Nygren CM, Eberhardt U, Karlsson M, Parrent JL, Lindahl BD, Taylor AF.. Growth on nitrate and occurrence of nitrate reductase-encoding genes in a phylogenetically diverse range of ectomycorrhizal fungi. New Phytol 180: 875-889

Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, PO Box 7026, SE-750 07 Uppsala, Sweden.
New Phytologist (Impact Factor: 7.67). 10/2008; 180(4):875-89. DOI: 10.1111/j.1469-8137.2008.02618.x
Source: PubMed


Ectomycorrhizal (ECM) fungi are often considered to be most prevalent under conditions where organic sources of N predominate. However, ECM fungi are increasingly exposed to nitrate from anthropogenic sources. Currently, the ability of ECM fungi to metabolize this nitrate is poorly understood. Here, growth was examined among 106 isolates, representing 68 species, of ECM fungi on nitrate as the sole N source. In addition, the occurrence of genes coding for the nitrate reductase enzyme (nar gene) in a broad range of ectomycorrhizal fungi was investigated. All isolates grew on nitrate, but there was a strong taxonomic signature in the biomass production, with the Russulaceae and Amanita showing the lowest growth. Thirty-five partial nar sequences were obtained from 43 tested strains comprising 31 species and 10 genera. These taxa represent three out of the four clades of the Agaricales within which ECM fungi occur. No nar sequences were recovered from the Russulaceae and Amanita, but Southern hybridization showed that the genes were present. The results demonstrate that the ability to utilize nitrate as an N source is widespread in ECM fungi, even in those fungi from boreal forests where the supply of nitrate may be very low.

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Available from: Andy FS Taylor, Jan 27, 2014
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    • "Soil fungi from temperate and boreal forests and from agricultural soils show a widespread capacity to grow on NO 3 − (Yamanaka, 1999; Nygren et al., 2008; Gorfer et al., 2011). While the majority of ECM fungi are reported to prefer NH 4 + as an inorganic nitrogen source, the capacity to grow on NO 3 − is also widely distributed among them (Nygren et al., 2008) and some ECM species even prefer NO 3 − over NH 4 + (Scheromm et al., 1990; Aouadj et al., 2000). Most importantly, the ECM interaction can drive the whole nitrogen uptake by the host tree that takes place via the extraradical (ERM) mycelium of the fungal partner (Gobert and Plassard, 2002; Gobert and Plassard , 2007; Guescini et al., 2003; Bailly et al., 2007). "
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