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Francis Martin - One of the best experts on this subject based on the ideXlab platform.
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The mutualism effector MiSSP7 of Laccaria bicolor alters the interactions between the poplar JAZ6 protein and its associated proteins.
Scientific reports, 2020Co-Authors: Yohann Daguerre, Francis Martin, Annegret Kohler, Jonathan M Plett, Veronica Basso, Sebastian Hartmann-wittulski, Romain Schellenberger, Laura Meyer, Justine Bailly, Claire Veneault-fourreyAbstract:Despite the pivotal role of jasmonic acid in the outcome of plant-microorganism interactions, JA-signaling components in roots of perennial trees like western balsam poplar (Populus trichocarpa) are poorly characterized. Here we decipher the poplar-root JA-perception complex centered on PtJAZ6, a co-repressor of JA-signaling targeted by the effector protein MiSSP7 from the ectomycorrhizal basidiomycete Laccaria bicolor during symbiotic development. Through protein-protein interaction studies in yeast we determined the poplar root proteins interacting with PtJAZ6. Moreover, we assessed via yeast triple-hybrid how the mutualistic effector MiSSP7 reshapes the association between PtJAZ6 and its partner proteins. In the absence of the symbiotic effector, PtJAZ6 interacts with the transcription factors PtMYC2s and PtJAM1.1. In addition, PtJAZ6 interacts with it-self and with other Populus JAZ proteins. Finally, MiSSP7 strengthens the binding of PtJAZ6 to PtMYC2.1 and antagonizes PtJAZ6 homo-/heterodimerization. We conclude that a symbiotic effector secreted by a mutualistic fungus may promote the symbiotic interaction through altered dynamics of a JA-signaling-associated protein-protein interaction network, maintaining the repression of PtMYC2.1-regulated genes.
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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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Development of the Poplar-Laccaria bicolor Ectomycorrhiza Modifies Root Auxin Metabolism, Signaling, and Response
Plant Physiology, 2015Co-Authors: Alice Vayssieres, Francis Martin, Annegret Kohler, Ales Pěnčík, Judith Felten, Karin Ljung, Valérie LeguéAbstract:Root systems of host trees are known to establish ectomycorrhizae (ECM) interactions with rhizospheric fungi. This mutualistic association leads to dramatic developmental modifications in root architecture, with the formation of numerous short and swollen lateral roots ensheathed by a fungal mantle. Knowing that auxin plays a crucial role in root development, we investigated how auxin metabolism, signaling, and response are affected in poplar (Populus spp.)-Laccaria bicolor ECM roots. The plant-fungus interaction leads to the arrest of lateral root growth with simultaneous attenuation of the synthetic auxin response element DR5. Measurement of auxin-related metabolites in the free-living partners revealed that the mycelium of L. bicolor produces high concentrations of the auxin indole-3-acetic acid (IAA). Metabolic profiling showed an accumulation of IAA and changes in the indol-3-pyruvic acid-dependent IAA biosynthesis and IAA conjugation and degradation pathways during ECM formation. The global analysis of auxin response gene expression and the regulation of AUXIN SIGNALING F-BOX PROTEIN5, AUXIN/IAA, and AUXIN RESPONSE FACTOR expression in ECM roots suggested that symbiosis-dependent auxin signaling is activated during the colonization by L. bicolor. Taking all this evidence into account, we propose a model in which auxin signaling plays a crucial role in the modification of root growth during ECM formation.
