Effect of calcium application on the tolerance of mycorrhizal lettuce plants to polyethylene glycol-induced water stress
Although the effect of arbuscular-mycorrhizal (AM) fungi on drought alleviation has been studied, there is little information on the role of Ca as a drought stress reliever in mycorrhizal symbiosis. Lactuca sativa plants were grown in a soil/ sand mixture (1 /9 v /v) with application of a nutrient s...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1997 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/278181 |
| Acceso en línea: | http://hdl.handle.net/10261/278181 |
| Access Level: | acceso abierto |
| Palabra clave: | Calcium Mycorrhizal plants Polyethylene glycol Water stress |
| Sumario: | Although the effect of arbuscular-mycorrhizal (AM) fungi on drought alleviation has been studied, there is little information on the role of Ca as a drought stress reliever in mycorrhizal symbiosis. Lactuca sativa plants were grown in a soil/ sand mixture (1 /9 v /v) with application of a nutrient solution containing increasing amounts of Ca. The water stress was imposed by dipping the plant root systems in the appropriate polyethylene glycol (PEG) solution for 22 h. The calcium increase in the medium decreased the colonizing ability of the fungi (Glomus mosseae and G. fasciculatum) assayed, but did not affect the growth of the mycorrhizal plants. In contrast, the control plants decreased their growth when the calcium reached 8 mM. Under both severe and moderate stress, mycorrhizal plants had decreased praline accumulation in response to the increase in Ca availability, indicating that mycorrhizal plants suffered less from the detrimental effect of PEG-induced water stress as a consequence of the Ca increase in the medium. Results of treatments on relative water content (RWC) paralleled those of praline. With 4 mM Ca in the medium, the mycorrhizal plants were more negatively affected by PEG application than the control plants, but above this calcium level the praline content decreased and the RWC increased in mycorrhizal plants. In the control plants the behaviour was reversed. This response could be due to the higher membranous surface area in mycorrhizal plants than in nonmycorrhizal plants. In conclusion, the application and uptake of increasing amounts of Ca enhances the tolerance of mycorrhizal plants to PEG-induced water stress. |
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