title: Carbon translocation from a plant to an insect-pathogenic endophytic fungus.
abstract: Metarhizium robertsii is a common soil fungus that occupies a specialized ecological niche as an endophyte and an insect pathogen. Previously, we showed that the endophytic capability and insect pathogenicity of Metarhizium are coupled to provide an active method of insect-derived nitrogen transfer to a host plant via fungal mycelia. We speculated that in exchange for this insect-derived nitrogen, the plant would provide photosynthate to the fungus. By using13CO2, we show the incorporation of13C into photosynthate and the subsequent translocation of13C into fungal-specific carbohydrates (trehalose and chitin) in the root/endophyte complex. We determined the amount of13C present in root-associated fungal biomass over a 21-day period by extracting fungal carbohydrates and analysing their composition using nuclear magnetic resonance (NMR) spectroscopy. These findings are evidence that the host plant is providing photosynthate to the fungus, likely in exchange for insect-derived nitrogen in a tripartite, and symbiotic, interaction.
authors.affiliation: Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada L2S 3A1.
authors.forename: Scott W
authors.initials: SW
authors.lastname: Behie
authors.affiliation: Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil.
authors.forename: Camila C
authors.initials: CC
authors.lastname: Moreira
authors.affiliation: Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada L2S 3A1.
authors.forename: Irina
authors.initials: I
authors.lastname: Sementchoukova
authors.affiliation: Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada L2S 3A1.
authors.forename: Larissa
authors.initials: L
authors.lastname: Barelli
authors.affiliation: Department of Chemistry, Brock University, St Catharines, Ontario, Canada L2S 3A1.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Zelisko
authors.affiliation: Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada L2S 3A1.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bidochka
mesh_terms: D000818:Animals; D001692:Biological Transport; D002247:Carbon Isotopes / Q000032:analysis / Q000378:metabolism*; D060026:Endophytes / Q000737:chemistry / Q000378:metabolism*; D007313:Insecta / Q000737:chemistry / Q000378:metabolism* / Q000382:microbiology*; D052981:Metarhizium / Q000737:chemistry / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology; D010944:Plants / Q000737:chemistry / Q000378:metabolism* / Q000469:parasitology; D014199:Trehalose / Q000032:analysis / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D014199:Trehalose; D009584:Nitrogen