title: Plant growth promotion, metabolite production and metal tolerance of dark septate endophytes isolated from metal-polluted poplar phytomanagement sites.
abstract: Numerous studies address the distribution and the diversity of dark septate endophytes (DSEs) in the literature, but little is known about their ecological role and their effect on host plants, especially in metal-polluted soils. Seven DSE strains belonging to Cadophora, Leptodontidium, Phialophora and Phialocephala were isolated from roots of poplar trees from metal-polluted sites. All strains developed on a wide range of carbohydrates, including cell-wall-related compounds. The strains evenly colonized birch, eucalyptus and ryegrass roots in re-synthesis experiments. Root and shoot growth promotion was observed and was both plant and strain dependent. Two Phialophora and Leptodontidium strains particularly improved plant growth. However, there was no correlation between the level of root colonization by DSEs and the intensity of growth promotion. All strains produced auxin and six also stimulated plant growth through the release of volatile organic compounds (VOCs). SPME-GC/MS analyses revealed four major VOCs emitted by Cadophora and Leptodontidium The strains exhibited growth at high concentrations of several metals. The ability of metal-resistant DSE strains to produce both soluble and volatile compounds for plant growth promotion indicates interesting microbial resources with high potential to support sustainable production of bioenergy crops within the context of the phytomanagement of metal-contaminated sites.
authors.affiliation: CNRS, LIEC UMR7360, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, F-54506 Vandoeuvre-lès-Nancy, France LIEC UMR7360, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, F-54506 Vandoeuvre-lès-Nancy, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Berthelot
authors.affiliation: CNRS, LIEC UMR7360, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, F-54506 Vandoeuvre-lès-Nancy, France LIEC UMR7360, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, F-54506 Vandoeuvre-lès-Nancy, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Leyval
authors.affiliation: CNRS, UMR6249 Laboratoire Chrono-Environnement, Pôle Universitaire du Pays de Montbéliard, 4 place Tharradin, BP 71427, F-25211, Montbéliard, France UMR6249 Laboratoire Chrono-Environnement, Université de Bourgogne Franche-Comté, Pôle Universitaire du Pays de Montbéliard, 4 place Tharradin, BP 71427, F-25211, Montbéliard, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Foulon
authors.affiliation: CNRS, UMR6249 Laboratoire Chrono-Environnement, Pôle Universitaire du Pays de Montbéliard, 4 place Tharradin, BP 71427, F-25211, Montbéliard, France UMR6249 Laboratoire Chrono-Environnement, Université de Bourgogne Franche-Comté, Pôle Universitaire du Pays de Montbéliard, 4 place Tharradin, BP 71427, F-25211, Montbéliard, France Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, F-54506, Vandoeuvre-lès-Nancy, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Chalot
authors.affiliation: CNRS, LIEC UMR7360, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, F-54506 Vandoeuvre-lès-Nancy, France LIEC UMR7360, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, F-54506 Vandoeuvre-lès-Nancy, France damien.blaudez@univ-lorraine.fr.
authors.forename: Damien
authors.initials: D
authors.lastname: Blaudez
mesh_terms: D001203:Ascomycota / Q000302:isolation & purification; D029662:Betula; D001673:Biodegradation, Environmental; D060026:Endophytes / Q000302:isolation & purification / Q000502:physiology*; D007210:Indoleacetic Acids / Q000378:metabolism; D008670:Metals / Q000378:metabolism*; D063245:Plant Development / Q000502:physiology*; D018517:Plant Roots; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D007210:Indoleacetic Acids; D008670:Metals; D012989:Soil Pollutants
keywords: auxin; dark septate endophytes; metal tolerance; plant growth promotion; volatile organic compounds