Project description:In F. graminearum, the transcriptional regulator TRI6 is encoded within the trichothecene gene cluster and regulates genes involved in the biosynthesis of the secondary metabolite deoxynivalenol (DON). Targeted disruption of TRI6 confirmed its role as a positive regulator of trichothecene genes and previous studies designated Tri6 as a pathway-specific transcriptional regulator. The Tri6 protein with its Cys2His2 zinc-finger may also conform to the class of broad-domain transcription regulators. This class of global transcriptional regulators mediate various environmental cues and generally responds to the demands of cellular metabolism. Expression profiling of F. graminearum grown under nitrogen-limiting conditions revealed that 49 out of 198 target genes are differentially regulated by TRI6. The identification of potential new targets together with deciphering novel binding site for Tri6, casts new light into the role of this transcriptional regulator in the overall growth and development of F. graminearum. Three biological replicates of Fusarium graminearum wildtype strain GZ3639 (NRRL 38155) (reference) and a tri6∆ mutant derived from GZ3639 were grown under nitrogen-limiting conditions in liquid culture for 5 hrs at 28oC
Project description:Fusarium head blight (FHB) is a major disease of cereal crops caused by the fungus Fusarium graminearum (Fg). FHB affects the flowering heads (or spikes) and developing seeds. This study compares the gene expression profile of heads from the susceptible cultivar Roblin after inoculation with either water (W) or the disarmed Fg strain tri6Δ (T6). Tri6 is a global transcription regulator affecting the trichothecene biosynthesis pathway.
Project description:In F. graminearum, the transcriptional regulator TRI6 is encoded within the trichothecene gene cluster and regulates genes involved in the biosynthesis of the secondary metabolite deoxynivalenol (DON). Targeted disruption of TRI6 confirmed its role as a positive regulator of trichothecene genes and previous studies designated Tri6 as a pathway-specific transcriptional regulator. The Tri6 protein with its Cys2His2 zinc-finger may also conform to the class of broad-domain transcription regulators. This class of global transcriptional regulators mediate various environmental cues and generally responds to the demands of cellular metabolism. Expression profiling of F. graminearum grown under nitrogen-limiting conditions revealed that 49 out of 198 target genes are differentially regulated by TRI6. The identification of potential new targets together with deciphering novel binding site for Tri6, casts new light into the role of this transcriptional regulator in the overall growth and development of F. graminearum.
Project description:TRI6 is a positive regulator of the trichothecene gene cluster and the production of trichothecene mycotoxins (deoxynivalenol [DON] and acetylated forms such as 15-ADON) in the cereal pathogen F. graminearum. As a global transcriptional regulator, TRI6 expression is modulated by nitrogen-limiting conditions, sources of nitrogen and carbon, pH, and light. However, the mechanism by which these diverse environmental factors affect TRI6 expression remains under-explored. In our effort to understand how nutrients affect TRI6 regulation, comparative digital expression profiling was performed with a wildtype F. graminearum and a Δtri6 mutant strain, grown in nutrient-rich conditions. Analysis showed that TRI6 negatively regulates genes of the branched-chain amino acid (BCAA) metabolic pathway. Feeding studies with deletion mutants of MCC, encoding methylcrotonyl-CoA-carboxylase, one of the key enzymes of leucine metabolism, showed that addition of leucine specifically down regulated TRI6 expression and reduced 15-ADON accumulation. Constitutive expression of TRI6 in the Δmcc mutant strain restored 15-ADON production. A combination of cellophane breach assays and pathogenicity experiments on wheat demonstrated that disrupting the leucine metabolic pathway significantly reduced disease. These findings suggest a complex interaction between one of the primary metabolic pathways with a global regulator of mycotoxin biosynthesis and virulence in F. graminearum.
Project description:Identifying the role of TRI6 in Fusarium graminearum isolate NRRL29169 by high-throughput RNA sequencing under two environemental conditions.
