Project description:Using 21K spruce microarray (that contains 21.8 thousand unique transcripts) we performed analysis of the transcriptome response of lodgepole pine (Pinus contorta) inoculated with the mountain pine beetle (Dendroctonus ponderosae) vectored fungal pathogen Grosmannia clavigera or treated with wounding. This microarray analysis revealed large transcriptome reorganization with close to 2000 transcripts (10% of the studied transcriptome) differentially expressed within two weeks of treatment, with the wounding response affecting close to 2% of the lodgepole pine transcriptome. RNA was isolated from the bark of lodgepole pine inoculated with Grosmannia clavigera, treated with wounding, or untreated control for three time points (6h, 2days and 2 weeks). Three independent biological replicates were included for each treatment and each time point. Three hybridizations were performed for each comparison of different treatments (fungal, wounding, control) within each time point (6 hours, 2 days, 2 weeks) and one hybridization was performed for the comparison of the same treatments between time points (total 36 hybridizations/slides).
Project description:BackgroundGrosmannia clavigera is a bark beetle-vectored fungal pathogen of pines that causes wood discoloration and may kill trees by disrupting nutrient and water transport. Trees respond to attacks from beetles and associated fungi by releasing terpenoid and phenolic defense compounds. It is unclear which genes are important for G. clavigera's ability to overcome antifungal pine terpenoids and phenolics.ResultsWe constructed seven cDNA libraries from eight G. clavigera isolates grown under various culture conditions, and Sanger sequenced the 5' and 3' ends of 25,000 cDNA clones, resulting in 44,288 high quality ESTs. The assembled dataset of unique transcripts (unigenes) consists of 6,265 contigs and 2,459 singletons that mapped to 6,467 locations on the G. clavigera reference genome, representing ~70% of the predicted G. clavigera genes. Although only 54% of the unigenes matched characterized proteins at the NCBI database, this dataset extensively covers major metabolic pathways, cellular processes, and genes necessary for response to environmental stimuli and genetic information processing. Furthermore, we identified genes expressed in spores prior to germination, and genes involved in response to treatment with lodgepole pine phloem extract (LPPE).ConclusionsWe provide a comprehensively annotated EST dataset for G. clavigera that represents a rich resource for gene characterization in this and other ophiostomatoid fungi. Genes expressed in response to LPPE treatment are indicative of fungal oxidative stress response. We identified two clusters of potentially functionally related genes responsive to LPPE treatment. Furthermore, we report a simple method for identifying contig misassemblies in de novo assembled EST collections caused by gene overlap on the genome.
Project description:Gc, a Mountain pine beetle associated pathogen, can survive from highly abundant pine chemicals ( e.g terpenes) and use some unflavored compound’s as carbon source. using RNA_Seq, we analyzed the transcriptome of Gc when it grew on limonene, mannose oliver-oil, oleic acid as carbon source, as well as when it survived from high concentration of limonene or heptane. We profiled the expression of some interesting genes ( ABC transporters, P450s) potentially involved in the tree-pathogen interaction. An ABC-G group transporter gene (GcABC-G1) was one of the most highly induced genes and characterized as a mono-terpene specific efflux transporter with genetic and molecular tools. RNA- seq also indicated Gc utilize limonene and oleic acid through the same beta-oxidation pathway. However the degradation of limonene is more complex and multiple pathways contributed to the survival/utilization.
Project description:Using 21K spruce microarray (that contains 21.8 thousand unique transcripts) we performed analysis of the transcriptome response of lodgepole pine (Pinus contorta) inoculated with the mountain pine beetle (Dendroctonus ponderosae) vectored fungal pathogen Grosmannia clavigera or treated with wounding. This microarray analysis revealed large transcriptome reorganization with close to 2000 transcripts (10% of the studied transcriptome) differentially expressed within two weeks of treatment, with the wounding response affecting close to 2% of the lodgepole pine transcriptome.
Project description:Gc, a Mountain pine beetle associated pathogen, can survive from highly abundant pine chemicals ( e.g terpenes) and use some unflavored compound’s as carbon source. using RNA_Seq, we analyzed the transcriptome of Gc when it grew on limonene, mannose oliver-oil, oleic acid as carbon source, as well as when it survived from high concentration of limonene or heptane. We profiled the expression of some interesting genes ( ABC transporters, P450s) potentially involved in the tree-pathogen interaction. An ABC-G group transporter gene (GcABC-G1) was one of the most highly induced genes and characterized as a mono-terpene specific efflux transporter with genetic and molecular tools. RNA- seq also indicated Gc utilize limonene and oleic acid through the same beta-oxidation pathway. However the degradation of limonene is more complex and multiple pathways contributed to the survival/utilization. mRNA was extracted from Gc mycelium under various conditions and cDNA libraries were generated for pair-end sequencing. The 70-100bp illumina sequence read was mapping to reference genome and RNA-Seq was carried out in CLC genomic work bench.