Project description:The transcriptome of Leptosphaeria maculans was analyzed in mycelium and during oilseed rape (Brassica napus) leaf infection. The array probes were designed from gene models from the L. maculans whole genome annotation. One aim of this study was to verify the expression of the automatically annotated gene models in various conditions. Another goal was to monitor gene expression profiles during oilseed rape leaf infection and to highlight tissue-specific transcripts, e.g. in plant up-regulated transcripts, for further analyses.
Project description:The transcriptome of Leptosphaeria maculans was analyzed in mycelium and during oilseed rape (Brassica napus) leaf infection. The array probes were designed from gene models from the L. maculans whole genome annotation. One aim of this study was to verify the expression of the automatically annotated gene models in various conditions. Another goal was to monitor gene expression profiles during oilseed rape leaf infection and to highlight tissue-specific transcripts, e.g. in plant up-regulated transcripts, for further analyses. We performed 9 hybridizations (NimbleGen) with samples derived from mycelium and infected oilseed rape leaves. Samples from infected oilseed rape leaves were harvested 7 and 14 days post infection. Three replicates each. All samples were labeled with Cy3.
Project description:The hemibiotrophic fungal pathogen Leptosphaeria maculans is the causal agent of blackleg disease in Brassica napus (canola, oilseed rape) and causes significant losses in crop yields worldwide. While genetic resistance has been used to mitigate the disease, little information about the genes and gene regulatory networks underlying blackleg resistance is currently available. High-throughput RNA sequencing and rigorous bioinformatics approaches revealed dynamic changes in the host transcriptome and identified plant defense pathways specific to the host-pathogen incompatible LepR1-AvrLepR1 interaction.
Project description:Full transcriptomes of Leptosphaeria maculans ‘brassicae’ v23.1.3 and Leptosphaeria maculans ‘lepidii’ IBCN84, grown in Fries medium, were studied.
Project description:Leptosphaeria maculans, causal agent of stem canker disease, colonises oilseed rape (Brassica napus) in two stages: a short and early colonisation stage corresponding to cotyledon or leaf colonisation, and a late colonisation stage during which the fungus colonises systemically and symptomlessly the plant during several months before stem canker appears. To date, determinants of the late colonisation stage are poorly understood; L. maculans may either successfully escape plant defences leading to the stem canker development, or the plant can develop an “adult-stage” resistance reducing canker incidence. To get insight into these determinants, we performed an RNA-seq pilot project comparing fungal gene expression in infected cotyledons and in symptomless and necrotic stems. Despite the low fraction of fungal material in infected stems, enough fungal transcripts were detected and a large portion of fungal genes were expressed, thus validating the feasibility of the approach. Our analysis showed that all avirulence genes previously identified are under-expressed during stem colonisation compared to cotyledon colonisation. A validation RNA-seq experiment was then done to investigate the expression of candidate effector genes during systemic colonisation. 307 "late" effector candidates, under-expressed in the early colonisation stage and over-expressed in the infected stems, were identified. Finally our analysis revealed a link between regulation of expression of effectors and their genomic location: the late effector candidates, putatively involved in the systemic colonisation, are located in gene-rich genomic regions, whereas the "early" effector genes, over-expressed in the early colonisation stage, are located in gene-poor regions of the genome.
Project description:The transcriptome of Leptosphaeria maculans was analysed in mycelium of the wild type isolate v23.1.3 or in transformants silenced for DIM5 or HP1, two genes encoding enzymes involved in chromatin remodelling. The array probes were designed from gene models from the L. maculans whole genome annotation. The aim of this study was to characterise the effect of chromatin remodelling on gene expression during in vitro growth.
Project description:The transcriptome of Leptosphaeria maculans was analysed in mycelium of the wild type isolate v23.1.3 or in transformants silenced for DIM5 or HP1, two genes encoding enzymes involved in chromatin remodelling. The array probes were designed from gene models from the L. maculans whole genome annotation. The aim of this study was to characterise the effect of chromatin remodelling on gene expression during in vitro growth. We performed 9 hybridizations (NimbleGen) with samples derived from mycelium of a wild type isolate, v23.1.3, of a transformant silenced for HP1 and for a transformant silenced for DIM5. Three replicates each. All samples were labeled with Cy3.
