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Sample records for quietus-quercus petraea ectomycorrhizas

  1. Gene transcription in Lactarius quietus-Quercus petraea ectomycorrhizas from a forest soil.

    PubMed

    Courty, P E; Poletto, M; Duchaussoy, F; Buée, M; Garbaye, J; Martin, F

    2008-11-01

    Extracting fungal mRNA from ectomycorrhizas (ECMs) and forest soil samples for monitoring in situ metabolic activities is a significant challenge when studying the role of ECMs in biogeochemical cycles. A robust, simple, rapid, and effective method was developed for extracting RNA from rhizospheric soil and ECMs by adapting previous grinding and lysis methods. The quality and yield of the extracted RNA were sufficient to be used for reverse transcription. RNA extracted from ECMs of Lactarius quietus in a 100-year-old oak stand was used to construct a cDNA library and sequence expressed sequence tags. The transcripts of many genes involved in primary metabolism and in the degradation of organic matter were found. The transcription levels of four targeted fungal genes (glutamine synthase, a general amino acid transporter, a tyrosinase, and N-acetylhexosaminidase) were measured by quantitative reverse transcription-PCR in ECMs and in the ectomycorrhizospheric soil (the soil surrounding the ECMs containing the extraradical mycelium) in forest samples. On average, levels of gene expression for the L. quietus ECM root tips were similar to those for the extraradical mycelium, although gene expression varied up to 10-fold among the samples. This study demonstrates that gene expression from ECMs and soil can be analyzed. These results provide new perspectives for investigating the role of ectomycorrhizal fungi in the functioning of forest ecosystems. PMID:18791033

  2. Gene Transcription in Lactarius quietus-Quercus petraea Ectomycorrhizas from a Forest Soil▿

    PubMed Central

    Courty, P. E.; Poletto, M.; Duchaussoy, F.; Buée, M.; Garbaye, J.; Martin, F.

    2008-01-01

    Extracting fungal mRNA from ectomycorrhizas (ECMs) and forest soil samples for monitoring in situ metabolic activities is a significant challenge when studying the role of ECMs in biogeochemical cycles. A robust, simple, rapid, and effective method was developed for extracting RNA from rhizospheric soil and ECMs by adapting previous grinding and lysis methods. The quality and yield of the extracted RNA were sufficient to be used for reverse transcription. RNA extracted from ECMs of Lactarius quietus in a 100-year-old oak stand was used to construct a cDNA library and sequence expressed sequence tags. The transcripts of many genes involved in primary metabolism and in the degradation of organic matter were found. The transcription levels of four targeted fungal genes (glutamine synthase, a general amino acid transporter, a tyrosinase, and N-acetylhexosaminidase) were measured by quantitative reverse transcription-PCR in ECMs and in the ectomycorrhizospheric soil (the soil surrounding the ECMs containing the extraradical mycelium) in forest samples. On average, levels of gene expression for the L. quietus ECM root tips were similar to those for the extraradical mycelium, although gene expression varied up to 10-fold among the samples. This study demonstrates that gene expression from ECMs and soil can be analyzed. These results provide new perspectives for investigating the role of ectomycorrhizal fungi in the functioning of forest ecosystems. PMID:18791033

  3. Ammonium assmilation in spruce ectomycorrhizas

    SciTech Connect

    Chalot, M.; Brun, A.; Botton, B. ); Stewart, G. )

    1990-05-01

    Assimilation of labelled NH{sub 4}{sup +} into amino acids has been followed in ectomycorrhizal roots of spruce. Over an 18 h period of NH{sub 4}{sup +} feeding, Gln, Glu and Ala became the most abundant amino acids. Gln was also the most highly labelled amino acid during the experiment, followed by Glu and Ala. This result indicates that Gln synthesis is an important ammonium utilization reaction in spruce mycorrhizas. Addition of MSX to NH{sub 4}{sup +} fed mycorrhizas caused an inhibition of Gln accumulation with a corresponding increase in Glu, Ala and Asn levels. The supply of MSX induced a sharp diminution of {sup 15}N enrichment in both amino and amido groups of glutamine. In contrast, the {sup 15}N incorporation into Glu and derivatives (Ala and Asp) remained very high. This study demonstrates that the fungal glutamate dehydrogenase is quite operative in spruce ectomycorrhizas since it is able to sustain ammonium assimilation when glutamine synthetase is inhibited.

  4. Population-specific metabolic phenotypes of Arabidopsis lyrata ssp. petraea.

    PubMed

    Davey, Matthew P; Burrell, Mike M; Woodward, F Ian; Quick, W Paul

    2008-01-01

    Plant populations growing at the margin of their range may exhibit traits that indicate genetic differentiation and adaptation to their local abiotic environment. Here, it was investigated whether geographically separated marginal populations of Arabidopsis lyrata ssp. petraea have distinct metabolic phenotypes within the plant foliage. Seeds of A. petraea were obtained from populations along a latitudinal gradient (49-64 N), namely Germany, Wales, Sweden and Iceland and grown in a controlled cabinet environment. Targeted metabolic profiles and fingerprints were obtained at the same initial developmental stage. The free amino acid compositions were population specific, with fold differences in arginine, aspartic acid, asparagines, glycine, phenylalanine, alanine, threonine, histidine, serine and gamma-aminobutyric acid (GABA) concentrations. Sucrose, mannose and fructose concentrations were also different between populations but polyhydric alcohol concentrations were not. Principal component analysis (PCA) of metabolite fingerprints revealed metabolic phenotypes for each population. It is suggested that glucosinolates were responsible for discriminating populations within the PCA. Metabolite fingerprinting and profiling has proved to be sufficiently sensitive to identify metabolic differences between plant populations. These findings show that there is significant natural variation in metabolism among populations of A. petraea. PMID:18028292

  5. Ectomycorrhizas from a Lower Eocene angiosperm forest.

    PubMed

    Beimforde, Christina; Schäfer, Nadine; Dörfelt, Heinrich; Nascimbene, Paul C; Singh, Hukam; Heinrichs, Jochen; Reitner, Joachim; Rana, Rajendra S; Schmidt, Alexander R

    2011-12-01

    The development of mycorrhizal associations is considered a key innovation that enabled vascular plants to extensively colonize terrestrial habitats. Here, we present the first known fossil ectomycorrhizas from an angiosperm forest. Our fossils are preserved in a 52 million-yr-old piece of amber from the Tadkeshwar Lignite Mine of Gujarat State, western India. The amber was produced by representatives of Dipterocarpaceae in an early tropical broadleaf forest. The ectomycorrhizas were investigated using light microscopy and field emission scanning electron microscopy. Dissolving the amber surrounding one of the fossils allowed ultrastructural analyses and Raman spectroscopy. Approx. 20 unramified, cruciform and monopodial-pinnate ectomycorrhizas are fossilized adjacent to rootlets, and different developmental stages of the fossil mycorrhizas are delicately preserved in the ancient resin. Compounds of melanins were detectable in the dark hyphae. The mycobiont, Eomelanomyces cenococcoides gen. et spec. nov., is considered to be an ascomycete; the host is most likely a dipterocarp representative. An early ectomycorrhizal association may have conferred an evolutionary advantage on dipterocarps. Our find indicates that ectomycorrhizas occurred contemporaneously within both gymnosperms (Pinaceae) and angiosperms (Dipterocarpaceae) by the Lower Eocene. PMID:22074339

  6. Effects of ectomycorrhizae removal on survival and growth of loblolly pine seedlings with pisolithus or natural ectomycorrhizae on an upland site in South Carolina. Progress report

    SciTech Connect

    Marx, D.H.

    1982-01-01

    This study was undertaken to ascertain the significance of mechanical loss of ectomycorrhizae formed by Pisolithus tinctorius or naturally occurring fungi encountered during lifting of nursery seedlings to the capacity of these seedlings to regenerate roots, survive, and grow. Seedlings were planted in January 1981. Seedlings with Pisolithus ectomycorrhizae formed in the nursery can tolerate more removal of ectomycorrhizae than routine nursery seedlings with natural ectomycorrhizae. However, seedlings in both ectomycorrhizal condition groups were severely impacted by removal of ectomycorrhizae. 1 table.