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Pairwise transcriptomic analysis of the interactions between the ectomycorrhizal fungus Laccaria bicolor S238N and three beneficial, neutral and antagonistic soil bacteria
Microbial Ecology, 2015Co-Authors: Aurélie Deveau, Francis Martin, Matthieu Barret, Abdala Gamby Diedhiou, Johan Leveau, Wietse De Boer, Alain Sarniguet, Pascale Frey-klettAbstract:Ectomycorrhizal fungi are surrounded by bacterial communities with which they interact physically and metabolically during their life cycle. These bacteria can have positive or negative effects on the formation and the functioning of ectomycorrhizae. However, relatively little is known about the mechanisms by which ectomycorrhizal fungi and associated bacteria interact. To understand how ectomycorrhizal fungi perceive their biotic environment and the mechanisms supporting interactions between ectomycorrhizal fungi and soil bacteria, we analysed the pairwise transcriptomic responses of the ectomycorrhizal fungus Laccaria bicolor (Basidiomycota: Agaricales) when confronted with beneficial, neutral or detrimental soil bacteria. Comparative analyses of the three transcriptomes indicated that the fungus reacted differently to each bacterial strain. Similarly, each bacterial strain produced a specific and distinct response to the presence of the fungus. Despite these differences in responses observed at the gene level, we found common classes of genes linked to cell-cell interaction, stress response and metabolic processes to be involved in the interaction of the four microorganisms.
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Characterization of Transposable Elements in the Ectomycorrhizal Fungus Laccaria bicolor
PLoS ONE, 2012Co-Authors: Jessy Labbé, François Le Tacon, Claude Murat, Emmanuelle Morin, Gerald A. Tuskan, Francis MartinAbstract:Background: The publicly available Laccaria bicolor genome sequence has provided a considerable genomic resource allowing systematic identification of transposable elements (TEs) in this symbiotic ectomycorrhizal fungus. Using a TE-specific annotation pipeline we have characterized and analyzed TEs in the L. bicolor S238N-H82 genome. Methodology/Principal Findings: TEs occupy 24% of the 60 Mb L. bicolor genome and represent 25,787 full-length and partial copies elements distributed within 172 families. The most abundant elements were the Copia-like. TEs are not randomly distributed across the genome, but are tightly nested or clustered. The majority of TEs are ancient except some terminal inverted repeats (TIRS), long terminal repeats (LTRs) and a large retrotransposon derivative (LARD) element. There were three main periods of TEs expansion in L. bicolor; the first from 57 to 10 Mya, the second from 5 to 1 Mya and the most recent from 500,000 years ago until now. LTR retrotransposons are closely related to retrotransposons found in another basidiomycete, Coprinopsis cinerea. Conclusions: This analysis represents an initial characterization of TEs in the L. bicolor genome, contributes to genome assembly and to a greater understanding of the role TEs played in genome organization and evolution, and provides a valuable resource for the ongoingmore » Laccaria Pan-Genome project supported by the U.S.-DOE Joint Genome Institute.« less
Annegret Kohler - One of the best experts on this subject based on the ideXlab platform.
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The mutualism effector MiSSP7 of Laccaria bicolor alters the interactions between the poplar JAZ6 protein and its associated proteins.
Scientific reports, 2020Co-Authors: Yohann Daguerre, Francis Martin, Annegret Kohler, Jonathan M Plett, Veronica Basso, Sebastian Hartmann-wittulski, Romain Schellenberger, Laura Meyer, Justine Bailly, Claire Veneault-fourreyAbstract:Despite the pivotal role of jasmonic acid in the outcome of plant-microorganism interactions, JA-signaling components in roots of perennial trees like western balsam poplar (Populus trichocarpa) are poorly characterized. Here we decipher the poplar-root JA-perception complex centered on PtJAZ6, a co-repressor of JA-signaling targeted by the effector protein MiSSP7 from the ectomycorrhizal basidiomycete Laccaria bicolor during symbiotic development. Through protein-protein interaction studies in yeast we determined the poplar root proteins interacting with PtJAZ6. Moreover, we assessed via yeast triple-hybrid how the mutualistic effector MiSSP7 reshapes the association between PtJAZ6 and its partner proteins. In the absence of the symbiotic effector, PtJAZ6 interacts with the transcription factors PtMYC2s and PtJAM1.1. In addition, PtJAZ6 interacts with it-self and with other Populus JAZ proteins. Finally, MiSSP7 strengthens the binding of PtJAZ6 to PtMYC2.1 and antagonizes PtJAZ6 homo-/heterodimerization. We conclude that a symbiotic effector secreted by a mutualistic fungus may promote the symbiotic interaction through altered dynamics of a JA-signaling-associated protein-protein interaction network, maintaining the repression of PtMYC2.1-regulated genes.