Project description:TRI6 is a positive regulator of the trichothecene gene cluster and the production of trichothecene mycotoxins (deoxynivalenol [DON] and acetylated forms such as 15-ADON) in the cereal pathogen F. graminearum. As a global transcriptional regulator, TRI6 expression is modulated by nitrogen-limiting conditions, sources of nitrogen and carbon, pH, and light. However, the mechanism by which these diverse environmental factors affect TRI6 expression remains under-explored. In our effort to understand how nutrients affect TRI6 regulation, comparative digital expression profiling was performed with a wildtype F. graminearum and a Δtri6 mutant strain, grown in nutrient-rich conditions. Analysis showed that TRI6 negatively regulates genes of the branched-chain amino acid (BCAA) metabolic pathway. Feeding studies with deletion mutants of MCC, encoding methylcrotonyl-CoA-carboxylase, one of the key enzymes of leucine metabolism, showed that addition of leucine specifically down regulated TRI6 expression and reduced 15-ADON accumulation. Constitutive expression of TRI6 in the Δmcc mutant strain restored 15-ADON production. A combination of cellophane breach assays and pathogenicity experiments on wheat demonstrated that disrupting the leucine metabolic pathway significantly reduced disease. These findings suggest a complex interaction between one of the primary metabolic pathways with a global regulator of mycotoxin biosynthesis and virulence in F. graminearum. Triplicate samples of digital gene expression profiling data for the Tri6 mutant and wildtype strains were compared. **Please note that the raw data files for the current study are no longer available, and therefore are not included in the submission.
Project description:Fusarium graminearum (teleomorph Gibberella zeae) is a prominent pathogen that infects major cereal crops, such as wheat, barley, and maize. Fhs1 contains a Zn(II)2Cys6 fungal-type DNA-binding domain and localized to nuclei , suggesting that Fhs1 is a transcription factor required for hydroxiurea. 6 samples examined: 24 h after inoculation of Fusarium graminearum wild-type Z-3639 and fhs1 (Îfhs1::GEN) strains in complete media
Project description:The plant pathogenic fungus Fusarium graminearum (Fgr) creates economic and health risks in cereals agriculture. Fgr causes head blight (or scab) of wheat and stalk rot of corn, reducing yield, degrading grain quality and polluting downstream food products with mycotoxins. Fungal plant pathogens must secrete proteases to access nutrition and to breakdown the structural protein component of the plant cell wall. Research into the proteolytic activity of Fgr is hindered by the complex nature of the suite of proteases secreted. We used a systems biology approach comprising genome analysis, transcriptomics and label-free quantitative proteomics to characterise the peptidases deployed by Fgr during growth. A combined analysis of published microarray transcriptome datasets revealed seven transcriptional groupings of peptidases based on in vitro growth, in planta growth, and sporulation behaviours. An orbitrap MS/MS proteomics technique defined the extracellular proteases secreted by Fusarium graminearum.
Project description:Fusarium graminearum (teleomorph Gibberella zeae) is a prominent pathogen that infects major cereal crops, such as wheat, barley, and maize. Conidiogenesis had been intensively studied in Aspergillus nidulans and regulatory pathway genes have been known to regulate conidiogenesis in stage specific manner. We reported the functional analyses of flbD, abaA, and wetA orthologs in F. graminearum. To understand genome-wide transcriptional profiling of conidiation, we employed RNA-seq of the wild-type Fusarium graminearum Z-3639 and each gene deletion mutants with three time courses (0 h, 6 h and 12 h after induction of conidiogenesis). AbaA experiment: 6 samples examined: 0 h, 6 h and 12 h after induction of conidiogenesis of Fusarium graminearum Z-3639 wild type and ΔabaA(ΔabaA::gen) mutant strains WetA experiment: 3 samples examined: 0 h, 6 h and 12 h after induction of conidiogenesis of Fusarium graminearum ΔwetA(ΔwetA::gen) mutant strains flbD experiment: 3 samples examined: 0 h, 6 h and 12 h after induction of conidiogenesis of Fusarium graminearum ΔflbD(ΔflbD::gen) mutant strains