Open AccessElevated CO 2 and nitrogen influence exudation of soluble organic compounds by ectomycorrhizal root systems
Author(s) -
Fransson Petra M.A.,
Johansson Emma M.
Publication year - 2010
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2009.00795.x
Subject(s) - mycelium , nitrogen , dissolved organic carbon , scots pine , biology , environmental chemistry , monosaccharide , carbon fibers , total organic carbon , deposition (geology) , botany , carbon dioxide , chemistry , pinus <genus> , biochemistry , ecology , sediment , organic chemistry , paleontology , materials science , composite number , composite material
Root and mycelial exudation contributes significantly to soil carbon (C) fluxes, and is likely to be altered by an elevated atmospheric carbon dioxide (CO 2 ) 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.) CO 2 concentrations and with different N sources. Scots pine seedlings, colonized by one of five different ectomycorrhizal or nonmycorrhizal fungi, received 70 μM N, either as NH 4 Cl 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 CO 2 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 CO 2 treatment. Elevated CO 2 had a clear impact on the production of individual LMWOAs, although with very contrasting effects depending on which N source was supplied.