Project description:Many trees form ectomycorrhizal symbiosis with fungi. During symbiosis, the tree roots supply sugar to the fungi in exchange for nitrogen, and this process is critical for the nitrogen and carbon cycles in forest ecosystems. However, the extents to which ectomycorrhizal fungi can liberate nitrogen and modify the soil organic matter and the mechanisms by which they do so remain unclear since they have lost many enzymes for litter decomposition that were present in their free-living, saprotrophic ancestors. Using time-series spectroscopy and transcriptomics, we examined the ability of two ectomycorrhizal fungi from two independently evolved ectomycorrhizal lineages to mobilize soil organic nitrogen. Both species oxidized the organic matter and accessed the organic nitrogen. The expression of those events was controlled by the availability of glucose and inorganic nitrogen. Despite those similarities, the decomposition mechanisms, including the type of genes involved as well as the patterns of their expression, differed markedly between the two species. Our results suggest that in agreement with their diverse evolutionary origins, ectomycorrhizal fungi use different decomposition mechanisms to access organic nitrogen entrapped in soil organic matter. The timing and magnitude of the expression of the decomposition activity can be controlled by the below-ground nitrogen quality and the above-ground carbon supply.
Project description:Illumina HiSeq technology was used to generate mRNA profiles from Cenococcum geophilum ectomycorrhizal Pine roots, sclerotia and extramatrical mycelium compared to free-living mycelium . Ectomycorrhizal pine roots, sclerotia, extramatrical mycelium and control mycelium were harvested after 90 days and used for RNA extraction. Reads of 150bp were generated and aligned to the C. geophilum reference genome (https://genome.jgi.doe.gov/Cenge3/Cenge3.home.html).
2018-03-01 | GSE108866 | GEO
Project description:Ectomycorrhizal fungal communities on pine seedlings
Project description:This study began with 72 male 4-week-old BALB/c mice. The mice were split evenly into one of four cohorts: Control, River, Pine, and Road. The control mice were raised with standard corn cob bedding whereas the remaining mice were raised with clean bedding amended with 300 mL of one of three different types of soil. The soil exposure continued throughout the experiment, with 300 mL of new soil added with bi-weekly cage changes. The soils used to amend the cage bedding were previously characterized as having high (Pine), medium (River), and low (Road) diversity. The River and Pine soil were collected from Duke Forest and the Road soil was collected adjacent to Highway 15-501 in Chapel Hill, North Carolina. All mice were given a standard diet and the cages were distributed reverse osmosis treated water through a centralized Lixit® system that was fed to each cage in parallel. After 32 days of standard rearing with amended soils, the mice were exposed via oropharyngeal aspiration to either live influenza A (PR8) virus or heat inactivated (HI) virus.
Project description:The response mechanisms, recognition and specificity of conifer trees during interaction with pathogenic, saprotrophic or symbiotic ectomycorrhizal fungus were investigated. The roots of Pinus sylvestris were challenged for fifteen days with either Heterobasidion annosum (a pathogenic root rot fungus which attacks Norway spruce, Scots pine and broad leaf trees); Laccaria bicolor (an obligate ectomycorrhizal symbiont); or Trichoderma aureoviride (an obligate saprotroph). The gene expression data from cDNA micro-arrays consisting of 2176 Pinus taeda genes were analysed using 2-interconnected mixed linear model statistical approach. The result of the pairwise comparisons of the different treatments against un-inoculated control led to identification of genes specifically differentially expressed in the pathogenic, saprotrophic and symbiotic interactions. The results were compared with similar data obtained for two other interaction stages: 1 and 5 days post inoculation. The result of this comprehensive expression profiling will hopefully shed more light on the mechanistic basis for recognition and response of conifer trees to pathogenic and non-pathogenic fungi. Keywords: stress response
Project description:The response mechanisms, recognition and specificity of conifer trees during interaction with pathogenic, saprotrophic or symbiotic ectomycorrhizal fungus were investigated. The roots of Pinus sylvestris were challenged for five days with either Heterobasidion annosum (a pathogenic root rot fungus which attacks Norway spruce, Scots pine and broad leaf trees); Laccaria bicolor (an obligate ectomycorrhizal symbiont); or Trichoderma aureoviride (an obligate saprotroph). The gene expression data from cDNA micro-arrays consisting of 2176 Pinus taeda genes were analysed using 2-interconnected mixed linear model statistical approach. The result of the pairwise comparisons of the different treatments against un-inoculated control led to identification of genes specifically differentially expressed in the pathogenic, saprotrophic and symbiotic interactions. The results were compared with similar data obtained for two other interaction stages: 1 and 15 days post inoculation. The result of this comprehensive expression profiling will hopefully shed more light on the mechanistic basis for recognition and response of conifer trees to pathogenic and non-pathogenic fungi. Keywords: stress response
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).