Amino Acids Dominate Diffusive Nitrogen Fluxes in Acidic Tussock Tundra
Organic nitrogen (N) is abundant in soils, but early conceptual frameworks considered it nonessential for plant growth. It is now well recognised that plants have the potential to take up organic N. However, it is still unclear whether plants supplement their N requirements by taking up organic N in...
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ftosti:oai:osti.gov:1861241 2023-07-30T04:07:20+02:00 Amino Acids Dominate Diffusive Nitrogen Fluxes in Acidic Tussock Tundra Homyak, P M Slessarev, E W Hagerty, S Greene, A C Marchus, K Dowdy, K Iverson, S Schimel, J P 2022-04-25 application/pdf http://www.osti.gov/servlets/purl/1861241 https://www.osti.gov/biblio/1861241 https://doi.org/10.1111/nph.17315 unknown http://www.osti.gov/servlets/purl/1861241 https://www.osti.gov/biblio/1861241 https://doi.org/10.1111/nph.17315 doi:10.1111/nph.17315 54 ENVIRONMENTAL SCIENCES 2022 ftosti https://doi.org/10.1111/nph.17315 2023-07-11T10:11:35Z Organic nitrogen (N) is abundant in soils, but early conceptual frameworks considered it nonessential for plant growth. It is now well recognised that plants have the potential to take up organic N. However, it is still unclear whether plants supplement their N requirements by taking up organic N in situ: at what rate is organic N diffusing towards roots and are plants taking it up? In this work, we combined microdialysis with live-root uptake experiments to measure amino acid speciation and diffusion rates towards roots of Eriophorum vaginatum. Amino acid diffusion rates (321 ng N cm -2 h -1 ) were c. 3× higher than those for inorganic N. Positively charged amino acids made up 68% of the N diffusing through soils compared with neutral and negatively charged amino acids. Live-root uptake experiments confirmed that amino acids are taken up by plants (up to 1 µg N g -1 min -1 potential net uptake). Amino acids must be considered when forecasting plant-available N, especially when they dominate the N supply, and when acidity favours proteolysis over net N mineralisation. Determining amino acid production pathways and supply rates will become increasingly important in projecting the extent and consequences of shrub expansion, especially considering the higher C : N ratio of plants relative to soil. Other/Unknown Material Tundra SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) New Phytologist 231 6 2162 2173 |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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54 ENVIRONMENTAL SCIENCES |
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54 ENVIRONMENTAL SCIENCES Homyak, P M Slessarev, E W Hagerty, S Greene, A C Marchus, K Dowdy, K Iverson, S Schimel, J P Amino Acids Dominate Diffusive Nitrogen Fluxes in Acidic Tussock Tundra |
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54 ENVIRONMENTAL SCIENCES |
description |
Organic nitrogen (N) is abundant in soils, but early conceptual frameworks considered it nonessential for plant growth. It is now well recognised that plants have the potential to take up organic N. However, it is still unclear whether plants supplement their N requirements by taking up organic N in situ: at what rate is organic N diffusing towards roots and are plants taking it up? In this work, we combined microdialysis with live-root uptake experiments to measure amino acid speciation and diffusion rates towards roots of Eriophorum vaginatum. Amino acid diffusion rates (321 ng N cm -2 h -1 ) were c. 3× higher than those for inorganic N. Positively charged amino acids made up 68% of the N diffusing through soils compared with neutral and negatively charged amino acids. Live-root uptake experiments confirmed that amino acids are taken up by plants (up to 1 µg N g -1 min -1 potential net uptake). Amino acids must be considered when forecasting plant-available N, especially when they dominate the N supply, and when acidity favours proteolysis over net N mineralisation. Determining amino acid production pathways and supply rates will become increasingly important in projecting the extent and consequences of shrub expansion, especially considering the higher C : N ratio of plants relative to soil. |
author |
Homyak, P M Slessarev, E W Hagerty, S Greene, A C Marchus, K Dowdy, K Iverson, S Schimel, J P |
author_facet |
Homyak, P M Slessarev, E W Hagerty, S Greene, A C Marchus, K Dowdy, K Iverson, S Schimel, J P |
author_sort |
Homyak, P M |
title |
Amino Acids Dominate Diffusive Nitrogen Fluxes in Acidic Tussock Tundra |
title_short |
Amino Acids Dominate Diffusive Nitrogen Fluxes in Acidic Tussock Tundra |
title_full |
Amino Acids Dominate Diffusive Nitrogen Fluxes in Acidic Tussock Tundra |
title_fullStr |
Amino Acids Dominate Diffusive Nitrogen Fluxes in Acidic Tussock Tundra |
title_full_unstemmed |
Amino Acids Dominate Diffusive Nitrogen Fluxes in Acidic Tussock Tundra |
title_sort |
amino acids dominate diffusive nitrogen fluxes in acidic tussock tundra |
publishDate |
2022 |
url |
http://www.osti.gov/servlets/purl/1861241 https://www.osti.gov/biblio/1861241 https://doi.org/10.1111/nph.17315 |
genre |
Tundra |
genre_facet |
Tundra |
op_relation |
http://www.osti.gov/servlets/purl/1861241 https://www.osti.gov/biblio/1861241 https://doi.org/10.1111/nph.17315 doi:10.1111/nph.17315 |
op_doi |
https://doi.org/10.1111/nph.17315 |
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New Phytologist |
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231 |
container_issue |
6 |
container_start_page |
2162 |
op_container_end_page |
2173 |
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1772820598719774720 |