  7. Calcium oxalate crystals in eucalypt ectomycorrhizae: morphochemical characterization.

    PubMed

    Pylro, Victor Satler; de Freitas, André Luiz Moreira; Otoni, Wagner Campos; da Silva, Ivo Ribeiro; Borges, Arnaldo Chaer; Costa, Maurício Dutra

    2013-01-01

    Ectomycorrhizal fungi are ubiquitous in forest ecosystems, benefitting plants principally by increasing the uptake of water and nutrients such as calcium from the soil. Previous work has demonstrated accumulation of crystallites in eucalypt ectomycorrhizas, but detailed morphological and chemical characterization of these crystals has not been performed. In this work, cross sections of acetic acid-treated and cleared ectomycorrhizal fragments were visualized by polarized light microscopy to evaluate the location of crystals within cortical root cells. Ectomycorrhizal sections were also observed by scanning electron microscopy (SEM) coupled with energy dispersive x-ray (EDS) microprobe analysis. The predominant forms of crystals were crystal sand (granules) and concretions. Calcium, carbon and oxygen were detected by EDS as constituent elements and similar elemental profiles were observed between both crystal morphologies. All analyzed crystalline structures were characterized as calcium oxalate crystals. This is the first report of the stoichiometry and morphology of crystals occurring in eucalypt ectomycorrhizas in tropical soils. The data corroborates the role of ectomycorrhizae in the uptake and accumulation of calcium in the form of calcium oxalate crystals in hybrid eucalypt plants. PMID:23844062

  8. Recovery of ectomycorrhiza after 'nitrogen saturation' of a conifer forest.

    PubMed

    Högberg, Peter; Johannisson, Christian; Yarwood, Stephanie; Callesen, Ingeborg; Näsholm, Torgny; Myrold, David D; Högberg, Mona N

    2011-01-01

    Trees reduce their carbon (C) allocation to roots and mycorrhizal fungi in response to high nitrogen (N) additions, which should reduce the N retention capacity of forests. The time needed for recovery of mycorrhizas after termination of N loading remains unknown. Here, we report the long-term impact of N loading and the recovery of ectomycorrhiza after high N loading on a Pinus sylvestris forest. We analysed the N% and abundance of the stable isotope (15) N in tree needles and soil, soil microbial fatty acid biomarkers and fungal DNA. Needles in N-loaded plots became enriched in (15) N, reflecting decreased N retention by mycorrhizal fungi and isotopic discrimination against (15) N during loss of N. Meanwhile, needles in N-limited (control) plots became depleted in (15) N, reflecting high retention of (15) N by mycorrhizal fungi. N loading was terminated after 20yr. The δ(15) N and N% of the needles decreased 6yr after N loading had been terminated, and approached values in control plots after 15yr. This decrease, and the larger contributions compared with N-loaded plots of a fungal fatty acid biomarker and ectomycorrhizal sequences, suggest recovery of ectomycorrhiza. High N loading rapidly decreased the functional role of ectomycorrhiza in the forest N cycle, but significant recovery occurred within 6-15yr after termination of N loading. PMID:20880225

  9. Calcium Oxalate Crystals in Eucalypt Ectomycorrhizae: Morphochemical Characterization

    PubMed Central

    Pylro, Victor Satler; de Freitas, André Luiz Moreira; Otoni, Wagner Campos; da Silva, Ivo Ribeiro; Borges, Arnaldo Chaer; Costa, Maurício Dutra

    2013-01-01

    Ectomycorrhizal fungi are ubiquitous in forest ecosystems, benefitting plants principally by increasing the uptake of water and nutrients such as calcium from the soil. Previous work has demonstrated accumulation of crystallites in eucalypt ectomycorrhizas, but detailed morphological and chemical characterization of these crystals has not been performed. In this work, cross sections of acetic acid-treated and cleared ectomycorrhizal fragments were visualized by polarized light microscopy to evaluate the location of crystals within cortical root cells. Ectomycorrhizal sections were also observed by scanning electron microscopy (SEM) coupled with energy dispersive x-ray (EDS) microprobe analysis. The predominant forms of crystals were crystal sand (granules) and concretions. Calcium, carbon and oxygen were detected by EDS as constituent elements and similar elemental profiles were observed between both crystal morphologies. All analyzed crystalline structures were characterized as calcium oxalate crystals. This is the first report of the stoichiometry and morphology of crystals occurring in eucalypt ectomycorrhizas in tropical soils. The data corroborates the role of ectomycorrhizae in the uptake and accumulation of calcium in the form of calcium oxalate crystals in hybrid eucalypt plants. PMID:23844062

  10. Genetic differentiation of oak populations within the Quercus robur/Quercus petraea complex in Central and Eastern Europe.

    PubMed

    Gömöry, D; Yakovlev, I; Zhelev, P; Jedináková, J; Paule, L

    2001-05-01

    Genetic structure of 25 indigenous populations of sessile and pedunculate oaks (Quercus petraea and Q. robur), originating from three geographical regions: Slovakia, Bulgaria and the Republic Mari-El (Russia), was investigated using isozyme markers. Mean number of alleles per locus ranged between 1.8 and 2.6 in Q. robur populations and from 2.0 to 3.0 in Q. petraea populations; slightly higher expected heterozygosity values were found in Q. robur compared to Q. petraea. One locus, coding for a substrate-nonspecific dehydrogenase, differentiated the two species. The interspecific component of gene diversity was 46.7% at this locus, compared to 0.4-7.8% at the remaining loci. PMID:11554972

  11. Different bacterial communities in ectomycorrhizae and surrounding soil

    PubMed Central

    Vik, Unni; Logares, Ramiro; Blaalid, Rakel; Halvorsen, Rune; Carlsen, Tor; Bakke, Ingrid; Kolstø, Anne-Brit; Økstad, Ole Andreas; Kauserud, Håvard

    2013-01-01

    Several eukaryotic symbioses have shown to host a rich diversity of prokaryotes that interact with their hosts. Here, we study bacterial communities associated with ectomycorrhizal root systems of Bistorta vivipara compared to bacterial communities in bulk soil using pyrosequencing of 16S rRNA amplicons. A high richness of Operational Taxonomic Units (OTUs) was found in plant roots (3,571 OTUs) and surrounding soil (3,476 OTUs). The community composition differed markedly between these two environments. Actinobacteria, Armatimonadetes, Chloroflexi and OTUs unclassified at phylum level were significantly more abundant in plant roots than in soil. A large proportion of the OTUs, especially those in plant roots, presented low similarity to Sanger 16S rRNA reference sequences, suggesting novel bacterial diversity in ectomycorrhizae. Furthermore, the bacterial communities of the plant roots were spatially structured up to a distance of 60 cm, which may be explained by bacteria using fungal hyphae as a transport vector. The analyzed ectomycorrhizae presents a distinct microbiome, which likely influence the functioning of the plant-fungus symbiosis. PMID:24326907

  12. Spatial and temporal ecology of Scots pine ectomycorrhizas.

    PubMed

    Pickles, Brian J; Genney, David R; Potts, Jacqueline M; Lennon, Jack J; Anderson, Ian C; Alexander, Ian J

    2010-05-01

    Spatial analysis was used to explore the distribution of individual species in an ectomycorrhizal (ECM) fungal community to address: whether mycorrhizas of individual ECM fungal species were patchily distributed, and at what scale; and what the causes of this patchiness might be. Ectomycorrhizas were extracted from spatially explicit samples of the surface organic horizons of a pine plantation. The number of mycorrhizas of each ECM fungal species was recorded using morphotyping combined with internal transcribed spacer (ITS) sequencing. Semivariograms, kriging and cluster analyses were used to determine both the extent and scale of spatial autocorrelation in species abundances, potential interactions between species, and change over time. The mycorrhizas of some, but not all, ECM fungal species were patchily distributed and the size of patches differed between species. The relative abundance of individual ECM fungal species and the position of patches of ectomycorrhizas changed between years. Spatial and temporal analysis revealed a dynamic ECM fungal community with many interspecific interactions taking place, despite the homogeneity of the host community. The spatial pattern of mycorrhizas was influenced by the underlying distribution of fine roots, but local root density was in turn influenced by the presence of specific fungal species. PMID:20202132

  13. A quick and precise technique for identifying ectomycorrhizas by PCR.

    PubMed

    Iotti, Mirco; Zambonelli, Alessandra

    2006-01-01

    A rapid procedure was developed to amplify ITS fragments directly from Tuber ectomycorrhizas either synthesized in a greenhouse or collected from the field. The addition of Bovine Serum Albumin (BSA) to the reaction mixtures overcame the presence of reaction inhibitors present in fungal and root cells, and enabled the amplification of the ITS regions directly from ectomycorrhizal tissues. This method is cheaper and less time-consuming than conventional procedures, and reduces the time required from 1-4 h to a few minutes. It is also much more sensitive, allowing the identification of just a small fragment of a mycorrhizal root tip. Because of this it is possible to select only the target fungal tissue and hence minimise the risk of contamination by saprobic or other mycorrhizal species. The method also avoids the use of toxic or hazardous substances. This method could have a wider application in other areas of applied mycology. PMID:16376063

  14. Assessing the Effect of Disturbances on Ectomycorrhiza Diversity

    PubMed Central

    Iordache, Virgil; Gherghel, Felicia; Kothe, Erika

    2009-01-01

    Ectomycorrhiza (ECM) communities can be described on a species level or on a larger scale at an ecosystem level. Here we show that the species level approach of successional processes in ECM communities is not appropriate for understanding the diversity patterns of ECM communities at contaminated sites. An ecosystem based approach improves predictability since different biotic and abiotic factors are included. However, it still does not take into account the hierarchical structure of the ecosystem. We suggest that diversity patterns of ECMs communities in forests can best be investigated at three levels. This hypothetical approach for investigation can be tested at sites of secondary succession in areas contaminated with metals. Once the diversity patterns are appropriately described by a hierarchical ecosystem approach, to the species level is used to explain these patterns by populational and ecotoxicological mechanisms. PMID:19440391

