor with homology to key developmental regulators in fungi. The deletion mutant was greatly reduced in pathogenicity on wheat heads and in production of secondary metabolites. Spore production was significantly impaired in 'FgStuA, which did not develop perithecia and sexual ascospores, and lacked conidiophores and phialides, leading to delayed production of aberrant macroconidia. FgStuAp appears to act as a global regulator that may affect many diverse aspects of the life cycle of F. graminearum. Transcriptome analysis shows that thousands of genes are differentially expressed in the mutant during asexual sporulation and infection of wheat heads and under conditions that induce secondary metabolites, including many that could account for the mutant phenotypes observed. The primary regulatory targets of FgStuAp are likely genes involved in cell-cycle control, and the predicted FgStuAp sequence has an APSES domain, with homology to helixloop-helix proteins involved in cell-cycle regulation. The Aspergillus StuAp response element (A/TCGCGT/ANA/C) was found highly enriched in the promoter sequences of cellcycle genes, which was upregulated in the 'FgStuA deletion mutant.