- Bodeker, Inga T. M.
- Clemmensen, Karina E.
- de Boer, Wietse
- Martin, Francis
- Olson, Ake
- Lindahl, Bjorn D.
In northern forests, belowground sequestration of nitrogen (N) in complex organic pools restricts nutrient availability to plants. Oxidative extracellular enzymes produced by ectomycorrhizal fungi may aid plant N acquisition by providing access to N in macromolecular complexes. We test the hypotheses that ectomycorrhizal Cortinarius species produce Mn-dependent peroxidases, and that the activity of these enzymes declines at elevated concentrations of inorganic N. In a boreal pine forest and a sub-arctic birch forest, Cortinarius DNA was assessed by 454-sequencing of ITS amplicons and related to Mn-peroxidase activity in humus samples with- and without previous N amendment. Transcription of Cortinarius Mn-peroxidase genes was investigated in field samples. Phylogenetic analyses of Cortinarius peroxidase amplicons and genome sequences were performed. We found a significant co-localization of high peroxidase activity and DNA from Cortinarius species. Peroxidase activity was reduced by high ammonium concentrations. Amplification of mRNA sequences indicated transcription of Cortinarius Mn-peroxidase genes under field conditions. The Cortinarius glaucopus genome encodes 11 peroxidases - a number comparable to many white-rot wood decomposers. These results support the hypothesis that some ectomycorrhizal fungi - Cortinarius species in particular - may play an important role in decomposition of complex organic matter, linked to their mobilization of organically bound N.
- carbon sequestration
- Class II peroxidases
- decomposition
- ectomycorrhizal fungi
- high throughput sequencing
- nitrogen limitation
- priming effect
- transcription
- SOIL ORGANIC-MATTER
- DEGRADING HEME PEROXIDASES
- MYCORRHIZAL FUNGI
- BOREAL FOREST
- C-14-LABELED LIGNIN
- HIGH-THROUGHPUT
- NITROGEN
- DECOMPOSITION
- CARBON
- DEGRADATION
[Bodeker, Inga T. M.; Clemmensen, Karina E.; Olson, Ake; Lindahl, Bjorn D.] Swedish Univ Agr Sci, Dept Forest Mycol & Plant Pathol, S-75007 Uppsala, Sweden; [Bodeker, Inga T. M.] Swedish Univ Agr Sci, Southern Swedish Forest Res Ctr, S-23053 Alnarp, Sweden; [de Boer, Wietse] NIOO KNAW, Dept Microbial Ecol, NL-6700 AB Wageningen, Netherlands; [Martin, Francis] INRA, UMR 1136, F-54280 Champenoux, France
Lindahl, BD (reprint author), Swedish Univ Agr Sci, Dept Forest Mycol & Plant Pathol, Box 7026, S-75007 Uppsala, Sweden.