Project description:Ustilago maydis, the causal agent of corn smut disease, is a dimorphic fungus alternating between a saprobic haploid budding form, and an obligate pathogenic filamentous dikaryon. Maize responds to U. maydis colonization by producing highly modified tumorous structures and it is only within these plant galls that the fungus sporulates giving rise to melanized sexual spores, the teliospores. Previously we identified a regulatory protein from the APSES family of transcription factors, which we named Ust1, whose absence in yeast cells led to filamentous growth and the production of highly pigmented spore-like structures in culture. In this study, we analyzed the transcriptome of a ∆ust1 deletion mutant.
Project description:Ustilago maydis, the causal agent of corn smut disease, is a dimorphic fungus alternating between a saprobic haploid budding form, and an obligate pathogenic filamentous dikaryon. Maize responds to U. maydis colonization by producing highly modified tumorous structures and it is only within these plant galls that the fungus sporulates giving rise to melanized sexual spores, the teliospores. Previously we identified a regulatory protein from the APSES family of transcription factors, which we named Ust1, whose absence in yeast cells led to filamentous growth and the production of highly pigmented spore-like structures in culture. In this study, we analyzed the transcriptome of a ?ust1 deletion mutant. To identify genes potentially involved in the sporulation program, we carried out microarray analysis comparing a haploid U. maydis WT strain (1/2) and ust1 (14/25) in vitro. Wild-type and ?ust1 strains were grown in potato dextrose broth (PDB) for 48 h at 30oC. To allow effective comparison with other array data generated by U. maydis researchers, cells were then transferred to liquid array medium (6.25% Holiday salt solution, 30mM L-glutamine, 1% glucose, pH7.0, filter sterilized) at 30 C. Total RNA samples from WT 1/2 and ?ust1 mutant strains grown in array medium for 24 h (mutant’s filamentous phase), and 48 h (mutant’s spore-like structure formation phase) were extracted and purified (Sigma Spectrum Plant Total RNA Kit, Cat.No.STRN50). RNA was sent to NimbleGen, where it was reverse transcribed to cDNA and Cy3 labeled. The cDNA samples were hybridized, microarray chips scanned, and raw data normalized with appropriate controls.
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.
Project description:The coding transcriptomes of filamentous cultures of the maize smut fungus Ustilago maydis and their extracellular vesicles (EVs) were compared. Protein-coding transcripts relatively enriched in EVs versus filament cells were identified and examined to identify potentially functional mRNA cargos of U. maydis EVs.
Project description:Plant pathogenic fungi cause massive crop losses and therefore, severe economic deficits. The smut Ustilago maydis, a ubiquitous pest of corn, is highly adapted to its host to parasitize on its organic carbon sources. Recently, we identified the U. maydis sucrose transporter Srt1 to be of crucial importance for biotrophic development. Here we report the identification of Hxt1, a further member of the U. maydis sugar transporter family, which is of importance for full fungal virulence. Hxt1 mainly utilizes the hexoses glucose, fructose and mannose, but with lower affinity also secondary carbon sources like galactose and xylose. Deletion of hxt1 in U. maydis reduces virulence and growth on hexoses, in contrast growth on the secondary carbon sources is enhanced. Expression analysis revealed that monosaccharide-dependent regulation of transcription is hampered in hxt1 deletion mutants, leading to the expression of genes involved in the metabolism of secondary sugars and in the initiation of pathogenicity. Thus, we propose that Hxt1 has a dual function as monosaccharide-transporter and -sensor. While Hxt1 aids the initiation of pathogenicity by sensing starvation conditions on the plant surface as a receptor, it feeds the fungus in planta as a transporter.
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:Plant pathogenic fungi cause massive crop losses and therefore, severe economic deficits. The smut Ustilago maydis, a ubiquitous pest of corn, is highly adapted to its host to parasitize on its organic carbon sources. Recently, we identified the U. maydis sucrose transporter Srt1 to be of crucial importance for biotrophic development. Here we report the identification of Hxt1, a further member of the U. maydis sugar transporter family, which is of importance for full fungal virulence. Hxt1 mainly utilizes the hexoses glucose, fructose and mannose, but with lower affinity also secondary carbon sources like galactose and xylose. Deletion of hxt1 in U. maydis reduces virulence and growth on hexoses, in contrast growth on the secondary carbon sources is enhanced. Expression analysis revealed that monosaccharide-dependent regulation of transcription is hampered in hxt1 deletion mutants, leading to the expression of genes involved in the metabolism of secondary sugars and in the initiation of pathogenicity. Thus, we propose that Hxt1 has a dual function as monosaccharide-transporter and -sensor. While Hxt1 aids the initiation of pathogenicity by sensing starvation conditions on the plant surface as a receptor, it feeds the fungus in planta as a transporter. To analyze expression changes of SG200 and SG200∆hxt1 both strains were grown in glutamine minimal array media supplemented with 1% glucose or 1 %xylose to an OD600 of 1.0 for 6 h, respectively. For each experiment two independent replicates were conducted.
Project description:The biotrophic fungal pathogen Ustilago maydis cause common smut in maize, and lead to gall formation on all aerial organs, especially on maize kernel thus reduce yield. The interaction of U. maydis with maize is a well-established model to study the interaction between maize and biotrophic pathogen. U. maydis infection could activate host immune responses including: ROS accumulation, protease activation, salicylic acid signaling. U. maydis employ several strategies to overcome maize immune response, thus initial the biotrophic interaction with host. It has been suggested that genetic factors of maize host affected the disease severity of U. maydis infection, here we investigated the transcriptome profile of resistance and susceptible maize lines upon U. maydis infection, thus propose candidate maize genes involved in the defense response in maize to corn smut cause by U. maydis.
Project description:The basidiomycete Ustilago maydis causes smut disease in maize. Colonization of the host plant is initiated by direct penetration of cuticle and cell wall of maize epidermis cells. The invading hyphae are surrounded by the plant plasma membrane and proliferate within the plant tissue. We identified a novel secreted protein, termed Pep1. Disruption mutants of pep1 are not affected in saprophytic growth and develop normal infection structures. However, Δpep1 mutants fail to penetrate the epidermal cell wall and elicit a strong plant defense response. Using Affymetrix maize arrays we identified about 110 plant genes which are differentially regulated in Δpep1 and wild type infections during the penetration stage.
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).