  15. Assessing the effect of disturbances on ectomycorrhiza diversity.

    PubMed

    Iordache, Virgil; Gherghel, Felicia; Kothe, Erika

    2009-02-01

    Ectomycorrhiza (ECM) communities can be described on a species level or on a larger scale at an ecosystem level. Here we show that the species level approach of successional processes in ECM communities is not appropriate for understanding the diversity patterns of ECM communities at contaminated sites. An ecosystem based approach improves predictability since different biotic and abiotic factors are included. However, it still does not take into account the hierarchical structure of the ecosystem. We suggest that diversity patterns of ECMs communities in forests can best be investigated at three levels. This hypothetical approach for investigation can be tested at sites of secondary succession in areas contaminated with metals. Once the diversity patterns are appropriately described by a hierarchical ecosystem approach, to the species level is used to explain these patterns by populational and ecotoxicological mechanisms. PMID:19440391

  16. Ectomycorrhizas and water relations of trees: a review.

    PubMed

    Lehto, Tarja; Zwiazek, Janusz J

    2011-02-01

    There is plenty of evidence for improved nutrient acquisition by ectomycorrhizas in trees; however, their role in water uptake is much less clear. In addition to experiments showing improved performance during drought by mycorrhizal plants, there are several studies showing reduced root hydraulic conductivity and reduced water uptake in mycorrhizal roots. The clearest direct mechanism for increased water uptake is the increased extension growth and absorbing surface area, particularly in fungal species with external mycelium of the long-distance exploration type. Some studies have found increased aquaporin function and, consequently, increased root hydraulic conductivity in ectomycorrhizal plants while other studies showed no effect of ectomycorrhizal associations on root water flow properties. The aquaporin function of the fungal hyphae is also likely to be important for the uptake of water by the ectomycorrhizal plant, but more work needs to be done in this area. The best-known indirect mechanism for mycorrhizal effects on water relations is improved nutrient status of the host. Others include altered carbohydrate assimilation via stomatal function, possibly mediated by changes in growth regulator balance; increased sink strength in mycorrhizal roots; antioxidant metabolism; and changes in osmotic adjustment. None of these possibilities has been sufficiently explored. The mycorrhizal structure may also reduce water movement because of different fine root architecture (thickness), cell wall hydrophobicity or the larger number of membranes that water has to cross on the way from the soil to the xylem. In future studies, pot experiments comparing mycorrhizal and nonmycorrhizal plants will still be useful in studying well-defined physiological details. However, the quantitative importance of ectomycorrhizas for tree water uptake and water relations can only be assessed by field studies using innovative approaches. Hydraulic redistribution can support nutrient uptake

  17. Floral and insect-induced volatile formation in Arabidopsis lyrata ssp. petraea, a perennial, outcrossing relative of A. thaliana.

    PubMed

    Abel, Christian; Clauss, Maria; Schaub, Andrea; Gershenzon, Jonathan; Tholl, Dorothea

    2009-06-01

    Volatile organic compounds have been reported to serve some important roles in plant communication with other organisms, but little is known about the biological functions of most of these substances. To gain insight into this problem, we have compared differences in floral and vegetative volatiles between two closely related plant species with different life histories. The self-pollinating annual, Arabidopsis thaliana, and its relative, the outcrossing perennial, Arabidopsis lyrata, have markedly divergent life cycles and breeding systems. We show that these differences are in part reflected in the formation of distinct volatile mixtures in flowers and foliage. Volatiles emitted from flowers of a German A. lyrata ssp. petraea population are dominated by benzenoid compounds in contrast to the previously described sesquiterpene-dominated emissions of A. thaliana flowers. Flowers of A. lyrata ssp. petraea release benzenoid volatiles in a diurnal rhythm with highest emission rates at midday coinciding with observed visitations of pollinating insects. Insect feeding on leaves of A. lyrata ssp. petraea causes a variable release of the volatiles methyl salicylate, C11- and C16-homoterpenes, nerolidol, plus the sesquiterpene (E)-beta-caryophyllene, which in A. thaliana is emitted exclusively from flowers. An insect-induced gene (AlCarS) with high sequence similarity to the florally expressed (E)-beta-caryophyllene synthase (AtTPS21) from A. thaliana was identified from individuals of a German A. lyrata ssp. petraea population. Recombinant AlCarS converts the sesquiterpene precursor, farnesyl diphosphate, into (E)-beta-caryophyllene with alpha-humulene and alpha-copaene as minor products indicating its close functional relationship to the A. thaliana AtTPS21. Differential regulation of these genes in flowers and foliage is consistent with the different functions of volatiles in the two Arabidopsis species. PMID:19322583

  18. Imprints of Natural Selection Along Environmental Gradients in Phenology-Related Genes of Quercus petraea

    PubMed Central

    Alberto, Florian J.; Derory, Jérémy; Boury, Christophe; Frigerio, Jean-Marc; Zimmermann, Niklaus E.; Kremer, Antoine

    2013-01-01

    We explored single nucleotide polymorphism (SNP) variation in candidate genes for bud burst from Quercus petraea populations sampled along gradients of latitude and altitude in Western Europe. SNP diversity was monitored for 106 candidate genes, in 758 individuals from 32 natural populations. We investigated whether SNP variation reflected the clinal pattern of bud burst observed in common garden experiments. We used different methods to detect imprints of natural selection (FST outlier, clinal variation at allelic frequencies, association tests) and compared the results obtained for the two gradients. FST outlier SNPs were found in 15 genes, 5 of which were common to both gradients. The type of selection differed between the two gradients (directional or balancing) for 3 of these 5. Clinal variations were observed for six SNPs, and one cline was conserved across both gradients. Association tests between the phenotypic or breeding values of trees and SNP genotypes identified 14 significant associations, involving 12 genes. The results of outlier detection on the basis of population differentiation or clinal variation were not very consistent with the results of association tests. The discrepancies between these approaches may reflect the different hierarchical levels of selection considered (inter- and intrapopulation selection). Finally, we obtained evidence for convergent selection (similar for gradients) and clinal variation for a few genes, suggesting that comparisons between parallel gradients could be used to screen for major candidate genes responding to natural selection in trees. PMID:23934884

  19. Effects of ozone, sulfur dioxide and acidic precipitation on formation of ectomycorrhizae by forest tree seedlings

    SciTech Connect

    Keane, K.D.; Manning, W.J. )

    1987-01-01

    Gaseous air pollutants and acidic precipitation impact upon forest ecosystems. Forest declines in central Europe and, more recently, in the northeastern United States have been largely attributed to these air pollutants. The possible direct effects of these air pollutants, such as foliar injury and growth reductions, on forests have been extensively investigated. Potential secondary effects of air pollutants, on tree root processes such as ectomycorrhizae, have received much less attention. These secondary effects are addressed in this paper. Ectomycorrhizae are symbiotic fungal-root associations in which fungal hyphae penetrate the cortex of plant roots intercellularly to form a structure called Hartig net. Mycorrhizal fungi typically become associated with the fine feeder roots of their hosts. The ectomyocorrhizae, once associated, results in distinct morphological changes in these roots. Ectomycorrhizae are known to associate with most tree species.

  20. Nutrient amounts of ectomycorrhizae analysed by EDX using ESEM and ICP.

    PubMed

    Rumberger, Michael D; Lentzsch, Peter; Münzenberger, Babette; Hüttl, Reinhard F

    2005-06-01

    Energy-dispersive X-ray (EDX) analysis coupled with an environmental scanning electron microscope (ESEM) was tested as an alternative to the inductively coupled argon plasma (ICP) spectrometer method for nutrient analyses of ectomycorrhizae. The results of EDX-ESEM and ICP were compared for 12 ectomycorrhizal morphotypes collected in beech and Scots pine forests in northern Brandenburg. The amounts of Al, Ca, Mg and S analysed in the outer hyphal layers of the sheath with the EDX-ESEM technique correlated well with the amounts of these elements in the whole mycorrhiza as assessed by ICP. For the elements P and K, no such correlation existed, indicating an uneven distribution of these elements in the ectomycorrhiza. It is concluded that the EDX-ESEM technique could be a useful and reliable tool for the analysis of nutrient elements in ectomycorrhizae, especially for studies focussing on small-scale soil heterogeneity or on infrequent morphotypes. PMID:15726433

  1. Ectomycorrhizas of Cortinarius helodes and Gyrodon monticola with Alnus acuminata from Argentina.

    PubMed

    Becerra, Alejandra; Nouhra, Eduardo; Daniele, Graciela; Domínguez, Laura; McKay, Donaraye

    2005-01-01

    Field ectomycorrhizas of Cortinarius helodes Moser, Matheny & Daniele (sp. nov) and Gyrodon monticola Sing. on Alnus acuminata Kunth (Andean alder, aliso del cerro) are described based on morphological and anatomical features. Ectomycorrhizal roots were sampled beneath fruitbodies of C. helodes and G. monticola from two homogeneous A. acuminata forest sites located in Tucuman and Catamarca Provinces in Argentina. C. helodes ectomycorrhizas showed a thick white to beige mantle exuding a milky juice when injured, were bluish toward the apex, and had hyphal strands in the mantle. G. monticola ectomycorrhizas showed some conspicuous features like highly differentiated rhizomorphs, inflated brown cells on the mantle surface, and hyaline and brown emanating hyphae with dolipores. Restriction fragment length polymorphism analysis of the nuclear rDNA internal transcribed spacer provided a distinctive profile for each of the collections of fruitbodies and the mycorrhizal morphotypes. PMID:14648309

  2. Enhancing our understanding of anatomical diversity in Tomentella ectomycorrhizas: characterization of six new morphotypes.

    PubMed

    Jakucs, Erzsébet; Erős-Honti, Zsolt; Seress, Diána; Kovács, Gábor M

    2015-08-01

    Ectomycorrhizas (ECM) formed by Tomentella species (Thelephorales, Basidiomycota) were collected in beech forests of Hungary and studied using anatomical and molecular phylogenetic methods. The mycobionts were identified by analysing the sequences of nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) regions together with sequences obtained from public databases. At the sampling plots, we found the occurrence of 11 Tomentella morphotypes. Among these, six morphotypes (four identified, Tomentella atroarenicolor, Tomentella bryophila, Tomentella lapida, Tomentella subclavigera, and two unidentified) were morpho-anatomically characterized for the first time. Although the six morphotypes differed anatomically from each other and from Tomentella ectomycorrhizas described previously, they shared anatomical features common to tomentelloid ectomycorrhizas fungi. These results expand our understanding of the diversity of this widely distributed ectomycorrhizal genus. PMID:25564437

  3. Soil bacterial diversity in a loblolly pine plantation: influence of ectomycorrhizas and fertilization.

    PubMed

    Burke, David J; Kretzer, Annette M; Rygiewicz, Paul T; Topa, Mary A

    2006-09-01

    We studied the effect of ectomycorrhizas and fertilization on soil microbial communities associated with roots of 10-year-old loblolly pine. Ectomycorrhizas were identified using a combination of community terminal restriction fragment profiling and matching of individual terminal restriction fragments to those produced from ectomycorrhizal clones and sequences recovered from roots and sporocarps. Differences between bacterial communities were initially determined using cluster analysis on community terminal restriction fragment profiles and through subsequent recovery of 16S rDNA clones. Analysis of bacterial clones revealed that terminal restriction fragment length was often shared between taxonomically dissimilar bacterial types. Consequently, we could not reliably infer the identity of peaks in the bacterial community profile with some exceptions, notably chloroplast rDNA that generated an approximate peak size of 80.2 bp. Fertilization increased the frequency of a Piloderma-like ectomycorrhiza. However, we did not detect clear effects of fertilization or the presence of viable ectomycorrhizas on bacterial communities. Bacterial communities seemed to be determined largely by the carbon and nitrogen content of soil. These results suggest that important soil microbial groups respond differently to soil conditions and management practices, with ectomycorrhizal communities reflecting past nutrient conditions and bacterial communities reflecting current environmental conditions of soil microsites. PMID:16907755

  4. Mixotrophy of Platanthera minor, an orchid associated with ectomycorrhiza-forming Ceratobasidiaceae fungi.

    PubMed

    Yagame, Takahiro; Orihara, Takamichi; Selosse, Marc-André; Yamato, Masahide; Iwase, Koji

    2012-01-01

    • We investigated the fungal symbionts and carbon nutrition of a Japanese forest photosynthetic orchid, Platanthera minor, whose ecology suggests a mixotrophic syndrome, that is, a mycorrhizal association with ectomycorrhiza (ECM)-forming fungi and partial exploitation of fungal carbon. • We performed molecular identification of symbionts by PCR amplifications of the fungal ribosomal DNA on hyphal coils extracted from P. minor roots. We tested for a (13)C and (15)N enrichment characteristic of mixotrophic plants. We also tested the ectomycorrhizal abilities of orchid symbionts using a new protocol of direct inoculation of hyphal coils onto roots of Pinus densiflora seedlings. • In phylogenetic analyses, most isolated fungi were close to ECM-forming Ceratobasidiaceae clades previously detected from a few fully heterotrophic orchids or environmental ectomycorrhiza surveys. The direct inoculation of fungal coils of these fungi resulted in ectomycorrhiza formation on P. densiflora seedlings. Stable isotope analyses indicated mixotrophic nutrition of P. minor, with fungal carbon contributing from 50% to 65%. • This is the first evidence of photosynthetic orchids associated with ectomycorrhizal Ceratobasidiaceae taxa, confirming the evolution of mixotrophy in the Orchideae orchid tribe, and of ectomycorrhizal abilities in the Ceratobasidiaceae. Our new ectomycorrhiza formation technique may enhance the study of unculturable orchid mycorrhizal fungi. PMID:21995447

  5. [Two cases of homicide from the pre-ceramic neolithic era of Arabia Petraea].

    PubMed

    Röhrer-Ertl, O; Frey, K W

    1987-01-01

    Human remains from Basta 1 (P PN B, 6. Mill. B.C.) and Sabra 1 (Khiamian, 7. Mill. B.C.) were prepared and studied; the results show that Basta 1 was a permanent settlement and Sabra 1 was a temporary summer camp. Both settlements are located in Arabia Petraea. Basta 1, No. 3477: The calvarium of a boy, aged 8 to 9 a, from Basta 1 was studied. The race can be determined as orientalide, according v. Eickstedt's classification. The boy was killed; as evidence by 2 blows to the skull occurring while he was alive. The cause of death has been reconstructed, using parallels taken from ethnological and forensic medical research. First, the boy received a light blow on the left forehead, with a sharp weapon. The authors present as a working hypothesis that the motivation for the death was rape, taking place as the boy was (probably) in a semi-conscious state. After recovering and rising to his feet, the boy suffered a deadly blow on the back of the skull (rabbit punch). A blunt instrument was used for the second blow. The body lay where it fell over 1 a or more; afterwards it was found by members of his own group. They removed the calvarium and buried it in their permanent settlement. The manner in which burial took place, would seem to indicate, that no further religious or ritual ceremony was involved. This type of crime has been observed e.g. as occurring among purely male groups-such as temporary herdsmen. In case of the boy from Basta 1, this would the earliest evidence for the occurrence of this type of sexual delinquency in prehistoric times. Sabra 1, No. 4088: Skull fragments of 2 individuals were recovered from a camp fire shifted by humans, in Sabra 1. Individual I is a male, aged 25 to 30 a; Individual II is a female of 25 to 30 a (or perhaps even younger). The examination showed that the bone fragments had been subjected to temperatures less than or equal to 200 degrees C (examination of bone material) and around 100 degrees C (evidence of charcoal material

  6. Ectomycorrhizae between Alnus acuminata H.B.K. and Naucoria escharoides (Fr.:Fr.) Kummer from Argentina.

    PubMed

    Becerra, Alejandra; Daniele, Graciela; Domínguez, Laura; Nouhra, Eduardo; Horton, Tom

    2002-04-01

    Field ectomycorrhizae of Naucoria escharoides on Alnus acuminata ("andean alder", "aliso del cerro") are described in detail for the first time. Naturally occurring ectomycorrhizal roots were sampled beneath sporocarps of N. escharoides. The samples were taken from four natural forest plots at two homogeneous A. acuminata sites (Tucumán and Catamarca Provinces, Argentina). The ectomycorrhizae were characterized morphologically and compared by means of PCR/RFLP analysis of the internal transcribed spacer region of the nuclear rDNA. The most important morphological features of the ectomycorrhizae are a white to pale yellow mantle, simple to monopodial branches, hyaline emanating hyphae, abundant hyphal bundles emerging more or less perpendicularly from a plectenchymatous mantle, and an acute or rounded apex with or without a mantle. N. escharoides fruitbodies have white basal mycelium with emanating hyphae similar to those of andean alder ectomycorrhizae. The RFLP profiles of sporocarps and mycorrhizae were the same. PMID:12035728

  7. UV light impact on ellagitannins and wood surface colour of European oak ( Quercus petraea and Quercus robur)

    NASA Astrophysics Data System (ADS)

    Zahri, S.; Belloncle, C.; Charrier, F.; Pardon, P.; Quideau, S.; Charrier, B.

