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Yosuke Matsuda - One of the best experts on this subject based on the ideXlab platform.
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An ectomycorrhizal fungus, Cenococcum geophilum, in a coastal pine forest has a high tolerance for an insecticide used to control pine wilt disease
Landscape and Ecological Engineering, 2021Co-Authors: Hirofumi Nakashima, Yosuke Matsuda, Naoki HijiiAbstract:Cenococcum geophilum Fr., one of several ectomycorrhizal species associated with black pine ( Pinus thunbergii Parl.), is dominant in the coastal forests of Japan, even under adverse abiotic environmental conditions. In these forests, many tonnes of Sumipine® (fenitrothion) are applied every year to protect P. thunbergii from pine wilt disease, which is transmitted by a beetle. Here, we examined the effect of this insecticide on the species of fungi found as ectomycorrhizae on naturally regenerated P. thunbergii seedlings collected from coastal forest sites that had or had not been sprayed with fenitrothion. The proportion of C. geophilum ectomycorrhizae on black pine root tips was significantly higher in areas where fenitrothion had been applied than in areas where it had not. We measured the in vitro mycelial growth of C. geophilum as well as other ectomycorrhizal fungi of coastal black pine, Rhizopogon roseolus (Corda) Th. Fr. and Pisolithus arhizus (Scop.) Rauschert, at three levels of fenitrothion (density: 1.32 g/cm^3), i.e., 0, 0.1 and 0.2 mL L^−1. The growth of all three species decreased significantly as the fenitrothion dosage increased. However, the reduction of mycelial growth in response to fenitrothion was lower in C. geophilum than in the other two species. These results suggest that C. geophilum has a high tolerance for fenitrothion, which may explain its dominance over other ectomycorrhizal species in coastal forests in Japan where fenitrothion is routinely sprayed.
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Comparison of Actinomycete Community Composition on the Surface and Inside of Japanese Black Pine (Pinus thunbergii) Tree Roots Colonized by the Ectomycorrhizal Fungus Cenococcum geophilum.
Microbial ecology, 2018Co-Authors: Shoyo Sakoda, Kana Aisu, Hiroki Imagami, Yosuke MatsudaAbstract:Various bacteria are associated with ectomycorrhizal roots, which are symbiotic complexes formed between plant roots and fungi. Among these associated bacteria, actinomycetes have received attention for their ubiquity and diverse roles in forest ecosystems. Here, to examine the association of actinomycetes with ectomycorrhizal root tips, we compared the bacterial and actinomycete communities on the surface and inside of root tips of coastal Japanese black pine (Pinus thunbergii) colonized by the fungus Cenococcum geophilum. Next-generation sequences of 16S rDNA of bacteria communities using the Ion Torrent Personal Genome Machine showed that the number of bacterial classes in the surface of C. geophilum ECM roots was significantly higher than that in non-ECM roots. The bacterial community structure of surface, inside, and non-ECM roots was significantly discriminated each other. For an isolation method, a total of 762 and 335 actinomycete isolates were obtained from the surface and inside of the roots, respectively. In addition, the isolation ratio of actinomycetes in these root tips varied depending on the age of the tree and the season. Identification of the isolates based on partial 16S rDNA sequencing revealed that the isolates belonged to nine genera of the order Actinomycetales. On the surface of the roots, most of the isolates belonged to genus Streptomyces (90.4%); inside of the roots, most of the isolates belonged to genus Actinoallomurus (40.0%), which is a relatively new taxon. Our results suggest that actinomycetes as well as bacteria are ubiquitously associated with C. geophilum ectomycorrhizal roots of P. thunbergii, although their communities can vary either surface or inside of individual root tips.
