Project description:Fusarium graminearum is a plant pathogen that can cause the devastating cereal grain disease fusarium head blight (FHB) in temperate regions of the world. Previous studies have shown that F. graminearum can synthetize indole-3-acetic acid (auxin) using L-tryptophan (L-TRP)-dependent pathways. In the present study, Gene expression profiles were obtained using microarray analysis of RNAs from F. graminearum cultures in auxin producing conditions, treated with L-TRP, tryptamine (TAM) and indole-3 acetaldehyde (IAAld). A comparative expression profiling of all treatments identified candidate genes for auxin production in F. graminearum. Additional analysis of the expression profiling between L-TRP-treated and control cultures showed that L-TRP treatment induce the up-regulation of a series of genes with predicted function in the metabolism of L-TRP via anthranilic acid and catechol towards the tricarboxylic acid cycle.
Project description:Salicylic acid (SA) is one of the key signal molecules in regulating plant resistance to diverse pathogens. It is predominantly associated with resistance against biotrophic and hemibiotrophic pathogens, and triggering systemic acquired resistance (SAR) in Arabidopsis. However, whether and how SA directly affects Fusarium graminearum and how SA influences the defence efficiency of wheat against fusarium head blight (FHB) are still poorly understood. Previous experiments have shown that the growth of F. graminearum mycelia and the germination of spores were significantly inhibited, and eventually stopped by increasing amounts of SA in both liquid and solid media cultures. Co-inoculation of SA and Fg spores has led to reduced FHB symptoms in the very susceptible Triticum aestivum cultivar ‘Roblin’. To better understand the effect of SA on F. graminearum mycelial growth, we have compared the expression profiles of SA-treated and untreated F. graminearum liquid cultures after 8 and 24 h of treatment, using an F. graminearum custom-commercial microarray. The microarray analysis suggests that F. graminearum can metabolize SA through two pathways, the gentisate and catechol pathways that are present in many fungal species. Additional experiments have confirmed the capacity of F. graminearum to metabolize SA. Our results demonstrate that, although F. graminearum has the capacity to metabolize SA, SA has a significant and direct impact on F. graminearum through a reduction in efficiency of germination and growth at higher concentrations.
Project description:Salicylic acid (SA) is one of the key signal molecules in regulating plant resistance to diverse pathogens. It is predominantly associated with resistance against biotrophic and hemibiotrophic pathogens, and triggering systemic acquired resistance (SAR) in Arabidopsis. However, whether and how SA directly affects Fusarium graminearum and how SA influences the defence efficiency of wheat against fusarium head blight (FHB) are still poorly understood. Previous experiments have shown that the growth of F. graminearum mycelia and the germination of spores were significantly inhibited, and eventually stopped by increasing amounts of SA in both liquid and solid media cultures. Co-inoculation of SA and Fg spores has led to reduced FHB symptoms in the very susceptible Triticum aestivum cultivar ‘Roblin’. To better understand the effect of SA on F. graminearum mycelial growth, we have compared the expression profiles of SA-treated and untreated F. graminearum liquid cultures after 8 and 24 h of treatment, using an F. graminearum custom-commercial microarray. The microarray analysis suggests that F. graminearum can metabolize SA through two pathways, the gentisate and catechol pathways that are present in many fungal species. Additional experiments have confirmed the capacity of F. graminearum to metabolize SA. Our results demonstrate that, although F. graminearum has the capacity to metabolize SA, SA has a significant and direct impact on F. graminearum through a reduction in efficiency of germination and growth at higher concentrations. Untreated and Salicylic Acid (SA) treated liquid cultures of F. graminearum at 8h and 24h collection times. Three biological replicates per time point and treatment, 2 technical replicates (dye flips) per sample.
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