Diazotrophic nitrogen fixation through aerial roots occurs in Avicennia marina : implications for adaptation of mangrove plant growth to low-nitrogen tidal flats
© 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.
| Veröffentlicht in: | The New phytologist. - 1979. - 241(2024), 4 vom: 05. Jan., Seite 1464-1475 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2024
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article 15N2 tracer aerenchyma nitrogenase partial pressure of N2 root aeration Nitrogen N762921K75 |
| Zusammenfassung: | © 2023 The Authors New Phytologist © 2023 New Phytologist Foundation. Nitrogen limitation of primary production is common in coastal ecosystems. Mangrove trees maintain high levels of nitrogen fixation around their roots. The interior aerial space of mangrove roots, in which atmospheric gas is supplied through lenticels, could be efficient sites for nitrogen fixation. We measured tidal variations of partial pressure of N2 in root aerenchyma and conducted field experiments using 15 N2 as a tracer to track N2 movement through aerial roots of Avicennia marina. We used the acetylene reduction assay to identify the root parts harboring diazotrophs. The nitrogenase activity and estimated nitrogen fixation through aerenchyma were higher in pneumatophores and absorbing roots than in cable roots. Positive correlations between root nitrogen contents and turnover rates of root nitrogen derived from N2 through aerenchyma suggested that the internal supply of N2 to diazotrophs could be the main source for nitrogen assimilation by A. marina roots. Our results confirmed that N2 is supplied to diazotrophs through aerial roots and that nitrogen fixation occurs in A. marina roots. The aerial root structures, which occur across families of mangrove plants, could be an adaptation to survival in not only low-oxygen environments but also tidal flats with little plant-available nitrogen |
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| Beschreibung: | Date Completed 26.01.2024 Date Revised 26.01.2024 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.19442 |