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Isolation source matters: sclerotia and ectomycorrhizal roots provide different views of genetic diversity in Cenococcum geophilum
2018Co-Authors: Keisuke Obase, Greg W. Douhan, Yosuke MatsudaAbstract:Cenococcum geophilum forms sclerotia and ectomycorrhizas with host plants in forest soils. We demonstrated the differences in genetic diversity of C. geophilum between cultured isolates from sclerotia and those from ectomycorrhizal roots in the same 73 soil samples based on glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene sequences and newly developed microsatellite markers. Based on GAPDH sequences, 759 cultured isolates (553 from sclerotia and 206 from ectomycorrhizas) were classified into 107 “genotypes” with sequence variation of up to 8.6%. The total number of GAPDH genotypes per soil sample ranged from 1 to 9, but genotypes that were shared between sclerotia and ectomycorrhizas were uncommon (0–3 per soil sample). More than 50% of GAPDH genotypes were unique to one source in most soil samples. Unique GAPDH genotypes were detected from either scleotia or ectomycorrhizal roots in most of the soil samples. Multilocus analysis using nine microsatellite markers provided additional resolution to differentiate fungal individuals and supported the results of GAPDH genotyping. The results indicated that sampling both sclerotia and ectomycorrhizal roots maximizes the detection of diversity at the soil core scale. On the other hand, when all isolates were viewed together, 82 GAPDH genotypes were unique to sclerotia whereas only 6 GAPDH genotypes were unique to ectomycorrhizas. Rarefaction analysis indicated that GAPDH genotypic diversity is significantly higher in sclerotia than ectomycorrhizal roots and the diversity within sclerotia is nearly the same as that of both sclerotia and ectomycorrhizas together. These findings suggest that sampling sclerotia alone is likely to detect the majority of GAPDH genotypes in Cenococcum at the regional scale. When deciding whether to sample sclerotia, ectomycorrhizas, or both types of tissues from Cenococcum, it is critical to consider the spatial scale and also the main questions and hypotheses of the study.
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Progress and Challenges in Understanding the Biology, Diversity, and Biogeography of Cenococcum geophilum
Biogeography of Mycorrhizal Symbiosis, 2017Co-Authors: Keisuke Obase, Greg W. Douhan, Yosuke MatsudaAbstract:Cenococcum geophilum (Dothideomycetes, Ascomycota) is one of the most common ectomycorrhizal fungi in boreal and temperate regions. Although C. geophilum was originally considered as a single species, accumulating evidence suggests that C. geophilum is actually a diverse species complex. Here we provide an overview of the current data on global host range, distribution and biogeography of C. geophilum and discuss what is known about the spatial genetic structure at scales from soil cores to biomes to continents. Recent molecular data indicate that the genetic diversity within C. geophilum can be incredibly high, even at the scale of a single soil core. This highlights the need to characterize Cenococcum samples phylogenetically prior to population studies so that cryptic, reproductively isolated species are not admixed together in the analyses. Also sampling design and effort are critical for understanding population and phylogenetic diversity of C. geophilum. A recent population study targeted one Cenococcum lineage in Japanese pine forests and found no spatial autocorrelation at the forest stand level but did find evidence for a pattern of isolation by distance at larger spatial scales. These observations are consistent with the possibility of cryptic recombination. Another recent phylogenetic study found that several Cenococcum lineages are widely distributed across multiple regions and continents. This indicates that some lineages within C. geophilum may be ancient or that cryptic long-distance dispersal is ongoing. Overall, our assessment and review of the recent literature suggests that additional research is needed to understand the population structure and biology of C. geophilum.
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Intraspecific variation in mycelial growth of Cenococcum geophilum isolates in response to salinity gradients
Mycoscience, 2017Co-Authors: Yosuke Matsuda, Keisuke Obase, Mai Yamakawa, Tomomi Inaba, Shin-ichiro ItoAbstract:Abstract Although interspecific variation in the response of ectomycorrhizal fungi to salinity has been examined, knowledge of the intraspecific variation is limited. We evaluated the salinity tolerance of Cenococcum geophilum isolated from ectomycorrhizal roots of Japanese black pine ( Pinus thunbergii ) from eight coastal pine forests in Japan. The identity of the obtained isolates was ensured by DNA sequencing of the internal transcribed spacer region. Mycelial growth of 56 C. geophilum isolates was examined on modified Melin-Norkrans medium containing NaCl at one of six concentrations (0–400 mM). The mycelial growth usually decreased at a NaCl concentration >100 mM and decreased significantly at 400 mM. For mycelial growth, no significant site × NaCl concentration interaction was observed. However, a significant interaction existed between isolate and NaCl concentration at each site, and some isolates (e.g., from Aichi and Shizuoka) showed no growth inhibition even at 400 mM NaCl. The results indicate that C. geophilum in coastal areas is salinity-tolerant, but the tolerance varies among isolates between sites and even within a site. Thus, salinity-tolerant isolates should be selected to examine their effects on the establishment and survival of woody plants in coastal areas that are occasionally exposed to high salinity.
