title: The host plant Pinus pinaster exerts specific effects on phosphate efflux and polyphosphate metabolism of the ectomycorrhizal fungus Hebeloma cylindrosporum: a radiotracer, cytological staining and31P NMR spectroscopy study.
abstract: Ectomycorrhizal (ECM) association can improve plant phosphorus (P) nutrition. Polyphosphates (polyP) synthesized in distant fungal cells after P uptake may contribute to P supply from the fungus to the host plant if they are hydrolyzed to phosphate in ECM roots then transferred to the host plant when required. In this study, we addressed this hypothesis for the ECM fungus Hebeloma cylindrosporum grown in vitro and incubated without plant or with host (Pinus pinaster) and non-host (Zea mays) plants, using an experimental system simulating the symbiotic interface. We used32P labelling to quantify P accumulation and P efflux and in vivo and in vitro nuclear magnetic resonance (NMR) spectroscopy and cytological staining to follow the fate of fungal polyP. Phosphate supply triggered a massive P accumulation as newly synthesized long-chain polyP in H. cylindrosporum if previously grown under P-deficient conditions. P efflux from H. cylindrosporum towards the roots was stimulated by both host and non-host plants. However, the host plant enhanced32P release compared with the non-host plant and specifically increased the proportion of short-chain polyP in the interacting mycelia. These results support the existence of specific host plant effects on fungal P metabolism able to provide P in the apoplast of ectomycorrhizal roots.
authors.affiliation: INRA, UMR Eco&Sols, 2 place Viala, 34060 CEDEX 1, Montpellier, France.|Colegio de Postgraduados, Campus San Luis Potosí, Agustín de Iturbide N 73, CP 78600, San Luis Potosí, Mexico.
authors.forename: Margarita
authors.initials: M
authors.lastname: Torres-Aquino
authors.affiliation: INRA, UMR Eco&Sols, 2 place Viala, 34060 CEDEX 1, Montpellier, France.
authors.forename: Adeline
authors.initials: A
authors.lastname: Becquer
authors.affiliation: INRA, UMR SPO (1083) Sciences pour l'Oenologie, 2 place Viala, 34060 CEDEX 1, Montpellier, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Le Guernevé
authors.affiliation: INRA, UMR Eco&Sols, 2 place Viala, 34060 CEDEX 1, Montpellier, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Louche
authors.affiliation: INRA, UMR Eco&Sols, 2 place Viala, 34060 CEDEX 1, Montpellier, France.
authors.forename: Laurie K
authors.initials: LK
authors.lastname: Amenc
authors.affiliation: INRA, UMR Eco&Sols, 2 place Viala, 34060 CEDEX 1, Montpellier, France.
authors.forename: Siobhan
authors.initials: S
authors.lastname: Staunton
authors.affiliation: INRA, UMR Eco&Sols, 2 place Viala, 34060 CEDEX 1, Montpellier, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Quiquampoix
authors.affiliation: INRA, UMR Eco&Sols, 2 place Viala, 34060 CEDEX 1, Montpellier, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Plassard
mesh_terms: D055364:Hebeloma / Q000502:physiology*; D054884:Host-Pathogen Interactions; D025301:Hyphae / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D038821:Mycorrhizae / Q000502:physiology*; D010758:Phosphorus / Q000378:metabolism*; D010761:Phosphorus Radioisotopes / Q000378:metabolism*; D028223:Pinus / Q000378:metabolism / Q000382:microbiology*; D011122:Polyphosphates / Q000378:metabolism*; D003313:Zea mays / Q000378:metabolism
chemical_list: D010761:Phosphorus Radioisotopes; D011122:Polyphosphates; D010758:Phosphorus
keywords: 32P labelling; Hebeloma cylindrosporum; Pinus pinaster; Zea mays; fungal P efflux; in vivo 31P NMR spectroscopy; polyphosphates