Gene expression of Ustilago maydis SG200, SG200∆hxt1 and the avirulent SG200∆hxt1 hxt1(R164K) on maize leaf surface
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ABSTRACT:
ORGANISM(S): Ustilago maydis
PROVIDER: GSE61069 | GEO | 2014/09/04
SECONDARY ACCESSION(S): PRJNA260180
REPOSITORIES: GEO
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Project description:Hxt1 is a high affinity hexose transporter important for virulence of the phytopathogenic basidiomycete Ustilago maydis on its host plant maize. Hxt1 shows the highest similarities to the glucose sensors Rgt2 and Snf3 from S. cereviciae (42% and 39% identity on amino acid level, respectively). In these sensors, the substitution of a highly conserved arginine to lysine leads to a constitutive active signal, resulting in expression of several glucose induced genes. Introduction of an analogous mutation in Hxt1 leads to loss of transport activity in the resulting Hxt1(R164K) protein. Expression of Hxt1(R164K) in hxt1 deletion strains results in a completely avirulent phenotype. Pathogenic developement of M-bM-^HM-^Fhxt1 hxt1(R164K) strains is blocked immediately after plant penetration. Expression analysis of M-bM-^HM-^Fhxt1 hxt1(R164K) cells 24 hours post inoculation revealed downregulation of a set of genes involved in carbohydrate metabolism indicating a role of Hxt1 in carbohydrate signaling during initiation of the pathogenic stage. To analyze expression changes of SG200 and SG200M-bM-^HM-^Fhxt1 and SG200M-bM-^HM-^Fhxt1 hxt1(R164K) cells were harvested from the surface of maize leaves 24 hour post inoculation. For each strain three independent replicates were conducted.
2014-09-04 | E-GEOD-61069 | biostudies-arrayexpress
Project description:Saccharomyces cerevisiae developed elegant mechanisms to monitor nutrient availability and trigger adaptative responses to nutrient deficiency. Nutrient sensing requires close coordination of cell surface sensors with intracellular mechanisms. This yeast senses the presence of glucose by two modified hexose transporters, Rgt2 and Snf3 (regulating expression of genes encoding hexose transporters) and the G-protein coupled receptor Gpr1 (modulating Protein Kinase A (PKA) activity).. It has been difficult to differentiate between cellular responses mediated by cell surface and intracellular sensors, respectively. Using a strain that is devoid of glucose uptake, we show that the mere presence of glucose does not elicit any glucose-dependent transcriptional responses. This indicates that signals generated by surface sensors are not sufficient to mediate glucose-dependent transcriptional responses. Instead, intracellular glucose or metabolites derived from it are required for transcriptional changes associated with glucose exposure. We used microarrays from biological triplicate samples to measure the global transcriptional response to sudden addition of glucose to yeast cells growing at steady state on ethanol. The experiment was conducted using a strain that is devoid of glucose uptake and compared with an isogenic strain. The CEN.PK strain was used in this research. A strain with all known hexose transporters deleted (Null strain) was compared with an isogenic reference. The two strains were grown in a chemostat (D = 0.1 h-1) using ethanol as the carbon source. Transcriptional responses between the strains were measured in biological triplicates at steady state and then pulsed with glucose at time t = 0. Transcriptional response was measured again after t = 20 min to determine changes in gene expression changes only in response to the presence of glucose.
2010-03-06 | E-GEOD-20566 | biostudies-arrayexpress
Project description:Saccharomyces cerevisiae developed elegant mechanisms to monitor nutrient availability and trigger adaptative responses to nutrient deficiency. Nutrient sensing requires close coordination of cell surface sensors with intracellular mechanisms. This yeast senses the presence of glucose by two modified hexose transporters, Rgt2 and Snf3 (regulating expression of genes encoding hexose transporters) and the G-protein coupled receptor Gpr1 (modulating Protein Kinase A (PKA) activity).. It has been difficult to differentiate between cellular responses mediated by cell surface and intracellular sensors, respectively. Using a strain that is devoid of glucose uptake, we show that the mere presence of glucose does not elicit any glucose-dependent transcriptional responses. This indicates that signals generated by surface sensors are not sufficient to mediate glucose-dependent transcriptional responses. Instead, intracellular glucose or metabolites derived from it are required for transcriptional changes associated with glucose exposure. We used microarrays from biological triplicate samples to measure the global transcriptional response to sudden addition of glucose to yeast cells growing at steady state on ethanol. The experiment was conducted using a strain that is devoid of glucose uptake and compared with an isogenic strain.
2010-03-02 | GSE20566 | GEO
Project description:Ustilago maydis is a plant-pathogenic fungus that establishes a biotrophic relationship with its host Zea mays. The biotrophic interaction is initiated upon host penetration, and involves expansion of the host plasma membrane around hyphae, which is thought to facilitate the exchange of nutrients and virulence factors. Transcriptional regulators involved in the establishment of an infectious dikaryon and penetration into the host have been identified, however, regulators involved in the post-penetration stages remained to be elucidated. In the study we report the identification of an Ustilago maydis forkhead transcription factor, Fox1, which is exclusively expressed during biotrophic development. Deletion of fox1 results in reduced virulence and impaired tumour development in planta. Δfox1 hyphae induce plant defences including the overproduction and accumulation of H2O2 in and around infected cells. This oxidative burst acts as an intercellular signal, which elicits a specific host defence response phenotypically represented by the encasement of proliferating hyphae in extensions of the plant cell wall. Maize microarrays experiments were performed to identify genes involved in the observed plant defence responses on leaf tissue infected with U. maydis strain SG200∆fox1 4 dpi.