Martina Peter - One of the best experts on this subject based on the ideXlab platform.
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cryptic genetic structure and copy number variation in the ubiquitous forest symbiotic fungus Cenococcum geophilum
Environmental Microbiology, 2021Co-Authors: Benjamin Dauphin, Maira De Freitas Pereira, Anna Lipzen, Francis Martin, Annegret Kohler, Igor V Grigoriev, Kerrie Barry, Mojgan Amirebrahimi, Martina PeterAbstract:Ectomycorrhizal (ECM) fungi associated with plants constitute one of the most successful symbiotic interactions in forest ecosystems. ECM support trophic exchanges with host plants and are important factors for the survival and stress resilience of trees. However, ECM clades often harbour morpho-species and cryptic lineages, with weak morphological differentiation. How this relates to intraspecific genome variability and ecological functioning is poorly known. Here, we analysed 16 European isolates of the ascomycete Cenococcum geophilum, an extremely ubiquitous forest symbiotic fungus with no known sexual or asexual spore-forming structures but with a massively enlarged genome. We carried out whole-genome sequencing to identify single-nucleotide polymorphisms. We found no geographic structure at the European scale but divergent lineages within sampling sites. Evidence for recombination was restricted to specific cryptic lineages. Lineage differentiation was supported by extensive copy-number variation. Finally, we confirmed heterothallism with a single MAT1 idiomorph per genome. Synteny analyses of the MAT1 locus revealed substantial rearrangements and a pseudogene of the opposite MAT1 idiomorph. Our study provides the first evidence for substantial genome-wide structural variation, lineage-specific recombination and low continent-wide genetic differentiation in C. geophilum. Our study provides a foundation for targeted analyses of intra-specific functional variation in this major symbiosis.
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Ectomycorrhizal ecology is imprinted in the genome of the dominant symbiotic fungus Cenococcum geophilum
Nature Communications, 2016Co-Authors: Martina Peter, Emmanuelle Morin, Kerrie W. Barry, Annegret Kohler, Robin A. Ohm, Alan Kuo, Jennifer Kruetzmann, Matthias Arend, Manfred Binder, Cindy ChoiAbstract:The most frequently encountered symbiont on tree roots is the ascomycete Cenococcum geophilum, the only mycorrhizal species within the largest fungal class Dothideomycetes, a class known for devastating plant pathogens. Here we show that the symbiotic genomic idiosyncrasies of ectomycorrhizal basidiomycetes are also present in C. geophilum with symbiosis-induced, taxon-specific genes of unknown function and reduced numbers of plant cell wall-degrading enzymes. C. geophilum still holds a significant set of genes in categories known to be involved in pathogenesis and shows an increased genome size due to transposable elements proliferation. Transcript profiling revealed a striking upregulation of membrane transporters, including aquaporin water channels and sugar transporters, and mycorrhiza-induced small secreted proteins (MiSSPs) in ectomycorrhiza compared with free-living mycelium. The frequency with which this symbiont is found on tree roots and its possible role in water and nutrient transport in symbiosis calls for further studies on mechanisms of host and environmental adaptation.
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Comprehensive proteome analysis in Cenococcum geophilum Fr. as a tool to discover drought-related proteins
Journal of proteomics, 2012Co-Authors: René Kerner, Martina Peter, Edgar Delgado-eckert, Estela Del Castillo, Gerhard Müller-starck, Bernhard Kuster, Emilie Tisserant, Karin PritschAbstract:Cenococcum geophilum is a widely distributed ectomycorrhizal fungus potentially playing a significant role in resistance and resilience mechanisms of its tree hosts exposed to drought stress. In this study, we performed a large scale protein analysis in pure cultures of C. geophilum in order to gain first global insights into the proteome assembly of this fungus. Using 1-D gel electrophoresis coupled with ESI-MS/MS, we indentified 638 unique proteins. Most of these proteins were related to the metabolic and cellular processes, and the transport machinery of cells. In a second step, we examined the influence of water deprivation on the proteome of C. geophilum pure cultures at three time points of gradually imposed drought. The results indicated that 12 proteins were differentially abundant in mycelia subjected to drought compared to controls. The induced responses in C. geophilum point towards regulation of osmotic stress, maintainance of cell integrity, and counteracting increased levels of reactive oxygen species formed during water deprivation.
