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L H Melville - One of the best experts on this subject based on the ideXlab platform.
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biology of the Ectomycorrhizal genus rhizopogon iii influence of co cultured conifer species on mycorrhizal specificity with the arbutoid hosts arctostaphylos uva ursi and arbutus menziesii
New Phytologist, 1997Co-Authors: Randy Molina, Donaraye Mckay, Jane E. Smith, L H MelvilleAbstract:Seedlings of Pseudotsuga menziesii (Mirb.) Franco, Pinus ponderosa Dougl. ex Laws, Arbutus menziesii Pursh., and cuttings of Arctostaphylos uva-ursi (L.) Spreng were grown in monoculture and in conifer-hardwood dual-culture combinations in the glasshouse and inoculated with spore slurries of six Rhizopogon species. The primary objectives were to assess and compare the pattern of host specificity between symbionts and to study the influence of co-cultured plants on Ectomycorrhiza development. The Rhizopogon spp. ranged from genus-specific to multiple-host compatible. In monoculture, four Rhizopogon sp. (R. ellenae Smith, R. occidentalis Zeller & Dodge, R. smithii Hosford and R. subcaerulescens Smith) formed Ectomycorrhizas with Pinus ponderosa, and two Rhizopogon sp. (R. parksii Smith and R. vinicolor Smith) formed Ectomycorrhizas with Pseudotsuga menziesii. None of the fungi tested developed Ectomycorrhizas on Arbutus menziesii or Arctostaphylos uva-ursi in monoculture. In dual culture, three of the four Rhizopogon species (R. ellenae, R. occidentalis and R. subcaerulescens) that formed Ectomycorrhizas on Pinus ponderosa, formed some Ectomycorrhizas on Arbutus menziesii and Arctostaphylos uva-ursi. Rhizopogon parksii and R. vinicolor only formed Ectomycorrhizas on Pseudotsuga menziesii.
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iii influence of co cultured conifer species on mycorrhizal specificity with the arbutoid hosts arctostaphylos uva ursi and arbutus menziesii
1997Co-Authors: Randy M Olina, Ane J E S Mith, L H MelvilleAbstract:summary Seedlings of Pseudotsuga menziesii (Mirb.) Franco, Pinus ponderosa Dougl. ex Laws, Arbutus menziesii Pursh., and cuttings of Arctostaphylos uva-ursi (L.) Spreng were grown in monoculture and in conifer-hardwood dual-culture combinations in the glasshouse and inoculated with spore slurries of six Rhizopogon species. The primary objectives were to assess and compare the pattern of host specificity between symbionts and to study the influence of co-cultured plants on Ectomycorrhiza development. The Rhizopogon spp. ranged from genus-specific to multiple-host compatible. In monoculture, four Rhizopogon sp. (R. ellenae Smith, R. occidentalis Zeller & Dodge, R. smithii Hosford and R. subcaerulescens Smith) formed Ectomycorrhizas with Pinus ponderosa, and two Rhizopogon sp. (R. parksii Smith and R. vinicolor Smith) formed Ectomycorrhizas with Pseudotsuga menziesii. None of the fungi tested developed Ectomycorrhizas on Arbutus menziesii or Arctostaphylos uva-ursi in monoculture. In dual culture, three of the four Rhizopogon species (R. ellenae, R. occidentalis and R. subcaerulescens) that formed Ectomycorrhizas on Pinus ponderosa, formed some Ectomycorrhizas on Arbutus menziesii and Arctostaphylos uva-ursi. Rhizopogon parksii and R. vinicolor only formed Ectomycorrhizas on Pseudotsuga menziesii.
Francis Martin - One of the best experts on this subject based on the ideXlab platform.