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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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Development of the Poplar-Laccaria bicolor Ectomycorrhiza Modifies Root Auxin Metabolism, Signaling, and Response
Plant Physiology, 2015Co-Authors: Alice Vayssieres, Francis Martin, Annegret Kohler, Ales Pěnčík, Judith Felten, Karin Ljung, Valérie LeguéAbstract:Root systems of host trees are known to establish ectomycorrhizae (ECM) interactions with rhizospheric fungi. This mutualistic association leads to dramatic developmental modifications in root architecture, with the formation of numerous short and swollen lateral roots ensheathed by a fungal mantle. Knowing that auxin plays a crucial role in root development, we investigated how auxin metabolism, signaling, and response are affected in poplar (Populus spp.)-Laccaria bicolor ECM roots. The plant-fungus interaction leads to the arrest of lateral root growth with simultaneous attenuation of the synthetic auxin response element DR5. Measurement of auxin-related metabolites in the free-living partners revealed that the mycelium of L. bicolor produces high concentrations of the auxin indole-3-acetic acid (IAA). Metabolic profiling showed an accumulation of IAA and changes in the indol-3-pyruvic acid-dependent IAA biosynthesis and IAA conjugation and degradation pathways during ECM formation. The global analysis of auxin response gene expression and the regulation of AUXIN SIGNALING F-BOX PROTEIN5, AUXIN/IAA, and AUXIN RESPONSE FACTOR expression in ECM roots suggested that symbiosis-dependent auxin signaling is activated during the colonization by L. bicolor. Taking all this evidence into account, we propose a model in which auxin signaling plays a crucial role in the modification of root growth during ECM formation.
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populus trichocarpa and populus deltoides exhibit different metabolomic responses to colonization by the symbiotic fungus Laccaria bicolor
Molecular Plant-microbe Interactions, 2014Co-Authors: Timothy J Tschaplinski, Aurélie Deveau, Gerald A. Tuskan, Annick Brun, Jonathan M Plett, Nancy L Engle, Katherine C Cushman, Madhavi Z Martin, Mitchel J Doktycz, Annegret KohlerAbstract:Within boreal and temperate forest ecosystems, the majority of trees and shrubs form beneficial relationships with mutualistic ectomycorrhizal (ECM) fungi that support plant health through increased access to nutrients as well as aiding in stress and pest tolerance. The intimate interaction between fungal hyphae and plant roots results in a new symbiotic “organ” called the ECM root tip. Little is understood concerning the metabolic reprogramming that favors the formation of this hybrid tissue in compatible interactions and what prevents the formation of ECM root tips in incompatible interactions. We show here that the metabolic changes during favorable colonization between the ECM fungus Laccaria bicolor and its compatible host, Populus trichocarpa, are characterized by shifts in aromatic acid, organic acid, and fatty acid metabolism. We demonstrate that this extensive metabolic reprogramming is repressed in incompatible interactions and that more defensive compounds are produced or retained. We also demo...
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Populus trichocarpa and Populus deltoides Exhibit Different Metabolomic Responses to Colonization by the Symbiotic Fungus Laccaria bicolor
Molecular Plant-Microbe Interactions, 2014Co-Authors: Timothy J Tschaplinski, Aurélie Deveau, Jonathan M. Plett, Annick Brun-jacob, Gerald A. Tuskan, Nancy L Engle, Katherine C Cushman, Madhavi Z Martin, Mitchel J Doktycz, Annegret KohlerAbstract:Within boreal and temperate forest ecosystems, the majority of trees and shrubs form beneficial relationships with mutualistic ectomycorrhizal (ECM) fungi that support plant health through increased access to nutrients as well as aiding in stress and pest tolerance. The intimate interaction between fungal hyphae and plant roots results in a new symbiotic "organ" called the ECM root tip. Little is understood concerning the metabolic reprogramming that favors the formation of this hybrid tissue in compatible interactions and what prevents the formation of ECM root tips in incompatible interactions. We show here that the metabolic changes during favorable colonization between the ECM fungus Laccaria bicolor and its compatible host, Populus trichocarpa, are characterized by shifts in aromatic acid, organic acid, and fatty acid metabolism. We demonstrate that this extensive metabolic reprogramming is repressed in incompatible interactions and that more defensive compounds are produced or retained. We also demonstrate that L. bicolor can metabolize a number of secreted defensive compounds and that the degradation of some of these compounds produces immune response metabolites (e.g., salicylic acid from salicin). Therefore, our results suggest that the metabolic responsiveness of plant roots to L. bicolor is a determinant factor in fungus host interactions.