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Comprehensive proteome analysis in Cenococcum geophilum Fr. as a tool to discover drought-related proteins
Journal of Proteomics, 2012Co-Authors: René Kerner, Martina Peter, Edgar Delgado-eckert, Estela Del Castillo, Bernhard Kuster, Emilie Tisserant, Gerhard Mueller-starck, Karin PritschAbstract:Cenococcum geophilum is a widely distributed ectomycorrhizal fungus potentially playing a significant role in resistance and resilience mechanisms of its tree hosts exposed to drought stress. In this study, we performed a large scale protein analysis in pure cultures of C. geophilum in order to gain first global insights into the proteome assembly of this fungus. Using 1-D gel electrophoresis coupled with ESI-MS/MS, we indentified 638 unique proteins. Most of these proteins were related to the metabolic and cellular processes, and the transport machinery of cells. In a second step, we examined the influence of water deprivation on the proteome of C. geophilum pure cultures at three time points of gradually imposed drought. The results indicated that 12 proteins were differentially abundant in mycelia subjected to drought compared to controls. The induced responses in C. geophilum point towards regulation of osmotic stress, maintainance of cell integrity, and counteracting increased levels of reactive oxygen species formed during water deprivation. (c) 2012 Elsevier B.V. All rights reserved.
Greg W. Douhan - One of the best experts on this subject based on the ideXlab platform.
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Isolation source matters: sclerotia and ectomycorrhizal roots provide different views of genetic diversity in Cenococcum geophilum
2018Co-Authors: Keisuke Obase, Greg W. Douhan, Yosuke MatsudaAbstract:Cenococcum geophilum forms sclerotia and ectomycorrhizas with host plants in forest soils. We demonstrated the differences in genetic diversity of C. geophilum between cultured isolates from sclerotia and those from ectomycorrhizal roots in the same 73 soil samples based on glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene sequences and newly developed microsatellite markers. Based on GAPDH sequences, 759 cultured isolates (553 from sclerotia and 206 from ectomycorrhizas) were classified into 107 “genotypes” with sequence variation of up to 8.6%. The total number of GAPDH genotypes per soil sample ranged from 1 to 9, but genotypes that were shared between sclerotia and ectomycorrhizas were uncommon (0–3 per soil sample). More than 50% of GAPDH genotypes were unique to one source in most soil samples. Unique GAPDH genotypes were detected from either scleotia or ectomycorrhizal roots in most of the soil samples. Multilocus analysis using nine microsatellite markers provided additional resolution to differentiate fungal individuals and supported the results of GAPDH genotyping. The results indicated that sampling both sclerotia and ectomycorrhizal roots maximizes the detection of diversity at the soil core scale. On the other hand, when all isolates were viewed together, 82 GAPDH genotypes were unique to sclerotia whereas only 6 GAPDH genotypes were unique to ectomycorrhizas. Rarefaction analysis indicated that GAPDH genotypic diversity is significantly higher in sclerotia than ectomycorrhizal roots and the diversity within sclerotia is nearly the same as that of both sclerotia and ectomycorrhizas together. These findings suggest that sampling sclerotia alone is likely to detect the majority of GAPDH genotypes in Cenococcum at the regional scale. When deciding whether to sample sclerotia, ectomycorrhizas, or both types of tissues from Cenococcum, it is critical to consider the spatial scale and also the main questions and hypotheses of the study.
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Progress and Challenges in Understanding the Biology, Diversity, and Biogeography of Cenococcum geophilum
Biogeography of Mycorrhizal Symbiosis, 2017Co-Authors: Keisuke Obase, Greg W. Douhan, Yosuke MatsudaAbstract:Cenococcum geophilum (Dothideomycetes, Ascomycota) is one of the most common ectomycorrhizal fungi in boreal and temperate regions. Although C. geophilum was originally considered as a single species, accumulating evidence suggests that C. geophilum is actually a diverse species complex. Here we provide an overview of the current data on global host range, distribution and biogeography of C. geophilum and discuss what is known about the spatial genetic structure at scales from soil cores to biomes to continents. Recent molecular data indicate that the genetic diversity within C. geophilum can be incredibly high, even at the scale of a single soil core. This highlights the need to characterize Cenococcum samples phylogenetically prior to population studies so that cryptic, reproductively isolated species are not admixed together in the analyses. Also sampling design and effort are critical for understanding population and phylogenetic diversity of C. geophilum. A recent population study targeted one Cenococcum lineage in Japanese pine forests and found no spatial autocorrelation at the forest stand level but did find evidence for a pattern of isolation by distance at larger spatial scales. These observations are consistent with the possibility of cryptic recombination. Another recent phylogenetic study found that several Cenococcum lineages are widely distributed across multiple regions and continents. This indicates that some lineages within C. geophilum may be ancient or that cryptic long-distance dispersal is ongoing. Overall, our assessment and review of the recent literature suggests that additional research is needed to understand the population structure and biology of C. geophilum.
