Project description:Mycorrhizae, symbiotic interactions between soil fungi and tree roots, are ubiquitous in terrestrial ecosystems. The fungi contribute phosphorous, nitrogen and mobilized nutrients from organic matter in the soil and in return the fungus receives photosynthetically-derived carbohydrates. This union of plant and fungal metabolisms is the mycorrhizal metabolome. Understanding this symbiotic relationship at a molecular level provides important contributions to the understanding of forest ecosystems and global carbon cycling. We generated next generation short-read transcriptomic sequencing data from fully-formed ectomycorrhizae between Laccaria bicolor and aspen (Populus tremuloides) roots. The transcriptomic data was used to identify statistically significantly expressed gene models using a bootstrap-style approach, and these expressed genes were mapped to specific metabolic pathways. Integration of expressed genes that code for metabolic enzymes and the set of expressed membrane transporters generates a predictive model of the ectomycorrhizal metabolome. Results indicate the specific compounds glycine, glutamate, and allantoin are synthesized by L. bicolor and that these compounds or their metabolites may be used for the benefit of aspen in exchange for the photosynthetically-derived sugars fructose and glucose.The analysis illustrates an approach to generate testable biological hypotheses to investigate the complex molecular interactions that drive ectomycorrhizal symbiosis. These models are consistent with experimental environmental data and provide insight into the molecular exchange processes for organisms in this complex ecosystem. The method used here for predicting metabolomic models of mycorrhizal systems from deep RNA sequencing data can be generalized and is broadly applicable to transcriptomic data derived from complex systems. Fully formed L.bicolor::P.trichocapra mycorrhizae in duplicate
Project description:Mycorrhizae, symbiotic interactions between soil fungi and tree roots, are ubiquitous in terrestrial ecosystems. The fungi contribute phosphorous, nitrogen and mobilized nutrients from organic matter in the soil and in return the fungus receives photosynthetically-derived carbohydrates. This union of plant and fungal metabolisms is the mycorrhizal metabolome. Understanding this symbiotic relationship at a molecular level provides important contributions to the understanding of forest ecosystems and global carbon cycling. We generated next generation short-read transcriptomic sequencing data from fully-formed ectomycorrhizae between Laccaria bicolor and aspen (Populus tremuloides) roots. The transcriptomic data was used to identify statistically significantly expressed gene models using a bootstrap-style approach, and these expressed genes were mapped to specific metabolic pathways. Integration of expressed genes that code for metabolic enzymes and the set of expressed membrane transporters generates a predictive model of the ectomycorrhizal metabolome. Results indicate the specific compounds glycine, glutamate, and allantoin are synthesized by L. bicolor and that these compounds or their metabolites may be used for the benefit of aspen in exchange for the photosynthetically-derived sugars fructose and glucose.The analysis illustrates an approach to generate testable biological hypotheses to investigate the complex molecular interactions that drive ectomycorrhizal symbiosis. These models are consistent with experimental environmental data and provide insight into the molecular exchange processes for organisms in this complex ecosystem. The method used here for predicting metabolomic models of mycorrhizal systems from deep RNA sequencing data can be generalized and is broadly applicable to transcriptomic data derived from complex systems.
Project description:Illumina HiSeq technology was used to generate mRNA profiles from Meliniomyces bicolor mycorrhizal roots compared to free-living mycelium . Mycorrhizal roots and control mycelium were harvested after 113 days and used for RNA extraction. Reads of 150bp were generated and aligned to Meliniomyces bicolor transcripts (https://genome.jgi.doe.gov/Melbi2/Melbi2.home.html) using CLC Genomics Workbench 8.
Project description:This study compared mycorrhizal-associated metabolome alterations across multiple plant-mycorrhizal fungus combinations. Specifically, we inoculated a phylogenetically diverse set of temperate tree species with either arbuscular mycorrhizal or ectomycorrhizal fungi (the two major mycorrhizal lifestyles). Using comprehensive metabolomics approaches, we then assessed the metabolome in mycorrhizal and non-mycorrhizal roots and the corresponding leaves.