François Le Tacon - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Transposable Elements in the Ectomycorrhizal Fungus Laccaria bicolor
PLoS ONE, 2012Co-Authors: Jessy Labbé, François Le Tacon, Claude Murat, Emmanuelle Morin, Gerald A. Tuskan, Francis MartinAbstract:Background: The publicly available Laccaria bicolor genome sequence has provided a considerable genomic resource allowing systematic identification of transposable elements (TEs) in this symbiotic ectomycorrhizal fungus. Using a TE-specific annotation pipeline we have characterized and analyzed TEs in the L. bicolor S238N-H82 genome. Methodology/Principal Findings: TEs occupy 24% of the 60 Mb L. bicolor genome and represent 25,787 full-length and partial copies elements distributed within 172 families. The most abundant elements were the Copia-like. TEs are not randomly distributed across the genome, but are tightly nested or clustered. The majority of TEs are ancient except some terminal inverted repeats (TIRS), long terminal repeats (LTRs) and a large retrotransposon derivative (LARD) element. There were three main periods of TEs expansion in L. bicolor; the first from 57 to 10 Mya, the second from 5 to 1 Mya and the most recent from 500,000 years ago until now. LTR retrotransposons are closely related to retrotransposons found in another basidiomycete, Coprinopsis cinerea. Conclusions: This analysis represents an initial characterization of TEs in the L. bicolor genome, contributes to genome assembly and to a greater understanding of the role TEs played in genome organization and evolution, and provides a valuable resource for the ongoingmore » Laccaria Pan-Genome project supported by the U.S.-DOE Joint Genome Institute.« less
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Characterization of transposable elements in the ectomycorrhizal fungus Laccaria bicolor
PLoS ONE, 2012Co-Authors: Jessy Labbé, François Le Tacon, Claude Murat, Emmanuelle Morin, Gerald A. Tuskan, Francis MartinAbstract:Background: The publicly available Laccaria bicolor genome sequence has provided a considerable genomic resource allowing systematic identification of transposable elements (TEs) in this symbiotic ectomycorrhizal fungus. Using a TE-specific annotation pipeline we have characterized and analyzed TEs in the L. bicolor S238N-H82 genome. Methodology/Principal Findings: TEs occupy 24% of the 60 Mb L. bicolor genome and represent 25,787 full-length and partial copy elements distributed within 171 families. The most abundant elements were the Copia-like. TEs are not randomly distributed across the genome, but are tightly nested or clustered. The majority of TEs exhibits signs of ancient transposition except some intact copies of terminal inverted repeats (TIRS), long terminal repeats (LTRs) and a large retrotransposon derivative (LARD) element. There were three main periods of TE expansion in L. bicolor: the first from 57 to 10 Mya, the second from 5 to 1 Mya and the most recent from 0.5 Mya ago until now. LTR retrotransposons are closely related to retrotransposons found in another basidiomycete, Coprinopsis cinerea. Conclusions: This analysis 1) represents an initial characterization of TEs in the L. bicolor genome, 2) contributes to improve genome annotation and a greater understanding of the role TEs played in genome organization and evolution and 3) provides a valuable resource for future research on the genome evolution within the Laccaria genus.
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Gene organization of the mating type regions in the ectomycorrhizal fungus Laccaria bicolor reveals distinct evolution between the two mating type loci.
