Amino acids dominate diffusive nitrogen fluxes across soil depths in acidic tussock tundra
© 2021 The Authors New Phytologist © 2021 New Phytologist Foundation.
| Veröffentlicht in: | The New phytologist. - 1984. - 231(2021), 6 vom: 15. Sept., Seite 2162-2173 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2021
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Eriophorum vaginatum Arctic amino acids microdialysis nitrogen (N) cycling soil organic N Amino Acids mehr... |
| Zusammenfassung: | © 2021 The Authors New Phytologist © 2021 New Phytologist Foundation. 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? 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 |
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| Beschreibung: | Date Completed 26.08.2021 Date Revised 26.08.2021 published: Print-Electronic CommentIn: New Phytol. 2021 Sep;231(6):2104-2106. doi: 10.1111/nph.17521. - PMID 34216151 Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.17315 |