title: Community profiling and gene expression of fungal assimilatory nitrate reductases in agricultural soil.
abstract: Although fungi contribute significantly to the microbial biomass in terrestrial ecosystems, little is known about their contribution to biogeochemical nitrogen cycles. Agricultural soils usually contain comparably high amounts of inorganic nitrogen, mainly in the form of nitrate. Many studies focused on bacterial and archaeal turnover of nitrate by nitrification, denitrification and assimilation, whereas the fungal role remained largely neglected. To enable research on the fungal contribution to the biogeochemical nitrogen cycle tools for monitoring the presence and expression of fungal assimilatory nitrate reductase genes were developed. To the ~100 currently available fungal full-length gene sequences, another 109 partial sequences were added by amplification from individual culture isolates, representing all major orders occurring in agricultural soils. The extended database led to the discovery of new horizontal gene transfer events within the fungal kingdom. The newly developed PCR primers were used to study gene pools and gene expression of fungal nitrate reductases in agricultural soils. The availability of the extended database allowed affiliation of many sequences to known species, genera or families. Energy supply by a carbon source seems to be the major regulator of nitrate reductase gene expression for fungi in agricultural soils, which is in good agreement with the high energy demand of complete reduction of nitrate to ammonium.
authors.affiliation: AIT Austrian Institute of Technology GmbH, Bioresources Unit, Seibersdorf, Austria. markus.gorfer@boku.ac.at
authors.forename: Markus
authors.initials: M
authors.lastname: Gorfer
authors.forename: Marzena
authors.initials: M
authors.lastname: Blumhoff
authors.forename: Sylvia
authors.initials: S
authors.lastname: Klaubauf
authors.forename: Alexander
authors.initials: A
authors.lastname: Urban
authors.forename: Erich
authors.initials: E
authors.lastname: Inselsbacher
authors.forename: Dragana
authors.initials: D
authors.lastname: Bandian
authors.forename: Birgit
authors.initials: B
authors.lastname: Mitter
authors.forename: Angela
authors.initials: A
authors.lastname: Sessitsch
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wanek
authors.forename: Joseph
authors.initials: J
authors.lastname: Strauss
mesh_terms: D018533:Biomass; D017753:Ecosystem; D005658:Fungi / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D005800:Genes, Fungal; D009565:Nitrate Reductases / Q000235:genetics* / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D009586:Nitrogen Fixation; D010802:Phylogeny; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012988:Soil Microbiology
chemical_list: D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D009565:Nitrate Reductases; D009584:Nitrogen