Project description:This dataset compared mycorrhizal-associated alterations in the plant primary metabolome across multiple plant-mycorrhizal fungus combinations. Specifically, we inoculated a phylogenetically diverse set of temperate tree species with either arbuscular mycorrhizal or ectomycorrhizal fungi (the two major mycorrhizal lifestyles). We then assessed the primary metabolome in mycorrhizal and non-mycorrhizal roots and the corresponding leaves.
Project description:Laccaria bicolor transcript profiles of different tissues and mycorrhizal root tips from different host trees were analyzed. The array probes were designed from gene models taken from the Joint Genome Institute (JGI, department of energy) Laccaria bicolor genome sequence version 1. One goal was to compare gene expression profiles from ectomycorrhizal root tips with different host plants.
Project description:This study characterizes the transcriptomic alterations of Laccaria bicolor S238N during interaction with P. trichocarpa. Four time-points were analyzed, two weeks, four weeks , six weeks and twelve weeks after inoculation and compared to the transcriptome of free-living mycelium from Laccaria bicolor S238N We performed 16 hybridizations (NimbleGen) with samples derived from P.trichocarpa/L.bicolor mycorrhizal root tips. Samples were taken after 2,4,6 and 12 weeks of interaction (four biological replicates). These samples were compared to free-living mycelium from Laccaria bicolor S238N (three biological replicates). All samples were labeled with Cy3.
Project description:Ecto- and endo-mycorrhizal colonization of Populus roots have a positive impact on the overall tree health and growth. A complete molecular understanding of these interactions will have important implications for increasing agricultural or forestry sustainability using plant:microbe-based strategies. These beneficial associations entail extensive morphological changes orchestrated by the genetic reprogramming in both organisms. In this study, we performed a comparative analysis of two Populus species (Populus deltoides and P. trichocarpa) that were colonized by either an arbuscular mycorrhizal fungus (AmF), Rhizophagus irregularis or an ectomycorrhizal fungus (EmF), Laccaria bicolor, to describe the small RNA (sRNA) landscape including small open reading frames (sORFs) and micro RNAs (miRNAs) involved in these mutualistic interactions. We identified differential expression of sRNAs that were, to a large extent, 1) within the genomic regions lacking annotated genes in the Populus genome and 2) distinct for each fungal interaction. These sRNAs may be a source of novel sORFs within a genome, and in this regard, we identified potential sORFs encoded by the sRNAs. We predicted a higher number of differentially-expressed miRNAs in P. trichocarpa (4 times more) than in P. deltoides (conserved and novel). In addition, 44 miRNAs were common in P. trichocarpa between the EmF and AmF treatments, and only 4 miRNAs were common in P. deltoides between the treatments.
Project description:This study characterizes the transcriptomic alterations of P. tremula x P. alba at three weeks after inoculation with the ectomycorrhizal fungus Laccaria bicolor. We performed 6 hybridizations (NimbleGen) with samples derived from Populus tremula x P. alba control roots and mycorrhizal root tips. Samples were taken after 3 weeks of interaction (three biological replicates). All samples were labeled with Cy3.
Project description:This study characterizes the transcriptomic alterations of Laccaria bicolor S238N during interaction with Pseudotsuga menziesii. Three time-points were analyzed, two weeks, four weeks and six weeks after inoculation and compared to the transcriptome of free-living mycelium from Laccaria bicolor S238N. We performed 9 hybridizations (NimbleGen) with samples derived from Pseudotsuga menziesii /L.bicolor mycorrhizal root tips. Samples were taken after 2,4 and 6 weeks of interaction (three biological replicates). These samples were compared to free-living mycelium from Laccaria bicolor S238N (three biological replicates). All samples were labeled with Cy3.