    2007-03-01

    Two European oak species ( Q. petraea and Q. robur) have a high content of phenols which may participate in the alteration of colour upon UV irradiation. To study the photodegradation process of oak surfaces, the two oak species extractives, vescalagin, castalagin, ellagic acid and gallic acid were analysed quantitatively by HPLC before and after UV irradiation. Irradiation time was altered between 3, 24, 72, 96, 120, 144, 192 and 216 h. In parallel, any colour changes of Oak wood surface was followed after 120 h of UV-irradiation by measuring CIELAB parameters (DL*, Da*, Db* and DE*). We observed that 60% of total phenol content of extractives decreased after the maximal exposure time. Our findings also showed that castalagin and gallic acid were destroyed after 216 h and vescalagin and ellagic acid after 72 h. This study proves the photosenibility of oakwood extractives which, supplementary to lignin degradation, would strongly result in the discolouration of oak heartwood.

  8. Fine-scale distribution of pine ectomycorrhizas and their extramatrical mycelium.

    PubMed

    Genney, David R; Anderson, Ian C; Alexander, Ian J

    2006-01-01

    In order to clarify the functional role of individual ectomycorrhizal (EcM) fungal species in the field, we need to relate their abundance and distribution as mycorrhizas to their abundance and distribution as extramatrical mycelium (EMM). We divided each of four 20 cm x 20 cm x 2 cm slices of pine forest soil into 100 cubes of 2 cm x 2 cm. For each cube, ectomycorrhizas were identified and the presence of EMM of the EcM fungi recorded as ectomycorrhizas was determined by terminal restriction fragment length polymorphism (T-RFLP) analysis of ITS rDNA. Ectomycorrhizas and EMM of seven EcM species were mapped. Spatial segregation of mycorrhizas and EMM was evident and some species produced their EMM in different soil layers from their mycorrhizas. The spatial relationship between mycorrhizas and their EMM generally conformed to their reported exploration types, but EMM of smooth types (e.g. Lactarius rufus) was more frequent than expected. Different EcM fungi foraged at different spatial scales. PMID:16608462

  9. Ascomycetes associated with ectomycorrhizas: molecular diversity and ecology with particular reference to the Helotiales.

    PubMed

    Tedersoo, Leho; Pärtel, Kadri; Jairus, Teele; Gates, Genevieve; Põldmaa, Kadri; Tamm, Heidi

    2009-12-01

    Mycorrhizosphere microbes enhance functioning of the plant-soil interface, but little is known of their ecology. This study aims to characterize the ascomycete communities associated with ectomycorrhizas in two Tasmanian wet sclerophyll forests. We hypothesize that both the phyto- and mycobiont, mantle type, soil microbiotope and geographical distance affect the diversity and occurrence of the associated ascomycetes. Using the culture-independent rDNA sequence analysis, we demonstrate a high diversity of these fungi on different hosts and habitats. Plant host has the strongest effect on the occurrence of the dominant species and community composition of ectomycorrhiza-associated fungi. Root endophytes, soil saprobes, myco-, phyto- and entomopathogens contribute to the ectomycorrhiza-associated ascomycete community. Taxonomically these Ascomycota mostly belong to the orders Helotiales, Hypocreales, Chaetothyriales and Sordariales. Members of Helotiales from both Tasmania and the Northern Hemisphere are phylogenetically closely related to root endophytes and ericoid mycorrhizal fungi, suggesting their strong ecological and evolutionary links. Ectomycorrhizal mycobionts from Australia and the Northern Hemisphere are taxonomically unrelated to each other and phylogenetically distant to other helotialean root-associated fungi, indicating independent evolution. The ubiquity and diversity of the secondary root-associated fungi should be considered in studies of mycorrhizal communities to avoid overestimating the richness of true symbionts. PMID:19671076

  10. Ectomycorrhizas associated with a relict population of Dryas octopetala in the Burren, western Ireland. I. Distribution of ectomycorrhizas in relation to vegetation and soil characteristics.

    PubMed

    Harrington, Thomas J; Mitchell, Derek T

    2005-09-01

    The distribution of ectomycorrhizas on Dryas octopetala L in grass heaths of the 450 km2 karst region known as the Burren in Western Ireland was examined in relation to soil factors and vegetation type. Ectomycorrhizas were identified or characterised from 56 soil cores from 30 sites, and the occurrence of each ectomycorrhizal (EM) type was quantified by estimating the total length of mycorrhizal tips of each type. Soil organic matter, total nitrogen, extractable phosphorus, pH and depth were the soil factors determined. In total, 24 EM types were recorded. The EM community of Dryas roots was significantly more species-rich in one vegetation type--Hyperico-Dryadetum--than in others (Arctostaphylo-Dryadetum or Asperulo-Seslerietum). Multiple linear regression analyses indicated that soil organic matter and soil depth explained a significant portion of the variation in EM abundance, while soil organic matter and extractable phosphorus explained a significant portion of the variation in EM diversity. Canonical correspondence analysis showed that some individual EM types (e.g. Craterellus lutescens, Cenococcum geophilum, Tomentella sp., Boletus sp.) exhibited distinct soil preferences, most markedly in relation to soil organic matter, which, in this analysis, was the main significant soil variable distinguishing the three vegetation types. PMID:15726435

  11. Seasonal Changes Affect Root Prunasin Concentration in Prunus serotina and Override Species Interactions between P. serotina and Quercus petraea.

    PubMed

    Robakowski, Piotr; Bielinis, Ernest; Stachowiak, Jerzy; Mejza, Iwona; Bułaj, Bartosz

    2016-03-01

    The allocation of resources to chemical defense can decrease plant growth and photosynthesis. Prunasin is a cyanogenic glycoside known for its role in defense against herbivores and other plants. In the present study, fluctuations of prunasin concentrations in roots of Prunus serotina seedlings were hypothesized to be: (1) dependent on light, air temperature, and humidity; (2) affected by competition between Prunus serotina and Quercus petraea seedlings, with mulching with Prunus serotina leaves; (3) connected with optimal allocation of resources. For the first time, we determined prunasin concentration in roots on several occasions during the vegetative season. The results indicate that seasonal changes have more pronounced effects on prunasin concentration than light regime and interspecific competition. Prunus serotina invested more nitrogen in the synthesis of prunasin under highly restricted light conditions than in higher light environments. In full sun, prunasin in roots of Prunus serotina growing in a monoculture was correlated with growth and photosynthesis, whereas these relationships were not found when interspecific competition with mulching was a factor. The study demonstrates that prunasin concentration in Prunus serotina roots is the result of species-specific adaptation, light and temperature conditions, ontogenetic shift, and, to a lesser extent, interspecific plant-plant interactions. PMID:26961681

  12. Characterization of the Tuber borchii nitrate reductase gene and its role in ectomycorrhizae.

    PubMed

    Guescini, M; Pierleoni, R; Palma, F; Zeppa, S; Vallorani, L; Potenza, L; Sacconi, C; Giomaro, G; Stocchi, V

    2003-09-01

    The nitrate assimilation pathway represents a useful model system in which to study the contribution of a mycorrhizal fungus to the nitrogen nutrition of its host plant. In the present work we cloned and characterized the nitrate reductase gene (tbnr1) from Tuber borchii. The coding region of tbnr1 is 2,787 nt in length, and it encodes a protein of 929 amino acids. Biochemical and Northern-blot analyses revealed that nitrate assimilation in T. borchii is an inducible system that responds mainly to nitrate. Furthermore, we cloned a nitrate reductase cDNA (tpnr1) from Tilia platyphyllos to set up a quantitative real-time PCR assay that would allow us to determine the fungal contribution to nitrate assimilation in ectomycorrhizal tissue. Using this approach we demonstrated that the level of tbnr1 expression in ectomycorhizae is eight times higher than in free-living mycelia, whereas tpnr1 transcription was found to be down-regulated after the establishment of the symbiosis. Enzymatic assays showed that NADPH-dependent nitrite formation markedly increases in ectomycorrhizae. These findings imply that the fungal partner plays a fundamental role in nitrate assimilation by ectomycorrhizae. Amino acid determination by HPLC revealed higher levels of glutamate, glutamine and asparagine in symbiotic tissues compared with mycelial controls, thus suggesting that these amino acids may represent the compounds that serve to transfer nitrogen to the host plant. PMID:12898221

  13. Persistence and detection of black truffle ectomycorrhizas in plantations: comparison between two field detection methods.

    PubMed

    Sánchez, Sergio; Ágreda, Teresa; Águeda, Beatriz; Martín, María; de Miguel, Ana María; Barriuso, Juan

    2014-04-01

    Owners of black truffle (Tuber melanosporum) plantations are concerned about the persistence of its mycorrhizas and mycelium in the soil, especially until the appearance of the "truffle burn" areas and the triggering of sporocarp production, at least 5-7 years after planting truffle-inoculated seedlings. During this period, the farmer does not know whether his management is promoting black truffle development. To study the presence and abundance of T. melanosporum ectomycorrhizas in plantations, two sampling methods, direct sampling of root tips and soil core collection, are compared by analyzing 48 evergreen oak trees (Quercus ilex) inoculated with truffle. Those trees are grouped by age (<6, 6-9, >9 years old) and presence or absence of truffle production. T. melanosporum was present in 46 out of the 48 studied trees, and its ectomycorrhizas appeared in 65% of the ectomycorrhizal tips. Its abundance is significantly higher with productive trees and young trees. Direct sampling of root tips and soil core collection were equally effective in detecting this species, although soil core collection proved a better method to also evaluate ectomycorrhizal fungal diversity. To detect the presence of T. melanosporum in a given plantation, three samples suffice, with a single sample per random tree. Although the presence of mycorrhizas is not a sure sign of the future success of a black truffle plantation, its absence influences managers as to whether to continue culturing truffles in a plantation. PMID:24509698

  14. Biosynthesis and Secretion of Indole-3-Acetic Acid and Its Morphological Effects on Tricholoma vaccinum-Spruce Ectomycorrhiza.

    PubMed

    Krause, Katrin; Henke, Catarina; Asiimwe, Theodore; Ulbricht, Andrea; Klemmer, Sandra; Schachtschabel, Doreen; Boland, Wilhelm; Kothe, Erika

    2015-10-01

    Fungus-derived indole-3-acetic acid (IAA), which is involved in development of ectomycorrhiza, affects both partners, i.e., the tree and the fungus. The biosynthesis pathway, excretion from fungal hyphae, the induction of branching in fungal cultures, and enhanced Hartig net formation in mycorrhiza were shown. Gene expression studies, incorporation of labeled compounds into IAA, heterologous expression of a transporter, and bioinformatics were applied to study the effect of IAA on fungal morphogenesis and on ectomycorrhiza. Tricholoma vaccinum produces IAA from tryptophan via indole-3-pyruvate, with the last step of this biosynthetic pathway being catalyzed by an aldehyde dehydrogenase. The gene ald1 was found to be highly expressed in ectomycorrhiza and induced by indole-3-acetaldehyde. The export of IAA from fungal cells is supported by the multidrug and toxic extrusion (MATE) transporter Mte1 found in T. vaccinum. The addition of IAA and its precursors induced elongated cells and hyphal ramification of mycorrhizal fungi; in contrast, in saprobic fungi such as Schizophyllum commune, IAA did not induce morphogenetic changes. Mycorrhiza responded by increasing its Hartig net formation. The IAA of fungal origin acts as a diffusible signal, influencing root colonization and increasing Hartig net formation in ectomycorrhiza. PMID:26231639

  15. Biosynthesis and Secretion of Indole-3-Acetic Acid and Its Morphological Effects on Tricholoma vaccinum-Spruce Ectomycorrhiza

    PubMed Central

    Krause, Katrin; Henke, Catarina; Asiimwe, Theodore; Ulbricht, Andrea; Klemmer, Sandra; Schachtschabel, Doreen; Boland, Wilhelm

    2015-01-01

    Fungus-derived indole-3-acetic acid (IAA), which is involved in development of ectomycorrhiza, affects both partners, i.e., the tree and the fungus. The biosynthesis pathway, excretion from fungal hyphae, the induction of branching in fungal cultures, and enhanced Hartig net formation in mycorrhiza were shown. Gene expression studies, incorporation of labeled compounds into IAA, heterologous expression of a transporter, and bioinformatics were applied to study the effect of IAA on fungal morphogenesis and on ectomycorrhiza. Tricholoma vaccinum produces IAA from tryptophan via indole-3-pyruvate, with the last step of this biosynthetic pathway being catalyzed by an aldehyde dehydrogenase. The gene ald1 was found to be highly expressed in ectomycorrhiza and induced by indole-3-acetaldehyde. The export of IAA from fungal cells is supported by the multidrug and toxic extrusion (MATE) transporter Mte1 found in T. vaccinum. The addition of IAA and its precursors induced elongated cells and hyphal ramification of mycorrhizal fungi; in contrast, in saprobic fungi such as Schizophyllum commune, IAA did not induce morphogenetic changes. Mycorrhiza responded by increasing its Hartig net formation. The IAA of fungal origin acts as a diffusible signal, influencing root colonization and increasing Hartig net formation in ectomycorrhiza. PMID:26231639

  16. Contrasting patterns of genetic structuring in natural populations of Arabidopsis lyrata Subsp. petraea across different regions in northern Europe.

    PubMed

    Falahati-Anbaran, Mohsen; Lundemo, Sverre; Ansell, Stephen W; Stenøien, Hans K

    2014-01-01

    Level and partitioning of genetic diversity is expected to vary between contrasting habitats, reflecting differences in strength of ecological and evolutionary processes. Therefore, it is necessary to consider processes acting on different time scales when trying to explain diversity patterns in different parts of species' distributions. To explore how historical and contemporary factors jointly may influence patterns of genetic diversity and population differentiation, we compared genetic composition in the perennial herb Arabidopsis lyrata ssp. petraea from the northernmost parts of its distribution range on Iceland to that previously documented in Scandinavia. Leaf tissue and soil were sampled from ten Icelandic populations of A. lyrata. Seedlings were grown from soil samples, and tissue from above-ground and seed bank individuals were genotyped with 21 microsatellite markers. Seed bank density in Icelandic populations was low but not significantly different from that observed in Norwegian populations. While within-population genetic diversity was relatively high on Iceland (H(E) = 0.35), among-population differentiation was low (F(ST) = 0.10) compared to Norwegian and Swedish populations. Population differentiation was positively associated with geographical distance in both Iceland and Scandinavia, but the strength of this relationship varied between regions. Although topography and a larger distribution range may explain the higher differentiation between mountainous Norwegian relative to lowland populations in Sweden, these factors cannot explain the lower differentiation in Icelandic compared to Swedish populations. We propose that low genetic differentiation among Icelandic populations is not caused by differences in connectivity, but is rather due to large historical effective population sizes. Thus, rather than contemporary processes, historical factors such as survival of Icelandic lineages in northern refugia during the last glacial period may have

  17. Early Summer Drought Stress During the First Growing Year Stimulates Extra Shoot Growth in Oak Seedlings (Quercus petraea).

    PubMed

    Turcsán, Arion; Steppe, Kathy; Sárközi, Edit; Erdélyi, Éva; Missoorten, Marc; Mees, Ghislain; Mijnsbrugge, Kristine V

    2016-01-01

    More severe summer droughts are predicted for mid-latitudes in Europe. To evaluate the impact on forest ecosystems and more specifically on forest regeneration, we studied the response to summer drought in oak seedlings (Quercus petraea). Acorns were collected from different mother trees in three stands in Belgium, sown in pots and grown in non-heated greenhouse conditions. We imposed drought on the seedlings in early summer by first watering the pots to saturation and then stopping any watering. Weight of the pots and stomatal conductance were regularly measured. Re-watering followed this drought period of 5 weeks. Height of the seedlings and apical bud development were observed. Stomatal resistance increased toward the end of the experiment in the drought-treated group and was restored after re-watering. The seedlings from the drought treatment displayed a higher probability to produce additional shoot growth after re-watering (p ≤ 0.05). A higher competition for water (two plants per pot) increased this chance. Although this chance was also higher for smaller seedlings, the actual length of the extra growth after re-watering was higher for larger seedlings (p ≤ 0.01). Both in the drought-treated and in the control group the autochthonous provenance growing on a xeric site produced less extra shoots compared to the two other provenances. Finally, stressed plants showed less developed apical buds compared to the control group after re-watering, suggesting a phenological effect on the growth cycle of oaks (p ≤ 0.0001). The higher chance for an extra shoot growth after the drought period can be considered as a compensation for the induced growth arrest during the drought period. PMID:26941760

  18. Early Summer Drought Stress During the First Growing Year Stimulates Extra Shoot Growth in Oak Seedlings (Quercus petraea)

    PubMed Central

    Turcsán, Arion; Steppe, Kathy; Sárközi, Edit; Erdélyi, Éva; Missoorten, Marc; Mees, Ghislain; Mijnsbrugge, Kristine V.

    2016-01-01

    More severe summer droughts are predicted for mid-latitudes in Europe. To evaluate the impact on forest ecosystems and more specifically on forest regeneration, we studied the response to summer drought in oak seedlings (Quercus petraea). Acorns were collected from different mother trees in three stands in Belgium, sown in pots and grown in non-heated greenhouse conditions. We imposed drought on the seedlings in early summer by first watering the pots to saturation and then stopping any watering. Weight of the pots and stomatal conductance were regularly measured. Re-watering followed this drought period of 5 weeks. Height of the seedlings and apical bud development were observed. Stomatal resistance increased toward the end of the experiment in the drought-treated group and was restored after re-watering. The seedlings from the drought treatment displayed a higher probability to produce additional shoot growth after re-watering (p ≤ 0.05). A higher competition for water (two plants per pot) increased this chance. Although this chance was also higher for smaller seedlings, the actual length of the extra growth after re-watering was higher for larger seedlings (p ≤ 0.01). Both in the drought-treated and in the control group the autochthonous provenance growing on a xeric site produced less extra shoots compared to the two other provenances. Finally, stressed plants showed less developed apical buds compared to the control group after re-watering, suggesting a phenological effect on the growth cycle of oaks (p ≤ 0.0001). The higher chance for an extra shoot growth after the drought period can be considered as a compensation for the induced growth arrest during the drought period. PMID:26941760

  19. Contrasting Patterns of Genetic Structuring in Natural Populations of Arabidopsis lyrata Subsp. petraea across Different Regions in Northern Europe

    PubMed Central

    Falahati-Anbaran, Mohsen; Lundemo, Sverre; Ansell, Stephen W.; Stenøien, Hans K.

    2014-01-01

    Level and partitioning of genetic diversity is expected to vary between contrasting habitats, reflecting differences in strength of ecological and evolutionary processes. Therefore, it is necessary to consider processes acting on different time scales when trying to explain diversity patterns in different parts of species' distributions. To explore how historical and contemporary factors jointly may influence patterns of genetic diversity and population differentiation, we compared genetic composition in the perennial herb Arabidopsis lyrata ssp. petraea from the northernmost parts of its distribution range on Iceland to that previously documented in Scandinavia. Leaf tissue and soil were sampled from ten Icelandic populations of A. lyrata. Seedlings were grown from soil samples, and tissue from above-ground and seed bank individuals were genotyped with 21 microsatellite markers. Seed bank density in Icelandic populations was low but not significantly different from that observed in Norwegian populations. While within-population genetic diversity was relatively high on Iceland (HE = 0.35), among-population differentiation was low (FST = 0.10) compared to Norwegian and Swedish populations. Population differentiation was positively associated with geographical distance in both Iceland and Scandinavia, but the strength of this relationship varied between regions. Although topography and a larger distribution range may explain the higher differentiation between mountainous Norwegian relative to lowland populations in Sweden, these factors cannot explain the lower differentiation in Icelandic compared to Swedish populations. We propose that low genetic differentiation among Icelandic populations is not caused by differences in connectivity, but is rather due to large historical effective population sizes. Thus, rather than contemporary processes, historical factors such as survival of Icelandic lineages in northern refugia during the last glacial period may have

  20. Regeneration Patterns of European Oak Species (Quercus petraea (Matt.) Liebl., Quercus robur L.) in Dependence of Environment and Neighborhood

    PubMed Central

    Annighöfer, Peter; Beckschäfer, Philip; Vor, Torsten; Ammer, Christian

    2015-01-01

    Quercus robur L. (pedunculate oak) and Quercus petraea (Matt.) Liebl. (sessile oak) are two European oak species of great economic and ecological importance. Even though both oaks have wide ecological amplitudes of suitable growing conditions, forests dominated by oaks often fail to regenerate naturally. The regeneration performance of both oak species is assumed to be subject to a variety of variables that interact with one another in complex ways. The novel approach of this research was to study the effect of many ecological variables on the regeneration performance of both oak species together and identify key variables and interactions for different development stages of the oak regeneration on a large scale in the field. For this purpose, overstory and regeneration inventories were conducted in oak dominated forests throughout southern Germany and paired with data on browsing, soil, and light availability. The study was able to verify the assumption that the occurrence of oak regeneration depends on a set of variables and their interactions. Specifically, combinations of site and stand specific variables such as light availability, soil pH and iron content on the one hand, and basal area and species composition of the overstory on the other hand. Also browsing pressure was related to oak abundance. The results also show that the importance of variables and their combinations differs among the development stages of the regeneration. Light availability becomes more important during later development stages, whereas the number of oaks in the overstory is important during early development stages. We conclude that successful natural oak regeneration is more likely to be achieved on sites with lower fertility and requires constantly controlling overstory density. Initially sufficient mature oaks in the overstory should be ensured. In later stages, overstory density should be reduced continuously to meet the increasing light demand of oak seedlings and saplings

  1. Regeneration patterns of European oak species (Quercus petraea (Matt.) Liebl., Quercus robur L.) in dependence of environment and neighborhood.

    PubMed

    Annighöfer, Peter; Beckschäfer, Philip; Vor, Torsten; Ammer, Christian

    2015-01-01

    Quercus robur L. (pedunculate oak) and Quercus petraea (Matt.) Liebl. (sessile oak) are two European oak species of great economic and ecological importance. Even though both oaks have wide ecological amplitudes of suitable growing conditions, forests dominated by oaks often fail to regenerate naturally. The regeneration performance of both oak species is assumed to be subject to a variety of variables that interact with one another in complex ways. The novel approach of this research was to study the effect of many ecological variables on the regeneration performance of both oak species together and identify key variables and interactions for different development stages of the oak regeneration on a large scale in the field. For this purpose, overstory and regeneration inventories were conducted in oak dominated forests throughout southern Germany and paired with data on browsing, soil, and light availability. The study was able to verify the assumption that the occurrence of oak regeneration depends on a set of variables and their interactions. Specifically, combinations of site and stand specific variables such as light availability, soil pH and iron content on the one hand, and basal area and species composition of the overstory on the other hand. Also browsing pressure was related to oak abundance. The results also show that the importance of variables and their combinations differs among the development stages of the regeneration. Light availability becomes more important during later development stages, whereas the number of oaks in the overstory is important during early development stages. We conclude that successful natural oak regeneration is more likely to be achieved on sites with lower fertility and requires constantly controlling overstory density. Initially sufficient mature oaks in the overstory should be ensured. In later stages, overstory density should be reduced continuously to meet the increasing light demand of oak seedlings and saplings

  2. Impact of short-term and long-term elevated CO2 on emission of carbonyls from adult Quercus petraea and Carpinus betulus trees.

    PubMed

    Kreuzwieser, Jürgen; Rennenberg, Heinz; Steinbrecher, Rainer

    2006-07-01

    The study aimed to elucidate the effect of elevated CO2 in short- and long-term experiments on the emission potential of carbonyls from mature oak (Quercus petraea) and hornbeam (Carpinus betulus). The trees were investigated using a canopy crane established in a mixed forest in Switzerland. Short-term CO2 experiments were performed on single leaves with a gas exchange measuring unit by increasing CO2 in the enclosure before and during the measurements. Long-term CO2 fumigation was performed for one vegetation period by a webFACE design. Short-term as well as long-term exposure of leaves resulted in no significant changes in carbonyl exchange in neither Q. petraea nor C. betulus. Carbonyl emission was not affected by stomatal closure under elevated CO2 levels. In contrast to the emission of isoprenoids from vegetation which is thought to be reduced at elevated atmospheric CO2, the exchange of carbonyls seems to be generally unaffected under these conditions. PMID:16314012

  3. The ectomycorrhizas of Lactarius cuspidoaurantiacus and Lactarius herrerae associated with Alnus acuminata in Central Mexico.

    PubMed

    Montoya, Leticia; Bandala, Victor M; Garay-Serrano, Edith

    2015-08-01

    Two pure Alnus acuminata stands established in a montane forest in central Mexico (Puebla State) were monitored between 2010 and 2013 to confirm and recognize the ectomycorrhizal (EcM) systems of A. acuminata with Lactarius cuspidoaurantiacus and Lactarius herrerae, two recently described species. Through comparison of internal transcribed spacer (ITS) of nuclear ribosomal DNA sequences from basidiomes and ectomycorrhizas sampled in the forest stands, we confirmed their ectomycorrhizal association. The phytobiont was corroborated by comparing ITS sequences obtained from EcM root tips and leaves collected in the study site and from other sequences of A. acuminata available in Genbank. Detailed morphological and anatomical descriptions of the ectomycorrhizal systems are presented and complemented with photographs. PMID:25619188

  4. Ectomycorrhizas impede phytoremediation of polycyclic aromatic hydrocarbons (PAHs) both within and beyond the rhizosphere.