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Revisiting phylogenetic diversity and cryptic species of Cenococcum geophilum sensu lato
Mycorrhiza, 2016Co-Authors: Keisuke Obase, Greg W. Douhan, Yosuke MatsudaAbstract:The fungus Cenococcum geophilum Fr. ( Dothideomycetes , Ascomycota ) is one of the most common ectomycorrhizal fungi in boreal to temperate regions. A series of molecular studies has demonstrated that C. geophilum is monophyletic but a heterogeneous species or a species complex. Here, we revisit the phylogenetic diversity of C. geophilum sensu lato from a regional to intercontinental scale by using new data from Florida (USA) along with existing data in GenBank from Japan, Europe, and North America. The combination of internal transcribed spacer (ITS) ribosomal DNA and the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene resolved six well-supported lineages (87–100 % bootstrap values) that are closely related to each other and a seventh lineage that is phylogenetically distinct. A multi-locus analysis (small subunit (SSU), large subunit (LSU), translational elongation factor (TEF), and the largest and second-largest subunits of RNA polymerase II (RPB1 and RPB2)) revealed that the divergent lineage is the sister group to all other known Cenococcum isolates. Isolates of the divergent lineage grow fast on nutrient media and do not form ectomycorrhizas on seedlings of several pine and oak species. Our results indicate that C. geophilum sensu lato includes more phylogenetically distinct cryptic species than have previously been reported. Furthermore, the divergent lineage appears to be a non-mycorrhizal sister group. We discuss the phylogenetic diversity of C. geophilum sensu lato and argue in favor of species recognition based on phylogenetic and ecological information in addition to morphological characteristics. A new genus and species ( PseudoCenococcum floridanum gen. et sp. nov.) is proposed to accommodate a divergent and putatively non-mycorrhizal lineage.
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cladophialophora floridana and cladophialophora tortuosa new species isolated from sclerotia of Cenococcum geophilum in forest soils of florida usa
Mycoscience, 2016Co-Authors: Keisuke Obase, Yosuke Matsuda, Greg W. Douhan, Matthew E SmithAbstract:Abstract Cladophialophora is a genus of asexual dematiaceous fungi that is characterized by the production of branched or unbranched chains of conidia that originate by blastic conidiogenesis and have hyaline conidial scars. Two novel species of Cladophialophora were isolated from surface-sterilized sclerotia of the ectomycorrhizal fungus Cenococcum geophilum that were extracted from soils of mixed pine-oak forests in Florida, USA. Cladophialophora floridana and C. tortuosa form melanized conidia produced in coherent and infrequently branched chains that often arise from semi-macronematous conidiophores. Both species form subglobose to oblong conidia but the conidia of C. tortuosa are more frequently and distinctly phaseoliform or sigmoid in shape. These two novel species are clearly distinct from all known species of Cladophialophora and closely-related other genera based on a combination of microscopic morphology and rRNA gene sequences, including the ITS and partial LSU regions.
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Using the putative asexual fungus Cenococcum geophilum as a model to test how species concepts influence recombination analyses using sequence data from multiple loci
Current Genetics, 2007Co-Authors: Greg W. Douhan, Darren P. Martin, Dave M. RizzoAbstract:Recent studies have found that three divergent lineages of the ectomycorrhizal fungus Cenococcum geophilum may co-occur within a single soil sample. To test how inference of population structure is affected by species concept, potential recombination in this putative asexual fungus was analyzed by sequencing 10 loci from 44 isolates from within one main lineage that is potentially sub-divisible into two phylogenetic species (A and B). Phylogenetic incongruence between these loci and recombination analyses using six different methods was consistent with recombination. However, most of the incongruence was caused by an apparently reciprocal recombination event between the actin locus and the other loci studied. Extreme divergence between the two types of actin loci suggests either an ancient recombination event or a more recent horizontal inheritance. We also found that random mating could not be rejected when A and B isolates were treated as members of a single species based on multilocus disequilibrium analyses, whereas random mating was rejected when all isolates were pooled. These results are significant and demonstrate that inferences of population structure can be confounded when isolates are pooled together based entirely on a morphological species concept.
