title: Temperature constraints on the growth and functioning of root organ cultures with arbuscular mycorrhizal fungi.
abstract: In this study we investigated the effects of temperature on fungal growth and tested whether the differences in fungal growth were related to the effects of temperature on carbon movement to, or within, the fungus. Growth curves and C uptake-transfer-translocation measurements were obtained for three arbuscular mycorrhizal fungi (AMF) isolates cultured within a 6-30 degrees C temperature range. A series of experiments with a model fungal isolate, Glomus intraradices, was used to examine the effects of temperature on lipid body and 33P movement, and to investigate the role of acclimation and incubation time. Temperature effects on AMF growth were both direct and indirect because, despite clear independent root and AMF growth responses in some cases, the uptake and translocation of 13C was also affected within the temperature range tested. Root C uptake and, to a lesser extent, C translocation in the fungus, were reduced by low temperatures (< 18 degrees C). Uptake and translocation of 33P by fungal hyphae were, by contrast, similar between 10 and 25 degrees C. We conclude that temperature, between 6 and 18 degrees C, reduces AMF growth, and that C movement to the fungus is involved in this response.
authors.affiliation: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, C/Profesor Albareda 1, E-18008 Granada, Spain. mgavito@oikos.unam.mx
authors.forename: Mayra E
authors.initials: ME
authors.lastname: Gavito
authors.forename: Pål A
authors.initials: PA
authors.lastname: Olsson
authors.forename: Hervé
authors.initials: H
authors.lastname: Rouhier
authors.forename: Almudena
authors.initials: A
authors.lastname: Medina-Peñafiel
authors.forename: Iver
authors.initials: I
authors.lastname: Jakobsen
authors.forename: Albert
authors.initials: A
authors.lastname: Bago
authors.forename: Concepción
authors.initials: C
authors.lastname: Azcón-Aguilar
mesh_terms: D002247:Carbon Isotopes; D046508:Culture Techniques; D018552:Daucus carota / Q000382:microbiology* / Q000502:physiology; D050356:Lipid Metabolism; D025282:Mycelium / Q000378:metabolism*; D038821:Mycorrhizae / Q000254:growth & development / Q000502:physiology*; D010759:Phosphorus Isotopes; D018517:Plant Roots / Q000382:microbiology* / Q000502:physiology; D013696:Temperature
chemical_list: D002247:Carbon Isotopes; D010759:Phosphorus Isotopes