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dc.contributorVirginia Tech. Department of Horticulture
dc.contributorDartmouth College. Department of Biological Sciences
dc.contributor.authorEaton, Gregory K.
dc.contributor.authorAyres, Matthew P.
dc.date.accessioned2015-04-23T19:03:57Z
dc.date.available2015-04-23T19:03:57Z
dc.date.issued2002
dc.identifier.citationEaton, G. K. & Ayres, M. P. (2002). Plasticity and constraint in growth and protein mineralization of ectomycorrhizal fungi under simulated nitrogen deposition. Mycologia, 94(6), 921-932. doi: 10.2307/3761860
dc.identifier.issn0027-5514
dc.identifier.urihttp://hdl.handle.net/10919/51773
dc.description.abstractEctomycorrhizal fungi allow their host plants access to organic forms of N through enzymatic mineralization of the substrate and enhanced absorption of amino acids and mineral N. The cost to the plant is carbohydrates that support fungal growth and metabolism. Enrichment of soils with mineral N, as through atmospheric deposition, may affect the growth and function of these fungi by direct effects of increased N availability on fungi and indirect effects through reduced plant C allocation to roots. We tested the potential of N enrichment and altered carbohydrate supply to affect the growth and protein mineralization activity of 10 ectomycorrhizal fungi in sterile liquid media. Nitrogen treatments consisted of organic N only vs organic plus mineral N. Carbon treatments consisted of 5 g per liter glucose vs. no glucose added. Fungi differed widely in their growth and mineralization responses to these variables. Seven of 10 fungi had at least 20% reduced growth with reduced carbohydrates. Only 2 of 10 increased growth by 20% or more with increased mineral N. Carbohydrates affected growth more in a purely organic N environment suggesting an energy limitation to mineralization. Protein mineralization activity tended to be depressed by reductions in carbohydrates and increased by increased mineral N. The high sensitivity of fungal growth to carbohydrates suggests important indirect effects of N enrichment via altered C allocation in host trees. Principal Components analysis separated most fungal species along an axis representing a gradient from high protein mineralization efficiency to high intrinsic growth rate. Those fungi with slow growth and efficient mineralization activity corresponded closely to fungi often cited as late successional species, while fungi with high growth rates and low mineralization efficiency are often categorized as early successional. One fungus, Cenococcum geophillum, separated from others on an axis representing strong N dependence in growth. Nitrogen enrichment has the potential to alter the composition and function of the ectomycorrhizal fungus community. Physiological differences among species provide a starting point for predicting community responses and anticipating ecosystem consequences.
dc.description.sponsorshipSigma Xi, the Scientific Research Society - Grants in Aid of Research
dc.description.sponsorshipDartmouth College. Department of Biological Sciences
dc.format.extent12 pages
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherMycological Society of America
dc.subjectAtmospheric deposition
dc.subjectCarbon-nitrogen interactions
dc.subjectMineralizing enzymes
dc.subjectNitrogen enrichment
dc.subjectProtease
dc.titlePlasticity and constraint in growth and protein mineralization of ectomycorrhizal fungi under simulated nitrogen deposition
dc.typeArticle - Refereed
dc.identifier.urlhttp://www.mycologia.org/content/94/6/921.abstract?sid=13acfd59-0c12-40da-a408-110f61a7f38d
dc.date.accessed2015-04-21
dc.title.serialMycologia
dc.identifier.doihttps://doi.org/10.2307/3761860
dc.type.dcmitypeText


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