Project description:The Mediator complex is an evolutionary conserved multiprotein complex that plays an essential role in initiating and regulating transcription. Its function is to act as a universal adaptor between RNA Polymerase II and DNA-bound transcription factors to translate regulatory information from activators and repressors to the transcriptional machinery. We have found that the PFT1 gene (which encodes the MED25 subunit of the Mediator complex) is required for the uncompromised expression of both salicylic acid- and jasmonate-dependent defense genes as well as resistance to the leaf-infecting fungal pathogens, Alternaria brassicicola and Botrytis cinerea in Arabidopsis. Surprisingly, we found that the pft1/med25 mutant showed increased resistance to the root infecting pathogen Fusarium oxysporum and that this resistance was independent of classical defense genes. In addition, the over-expression of PFT1 led to increased susceptibility to F. oxysporum. Therefore, to explore this phenomenon further, we wished to use whole genome transcript profiling to identify which genes may be playing a role in pft1/med25-mediated resistance to F. oxysporum. Experiment Overall Design: We grew both WT and pft1/med25 plants for four weeks in soil. After four weeks we treated the plants by root-dipping in either water or a F. oxysporum spore suspension before replanting them back into soil. There were four independent replicates of each treatment and each replicate contained 20 plants each. The treatments were WT (mock): pft1 (mock): WT (infected): pft1 (infected). Each replicate (16 in total) was harvested after 48 hours and the resulting RNA was used for hybridization to an Affymetrix ATH1 chip.
Project description:The Mediator complex is an evolutionary conserved multiprotein complex that plays an essential role in initiating and regulating transcription. Its function is to act as a universal adaptor between RNA Polymerase II and DNA-bound transcription factors to translate regulatory information from activators and repressors to the transcriptional machinery. We have found that the PFT1 gene (which encodes the MED25 subunit of the Mediator complex) is required for the uncompromised expression of both salicylic acid- and jasmonate-dependent defense genes as well as resistance to the leaf-infecting fungal pathogens, Alternaria brassicicola and Botrytis cinerea in Arabidopsis. Surprisingly, we found that the pft1/med25 mutant showed increased resistance to the root infecting pathogen Fusarium oxysporum and that this resistance was independent of classical defense genes. In addition, the over-expression of PFT1 led to increased susceptibility to F. oxysporum. Therefore, to explore this phenomenon further, we wished to use whole genome transcript profiling to identify which genes may be playing a role in pft1/med25-mediated resistance to F. oxysporum.
Project description:Comparison of expression differences between Col-0 Arabidopsis thaliana and transgenic plants in the same background carrying three different Fusarium oxysporum effector genes
Project description:A GSTF8 promoter fragment fused to the luciferase reporter gene was used in a forward genetic screen for Arabidopsis mutants with up-regulated GSTF8 promoter activity and identified the esr1-1 (enhanced stress response 1) mutant which also conferred increased resistance to the fungal pathogen Fusarium oxysporum. RNA-Seq was conducted to compare esr1-1 and wild-type (GSTF8 promoter::luciferase reporter line JC66 in Col-0 background) transcriptomes for altered gene expression.
Project description:Determining the role of the Mediator subunit MED25/PFT1 in coordinating the expression of glucose responsive genes in Arabidopsis thaliana
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:Fungal effectors play important roles in inciting disease development on host plants. We identified an effector (Secreted in Xylem4, SIX4) in an Arabidopsis infecting isolate (Fo5176) of the root-infecting fungal pathogen Fusarium oxysporum and demonstrated this effector is required for full virulence. To explore the role of Fo5176_SIX4 we use whole transcriptome profiling of root tissues from plants overexpressing this effector (35sSIX4) versus wild-type (Col-0) plants after F. oxysporum infection. We grew both WT and 35sSIX4 plants for four weeks in soil. After four weeks the plants were infected with Fusarium oxyporum isolate Fo5176, trays covered with a plastic dome and incubated at 28C. There were four independent replicates of each treatment and each replicate contained root tissue from 20 plants. Each replicate (8 in total) was harvested 4 days post inoculation and the resulting RNA was used for hybridization to an Affymetrix ATH1 chip.
Project description:PFT1, the MED25 subunit of the plant Mediator complex, promotes flowering through CONSTANS dependent and independent mechanisms in Arabidopsis
Project description:To better understand the regulatory mechanisms of IbBBX24-mediated Fusarium oxysporum Schlecht. f. sp. batatas (Fob) resistance, we performed ChIP-Seq analysis using overexpression line infected with Fob at 1 dpi.