Project description:Goals: Comparing the infection between Ustilago maydis SG200 with the wild-type strain FB1xFB2 previously published Methods: Comparative RNASeq analysis between U. maydis SG200 and U. maydis FB1xFB2 at three timepoints (axenic, 2dpi, 12dpi) Results: The RNASeq analysis in SG200 identifies differences in gene expression with FB1xFB2. These differences could be the result of a unequal contribution of each nuclei to transcription. Further analysis identified a set of differentially transcribed genes.
Project description:Zea mays transcriptome profiling of infected seedlings by the Ustilago maydis wildtype and the seedling specific effector mutant demonstrated the variation of gene expression in the mutant and the classes of genes that are absent in the mutant as compared to the wildtype U. maydis SG200 strain. Two dye competitive hybridizations were performed on Agilent Oligo arrays.
Project description:The fungal pathogen Ustilago maydis establishes a biotrophic relationship with its host plant maize. Hallmarks of the disease are large plant tumors in which fungal proliferation occurs. Plants have developed various defense pathways to cope with pathogens. We used microarrays to detail the global programme of gene expression during the infection process of Ustilago maydis in its host plant to get insights into the defense programs and the metabolic reprogramming needed to supply the fungus with nutrients. Experiment Overall Design: In three independent experiments plants were infected with the solopathogenic U. maydis strain SG200. Samples from infected leaves were taken at 12 and 24 hours post infection, as well as 2, 4 and 8 days post infection. Samples from uninfected control plants were taken at the same time points.
Project description:Ustilago maydis is a basidiomycete fungus that causes smut disease in maize. Most prominent symptoms of the disease are plant tumors, which can be induced by U. maydis on all aerial parts of the plant. We identified two linked genes, pit1 and pit2, which are specifically expressed during plant colonization. Deletion mutants for either pit1 or pit2 are unable to induce tumor development and elicit plant defense responses. We used the Affymetrix maize genome array to analyze the transcriptional responses of maize to deletion pit1 and pit2 mutants and found plant responses to both mutants being not significantly distinguishable. U. maydis infected parts of maize seedling leaves were dissected 4 days after inoculation with strain SG200Dpit1 and SG200Dpit2, respectively. We previously submitted data of maize leaves that were treated with the progenitor wild type strain SG200 as well as mock-infections under identical experimetal conditions (GEO: GSE10023, 4d mock and 4d SG200 Samples, equivalent record in Arrayexpress: E-GEOD-10023). These data served as controls for this experiment.
Project description:The rep1 gene of the maize pathogen Ustilago maydis encodes a pre-pro-protein that is processed in the secretory pathway into 11 peptides. These so-called repellents form amphipathic amyloid fibrils at the surface of aerial hyphae. Strains in which the rep1 gene is inactivated (∆rep1 strain) are affected in aerial hyphae formation. This makes these strains instrumental to assess changes in global gene expression as a consequence of aerial growth. Microarray analysis revealed that only 31 genes in the ∆rep1 SG200 strain had a fold change in expression of >= 2. Twenty-two of these genes are up-regulated and half of them encode small secreted proteins (SSP’s) with unknown functions. Seven of the SSP genes and two other genes that are over-expressed in the ∆rep1 SG200 strain encode secreted cysteine-rich proteins (SCRP’s). Interestingly, most of the SCRP’s are predicted to form amyloids. The SCRP gene um00792 showed the highest up-regulation in the ∆rep1 strain. Using GFP as a reporter, it was shown that this gene is over-expressed in the layer of hyphae at the medium-air interface. Taken together, it is concluded that only minor changes occur in the expression profile when U. maydis forms aerial structures. Key words: aerial hypha, repellent, hydrophobin-like protein, Ustilago maydis, SSP, SCRP, fungal pathogenicity.
Project description:Anthocyanin induction in plant is considered a general defense response against biotic and abiotic stresses. The infection by Ustilago maydis, the corn smut pathogen, is accompanied with anthocyanin induction in leaf tissue. We revealed that anthocyanin is intentionally induced by the virulence promoting secreted effector protein Tin2. Tin2 protein functions inside plant cells where it interacts with cytoplasmic maize protein kinase ZmTTK1. Tin2 masks an ubiquitin-proteasome degradation motif in ZmTTK1 leading to a more stable active kinase. Active ZmTTK1 controls transcriptional activation of genes in the anthocyanin biosynthesis pathway rerouting phenylalanine away from lignin biosynthesis. Therefore, we performed microarray analysis to understand how maize gene transcription in phenylpropanoid pathway is differentially changed after infection with Ustilago maydis SG200 (wild type) and SG200Dtin2 (anthocyanin-inducing effector mutant).
Project description:Anthocyanin induction in plant is considered a general defense response against biotic and abiotic stresses. The infection by Ustilago maydis, the corn smut pathogen, is accompanied with anthocyanin induction in leaf tissue. We revealed that anthocyanin is intentionally induced by the virulence promoting secreted effector protein Tin2. Tin2 protein functions inside plant cells where it interacts with cytoplasmic maize protein kinase ZmTTK1. Tin2 masks an ubiquitin-proteasome degradation motif in ZmTTK1 leading to a more stable active kinase. Active ZmTTK1 controls transcriptional activation of genes in the anthocyanin biosynthesis pathway rerouting phenylalanine away from lignin biosynthesis. Therefore, we performed microarray analysis to understand how maize gene transcription in phenylpropanoid pathway is differentially changed after infection with Ustilago maydis SG200 (wild type) and SG200Dtin2 (anthocyanin-inducing effector mutant). We prepared three biological replicates for mock-inoculated maize (control), SG200-infected maize and SG200M-NM-^Ttin2-infected maize. For 1 sample, we harvested the leaves (1-3cm below injection hole) from 20 plants and pooled them. At 4 days post inoculation, total RNA was extracted.
Project description:The rep1 gene of the maize pathogen Ustilago maydis encodes a pre-pro-protein that is processed in the secretory pathway into 11 peptides. These so-called repellents form amphipathic amyloid fibrils at the surface of aerial hyphae. Strains in which the rep1 gene is inactivated (M-bM-^HM-^Frep1 strain) are affected in aerial hyphae formation. This makes these strains instrumental to assess changes in global gene expression as a consequence of aerial growth. Microarray analysis revealed that only 31 genes in the M-bM-^HM-^Frep1 SG200 strain had a fold change in expression of >= 2. Twenty-two of these genes are up-regulated and half of them encode small secreted proteins (SSPM-bM-^@M-^Ys) with unknown functions. Seven of the SSP genes and two other genes that are over-expressed in the M-bM-^HM-^Frep1 SG200 strain encode secreted cysteine-rich proteins (SCRPM-bM-^@M-^Ys). Interestingly, most of the SCRPM-bM-^@M-^Ys are predicted to form amyloids. The SCRP gene um00792 showed the highest up-regulation in the M-bM-^HM-^Frep1 strain. Using GFP as a reporter, it was shown that this gene is over-expressed in the layer of hyphae at the medium-air interface. Taken together, it is concluded that only minor changes occur in the expression profile when U. maydis forms aerial structures. Key words: aerial hypha, repellent, hydrophobin-like protein, Ustilago maydis, SSP, SCRP, fungal pathogenicity. To analyze expression changes in aerial hyphae upon deletion of the rep1 gene, strains SG200 and SG200M-bM-^HM-^Frep1 were grown on charcoal nitrate minimal array media supplemented with vitamins and 1% glucose at 22 C for 48 h. For each experiment three biological replicates were performed.