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The small secreted effector protein MiSSP7.6 of Laccaria bicolor is required for the establishment of Ectomycorrhizal symbiosis
Environmental Microbiology, 2020Co-Authors: Heng Kang, Annegret Kohler, Xin Chen, Minna Kemppainen, Alejandro Pardo, Claire Veneault‐fourrey, Francis MartinAbstract:To establish and maintain a symbiotic relationship, the Ectomycorrhizal fungus Laccaria bicolor releases mycorrhiza‐induced small secreted proteins (MiSSPs) into host roots. Here, we have functionally characterized the MYCORRHIZA‐iNDUCED SMALL SECRETED PROTEIN OF 7 .6 kDa (MiSSP7 .6 ) from L . bicolor by assessing its induced expression in Ectomycorrhizae, silencing its expression by RNAi, and tracking in planta subcellular localization of its protein product. We also carried out yeast two‐hybrid assays and bimolecular fluorescence complementation analysis to identify possible protein targets of the MiSSP7.6 effector in Populus roots. We showed that MiSSP7 .6 expression is upregulated in Ectomycorrhizal rootlets and associated extramatrical mycelium during the late stage of symbiosis development. RNAi mutants with a decreased MiSSP7 .6 expression have a lower mycorrhization rate , suggesting a key role in the establishment of the symbiosis with plants. MiSSP7.6 is secreted, and it localizes both to the nuclei and cytoplasm in plant cells. MiSSP7.6 protein was shown to interact with two Populus Trihelix transcription factors. Furthermore, when coexpressed with one of the Trihelix transcription factors, MiSSP7.6 is localized to plant nuclei only. Our data suggest that MiSSP7.6 is a novel secreted symbiotic effector and is a potential determinant for Ectomycorrhiza formation.
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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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genetic analysis of phenotypic variation for Ectomycorrhiza formation in an interspecific f1 poplar full sib family
Mycorrhiza, 2005Co-Authors: Denis Tagu, Patrice Vion, Marc Villar, Catherine Bastien, Patricia Faivrerampant, J Garbaye, Francis MartinAbstract:A plant's capability to develop Ectomycorrhizal symbiosis is under the control of both genetic and environmental factors. In order to determine the roles played by these different factors, we have performed a quantitative genetic analysis of the ability of poplar trees to form Ectomycorrhizas. Quantitative genetics were applied to an interspecific family of poplar for which the two parental genetic maps had already been described, and for which data analyses concerning fungal aggressors were obtained. Quantitative trait loci (QTL) related to Ectomycorrhiza formation were identified and located in the genetic maps of the two parents. One QTL was located at a linkage group of the genetic map of Populus trichocarpa showing a high concentration of several QTL involved in the pathogenic interaction with the fungus Melampsora larici-populina, the causal agent of leaf rust.
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ribosomal dna internal transcribed spacers to estimate the proportion of pisolithus tinctorius and eucalyptus rnas in Ectomycorrhiza
Applied and Environmental Microbiology, 1997Co-Authors: E C Diaz, Denis Tagu, Francis MartinAbstract:Ectomycorrhiza is a complex association of several types of plant and fungal cells. Differentiation of symbiotic structures is correlated with large changes in mRNA synthesis, leading to novel protein patterns. Quantification of up- and down-regulated specific transcripts is complicated by the intermingling of root and hyphal components. Determination of steady-state levels of symbiosis-regulated mRNA requires a normalization to the housekeeping RNA content of each partner. In this study, the usefulness of the internal transcribed spacer (ITS)-5.8S ribosomal DNAs (rDNAs) as molecular markers of the root colonization by fungal mycelium was assayed. The rDNA ITSs of Pisolithus tinctorius and Eucalyptus globulus were cloned by PCR amplification, and their sequences were determined. They contained the 5.8S rDNAs, and these two probes did not cross-hybridize. Steady-state levels of the ITS-5.8S rRNAs in the vegetative mycelium, in the noninfected root, and in Ectomycorrhizas of E. globulus-P. tinctorius 441 were estimated at different stages of development. Colonization of roots by the mycelium provoked a large decrease in the proportion of root rRNAs. At the end of mycorrhiza formation, about 80% of the Ectomycorrhizal RNA belonged to the mycobiont. The ITS-5.8S can be used as a specific probe for the estimation of fungal or plant rRNA in the symbiotic tissues and to determine whether an mRNA is down- or up-regulated in Ectomycorrhiza.
Randy Molina - One of the best experts on this subject based on the ideXlab platform.
