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Vilberto Stocchi - One of the best experts on this subject based on the ideXlab platform.
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headspace solid phase microextraction with gas chromatography and mass spectrometry in the investigation of volatile organic compounds in an Ectomycorrhizae synthesis system
Rapid Communications in Mass Spectrometry, 2004Co-Authors: Michele Menotta, Anna Maria Gioacchini, Antonella Amicucci, Michele Buffalini, Davide Sisti, Vilberto StocchiAbstract:Ectomycorrhizae formation represents one of the most significant steps in the truffle life cycle and is determined by a complex molecular signaling between two symbionts. In order to understand the molecular pathway of ectomycorrhiza development, we focused on the signaling interaction between the ectomycorrhizal fungus Tuber borchii Vittad. and the Tilia americana L. plant roots. The medium of a pre-symbiotic (T. americana-T. borchii) in vitro system was analysed by headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry. In total, 73 volatile organic compounds (VOCs) were identified. Twenty-nine of these VOCs were produced only during the interaction phase between the two partners, leading to a hypothesis that these molecules might act as molecular messengers in order to pilot the Ectomycorrhizae formation.
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characterization of the tuber borchii nitrate reductase gene and its role in Ectomycorrhizae
Molecular Genetics and Genomics, 2003Co-Authors: Michele Guescini, Sabrina Zeppa, Lucia Potenza, Francesco Palma, Raffaella Pierleoni, Luciana Vallorani, Cinzia Sacconi, G Giomaro, Vilberto StocchiAbstract:The nitrate assimilation pathway represents a useful model system in which to study the contribution of a mycorrhizal fungus to the nitrogen nutrition of its host plant. In the present work we cloned and characterized the nitrate reductase gene (tbnr1) from Tuber borchii. The coding region of tbnr1 is 2,787 nt in length, and it encodes a protein of 929 amino acids. Biochemical and Northern-blot analyses revealed that nitrate assimilation in T. borchii is an inducible system that responds mainly to nitrate. Furthermore, we cloned a nitrate reductase cDNA (tpnr1) from Tilia platyphyllos to set up a quantitative real-time PCR assay that would allow us to determine the fungal contribution to nitrate assimilation in ectomycorrhizal tissue. Using this approach we demonstrated that the level of tbnr1 expression in ectomycorhizae is eight times higher than in free-living mycelia, whereas tpnr1 transcription was found to be down-regulated after the establishment of the symbiosis. Enzymatic assays showed that NADPH-dependent nitrite formation markedly increases in Ectomycorrhizae. These findings imply that the fungal partner plays a fundamental role in nitrate assimilation by Ectomycorrhizae. Amino acid determination by HPLC revealed higher levels of glutamate, glutamine and asparagine in symbiotic tissues compared with mycelial controls, thus suggesting that these amino acids may represent the compounds that serve to transfer nitrogen to the host plant.
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identification of differentially expressed cdna clones in tilia platyphyllos tuber borchii Ectomycorrhizae using a differential screening approach
Molecular Genetics and Genomics, 2002Co-Authors: Emanuela Polidori, Davide Sisti, Deborah Agostini, Sabrina Zeppa, Lucia Potenza, Francesco Palma, Vilberto StocchiAbstract:No information is presently available on the molecular mechanisms that control the morphogenesis of the truffle, an ectomycorrhizal ascomycetous fungus of great economic interest not only for forestry and agronomy but also for the organoleptic properties of its hypogeous fruitbodies. A Tilia platyphyllos-Tuber borchii model system was used in order to identify genes induced or up-regulated during symbiosis, since their isolation is a prerequisite for the understanding of the molecular bases of mycorrhizal development and regulation. The strategy applied involved the construction of an ectomycorrhizal cDNA library and random selection of clones, followed by a differential screening procedure to analyse cDNA expression in uninfected roots, Ectomycorrhizae and free-living mycelia. The results revealed that many genes – and more plant genes than fungal genes – are expressed at higher levels during the symbiotic phase. Several clones were also investigated in order to understand their biological function. This study represents the first attempt to extend our knowledge of the molecular mechanisms underlying the establishment of ectomycorrhiza in Tuber species.