2010-12-31 | GSE19559 | GEO
Project description:There are two principal mechanisms underlie sugar perception and signal transduction in biological systems. Direct sensing and signaling is triggered by sugar direct binding sensors such as Hexokiase 1 (HXK1) with a broad range of affinity and specificity, and indirect sensing signaling via a variety of energy and metabolite sensor, such as Target of Rapamycin (TOR). To investigate the intertwined interaction between glucose and plant hormones ethylene, the transcriptome regulated by ethylene, glucose-TOR, and glucose-HXK1 were analyzed and compared. Our results unexpectedly revealed a deep antagonistic interaction between glucose-TOR-energy signaling and the plant stress hormone ethylene.
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Project description:affy_riz_2011_7 - affy_riz_2011_7 - The Bacterial Leaf Blight disease of rice is due to Xanthomonas oryzae pv. oryzae. As for many pathogenic bacteria, it relies on a type 3 secretion system (TTSS) that is devoted to the injection of type 3 effectors (T3Es) into the eukaryotic host cell. These proteins are meant to suppress host basal defense responses and/or mimic some host regulatory function promoting bacterial survey in the plant. During an incompatible interaction, T3Es may act as Avr proteins and stimulate Effector-Triggered-Immunity. We aim at evaluating the transcriptomic response of rice leaves challenged with avirulent strains of Xoo BAI3 and MAI1 on resistant lines IR64 and IRBB4 versus the reference susceptible rice line Nipponbare. In addition, we investigated the transcriptomic response of rice leaves upon inoculation of an XoohrcC mutant strain affected in the production of a functional TTSS.-The goal of the experiment is to characterize the rice leaf transcriptome response, upon the inoculation of susceptible and resistant rice leaves 24 hours post-infection. To that end, the experimental design includes the inoculation of susceptible Nipponbare rice leaves with Xoo strains BAI3 (race A1) and MAI1 (race A3), that will be compared to the response of resistant lines IRBB4 and IR64 rice lines. In addition, Nipponbare rice leaves will also be challenged with the BAI3hrcC mutant that is affected in the production of a functional TTSS.
2012-10-15 | GSE34192 | GEO
Project description:affy_riz_2011_7 - affy_riz_2011_7 - The Bacterial Leaf Blight disease of rice is due to Xanthomonas oryzae pv. oryzae. As for many pathogenic bacteria, it relies on a type 3 secretion system (TTSS) that is devoted to the injection of type 3 effectors (T3Es) into the eukaryotic host cell. These proteins are meant to suppress host basal defense responses and/or mimic some host regulatory function promoting bacterial survey in the plant. During an incompatible interaction, T3Es may act as Avr proteins and stimulate Effector-Triggered-Immunity. We aim at evaluating the transcriptomic response of rice leaves challenged with avirulent strains of Xoo BAI3 and MAI1 on resistant lines IR64 and IRBB4 versus the reference susceptible rice line Nipponbare. In addition, we investigated the transcriptomic response of rice leaves upon inoculation of an XoohrcC mutant strain affected in the production of a functional TTSS.-The goal of the experiment is to characterize the rice leaf transcriptome response, upon the inoculation of susceptible and resistant rice leaves 24 hours post-infection. To that end, the experimental design includes the inoculation of susceptible Nipponbare rice leaves with Xoo strains BAI3 (race A1) and MAI1 (race A3), that will be compared to the response of resistant lines IRBB4 and IR64 rice lines. In addition, Nipponbare rice leaves will also be challenged with the BAI3hrcC mutant that is affected in the production of a functional TTSS. 18 arrays - rice; avirulent vs virulent
2012-10-15 | E-GEOD-34192 | biostudies-arrayexpress
Project description:Members of the genus Bifidobacterium are common inhabitants of the gastrointestinal tract of humans and other mammals, where they ferment many diet-derived carbohydrates that cannot be digested by their host. To extend our understanding of bifidobacterial carbohydrate utilisation, we investigated the molecular mechanisms by which various strains of Bifidobacterium breve metabolize four distinct α-glucose and/or α-galactose-containing oligosaccharides, namely raffinose, stachyose, melibiose and melezitose. Here we demonstrate that all B. breve strains examined possess the ability to utilise raffinose, stachyose and melibiose. However, the ability to metabolize melezitose was not ubiquitous for all tested B. breve strains. Transcriptomic and functional genomic approaches identified a gene cluster dedicated to the metabolism of α-galactose-containing carbohydrates, while an adjacent gene cluster, dedicated to the metabolism of α-glucose-containing melezitose, was identified, yet being present only in those B. breve strains that were able to support growth on this carbohydrate.
2013-08-16 | GSE47448 | GEO
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2018-10-31 | PXD011417 | Pride