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biology of the Ectomycorrhizal genus rhizopogon iii influence of co cultured conifer species on mycorrhizal specificity with the arbutoid hosts arctostaphylos uva ursi and arbutus menziesii
New Phytologist, 1997Co-Authors: Randy Molina, Donaraye Mckay, Jane E. Smith, L H MelvilleAbstract:Seedlings of Pseudotsuga menziesii (Mirb.) Franco, Pinus ponderosa Dougl. ex Laws, Arbutus menziesii Pursh., and cuttings of Arctostaphylos uva-ursi (L.) Spreng were grown in monoculture and in conifer-hardwood dual-culture combinations in the glasshouse and inoculated with spore slurries of six Rhizopogon species. The primary objectives were to assess and compare the pattern of host specificity between symbionts and to study the influence of co-cultured plants on Ectomycorrhiza development. The Rhizopogon spp. ranged from genus-specific to multiple-host compatible. In monoculture, four Rhizopogon sp. (R. ellenae Smith, R. occidentalis Zeller & Dodge, R. smithii Hosford and R. subcaerulescens Smith) formed Ectomycorrhizas with Pinus ponderosa, and two Rhizopogon sp. (R. parksii Smith and R. vinicolor Smith) formed Ectomycorrhizas with Pseudotsuga menziesii. None of the fungi tested developed Ectomycorrhizas on Arbutus menziesii or Arctostaphylos uva-ursi in monoculture. In dual culture, three of the four Rhizopogon species (R. ellenae, R. occidentalis and R. subcaerulescens) that formed Ectomycorrhizas on Pinus ponderosa, formed some Ectomycorrhizas on Arbutus menziesii and Arctostaphylos uva-ursi. Rhizopogon parksii and R. vinicolor only formed Ectomycorrhizas on Pseudotsuga menziesii.
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biology of the Ectomycorrhizal genus rhizopogon
New Phytologist, 1994Co-Authors: Randy Molina, James M TrappeAbstract:SUMMARY Twenty nine isolates of Rhizopogon from 20 spp. differed markedly in their ability to form Ectomycorrhizas with Douglas fir, western hemlock and lodgepole pine in pure-culture syntheses, Within the four sections of Rhizopogon there were similarities in Ectomycorrhizal appearance and range of potential hosts. Intermediate and overlapping Ectomycorrhiza! characters were evident in closely related species complexes. Although the host-specificity of many species, based on field observations of sporocarps, often correlated with their host range in the syntheses, some fungi formed well-developed Ectomycorrhiza on hosts with which they appear not to be associated in the field. The specificity of host associations is suggested as a major contributor to the speciation and diversification of Rhtzopogon in the Pacific Northwest of the USA and Canada.
Uwe Nehls - One of the best experts on this subject based on the ideXlab platform.
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the aquaporin gene family of the Ectomycorrhizal fungus laccaria bicolor lessons for symbiotic functions
New Phytologist, 2011Co-Authors: Sandra Dietz, Julia Von Bulow, Eric Beitz, Uwe NehlsAbstract:P>Soil humidity and bulk water transport are essential for nutrient mobilization. Ectomycorrhizal fungi, bridging soil and fine roots of woody plants, are capable of modulating both by being integrated into water movement driven by plant transpiration and the nocturnal hydraulic lift. Aquaporins are integral membrane proteins that function as gradient-driven water and/or solute channels. Seven aquaporins were identified in the genome of the Ectomycorrhizal basidiomycete Laccaria bicolor and their role in fungal transfer processes was analyzed. Heterologous expression in Xenopus laevis oocytes revealed relevant water permeabilities for three aquaporins. In fungal mycelia, expression of the corresponding genes was high compared with other members of the gene family, indicating the significance of the respective proteins for plasma membrane water permeability. As growth temperature and Ectomycorrhiza formation modified gene expression profiles of these water-conducting aquaporins, specific roles in those aspects of fungal physiology are suggested. Two aquaporins, which were highly expressed in Ectomycorrhizas, conferred plasma membrane ammonia permeability in yeast. This indicates that these proteins are an integral part of Ectomycorrhizal fungus-based plant nitrogen nutrition in symbiosis.