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biotechnology of Ectomycorrhizae molecular approaches
1995Co-Authors: Vilberto Stocchi, Paola Bonfante, Marco P NutiAbstract:Ectomycorrhizas in the Ecosystem: Structural, Functional, and Community Aspects (D.J. Read). Taxonomy of Ectomycorrhizal Fungi: A Starting Point for Their Biotechnology (J.M. Trappe, A. Jumpponen). Molecular Approach to the Identification of Mycorrhizal Fungi (L. Simon). Coincidence between Molecularly or Morphologically Classified Ectomycorrhizal Morphotypes and Fruitbodies in a Spruce Forest (B. Mehmann et al.). Ectomycorrhiza Morphogenesis: Insights from Studies of Developmentally Regulated Genes and Proteins (F. Martin et al.). Molecules and Genes Involved in Mycorrhiza Functioning (S. Gianinazzi et al.). Cloning Functional Endomycorrhiza Genes: Potential for Use in Plant Breeding (P.J. Murphy et al.). The Sexual Cycle in Neurospora, from Fertilization to Ascospore Discharge (R.L. Metzenberg). Genetics of Ectomycorrhizal Fungi and Their Transformation (R. Marmeisse et al.). Inactivation of Gene Expression Triggered by Sequence Duplication (C. Cogoni et al.). Gene Expression in Plant Roots during Ectomycorrhiza Development (U. Nehls, F. Martin). Truffles: Their Life Cycle and Molecular Characterization (L. Lanfranco et al.). Molecular Identification of Tuber Species and Isolates by PCRbased Techniques (D. Gandeboeuf et al.). 8 additional articles. Index.
Geoffrey M Gadd - One of the best experts on this subject based on the ideXlab platform.
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zinc phosphate transformations by the paxillus involutus pine ectomycorrhizal association
Microbial Ecology, 2006Co-Authors: Marina Fomina, John M Charnock, Ian J. Alexander, Stephen Hillier, Geoffrey M GaddAbstract:In this research, we investigate zinc phosphate transformations by Paxillus involutus/pine ectomycorrhizas using zinc-resistant and zinc-sensitive strains of the ectomycorrhizal fungus under high- and low-phosphorus conditions to further understand fungal roles in the transformation of toxic metal minerals in the mycorrhizosphere. Mesocosm experiments with ectomycorrhizas were performed under sterile conditions with zinc phosphate localized in cellophane bags: zinc and phosphorus mobilization and uptake by the ectomycorrhizal biomass were analyzed. In the presence of a phosphorus source, an ectomycorrhizal association with a zinc-resistant strain accumulated the least zinc compared to a zinc-sensitive ectomycorrhizal association and non-mycorrhizal plants. Under low-phosphorus conditions, mycorrhizal seedlings infected with the zinc-resistant strain increased the dissolution of zinc phosphate and zinc accumulation by the plant. Extended X-ray absorption fine structure analysis of both mycorrhizal and nonmycorrhizal roots showed octahedral coordination of zinc by oxygen-containing ligands such as carboxylates or phosphate. We conclude that zinc phosphate solubilization and zinc and phosphorus uptake by the association depend on ectomycorrhizal infection, strain of the mycobiont, and the phosphorus status of the matrix.
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Zinc phosphate transformations by the Paxillus involutus/pine ectomycorrhizal association.
Microbial Ecology, 2006Co-Authors: Marina Fomina, John M Charnock, Ian J. Alexander, Stephen Hillier, Geoffrey M GaddAbstract:In this research, we investigate zinc phosphate transformations by Paxillus involutus/pine ectomycorrhizas using zinc-resistant and zinc-sensitive strains of the ectomycorrhizal fungus under high- and low-phosphorus conditions to further understand fungal roles in the transformation of toxic metal minerals in the mycorrhizosphere. Mesocosm experiments with ectomycorrhizas were performed under sterile conditions with zinc phosphate localized in cellophane bags: zinc and phosphorus mobilization and uptake by the ectomycorrhizal biomass were analyzed. In the presence of a phosphorus source, an ectomycorrhizal association with a zinc-resistant strain accumulated the least zinc compared to a zinc-sensitive ectomycorrhizal association and non-mycorrhizal plants. Under low-phosphorus conditions, mycorrhizal seedlings infected with the zinc-resistant strain increased the dissolution of zinc phosphate and zinc accumulation by the plant. Extended X-ray absorption fine structure analysis of both mycorrhizal and nonmycorrhizal roots showed octahedral coordination of zinc by oxygen-containing ligands such as carboxylates or phosphate. We conclude that zinc phosphate solubilization and zinc and phosphorus uptake by the association depend on ectomycorrhizal infection, strain of the mycobiont, and the phosphorus status of the matrix.
Ian J. Alexander - One of the best experts on this subject based on the ideXlab platform.
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zinc phosphate transformations by the paxillus involutus pine ectomycorrhizal association
Microbial Ecology, 2006Co-Authors: Marina Fomina, John M Charnock, Ian J. Alexander, Stephen Hillier, Geoffrey M GaddAbstract:In this research, we investigate zinc phosphate transformations by Paxillus involutus/pine ectomycorrhizas using zinc-resistant and zinc-sensitive strains of the ectomycorrhizal fungus under high- and low-phosphorus conditions to further understand fungal roles in the transformation of toxic metal minerals in the mycorrhizosphere. Mesocosm experiments with ectomycorrhizas were performed under sterile conditions with zinc phosphate localized in cellophane bags: zinc and phosphorus mobilization and uptake by the ectomycorrhizal biomass were analyzed. In the presence of a phosphorus source, an ectomycorrhizal association with a zinc-resistant strain accumulated the least zinc compared to a zinc-sensitive ectomycorrhizal association and non-mycorrhizal plants. Under low-phosphorus conditions, mycorrhizal seedlings infected with the zinc-resistant strain increased the dissolution of zinc phosphate and zinc accumulation by the plant. Extended X-ray absorption fine structure analysis of both mycorrhizal and nonmycorrhizal roots showed octahedral coordination of zinc by oxygen-containing ligands such as carboxylates or phosphate. We conclude that zinc phosphate solubilization and zinc and phosphorus uptake by the association depend on ectomycorrhizal infection, strain of the mycobiont, and the phosphorus status of the matrix.
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Zinc phosphate transformations by the Paxillus involutus/pine ectomycorrhizal association.
Microbial Ecology, 2006Co-Authors: Marina Fomina, John M Charnock, Ian J. Alexander, Stephen Hillier, Geoffrey M GaddAbstract:In this research, we investigate zinc phosphate transformations by Paxillus involutus/pine ectomycorrhizas using zinc-resistant and zinc-sensitive strains of the ectomycorrhizal fungus under high- and low-phosphorus conditions to further understand fungal roles in the transformation of toxic metal minerals in the mycorrhizosphere. Mesocosm experiments with ectomycorrhizas were performed under sterile conditions with zinc phosphate localized in cellophane bags: zinc and phosphorus mobilization and uptake by the ectomycorrhizal biomass were analyzed. In the presence of a phosphorus source, an ectomycorrhizal association with a zinc-resistant strain accumulated the least zinc compared to a zinc-sensitive ectomycorrhizal association and non-mycorrhizal plants. Under low-phosphorus conditions, mycorrhizal seedlings infected with the zinc-resistant strain increased the dissolution of zinc phosphate and zinc accumulation by the plant. Extended X-ray absorption fine structure analysis of both mycorrhizal and nonmycorrhizal roots showed octahedral coordination of zinc by oxygen-containing ligands such as carboxylates or phosphate. We conclude that zinc phosphate solubilization and zinc and phosphorus uptake by the association depend on ectomycorrhizal infection, strain of the mycobiont, and the phosphorus status of the matrix.
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ectomycorrhizas and putative ectomycorrhizal fungi of shorea leprosula miq dipterocarpaceae
Mycorrhiza, 1997Co-Authors: Lee Su Lee, Ian J. Alexander, Roy WatlingAbstract:The ectomycorrhizas of Shorea leprosula Miq. are described and their putative fungal associates discussed. Of the 24 ectomycorrhizal types reported from seedlings, wildlings and 20-year-old trees of Shorea leprosula, 20 were associated with the Basidiomycotina, two with the Ascomycotina and two with either members of the Ascomycotina or the Russulaceae. The dominant group of fungi associated with Shorea leprosula ectomycorrhizas were members of the Russulaceae. This was confirmed by collections of fungal fruiting bodies made under adult Shorea leprosula trees in various parts of Peninsular Malaysia over a period of 3 years. Of the 28 species of putative ectomycorrhizal fungi collected, 15 were members of the Russulaceae.
Marina Fomina - One of the best experts on this subject based on the ideXlab platform.
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zinc phosphate transformations by the paxillus involutus pine ectomycorrhizal association
Microbial Ecology, 2006Co-Authors: Marina Fomina, John M Charnock, Ian J. Alexander, Stephen Hillier, Geoffrey M GaddAbstract:In this research, we investigate zinc phosphate transformations by Paxillus involutus/pine ectomycorrhizas using zinc-resistant and zinc-sensitive strains of the ectomycorrhizal fungus under high- and low-phosphorus conditions to further understand fungal roles in the transformation of toxic metal minerals in the mycorrhizosphere. Mesocosm experiments with ectomycorrhizas were performed under sterile conditions with zinc phosphate localized in cellophane bags: zinc and phosphorus mobilization and uptake by the ectomycorrhizal biomass were analyzed. In the presence of a phosphorus source, an ectomycorrhizal association with a zinc-resistant strain accumulated the least zinc compared to a zinc-sensitive ectomycorrhizal association and non-mycorrhizal plants. Under low-phosphorus conditions, mycorrhizal seedlings infected with the zinc-resistant strain increased the dissolution of zinc phosphate and zinc accumulation by the plant. Extended X-ray absorption fine structure analysis of both mycorrhizal and nonmycorrhizal roots showed octahedral coordination of zinc by oxygen-containing ligands such as carboxylates or phosphate. We conclude that zinc phosphate solubilization and zinc and phosphorus uptake by the association depend on ectomycorrhizal infection, strain of the mycobiont, and the phosphorus status of the matrix.
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Zinc phosphate transformations by the Paxillus involutus/pine ectomycorrhizal association.
Microbial Ecology, 2006Co-Authors: Marina Fomina, John M Charnock, Ian J. Alexander, Stephen Hillier, Geoffrey M GaddAbstract:In this research, we investigate zinc phosphate transformations by Paxillus involutus/pine ectomycorrhizas using zinc-resistant and zinc-sensitive strains of the ectomycorrhizal fungus under high- and low-phosphorus conditions to further understand fungal roles in the transformation of toxic metal minerals in the mycorrhizosphere. Mesocosm experiments with ectomycorrhizas were performed under sterile conditions with zinc phosphate localized in cellophane bags: zinc and phosphorus mobilization and uptake by the ectomycorrhizal biomass were analyzed. In the presence of a phosphorus source, an ectomycorrhizal association with a zinc-resistant strain accumulated the least zinc compared to a zinc-sensitive ectomycorrhizal association and non-mycorrhizal plants. Under low-phosphorus conditions, mycorrhizal seedlings infected with the zinc-resistant strain increased the dissolution of zinc phosphate and zinc accumulation by the plant. Extended X-ray absorption fine structure analysis of both mycorrhizal and nonmycorrhizal roots showed octahedral coordination of zinc by oxygen-containing ligands such as carboxylates or phosphate. We conclude that zinc phosphate solubilization and zinc and phosphorus uptake by the association depend on ectomycorrhizal infection, strain of the mycobiont, and the phosphorus status of the matrix.
Pascale Frey-klett - One of the best experts on this subject based on the ideXlab platform.
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Temporal changes of bacterial communities in the Tuber melanosporum ectomycorrhizosphere during ascocarp development
Mycorrhiza, 2016Co-Authors: Aurélie Deveau, Pascale Frey-klett, Sanjay Antony-babu, François Le Tacon, Christophe Robin, Stéphane UrozAbstract:Ectomycorrhizae create a multitrophic ecosystem formed by the association between tree roots, mycelium of the ectomycorrhizal fungus, and a complex microbiome. Despite their importance in the host tree’s physiology and in the functioning of the ectomycorrhizal symbiosis, detailed studies on ectomycorrhiza-associated bacterial community composition and their temporal dynamics are rare. Our objective was to investigate the composition and dynamics of Tuber melanosporum ectomycorrhiza-associated bacterial communities from summer to winter seasons in a Corylus avellana tree plantation. We used 16S ribosomal RNA (rRNA)-based pyrosequencing to compare the bacterial community structure and the richness in T. melanosporum ’s Ectomycorrhizae with those of the bulk soil. The T. melanosporum Ectomycorrhizae harbored distinct bacterial communities from those of the bulk soil, with an enrichment in Alpha- and Gamma-proteobacteria. In contrast to the bacterial communities of truffle ascocarps that vastly varies in composition and richness during the maturation of the fruiting body and to those from the bulk soil, T. melanosporum ectomycorrhiza-associated bacterial community composition stayed rather stable from September to January. Our results fit with a recent finding from the same experimental site at the same period that a continuous supply of carbohydrates and nitrogen occurs from Ectomycorrhizae to the fruiting bodies during the maturation of the ascocarps. We propose that this creates a stable niche in the ectomycorrhizosphere although the phenology of the tree changes.
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Functional Profiling and Distribution of the Forest Soil Bacterial Communities Along the Soil Mycorrhizosphere Continuum
Microbial Ecology, 2013Co-Authors: Stéphane Uroz, Jean Garbaye, Pierre-emmanuel Courty, J-claude Pierrat, M. Peter, Marc Buee, Marie-pierre Turpault, Pascale Frey-klettAbstract:An ectomycorrhiza is a multitrophic association between a tree root, an ectomycorrhizal fungus, free-living fungi and the associated bacterial communities. Enzymatic activities of ectomycorrhizal root tips are therefore result of the contribution from different partners of the symbiotic organ. However, the functional potential of the fungus-associated bacterial communities remains unknown. In this study, a collection of 80 bacterial strains randomly selected and isolated from a soil-ectomycorrhiza continuum (oak-Scleroderma citrinum ectomycorrhizas, the ectomycorrhizosphere and the surrounding bulk soil) were characterized. All the bacterial isolates were identified by partial 16S rRNA gene sequences as members of the genera Burkholderia, Collimonas, Dyella, Mesorhizobium, Pseudomonas, Rhizobium and Sphingomonas. The bacterial strains were then assayed for beta-xylosidase, beta-glucosidase, N-acetyl-hexosaminidase, beta-glucuronidase, cellobiohydrolase, phosphomonoesterase, leucine-aminopeptidase and laccase activities, chitin solubilization and auxin production. Using these bioassays, we demonstrated significant differences in the functional distribution of the bacterial communities living in the different compartments of the soil-ectomycorrhiza continuum. The surrounding bulk soil was significantly enriched in bacterial isolates capable of hydrolysing cellobiose and N-acetylglucosamine. In contrast, the ectomycorrhizosphere appeared significantly enriched in bacterial isolates capable of hydrolysing glucopyranoside and chitin. Notably, chitinase and laccase activities were found only in bacterial isolates belonging to the Collimonas and Pseudomonas genera. Overall, the results suggest that the ectomycorrhizal fungi favour specific bacterial communities with contrasting functional characteristics from the surrounding soil.
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The major pathways of carbohydrate metabolism in the ectomycorrhizal basidiomycete Laccaria bicolor S238N
New Phytologist, 2008Co-Authors: Aurélie Deveau, Annegret Kohler, Pascale Frey-klett, Francis MartinAbstract:• The primary carbohydrate metabolism of an ectomycorrhizal fungus and its transcriptional regulation has never been characterized at the genome scale although it plays a fundamental role in the functioning of the symbiosis. In this study, the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor S238N-H82 was explored to construct a comprehensive genome-wide inventory of pathways involved in primary carbohydrate metabolism. • Several genes and gene families were annotated, including those of the glycolysis, pentose phosphate pathway, tricarboxylic acid cycle, and trehalose and mannitol metabolism. The transcriptional regulation of these pathways was studied using whole-genome expression oligoarrays and quantitative polymerase chain reaction in free-living mycelium, ectomycorrhizas and fruiting bodies. • Pathways of carbohydrate biosynthesis and catabolism are identical in L. bicolor compared with other sequenced saprotrophic basidiomycetes. • Ectomycorrhiza and fruiting body development induced the regulation of a restricted set of transcripts of the glycolytic, mannitol and trehalose metabolisms.
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Variation in the ability to form ectomycorrhizas in the F1 progeny of an interspecific poplar (Populus spp.) cross
Mycorrhiza, 2001Co-Authors: Denis Tagu, Frederic Lapeyrie, Pascale Frey-klett, Patricia Faivre-rampant, Patrice Vion, Marc VillarAbstract:The aim of this study was to determine the existence of a genetic basis for the ability to form ectomycorrhiza on a model angiosperm tree (Populus, poplar). Parental clones and 18 progeny from a controlled interspecific cross between Populus deltoides and Populus trichocarpa were grown in a glasshouse and inoculated with mycelium of the ectomycorrhizal fungus Laccaria bicolor. Three months after inoculation, the percentage of mycorrhizal root tips was determined for each inoculated plant. The data indicate variability in the ability to form ectomycorrhizas among the Fl progeny, including individual progeny which are different to either parent. This suggests a genetic basis for mycorrhiza formation
