title: Options of partners improve carbon for phosphorus trade in the arbuscular mycorrhizal mutualism.
abstract: The mutualism between plants and arbuscular mycorrhizal fungi (AMF) is widespread and has persisted for over 400 million years. Although this mutualism depends on fair resource exchange between plants and fungi, inequality exists among partners despite mechanisms that regulate trade. Here, we use (33) P and (14) C isotopes and a split-root system to test for preferential allocation and reciprocal rewards in the plant-AMF symbiosis by presenting a plant with two AMF that differ in cooperativeness. We found that plants received more (33) P from less cooperative AMF in the presence of another AMF species. This increase in (33) P resulted in a reduced (14) C cost per unit of (33) P from less cooperative AMF when alternative options were available. Our results indicate that AMF diversity promotes cooperation between plants and AMF, which may be an important mechanism maintaining the evolutionary persistence of and diversity within the plant-AMF mutualism.
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.
authors.forename: Alicia
authors.initials: A
authors.lastname: Argüello
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.|Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, Carretera de Sacramento s/n, E-04120 La Cañada, Almería, Spain.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: O'Brien
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.|Plant-Soil Interactions, Institute for Sustainability Sciences, Agroscope, Reckenholzstrasse 191, CH-8046, Zürich, Switzerland.
authors.forename: Marcel G A
authors.initials: MG
authors.lastname: van der Heijden
authors.affiliation: Botanical Institute, University of Basel, Basel, 4056, Switzerland.
authors.forename: Andres
authors.initials: A
authors.lastname: Wiemken
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schmid
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.
authors.forename: Pascal A
authors.initials: PA
authors.lastname: Niklaus
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D002247:Carbon Isotopes / Q000032:analysis; D038821:Mycorrhizae / Q000502:physiology*; D010758:Phosphorus / Q000378:metabolism*; D010759:Phosphorus Isotopes / Q000032:analysis; D018517:Plant Roots / Q000382:microbiology*; D010943:Plantago / Q000254:growth & development / Q000382:microbiology; D013559:Symbiosis / Q000502:physiology*; D029921:Trifolium / Q000254:growth & development / Q000382:microbiology
chemical_list: D002247:Carbon Isotopes; D010759:Phosphorus Isotopes; D010758:Phosphorus; D002244:Carbon
keywords: biological markets; isotopes; microbial diversity; plant-AMF mutualism; split-root system; supply and demand