New Phytologist, 2008Co-Authors: Hélène Niculita-hirzel, Francis Martin, Annegret Kohler, François Le Tacon, Jessy Labbé, Ian R. Sanders, Ursula KüesAbstract:In natural conditions, basidiomycete ectomycorrhizal fungi such as Laccaria bicolor are typically in the dikaryotic state when forming symbioses with trees, meaning that two genetically different individuals have to fuse or 'mate'. Nevertheless, nothing is known about the molecular mechanisms of mating in these ecologically important fungi. Here, advantage was taken of the first sequenced genome of the ectomycorrhizal fungus, Laccaria bicolor, to determine the genes that govern the establishment of cell-type identity and orchestrate mating. The L. bicolor mating type loci were identified through genomic screening. The evolutionary history of the genomic regions that contained them was determined by genome-wide comparison of L. bicolor sequences with those of known tetrapolar and bipolar basidiomycete species, and by phylogenetic reconstruction of gene family history. It is shown that the genes of the two mating type loci, A and B, are conserved across the Agaricales, but they are contained in regions of the genome with different evolutionary histories. The A locus is in a region where the gene order is under strong selection across the Agaricales. By contrast, the B locus is in a region where the gene order is likely under a low selection pressure but where gene duplication, translocation and transposon insertion are frequent.
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SCAR markers to detect mycorrhizas of an American Laccaria bicolor strain inoculated in European Douglas-fir plantations
Mycorrhiza, 2002Co-Authors: Jean Weber, Marc-andré Selosse, Jesús Díez, Denis Tagu, François Le TaconAbstract:The American strain S238N of the ectomycorrhizal fungus Laccaria bicolor (Maire) Orton has been used to inoculate Douglas-fir [Pseudotsuga menziesii (Mir.) Franco] plantations in France over the last two decades. Laccaria fruit bodies are scarce in mature plantations, which precludes further assessment of its persistence by fruit body surveys. Our objective was to develop new markers to identify this strain and its eventual non-fruiting progeny on root tips. We converted nine random amplified polymorphic DNA markers into sequence characterized amplified region (SCAR) markers. Two of these SCAR markers enabled us to detect S238N on roots of seedlings and mature trees. No amplification of non-fungal (host plant, bacterial, etc.) DNA was observed. Moreover, both SCARs were amplified from Laccaria-like mycorrhizas in a Douglas-fir plantation inoculated 14 years ago, demonstrating the long-term persistence of the inoculant strain. We also obtained a SCAR marker to detect one strain of European origin (L. bicolor 81306), indicating that SCARs are potential markers to type the naturally occurring genets. Thus, SCAR markers are of great value in studying the persistence of inoculant strains and the effects on local populations of introducing foreign strains.
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Effect of an auxin transport inhibitor on aggregation and attachment processes during ectomycorrhiza formation between Laccaria bicolor S238N and Picea abies
Canadian Journal of Botany, 2001Co-Authors: Ana Rincón, Joëlle Gérard, Jean Dexheimer, François Le TaconAbstract:Transmission electron microscopy observations performed with cytochemical stains to detect polysaccharides and cysteine-rich proteins have been done to study the effect of an auxin transport inhibitor (2,3,5-triiodobenzoic acid, TIBA) on Laccaria bicolor (Marie) Orton. hypha attachment and aggregation during mycorrhiza formation in Picea abies (L.) Karst. roots. When the two partners were growing separately without any exchange of information, TIBA did not affect the cell wall's polysaccharide or protein structures, which could play a role in the aggregation or attachment process. The presence of the host strongly increased the production of fungal polysaccharide fibrils, allowing hypha aggregation and attachment with the roots. TIBA inhibited this host effect. Thus, we can hypothesize that TIBA, by preventing fungal indole-3-acetic acid (IAA) transport towards the root, inhibited the production or the efflux of host elicitors responsible for the increase of fungal polysaccharide fibril production. However, we cannot exclude that TIBA had other effects than inhibiting fungal IAA transport.Key words: ectomycorrhizas, auxin transport inhibitor, polysaccharide fibrils.
Gopi K. Podila - One of the best experts on this subject based on the ideXlab platform.
