title: Enzymatic activities and stable isotope patterns of ectomycorrhizal fungi in relation to phylogeny and exploration types in an afrotropical rain forest.
abstract: Ectomycorrhizal (ECM) fungi obtain both mineral and simple organic nutrients from soil and transport these to plant roots. Natural abundance of stable isotopes (¹⁵N and ¹³C) in fruit bodies and potential enzymatic activities of ECM root tips provide insights into mineral nutrition of these mutualistic partners. By combining rDNA sequence analysis with enzymatic and stable isotope assays of root tips, we hypothesized that phylogenetic affinities of ECM fungi are more important than ECM exploration type, soil horizon and host plant in explaining the differences in mineral nutrition of trees in an African lowland rainforest. Ectomycorrhizal fungal species belonging to extraradical mycelium-rich morphotypes generally displayed the strongest potential activities of degradation enzymes, except for laccase. The signature of ¹⁵N was determined by the ECM fungal lineage, but not by the exploration type. Potential enzymatic activities of root tips were unrelated to ¹⁵N signature of ECM root tip. The lack of correlation suggests that these methods address different aspects in plant nutrient uptake. Stable isotope analysis of root tips could provide an additional indirect assessment of fungal and plant nutrition that enables enhancement of taxonomic coverage and control for soil depth and internal nitrogen cycling in fungal tissues.
authors: Natural History Museum of Tartu University, 46 Vanemuise, 51005 Tartu, Estonia.|Institute of Ecology and Earth Sciences, University of Tartu, 14a Ravila, 50411 Tartu, Estonia.
authors: Leho
authors: L
authors: Tedersoo
authors: Institute of Ecology and Earth Sciences, University of Tartu, 14a Ravila, 50411 Tartu, Estonia.
authors: Triin
authors: T
authors: Naadel
authors: Institute of Ecology and Earth Sciences, University of Tartu, 14a Ravila, 50411 Tartu, Estonia.
authors: Mohammad
authors: M
authors: Bahram
authors: Institute of Soil Ecology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany.
authors: Karin
authors: K
authors: Pritsch
authors: Institute of Soil Ecology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany.
authors: Franz
authors: F
authors: Buegger
authors: Wildlife Conservation Society, Plot 802, Kiwafu Road (Kansanga), PO Box 7487, Kampala, Uganda.
authors: Miguel
authors: M
authors: Leal
authors: Natural History Museum of Tartu University, 46 Vanemuise, 51005 Tartu, Estonia.
authors: Urmas
authors: U
authors: Kõljalg
authors: Natural History Museum of Tartu University, 46 Vanemuise, 51005 Tartu, Estonia.
authors: Kadri
authors: K
authors: Põldmaa
mesh_terms: D002247:Carbon Isotopes; D048690:Fruiting Bodies, Fungal / Q000378:metabolism; D005681:Gabon; D007553:Isotope Labeling; D018519:Meristem / Q000033:anatomy & histology / Q000382:microbiology; D038821:Mycorrhizae / Q000201:enzymology* / Q000235:genetics*; D009587:Nitrogen Isotopes; D010802:Phylogeny; D011891:Rain; D014197:Trees / Q000382:microbiology*; D014329:Tropical Climate
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes