Project description:Transcriptional profiling of Arabidopsis in response to infection with TMV in the initial infection stage (0.5, 4 and 6 hours post inoculation). Analyze the relative transcriptome change of TMV*CP.MP- and TMV*rep-inoculated samples.
Project description:Transcriptional profiling of Arabidopsis in response to infection with TMV in the initial infection stage (0.5, 4 and 6 hours post inoculation). Analyze the relative transcriptome change of TMV*CP.MP- and TMV*rep-inoculated samples. TMV*rep vs. TMV*CP.MP transfected cells. 2 biological replicates conducted at each time (0.5, 4 and 6 hours post inoculation)
Project description:microRNAs (miRNAs) are small non-coding RNA-molecules that influence translation by binding to the target gene mRNA. Many miRNAs are found in nested arrangements within introns, or exons, of larger protein-coding host genes. miRNAs and host genes in a nested arrangement are often transcribed simultaneously, which may indicate that both have similar functions. miRNAs have been implicated in regulating defense responses against pathogen infection in C. elegans and in mammals. Here, we asked if miRNAs in nested arrangements and their host genes are involved in the C. elegans response against infection with Bacillus thuringiensis (Bt). We performed miRNA sequencing and functional genetic analysis of miRNA and/or host gene in four nested arrangements. We identified mir-58.1 and mir-2 as negative regulators of C. elegans resistance to Bt infection. However, we did not find any miRNA/host gene pair in which both contribute to defense against Bt.
Project description:Using a crucifer-infecting strain of Tobacco Mosaic Virus (TMV-Cg) and Arabidopsis thaliana as a model system, we analyzed the viral small RNA profile in wild-type plants as well as rdr mutants by applying small RNA deep sequencing technology. Over 100,000 TMV-Cg-specific small RNA reads, mostly of 21- (78.4%) and 22-nucleotide (12.9%) in size and originating predominately (79.9%) from the genomic sense RNA strand, were captured at an early infection stage, yielding the first high-resolution small RNA map for a plant virus. The TMV-Cg genome harbored multiple, highly reproducible small RNA-generating hot spots that corresponded to regions with no apparent local hairpin-forming capacity. Significantly, both the rdr1 and rdr6 mutants exhibited globally reduced levels of viral small RNA production as well as reduced strand bias in viral small RNA population, revealing an important role for these host RDRs in viral siRNA biogenesis. In addition, an informatics analysis showed that a large set of host genes could be potentially targeted by TMV-Cg-derived siRNAs for posttranscriptional silencing, raising the interesting possibility for a hidden layer of widespread virus-host interactions that may contribute to viral pathogenicity and host specificity. Profiling of TMV-Cg derived small RNAs in systemically infected tissues of wild type (Col-0) Arabidopsis as well as the rdr1and rdr6 mutants, at 3 days post-infection.
Project description:Using a crucifer-infecting strain of Tobacco Mosaic Virus (TMV-Cg) and Arabidopsis thaliana as a model system, we analyzed the viral small RNA profile in wild-type plants as well as rdr mutants by applying small RNA deep sequencing technology. Over 100,000 TMV-Cg-specific small RNA reads, mostly of 21- (78.4%) and 22-nucleotide (12.9%) in size and originating predominately (79.9%) from the genomic sense RNA strand, were captured at an early infection stage, yielding the first high-resolution small RNA map for a plant virus. The TMV-Cg genome harbored multiple, highly reproducible small RNA-generating hot spots that corresponded to regions with no apparent local hairpin-forming capacity. Significantly, both the rdr1 and rdr6 mutants exhibited globally reduced levels of viral small RNA production as well as reduced strand bias in viral small RNA population, revealing an important role for these host RDRs in viral siRNA biogenesis. In addition, an informatics analysis showed that a large set of host genes could be potentially targeted by TMV-Cg-derived siRNAs for posttranscriptional silencing, raising the interesting possibility for a hidden layer of widespread virus-host interactions that may contribute to viral pathogenicity and host specificity.
Project description:Pathogen infection triggers transcriptional reprogramming in host plants, however we still know little about the dynamics of the pathogen-induced defense transcriptome. The goal of this study was to investigate the dynamic reprogramming of the defense transcriptome in response to Fusarium oxysporum infection in Arabidopsis using RNA-seq technology and to provide a comprehensive analysis of genes underlying the innate immune response against the fungal pathogen. Our results suggest that the Arabidopsis transcriptome is reprogrammed to co-ordinately express multiple positive and negative regulators following pathogen infection to modulate defense gene expression and disease resistance. Our study identified a number of novel genes responsive to pathogen infection and provided a rich source of pathogen responsive genes for further functional characterization.
Project description:Pathogen infection triggers transcriptional reprogramming in host plants, however we still know little about the dynamics of the pathogen-induced defense transcriptome. The goal of this study was to investigate the dynamic reprogramming of the defense transcriptome in response to Fusarium oxysporum infection in Arabidopsis using RNA-seq technology and to provide a comprehensive analysis of genes underlying the innate immune response against the fungal pathogen. Our results suggest that the Arabidopsis transcriptome is reprogrammed to co-ordinately express multiple positive and negative regulators following pathogen infection to modulate defense gene expression and disease resistance. Our study identified a number of novel genes responsive to pathogen infection and provided a rich source of pathogen responsive genes for further functional characterization. Four samples (M1DPI, M6DPI, F1DPI and F6DPI; M=mock treated; F=Fusarium oxysporum infected; DPI=day post inoculation) were sequenced to identify pathogen responsive genes in each time point. Each sample was sequenced once, i.e. without biological replicate.
Project description:The host innate immune response is the first line of defense against pathogens and is orchestrated by the concerted expression of genes induced by microbial stimuli. Deregulated expression of these genes is linked to the initiation and progression of numerous diseases associated with exacerbated inflammation. Here, we identify Topoisomerase 1 (Top1) as a critical positive regulator of RNA polymerase II (RNAPII) transcriptional activity at pathogen-induced genes. Notably, depletion or chemical inhibition of Top1 suppresses the host response against replicating Influenza and Ebola viruses as well as bacterial products. As a result, therapeutic pharmacological inhibition of Top1 protects mice from death in experimental models of chemical- and pathogen-induced lethal inflammation. Our results indicate that Top1 inhibition could be used as therapy against life threatening infections characterized by an acutely exacerbated immune response.
Project description:Kac, a reversible PTM, plays essential roles in various biological processes, including those involving metabolic pathways, pathogen resistance and transcription, in both prokaryotes and eukaryotes. TMV, the major factor that causes poor quality of Solanaceae crops worldwide, directly alters many metabolic processes in tobacco. However, the extent and function of Kac during TMV infection have not been determined. Here, using LC−MS/MS in conjunction with highly sensitive immune-affinity purification, we comprehensively analyzed the changes in the proteome and acetylome of TMV-infected tobacco (Nicotiana benthamiana) seedlings. In total, 2082 lysine-acetylated sites on 1319 proteins differentially expressed in response to TMV infection were identified. Extensive bioinformatic studies disclosed changes in acetylation of proteins engaged in cellular metabolism and biological processes. The vital influence of Kac in fatty acid degradation and alpha-linolenic acid metabolism was also revealed in TMV-infected seedlings. This study first revealed Kac information in N. benthamiana under TMV infection and expands upon the existing landscape of acetylation in pathogen infection.