Improved nitrogen uptake and transport from 15N-labelled nitrate by external hyphae of arbuscular mycorrhiza under water-stressed conditions
The significance of the external mycelium of arbuscular mycorrhiza for uptake and transport of N from 15N-labelled nitrate in benefiting plant nutrition, was evaluated under either well-irrigated or water-stressed conditions. Plants of lettuce (Lactuca sativa L.) were grown under controlled conditio...
| Autores: | , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1994 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/278039 |
| Acceso en línea: | http://hdl.handle.net/10261/278039 |
| Access Level: | acceso abierto |
| Palabra clave: | Arbuscular mycorrhiza Drought stress 15N-labelled fertilizers Nitrate uptake |
| Sumario: | The significance of the external mycelium of arbuscular mycorrhiza for uptake and transport of N from 15N-labelled nitrate in benefiting plant nutrition, was evaluated under either well-irrigated or water-stressed conditions. Plants of lettuce (Lactuca sativa L.) were grown under controlled conditions in a neutral agricultural soil/sand mix either non-mycorrhizal or in association with the arbuscular-mycorrhizal fungus, Glomus fasciculatum (Taxter sensu Gerd.) Gerd. and Trappe. The pots comprised a two-compartment system, where a fine nylon mesh screen prevented the development of roots in a hyphal compartment. 15NO3− was applied to this hyphal compartment where access of the root was not possible. At harvest, the 15N enrichment in plant tissues was the same for both mycorrhizal and non-mycorrhizal plants under optimal water supply conditions. However, under water-stressed conditions, where the mass flow and diffusion of NO3− ions to the roots can be affected, the 15N enrichment was four times higher in mycorrhizal than in non-mycorrhizal plants. This provides evidence of hyphal transport of N from a nitrate source, supporting the view that arbuscular mycorrhiza can be important for the N-nutrition of plants in relatively dry agricultural soil where nitrate is actually the predominant nitrogen form. |
|---|