title: Carbon and phosphorus exchange may enable cooperation between an arbuscular mycorrhizal fungus and a phosphate-solubilizing bacterium.
abstract: Arbuscular mycorrhizal fungi (AMF) transfer plant photosynthate underground which can stimulate soil microbial growth. In this study, we examined whether there was a potential link between carbon (C) release from an AMF and phosphorus (P) availability via a phosphate-solubilizing bacterium (PSB). We investigated the outcome of the interaction between the AMF and the PSB by conducting a microcosm and two Petri plate experiments. An in vitro culture experiment was also conducted to determine the direct impact of AMF hyphal exudates on growth of the PSB. The AMF released substantial C to the environment, triggering PSB growth and activity. In return, the PSB enhanced mineralization of organic P, increasing P availability for the AMF. When soil available P was low, the PSB competed with the AMF for P, and its activity was not stimulated by the fungus. When additional P was added to increase soil available P, the PSB enhanced AMF hyphal growth, and PSB activity was also stimulated by the fungus. Our results suggest that an AMF and a free-living PSB interacted to the benefit of each other by providing the C or P that the other microorganism required, but these interactions depended upon background P availability.
authors.affiliation: College of Resources and Environmental Sciences, Research Center for Resources, the Environment and Food Safety, China Agricultural University, Beijing, 100193, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Minggang
authors.initials: M
authors.lastname: Xu
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Resources and Environmental Sciences, Research Center for Resources, the Environment and Food Safety, China Agricultural University, Beijing, 100193, China.
authors.forename: Fusuo
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK.
authors.forename: Angela
authors.initials: A
authors.lastname: Hodge
authors.affiliation: College of Resources and Environmental Sciences, Research Center for Resources, the Environment and Food Safety, China Agricultural University, Beijing, 100193, China.
authors.forename: Gu
authors.initials: G
authors.lastname: Feng
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism*; D025301:Hyphae / Q000254:growth & development; D000455:Medicago sativa / Q000382:microbiology; D038821:Mycorrhizae / Q000502:physiology*; D010710:Phosphates / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D010833:Phytic Acid / Q000378:metabolism
chemical_list: D010710:Phosphates; D010758:Phosphorus; D002244:Carbon; D010833:Phytic Acid; D000135:Acid Phosphatase
keywords: arbuscular mycorrhizal fungus (AMF)-phosphate-solubilizing bacterium (PSB) interactions; carbon-phosphorus exchange; cooperation; hyphal exudates; phosphatase activity