{"id":10527,"date":"2020-07-16T13:02:45","date_gmt":"2020-07-16T13:02:45","guid":{"rendered":"https:\/\/mycor.iam.inrae.fr\/IAM\/?page_id=10527"},"modified":"2020-07-16T13:40:00","modified_gmt":"2020-07-16T13:40:00","slug":"metatranscriptomics-of-forest-soil-ecosystems","status":"publish","type":"page","link":"https:\/\/mycor.iam.inrae.fr\/IAM\/?page_id=10527","title":{"rendered":"Metatranscriptomics of Forest Soil Ecosystems"},"content":{"rendered":"
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Forest soils (including litter, humus and coarse woody debris) host diverse microbial communities that impact tree health and productivity, and which play pivotal roles in terrestrial carbon sequestration, and biogeochemical cycles. Among these microbial communities, fungi are undoubtly major players. Traditionally, they have been divided into discrete ecological guilds, such as leaf litter-decomposers, humus saprobes, white- and brown-rot wood decayers, parasites and mycorrhizal symbionts. However, the actual functional properties of individual species, and the synergistic effects among them, are often obscure. Moreover, the basic biodiversity of the vast majority of soil systems (e.g., boreal forests and subartic taiga) remains unexplored using high-throughput DNA barcoding approaches.<\/p>\n<\/div>\n

We hypothesize that firm distinctions between fungi commonly labeled mycorrhizal, wood decomposer, humus and litter saprobes are, in some instances, unwarranted, and that crucial ecosystem processes, such as carbon sequestration, wood and litter decay and trophic mutualism, can only be understood in the context of interactions among multiple species representing a functional continuum. The number of available fungal genomes has expanded dramatically in recent months, and this provides unprecedented opportunities to study the functional (and taxonomic) diversity of soil communities.<\/p>\n

Within the framework of the DOE Joint Genome Institute Community Sequencing Program<\/a>, we have therefore embarked in a challenging large-scale metatranscriptomics project to explore the interaction of forest trees with communities of soil fungi, including ectomycorrhizal symbionts that dramatically affect tree growth, and saprotrophic soil fungi impacting carbon sequestration in forests. We are going to sequence the metatranscriptome of soil fungi (i.e., wood decayers, litter and humus saprotrophs, and ectomycorrhizal symbionts) in woody debris, litter\/humus, rhizosphere and ectomycorrhizal roots of ecosystems representative of major Earth biomes, the boreal, temperate and mediterranean forests.<\/p>\n

\"\"Metatranscriptome samples.<\/em> A range of forest ecosystems has been selected on the basis of their ecological importance and the availability of metadata linked to these forest sites. In contrast to agricultural soils, forest soils, in particular those of boreal forests with low pH values, are characterised by strong vertical stratification due to the resulting absence of fauna causing mixing. This provides a spatial structure for evaluation of hypotheses concerning functional attributes of taxa occupying spatially distinct horizons.<\/p>\n

Sampling will be conducted on selected stands in long-term observatories (LTOs) or national survey sites:<\/p>\n