Shin-ichiro Ito - One of the best experts on this subject based on the ideXlab platform.
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Intraspecific variation in mycelial growth of Cenococcum geophilum isolates in response to salinity gradients
Mycoscience, 2017Co-Authors: Yosuke Matsuda, Keisuke Obase, Mai Yamakawa, Tomomi Inaba, Shin-ichiro ItoAbstract:Abstract Although interspecific variation in the response of ectomycorrhizal fungi to salinity has been examined, knowledge of the intraspecific variation is limited. We evaluated the salinity tolerance of Cenococcum geophilum isolated from ectomycorrhizal roots of Japanese black pine ( Pinus thunbergii ) from eight coastal pine forests in Japan. The identity of the obtained isolates was ensured by DNA sequencing of the internal transcribed spacer region. Mycelial growth of 56 C. geophilum isolates was examined on modified Melin-Norkrans medium containing NaCl at one of six concentrations (0–400 mM). The mycelial growth usually decreased at a NaCl concentration >100 mM and decreased significantly at 400 mM. For mycelial growth, no significant site × NaCl concentration interaction was observed. However, a significant interaction existed between isolate and NaCl concentration at each site, and some isolates (e.g., from Aichi and Shizuoka) showed no growth inhibition even at 400 mM NaCl. The results indicate that C. geophilum in coastal areas is salinity-tolerant, but the tolerance varies among isolates between sites and even within a site. Thus, salinity-tolerant isolates should be selected to examine their effects on the establishment and survival of woody plants in coastal areas that are occasionally exposed to high salinity.
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Spatial distribution and genetic structure of Cenococcum geophilum in coastal pine forests in Japan.
FEMS microbiology ecology, 2015Co-Authors: Yosuke Matsuda, Keisuke Obase, Kosuke Takeuchi, Shin-ichiro ItoAbstract:The asexual ectomycorrhizal fungus Cenococcum geophilum has a wide geographic range in diverse forest ecosystems. Although its genetic diversity has been documented at a stand or regional scale, knowledge of spatial genetic structure is limited. We studied the genetic diversity and spatial structure of C. geophilum in eight Japanese coastal pine forests with a maximum geographic range of 1364 km. A total of 225 samples were subjected to phylogenetic analysis based on the glyceraldehyde 3-phosphate dehydrogenase gene ( GAPDH ) followed by microsatellite analysis with five loci. The phylogenetic analysis based on GAPDH resolved three groups with most isolates falling into one dominant lineage. Microsatellite analyses generated 104 multilocus genotypes in the overall populations. We detected significant genetic variation within populations and genetic clusters indicating that high genetic diversity may be maintained by possible recombination processes at a stand scale. Although no spatial autocorrelation was detected at a stand scale, the relationship between genetic and geographic distances among the populations was significant, suggesting a pattern of isolation by distance. These results indicate that cryptic recombination events at a local scale and unknown migration events at both stand and regional scales influence spatial distribution and genetic structure of C. geophilum in coastal pine forests of Japan.
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Local and microscale distributions of Cenococcum geophilum in soils of coastal pine forests
Fungal Ecology, 2009Co-Authors: Yosuke Matsuda, N. Hayakawa, Shin-ichiro ItoAbstract:Abstract To clarify the local and microscale distribution patterns of Cenococcum geophilum at soil surfaces in coastal pine forests, we collected soil samples in Pinus thunbergii stands. To investigate the local distribution of C. geophilum , five soil samples were collected randomly to obtain roots of P. thunbergii at four study sites. To examine the microscale distribution of fungi, 19 soil samples were collected from a 5 × 5 m quadrat at a minimum interval of 15 cm. Ectomycorrhizas of P. thunbergii were examined and identified morphologically. C. geophilum mycorrhizas were retrieved from all the sites at the local scale and from all sampling points within a site at the microscale. The occurrence frequency of C. geophilum ectomycorrhizas ranged from 20.0 to 62.6 % at the sites studied. These results suggest that C. geophilum is the dominant ectomycorrhizal fungus and is distributed ubiquitously in coastal pine forests of Japan.
