Abstract

Root and mycelial exudation contributes significantly to soil carbon (C) fluxes, and is likely to be altered by an elevated atmospheric carbon dioxide (CO2) concentration and nitrogen (N) deposition. We quantified soluble, low-molecular-weight (LMW) organic compounds exuded by ectomycorrhizal plants grown under ambient (360 p.p.m.) or elevated (710 p.p.m.) CO2 concentrations and with different N sources. Scots pine seedlings, colonized by one of five different ectomycorrhizal or nonmycorrhizal fungi, received 70 mu M N, either as NH4Cl or as alanine, in a liquid growth medium. Exudation of LMW organic acids (LMWOAs), dissolved monosaccharides and total dissolved organic carbon were determined. Both N and CO2 had a significant impact on exudation, especially of LMWOAs. Exudation of LMWOAs was negatively affected by inorganic N and decreased by 30-85% compared with the organic N treatment, irrespective of the CO2 treatment. Elevated CO2 had a clear impact on the production of individual LMWOAs, although with very contrasting effects depending on which N source was supplied.

Keywords

global change; carbon cycling; oxalate; Pinus sylvestris; organic nitrogen; LMWOAs

Published in

FEMS Microbiology Ecology
2010, Volume: 71, number: 2, pages: 186-196
Publisher: WILEY-BLACKWELL

SLU Authors

• Fransson, Petra

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)


Publication identifier

DOI: https://doi.org/10.1111/j.1574-6941.2009.00795.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/48799