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Assimilation and isotopic fractionation of nitrogen by mycorrhizal fungi
Author(s) -
Emmerton K. S.,
Callaghan T. V.,
Jones H. E.,
Leake J. R.,
Michelsen A.,
Read D. J.
Publication year - 2001
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.1469-8137.2001.00178.x
Subject(s) - fractionation , isotopes of nitrogen , ammonium , isotope fractionation , assimilation (phonology) , nitrogen , nitrogen cycle , botany , fungus , abundance (ecology) , δ15n , biology , environmental chemistry , stable isotope ratio , nitrate , isotope analysis , chemistry , δ13c , ecology , chromatography , linguistics , philosophy , physics , organic chemistry , quantum mechanics
Summary• The patterns of nitrogen (N) utilization and of N isotope fractionation were determined when two ecto‐(ECM) and an ericoid (ERM) mycorrhizal fungus were grown with inorganic (ammonium or nitrate) or organic (glutamic acid or glycine) N sources of predetermined N isotope composition. • All N sources were readily utilized by each of the fungi but substantial differences in the pattern of N isotope fractionation were observed both between the fungi and the N sources. • Whereas several of the ECM‐N source combinations exhibited significant net fractionation in favour of 15 N, no such effect was seen in the ERM fungus, where, on ammonium, there was preferential assimilation of 14 N. • It is concluded that isotopic fractionation during N uptake and metabolism can cause significant shifts in the 15 N abundance of mycorrhizal fungi and that, as a result, any attempt to use the tissue 15 N abundance as a means of identifying the substrates being exploited by mycorrhizal fungi, or their plant partners, in nature, are likely to be unrealistic.