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Isolation and analysis of a symbiosis-regulated and Ras-interacting vesicular assembly protein gene from the ectomycorrhizal fungus Laccaria bicolor
New Phytologist, 2004Co-Authors: Sathish Sundaram, Joshua H. Brand, Matthew J. Hymes, Shivanand T. Hiremath, Gopi K. PodilaAbstract:Summary •A yeast two-hybrid library prepared from Laccaria bicolor × Pinus resinosa mycorrhizas was screened using a LbRAS clone, previously characterized, as a bait to isolate LbRAS interacting signaling-related genes from L. bicolor . • Using this method, a novel line of Ras-interacting yeast two-hybrid mycorrhizal ( Rythm ) clones were isolated and analysed for their symbiosis-regulation. One such clone identified ( RythmA ) had homology to Ap180-like vesicular proteins. • Sequence homology and parsimony-based phylogenetic analysis showed its relatedness to Ap180-like proteins from other systems. DNA analysis suggested that L. bicolor had one or two copies of the RythmA gene. • An RNA analysis showed that the expression of RythmA could be detected 36 h after interaction with the host, which follows the expression of Lbras . Immunolocalization of LbRAS near dolipore septum of the fungal cells in the Hartig net area suggests that RythmA protein may be involved in the transport of signaling proteins such as LbRAS.
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analysis of expressed sequence tags from the ectomycorrhizal basidiomycetes Laccaria bicolor and pisolithus microcarpus
New Phytologist, 2003Co-Authors: Martina Peter, Annegret Kohler, Denis Tagu, Michel Chalot, Pascale Freyklett, Pierreemmanuel Courty, Christine Delaruelle, David Martin, Sebastien Duplessis, Gopi K. PodilaAbstract:Summary • In an effort to discover genes that are expressed in the ectomycorrhizal basidiomycetes Laccaria bicolor and Pisolithus microcarpus, and in P. microcarpus/Eucalyptus globulus ectomycorrhizas, we have sequenced 1519 and 1681 expressed sequence tags (ESTs) from L. bicolor and P. microcarpus cDNA libraries. • Contig analysis resulted in 905 and 806 tentative consensus sequences (unique transcripts) in L. bicolor and P. microcarpus, respectively. For 36% of the ESTs, significant similarities to sequences in databases were detected. The most abundant transcripts showed no similarity to previously identified genes. Sequence redundancy analysis between different developmental stages indicated that several genes were differentially expressed in free-living mycelium and symbiotic tissues of P. microcarpus. • Based on sequence similarity, 11% of L. bicolor unique transcripts were also detected in P. microcarpus. Similarly, L. bicolor and P. microcarpus shared only a low proportion of common transcripts with other basidiomycetous fungi, such as Pleurotus ostreatus and Agaricus bisporus. Such a low proportion of shared transcripts between basidiomycetes suggests, on the one hand, that the variability of expressed transcripts in different fungi and fungal tissues is considerably high. On the other hand, it might reflect the low number of GenBank entries of basidiomycetous origin and stresses the necessity of an additional sequencing effort. • The present ESTs provide a valuable resource for future research on the development and functioning of ectomycorrhizas.
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fungal gene expression in early symbiotic interactions between Laccaria bicolor and red pine
Plant and Soil, 2002Co-Authors: Gopi K. Podila, J Zheng, S Balasubramanian, S Sundaram, S T Hiremath, J H Brand, Matthew J. HymesAbstract:Ectomycorrhizas are mutualistic symbiotic organs formed by interaction between plant roots and fungi. Mycorrhizal initiation, development and functional maintenance involve morphological changes that are mediated by activation and suppression of several fungal and plant genes. During the pre-infection stage, a harmonized crosstalk takes place between the symbionts, to determine their compatibility. Upon mutual recognition, the symbionts initiate further physiological and morphological changes essential for the formation of the symbiotic organ. In order to understand the molecular mechanisms underlying these events, we developed an interaction-specific cDNA library from Laccaria bicolor that represents fungal genes regulated by its interaction with Pinus resinosa roots. Membrane array analyses of these cDNAs suggested that a wide variety of genes are involved in the pre-infection stage processes.
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lb aut7 a novel symbiosis regulated gene from an ectomycorrhizal fungus Laccaria bicolor is functionally related to vesicular transport and autophagocytosis
Journal of Bacteriology, 1999Co-Authors: Sung-jae Kim, Daniela Bernreuther, Michael Thumm, Gopi K. PodilaAbstract:Ectomycorrhizal fungi such as Laccaria bicolor are ubiquitous symbiotic fungi found all over the world (16, 29, 30). The host range of these fungi includes most gymnosperm and angiosperm trees as well as economically important timber-producing species (27). Mycorrhizal fungi play an important role in the health and survival of many tree species. Mycorrhizal symbiosis is especially important for transplanted trees and seedlings and when the soil conditions are unfavorable (6, 34). The fungi form a network of hyphae called the Hartig network, penetrating between the cortical cells of the root system. The ectomycorrhizal fungi provide the plant several benefits, which include the enhanced ability to absorb water and important ions such as phosphorus and nitrogen (8, 13, 33), and protec
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Genetic engineering of an ectomycorrhizal fungus Laccaria bicolor for use as a biological control agent
Mycologia, 1999Co-Authors: Steven N. Bills, Gopi K. Podila, Shiv HiremathAbstract:We are developing genetically engineered ectomycorrhizal fungi for use as biological control agents. Using the gold particle bombardment tech- nique, we transformed Laccaria bicolor, an ectomy- corrhizal fungus capable of forming ectomycorrhizae on a wide range of plant hosts. Structural gene se- quences of the hygromycin B phosphotransferase (hph) gene (hygromycin resistance for selection of transformants), r3-glucuronidase (GUS) gene (re- porter gene for tracking transformants) and Bacillus thuringiensis 8-endotoxin (BtCryIIIA) gene (Coleop- teran specific insecticidal gene from Bacillus thurin- giensis var tenebrionis) were introduced into L. bicolor simultaneously. Southern and western blot analyses showed that the introduced sequences were inserted into the fungal genome and transcribed and trans- lated. One of the transformants produced the insec- ticidal toxin; however, the levels were not sufficient to perform toxicity assays. The technique developed can be employed to generate superior strains of L. bicolor suitable for use as biological control agents in various soil and plant conditions.
Aurélie Deveau - One of the best experts on this subject based on the ideXlab platform.
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Pairwise transcriptomic analysis of the interactions between the ectomycorrhizal fungus Laccaria bicolor S238N and three beneficial, neutral and antagonistic soil bacteria
Microbial Ecology, 2015Co-Authors: Aurélie Deveau, Francis Martin, Matthieu Barret, Abdala Gamby Diedhiou, Johan Leveau, Wietse De Boer, Alain Sarniguet, Pascale Frey-klettAbstract:Ectomycorrhizal fungi are surrounded by bacterial communities with which they interact physically and metabolically during their life cycle. These bacteria can have positive or negative effects on the formation and the functioning of ectomycorrhizae. However, relatively little is known about the mechanisms by which ectomycorrhizal fungi and associated bacteria interact. To understand how ectomycorrhizal fungi perceive their biotic environment and the mechanisms supporting interactions between ectomycorrhizal fungi and soil bacteria, we analysed the pairwise transcriptomic responses of the ectomycorrhizal fungus Laccaria bicolor (Basidiomycota: Agaricales) when confronted with beneficial, neutral or detrimental soil bacteria. Comparative analyses of the three transcriptomes indicated that the fungus reacted differently to each bacterial strain. Similarly, each bacterial strain produced a specific and distinct response to the presence of the fungus. Despite these differences in responses observed at the gene level, we found common classes of genes linked to cell-cell interaction, stress response and metabolic processes to be involved in the interaction of the four microorganisms.