Andrea Polle - One of the best experts on this subject based on the ideXlab platform.
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Volatile signalling by sesquiterpenes from ectomycorrhizal fungi reprogrammes root architecture
Nature Communications, 2015Co-Authors: Frank A. Ditengou, Anna Müller, Maaria Rosenkranz, Judith Felten, Hanna Lasok, Maja Miloradovic Van Doorn, Valérie Legué, Klaus Palme, Jörg-peter Schnitzler, Andrea PolleAbstract:The mutualistic association of roots with ectomycorrhizal fungi promotes plant health and is a hallmark of boreal and temperate forests worldwide. In the pre-colonization phase, before direct contact, lateral root (LR) production is massively stimulated, yet little is known about the signals exchanged during this step. Here, we identify sesquiterpenes (SQTs) as biologically active agents emitted by Laccaria bicolor while interacting with Populus or Arabidopsis. We show that inhibition of fungal SQT production by lovastatin strongly reduces LR proliferation and that (-)-thujopsene, a low-abundance SQT, is sufficient to stimulate LR formation in the absence of the fungus. Further, we show that the ectomycorrhizal ascomycote, Cenococcum geophilum, which cannot synthesize SQTs, does not promote LRs. We propose that the LR-promoting SQT signal creates a win-win situation by enhancing the root surface area for plant nutrient uptake and by improving fungal access to plant-derived carbon via root exudates.
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subcellular nutrient element localization and enrichment in ecto and arbuscular mycorrhizas of field grown beech and ash trees indicate functional differences
PLOS ONE, 2014Co-Authors: Jasmin Seven, Andrea PolleAbstract:Mycorrhizas are the chief organ for plant mineral nutrient acquisition. In temperate, mixed forests, ash roots (Fraxinus excelsior) are colonized by arbuscular mycorrhizal fungi (AM) and beech roots (Fagus sylvatica) by ectomycorrhizal fungi (EcM). Knowledge on the functions of different mycorrhizal species that coexist in the same environment is scarce. The concentrations of nutrient elements in plant and fungal cells can inform on nutrient accessibility and interspecific differences of mycorrhizal life forms. Here, we hypothesized that mycorrhizal fungal species exhibit interspecific differences in mineral nutrient concentrations and that the differences correlate with the mineral nutrient concentrations of their associated root cells. Abundant mycorrhizal fungal species of mature beech and ash trees in a long-term undisturbed forest ecosystem were the EcM Lactarius subdulcis, Clavulina cristata and Cenococcum geophilum and the AM Glomus sp. Mineral nutrient subcellular localization and quantities of the mycorrhizas were analysed after non-aqueous sample preparation by electron dispersive X-ray transmission electron microscopy. Cenococcum geophilum contained the highest sulphur, Clavulina cristata the highest calcium levels, and Glomus, in which cations and P were generally high, exhibited the highest potassium levels. Lactarius subdulcis-associated root cells contained the highest phosphorus levels. The root cell concentrations of K, Mg and P were unrelated to those of the associated fungal structures, whereas S and Ca showed significant correlations between fungal and plant concentrations of those elements. Our results support profound interspecific differences for mineral nutrient acquisition among mycorrhizas formed by different fungal taxa. The lack of correlation between some plant and fungal nutrient element concentrations may reflect different retention of mineral nutrients in the fungal part of the symbiosis. High mineral concentrations, especially of potassium, in Glomus sp. suggest that the well-known influence of tree species on chemical soil properties may be related to their mycorrhizal associates.
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Subcellular nutrient element levels in different subcellular structures of mycorrhizal roots associated with different mycorrhizal taxa [(A) Magnesium, (B) Potassium, (C) Calcium, (D) Phosphorus, (E) Sulphur] and principle component analysis (F).
2014Co-Authors: Jasmin Seven, Andrea PolleAbstract:Data indicate means (n≥20 to 60±SE). Different letters for a given structure (EcM) or between the different compartments (AM) indicate significant differences at P≤0.05. La = Lactarius subdulcis, Ce = Cenococcum geophilum, Cl = Clavulina cristata, Gl = Glomus sp., C = cell, W = Wall, HM = Hyphal mantle, HN = Hartig net, InterH = intercellular hyphae, intraH = intracellular hyphae, Arb = arbuscules, F = fungus, P = plant.