Project description:The assess the effect of AvrSr35 knock-out on host-pathogen interaction in the compatible host, we have performed time-course analysis of leaf transcriptomes obtained by infecting susceptible wheat cultivar Fielder with the wild type Puccinia graminis f.sp. tritici (Pgt) isolate 99KS76A-1 and its three mutants, M1, M4 and M7, that carry loss-of-function mutations in the AvrSr35 gene.
Project description:The zebrafish embryo has repeatedly proved to be a useful model for the analysis of effects by environmental toxicants. This study was performed to investigate if an approach combining mechanism-specific bioassays with microarray techniques can obtain more in-depth insights into the ecotoxicity of complex pollutant mixtures as present, e.g., in freeze-dried whole sediment samples and their corresponding organic extracts in parallel. To this end, altered gene expression was compared to data from established bioassays as well as to results from chemical analysis. Microarray analysis revealed several classes of significantly regulated genes which could to a considerable extent be related to the hazard potential. Results indicate that potential classes of contaminants can be assigned to sediment extracts by both classical biomarker genes and corresponding expression profile analyses of known substances. However, it is difficult to distinguish between specific responses and more universal detoxification of the organism. Additionally, different gene expression was shown to be less influenced by the sampling site than by the method of exposure, which could be attributed to differential bioavailability of contaminants. Microarray analyses were performed with early life stages of zebrafish exposed to sediment extracts or freeze-dried sediment from three sampling sites (Ehingen, Lauchert, Sigmaringen) along the Upper part of the Danube River, Germany. The expression profiles were compared within the sampling sites, between the exposure scheme and to the expression pattern of model toxicants, such as 4-chloroaniline, Cadmium, DDT, TCDD, and Valproic acid (Gene Expression Omnibus Series GSE9357). Additionally, mechanism-specific bioassays and chemical analysis of the sediments have been combined and compared to the present gene expression data.
Project description:Transcriptional profiling of pear tree comparing a resistant/tolerant cultivar with a susceptible cultivar to the Stemphylium vesicarium fungus Rocha' pear is an economically important portuguese Pyrus communis L. cultivar very susceptible to the Stemphylium vesicarium pathogenic fungus, the brown spot agent, causing huge decrease on fruit quality and yield production. Field control of brown spot disease is based in systemic application of antifungal chemicals with high economic costs and dramatic consequences to public health and environmental pollution. Plant-pathogen interactions involve a series of events encompassing constitutive and induced plant defence responses whose dissection has been a research target for control many crop diseases. The biosynthesis of cell wall polymers and antifungal compounds appear to be an efficient physical and chemical barrier to infection.To understand the molecular responses behind defence mechanisms of resistant/tolerant and susceptible cultivars of Pyrus communis L. to the S. vesicarium fungus, cDNA microarray technology was used to identify the genes differentially expressed along a time course leaf inoculation between 'Rocha' pear cultivar (a high susceptible cultivar) and 'Ercolini' pear cultivar (a resistant/tolerant pear cultivar). This study aims to contribute with information on the molecular mechanisms involved in host-pathogen interactions responsible for pear tree brown spot disease and resistance to Stemphylium vesicarium.
Project description:The zebrafish embryo has repeatedly proved to be a useful model for the analysis of effects by environmental toxicants. This study was performed to investigate if an approach combining mechanism-specific bioassays with microarray techniques can obtain more in-depth insights into the ecotoxicity of complex pollutant mixtures as present, e.g., in freeze-dried whole sediment samples and their corresponding organic extracts in parallel. To this end, altered gene expression was compared to data from established bioassays as well as to results from chemical analysis. Microarray analysis revealed several classes of significantly regulated genes which could to a considerable extent be related to the hazard potential. Results indicate that potential classes of contaminants can be assigned to sediment extracts by both classical biomarker genes and corresponding expression profile analyses of known substances. However, it is difficult to distinguish between specific responses and more universal detoxification of the organism. Additionally, different gene expression was shown to be less influenced by the sampling site than by the method of exposure, which could be attributed to differential bioavailability of contaminants.
Project description:The zebrafish embryo has repeatedly proved to be a useful model for the analysis of effects by environmental toxicants. This proof-of-concept study was performed to investigate if an approach combining mechanism-specific bioassays with microarray techniques can obtain more in-depth insights into the ecotoxicity of complex pollutant mixtures as present, e.g., in sediment extracts. For this end, altered gene expression was compared to data from established bioassays as well as to results from chemical analysis. Microarray analysis revealed several classes of significantly regulated genes which could to a considerably extend be related to the hazard potential. Results indicate that potential classes of contaminants can be assigned to sediment extracts by both classical biomarker genes and corresponding expression profile analyses of known substances. However, it is difficult to distinguish between specific responses and more universal detoxification of the organism.