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populus trichocarpa and populus deltoides exhibit different metabolomic responses to colonization by the symbiotic fungus Laccaria bicolor
Molecular Plant-microbe Interactions, 2014Co-Authors: Timothy J Tschaplinski, Aurélie Deveau, Gerald A. Tuskan, Annick Brun, Jonathan M Plett, Nancy L Engle, Katherine C Cushman, Madhavi Z Martin, Mitchel J Doktycz, Annegret KohlerAbstract:Within boreal and temperate forest ecosystems, the majority of trees and shrubs form beneficial relationships with mutualistic ectomycorrhizal (ECM) fungi that support plant health through increased access to nutrients as well as aiding in stress and pest tolerance. The intimate interaction between fungal hyphae and plant roots results in a new symbiotic “organ” called the ECM root tip. Little is understood concerning the metabolic reprogramming that favors the formation of this hybrid tissue in compatible interactions and what prevents the formation of ECM root tips in incompatible interactions. We show here that the metabolic changes during favorable colonization between the ECM fungus Laccaria bicolor and its compatible host, Populus trichocarpa, are characterized by shifts in aromatic acid, organic acid, and fatty acid metabolism. We demonstrate that this extensive metabolic reprogramming is repressed in incompatible interactions and that more defensive compounds are produced or retained. We also demo...
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Populus trichocarpa and Populus deltoides Exhibit Different Metabolomic Responses to Colonization by the Symbiotic Fungus Laccaria bicolor
Molecular Plant-Microbe Interactions, 2014Co-Authors: Timothy J Tschaplinski, Aurélie Deveau, Jonathan M. Plett, Annick Brun-jacob, Gerald A. Tuskan, Nancy L Engle, Katherine C Cushman, Madhavi Z Martin, Mitchel J Doktycz, Annegret KohlerAbstract:Within boreal and temperate forest ecosystems, the majority of trees and shrubs form beneficial relationships with mutualistic ectomycorrhizal (ECM) fungi that support plant health through increased access to nutrients as well as aiding in stress and pest tolerance. The intimate interaction between fungal hyphae and plant roots results in a new symbiotic "organ" called the ECM root tip. Little is understood concerning the metabolic reprogramming that favors the formation of this hybrid tissue in compatible interactions and what prevents the formation of ECM root tips in incompatible interactions. We show here that the metabolic changes during favorable colonization between the ECM fungus Laccaria bicolor and its compatible host, Populus trichocarpa, are characterized by shifts in aromatic acid, organic acid, and fatty acid metabolism. We demonstrate that this extensive metabolic reprogramming is repressed in incompatible interactions and that more defensive compounds are produced or retained. We also demonstrate that L. bicolor can metabolize a number of secreted defensive compounds and that the degradation of some of these compounds produces immune response metabolites (e.g., salicylic acid from salicin). Therefore, our results suggest that the metabolic responsiveness of plant roots to L. bicolor is a determinant factor in fungus host interactions.
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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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Déterminisme moléculaire des interactions entre le champignon ectomycorhizien Laccaria bicolor S238N et des bactéries du sol
2007Co-Authors: Aurélie DeveauAbstract:La symbiose ectomycorhizienne a un effet bénéfique sur la nutrition et le développement des arbres. Dans les sols, les champignons ectomycorhiziens interagissent continuellement avec des communautés bactériennes qui peuvent avoir une action bénéfique, neutre ou antagoniste vis-à-vis du champignon. Parmi ces bactéries, une attention particulière a été portée au cours de ces dernières années sur les bactéries auxiliaires de la mycorhization qui favorisent la symbiose ectomycorhizienne. La souche auxiliaire Pseudomonas fluorescens BBc6R8 améliore la survie pré-symbiotique et la croissance du champignon ectomycorhizien Laccaria bicolor S238N, et favorise son établissement en symbiose avec le Douglas. Mais les mécanismes moléculaires sous-jacents sont inconnus. A l'aide d'un dispositif de confrontation bactérie-champignon in vitro et d'outils transcriptomiques, nous avons analysé les réseaux de gènes fongiques impliqués dans l?interaction entre P. fluorescens BBc6R8 et L. bicolor S238N ainsi que le degré de spécificité de la réponse du champignon. De plus, nous avons examiné le rôle joué par certains métabolites fongiques et bactériens dans l'interaction : thiamine, tréhalose, système de sécrétion de type III. Nos résultats suggèrent que l'effet auxiliaire de la souche BBc6R8 soit dû à une combinaison de mécanismes : d'une part une amélioration du statut nutritionnel du mycélium, d'autre part une préparation des racines et des hyphes à l'infection mycorhienne.
