@article{57a17843a1e442f7af4c72a7355c8fc2,
title = "Isotopic evidence of biotrophy and unusual nitrogen nutrition in soil‐dwelling Hygrophoraceae",
abstract = "Several lines of evidence suggest that the agaricoid, non-ectomycorrhizal members of the family Hygrophoraceae (waxcaps) are biotrophic with unusual nitrogen nutrition. However, methods for the axenic culture and lab-based study of these organisms remain to be developed, so our current knowledge is limited to field-based investigations. Addition of nitrogen, lime or organophosphate pesticide at an experimental field site (Sourhope) suppressed fruiting of waxcap basidiocarps. Furthermore, stable isotope natural abundance in basidiocarps were unusually high in 15N and low in 13C, the latter consistent with mycorrhizal nutritional status. Similar patterns were found in waxcap basidiocarps from diverse habitats across four continents. Additional data from 14C analysis of basidiocarps and 13C pulse label experiments suggest that these fungi are not saprotrophs but rather biotrophic endophytes and possibly mycorrhizal. The consistently high but variable δ 15N values (10–20‰) of basidiocarps further indicate that N acquisition or processing differ from other fungi; we suggest that N may be derived from acquisition of N via soil fauna high in the food chain.",
keywords = "waxcap, biotrophy, mutualism, stable isotopes, 15N, nitrogen uptake, invertebrates, mycorrhiza, Soil Microbiology, Mycorrhizae/metabolism, Fruiting Bodies, Fungal/metabolism, Nitrogen/metabolism, Agaricales/metabolism",
author = "Hans Halbwachs and Easton, {Gary L.} and Roland Bol and Hobbie, {Erik A.} and Garnett, {Mark H.} and Derek Per{\v s}oh and Liz Dixon and Ostle, {Nick J.} and Peter Karasch and Gareth Griffith",
note = "Funding Information: This work was funded by the Natural Environment Research Council under the Soil Biodiversity Thematic Programme (Grant number: NER/T/S/2001/00143), (NERC Radiocarbon Facility NRCF010001 (alloc. 1100.1004) and funding via Memorandum of Agreement from CCW, SNH, DENI, NE and Plan-tlife to GWG. The Institute of Biological, Environmental, and Rural Sciences receives strategic funding from the BBSRC. This work was supported through grant NSF IOS-0843366 to E.H. We thank Andy Stott, Darren Sleep and Helen Grant (CEH) and staff in the isotope laboratories at Bayreuth and North Wyke at for efficient isotope analyses, and Graham Burt-Smith and Sarah Buckland (Soil Biodiversity Site Managers) for support during field sampling at Sourhope. We thank Brian Spooner (RBG Kew), Shirley Kerr, John Hedger, Debbie Evans, David Mitchel for access to fungarium samples. Finally we thank Reinhard Agerer (Munich) for inspiring discussions about the trophic mode of waxcaps during recent years and Gu{\dh}r{\'i}{\dh}ur Gy{\dh}a Eyj{\'o}lfsd{\'o}ttir (Icelandic Institute of Natural History) for her support in sampling fungi. We are grateful to Prof. Marc-Andr{\'e} Selosse for helpful comments on the manuscript. Publisher Copyright: {\textcopyright} 2018 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.",
year = "2018",
month = oct,
day = "1",
doi = "10.1111/1462-2920.14327",
language = "English",
volume = "20",
pages = "3573--3588",
journal = "Environmental Microbiology",
issn = "1462-2912",
publisher = "Wiley",
number = "10",
}