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the sugar porter gene family of laccaria bicolor function in Ectomycorrhizal symbiosis and soil growing hyphae
New Phytologist, 2008Co-Authors: Monica Fajardo Lopez, Sandra Dietz, Nina Grunze, Jutta Bloschies, Michael Weis, Uwe NehlsAbstract:Summary • Formation of Ectomycorrhizas, a symbiosis with fine roots of woody plants, is one way for soil fungi to overcome carbohydrate limitation in forest ecosystems. Fifteen potential hexose transporter proteins, of which 10 group within three clusters, are encoded in the genome of the Ectomycorrhizal model fungus Laccaria bicolor. For 14 of them, transcripts were detectable. When grown in liquid culture, carbon starvation resulted in at least twofold higher transcript abundances for seven genes. Temporarily elevated transcript abundance after sugar addition was observed for three genes. Compared with the extraradical mycelium, Ectomycorrhiza formation resulted in a strongly enhanced expression of six genes, of which four revealed their highest observed transcript abundances in symbiosis. A function as hexose importer was proven for three of them. Only three genes, of which just one was expressed at a considerable level, revealed a reduced transcript content in mycorrhizas. From gene expression patterns and import kinetics, the L. bicolor hexose transporters could be divided into two groups: those responsible for uptake of carbohydrates by soil-growing hyphae, for improved carbon nutrition, and to reduce nutrient uptake competition by other soil microorganisms; and those responsible for efficient hexose uptake at the plant–fungus interface.
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The α-tubulin gene AmTuba1: a marker for rapid mycelial growth in the Ectomycorrhizal basidiomycete Amanita muscaria
Current Genetics, 2006Co-Authors: Mika T. Tarkka, Silvia Schrey, Uwe NehlsAbstract:The apical extension of hyphae is of central importance for extensive spread of fungal mycelium in forest soils and for effective Ectomycorrhiza development. Since the tubulin cytoskeleton is known to be important for fungal tip growth, we have investigated the expression of an α-tubulin gene from the Ectomycorrhizal basidiomycete Amanita muscaria ( AmTuba1 ). The phylogenetic analysis of protein sequences revealed the existence of two subgroups of α-tubulins in homobasidiomycetes, clearly distinguishable by defined amino acids. AmTuba1 belongs to subgroup1. The AmTuba1 transcript level is related to mycelial growth rate. Growth induction of carbohydrate starved (non-growing) hyphae resulted in an enhanced AmTuba1 expression as soon as hyphal growth started, reaching a maximum at highest mycelial growth rate. Bacterium-induced hyphal elongation also leads to increased AmTuba1 transcript levels. In mature A. muscaria / P. abies Ectomycorrhizas, where fungal hyphae are highly branched, and slowly growing, AmTuba1 expression were even lower than in carbohydrate-starved mycelium, indicating a further down-regulation of gene expression in symbiosis. In conclusion, our analyses show that the AmTuba1 gene can be used as a marker for active apical extension in fly agaric, and that α-tubulin proteins are promising tools for the classification of fungi.
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a novel class of Ectomycorrhiza regulated cell wall polypeptides in pisolithus tinctorius
Molecular Plant-microbe Interactions, 1999Co-Authors: P. Laurent, Catherine Voiblet, Denis Tagu, Ray Bellis, Guy Bauw, D. Carvalho, Paola Bonfante, Raffaella Balestrini, Uwe Nehls, F MartinAbstract:Development of the Ectomycorrhizal symbiosis leads to the aggregation of fungal hyphae to form the mantle. To identify cell surface proteins involved in this developmental step, changes in the biosynthesis of fungal cell wall proteins were examined in Eucalyptus globulus-Pisolithus tinctorius Ectomycorrhizas by two-dimensional polyacrylamide gel electrophoresis. Enhanced synthesis of several immunologically related fungal 31- and 32-kDa polypeptides, so-called symbiosis-regulated acidic polypeptides (SRAPs), was observed. Peptide sequences of SRAP32d were obtained after trypsin digestion. These peptides were found in the predicted sequence of six closely related fungal cDNAs coding for Ectomycorrhiza up-regulated transcripts. The PtSRAP32 cDNAs represented about 10% of the differentially expressed cDNAs in Ectomycorrhiza and are predicted to encode alanine-rich proteins of 28.2 kDa. There are no sequence homologies between SRAPs and previously identified proteins, but they contain the Arg-Gly-Asp (RGD) mo...
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.