    PubMed

    Joner, Erik J; Leyval, Corinne; Colpaert, Jan V

    2006-07-01

    Exploitation of mycorrhizas to enhance phytoremediation of organic pollutants has received attention recently due to their positive effects on establishment of plants in polluted soils. Some evidence exist that ectomycorrhizas enhance the degradation of pollutants of low recalcitrance, while less easily degradable polyaromatic molecules have been degraded only by some of these fungi in vitro. Natural polyaromatic (humic) substances are degraded more slowly in soil where ectomycorrhizal fungi are present, thus phytoremediation of recalcitrant pollutants may not benefit from the presence of these fungi. Using a soil spiked with three polycyclic aromatic hydrocarbons (PAHs) and an industrially polluted soil (1 g kg(-1) of summation operator12 PAHs), we show that the ectomycorrhizal fungus Suillus bovinus, forming hydrophobic mycelium in soil that would easily enter into contact with hydrophobic pollutants, impedes rather than promotes PAH degradation. This result is likely to be a nutrient depletion effect caused by fungal scavenging of mineral nutrients. PMID:16325973

  5. Description and identification of Alnus acuminata ectomycorrhizae from Argentinean alder stands.

    PubMed

    Pritsch, Karin; Becerra, Alejandra; Põlme, Sergei; Tedersoo, Leho; Schloter, Michael; Agerer, Reinhard

    2010-01-01

    The objective of this study was to describe the morphological and anatomical features of five unidentified ectomycorrhizal types of Alnus acuminata and to complement their identification based on ITS-rDNA sequence analysis. The combined approach of morphotyping and sequence analysis based on ITS sequence comparison with sequences contained in GenBank and the UNITE database let us assign three of the five field-collected ectomycorrhiza morphotypes to the tomentella-thelephora lineage that closely matched European and North American species. The sequencing results within Tomentella point toward alder specific clades within T. sublilacina, T. ellisii and T. stuposa sensu lato. The two other EcM morphotypes matched Lactarius omphaliiformis and a Russula sp. Better focused, concomitant fruit body surveys are needed for accurate identification of South American ectomycorrhizal fungi because of the evidence of cryptic speciation in both agaricoid and resupinate mycobionts. PMID:20943556

  6. Identification of a far-red reflectance response to ectomycorrhizae in slash pine

    NASA Technical Reports Server (NTRS)

    Cibula, W. G.; Carter, G. A.

    1992-01-01

    Spectral reflectances were measured for the canopies of Pinus elliottii seedlings that were inoculated versus noninoculated with the ectomycorrhizal fungus Pisolithus tinctorius. Reflectances of the less vigorous, noninoculated seedlings increased substantially at visible and near-IR wavelengths compared to the more vigorous, inoculated seedlings. An algorithm was developed to indicate the spectral regions in which reflectance was most sensitive to ectomycorrhizae. The reflectance curve of the more vigorous seedlings was used as a standard of comparison. The spectral regions defined by this algorithm are denoted as regions of maximum reflectance sensitivity. Far-red and near-IR photography filtered to the region of maximum sensitivity (700 nm) were used to enable visualization of a 'blue shift' reflectance response to decreased vigor in the noninoculated seedlings in response to these differences of mycorrhizal development.

  7. [Crystal chemical and micromorphologic evaluation of ancient bone discoveries (Arabia Petraea, Jordan) from the 10th millennium B.C].

    PubMed

    Newesely, H

    1987-01-01

    As specialisations of osteoarchaeometry become increasingly developed, so the need of new analytical techniques and tests of a skillful applicability becomes more necessary. The crystal-chemical and micromorphological evaluations of preserved bone discoveries implicate reliable methods as X-ray diffraction, electron microscopy, and spectroscopy with the skeletal materials and the soil environment in which bones are found. The reactivity of soils varies widely as geological and sedimentological conditions offer typical but different environments: gravels, chalk soil, clay, salt soils, sands, cave earths are examples of this wide variety, including atmospheric and biogenetic implications. The last mentioned features are strongly effective also in aride regions, with the well known fluctations of high parching and dewiness. However, despite the diversity in deposition and burial modes only few parameters govern the gradual decomposition of bone material: 1. pH value of the surrounding medium; 2. humidity of the surrounding medium, may be governed directly by autolysis; 3. transport of matter, related to grain size, pore volume, solubility behaviour; 4. physical pressure; 5. destruction by microorganisms; as well as the surrounding medium will be altered by the uptake and the transformation of the products of bone decomposition. The materials of investigation were skeletal fragments buried of ea. 10,000 a within the soft dune sediment of the western border mountains of Wadi el Araba (Arabia Petraea, Jordan). The discovered bones are, as a common feature of this locality Basta, strongly sintered--indication on the afore mentioned reactivity of the aride soil as well. Bone fragments were partially burnt at Sabra locality and discolored, and sintered also at these circumstances. The reactivity of the bone fragments is shown in terms of exchange reactions within the crystal structure of the bone mineral, apatite Ca5(PO4)3OH at the calcium sites, hydroxyl sites, and

  8. Stand density, tree social status and water stress influence allocation in height and diameter growth of Quercus petraea (Liebl.).

    PubMed

    Trouvé, Raphaël; Bontemps, Jean-Daniel; Seynave, Ingrid; Collet, Catherine; Lebourgeois, François

    2015-10-01

    Even-aged forest stands are competitive communities where competition for light gives advantages to tall individuals, thereby inducing a race for height. These same individuals must however balance this competitive advantage with height-related mechanical and hydraulic risks. These phenomena may induce variations in height-diameter growth relationships, with primary dependences on stand density and tree social status as proxies for competition pressure and access to light, and on availability of local environmental resources, including water. We aimed to investigate the effects of stand density, tree social status and water stress on the individual height-circumference growth allocation (Δh-Δc), in even-aged stands of Quercus petraea Liebl. (sessile oak). Within-stand Δc was used as surrogate for tree social status. We used an original long-term experimental plot network, set up in the species production area in France, and designed to explore stand dynamics on a maximum density gradient. Growth allocation was modelled statistically by relating the shape of the Δh-Δc relationship to stand density, stand age and water deficit. The shape of the Δh-Δc relationship shifted from linear with a moderate slope in open-grown stands to concave saturating with an initial steep slope in closed stands. Maximum height growth was found to follow a typical mono-modal response to stand age. In open-grown stands, increasing summer soil water deficit was found to decrease height growth relative to radial growth, suggesting hydraulic constraints on height growth. A similar pattern was found in closed stands, the magnitude of the effect however lowering from suppressed to dominant trees. We highlight the high phenotypic plasticity of growth in sessile oak trees that further adapt their allocation scheme to their environment. Stand density and tree social status were major drivers of growth allocation variations, while water stress had a detrimental effect on height in the

  9. Recent advances in exploring physiology and biodiversity of ectomycorrhizas highlight the functioning of these symbioses in ecosystems.

    PubMed

    Buscot, F; Munch, J C; Charcosset, J Y; Gardes, M; Nehls, U; Hampp, R

    2000-12-01

    Ectomycorrhizas, the dominating mycorrhizal symbiosis in boreal, temperate and some tropical forests, are formed by 5000-6000 species of the asco- and basidiomycetes. This high diversity of fungal partners allows optimal foraging and mobilisation of various nitrogen and phosphorus forms from organic soil layers. In this review, two approaches to study the functioning of this multitude of symbiotic associations are presented. On selected culture models, physiological and molecular investigations have shown that the supply of hexoses has a key function in controlling the plant-fungus interaction via partner-specific regulation of gene expression. Environmental factors which affect fungal carbon supply, such as increased nitrogen availability, also affect mycorrhiza formation. Based on such laboratory results, the adaptative capability of ectomycorrhizas to changing field conditions is discussed. The second approach consists of analysing the distribution of mycorrhizas in ecosystem compartments and to relate distribution patterns to variations of ecological factors. Recent advances in identification of fungal partners in ectomycorrhizas by analysing the internal transcribed spacer of ribosomal DNA are presented, which can help to resolve sampling problems in field studies. The limits of the laboratory and the field approaches are discussed. Despite some problems, this combined approach is the most promising. Direct investigation of gene expression, which has been introduced for soil bacteria, will be difficult in the case of mycorrhizal fungi which constitute organisms with functionally varying structures. PMID:11077153

  10. Comparison of ectomycorrhizas of Quercus garryana (Fagaceae) on serpentine and non-serpentine soils in southwestern Oregon.

    PubMed

    Moser, A Mariah; Petersen, Carolyn A; D'Allura, Jad A; Southworth, Darlene

    2005-02-01

    The diversity of ectomycorrhizal communities associated with Quercus garryana on and off serpentine soils was compared and related to landscape-level diversity. Serpentine soils are high in magnesium, iron, and heavy metals and low in fertility. In plant communities on serpentine soils, a high proportion of flowering plant species are endemic. At three sites with paired serpentine and nonserpentine soils in southwestern Oregon, we sampled Q. garryana roots and categorized ectomycorrhizas by morphotyping and by restriction fragment length patterns. Ectomycorrhizas were abundant at all sites; no single fungal species dominated in the ectomycorrhizas. Of 74 fungal species characterized by morphotype and pattern of restriction fragment length polymorphisms, 46 occurred on serpentine soils, and 32 were unique to serpentine soil. These species are potentially endemic to serpentine soil. Similarities in species composition between paired serpentine and nonserpentine soils were not significantly lower than among three serpentine sites or among three nonserpentine sites. We conclude that mycorrhizal communities associated with oaks on serpentine soil do not differ in species richness or species evenness from those on neighboring nonserpentine soil. PMID:21652399

  11. Comparative cDNA-AFLP analysis of Cd-tolerant and -sensitive genotypes derived from crosses between the Cd hyperaccumulator Arabidopsis halleri and Arabidopsis lyrata ssp. petraea.

    PubMed

    Craciun, Adrian Radu; Courbot, Mikael; Bourgis, Fabienne; Salis, Pietrino; Saumitou-Laprade, Pierre; Verbruggen, Nathalie

    2006-01-01

    Cadmium (Cd) tolerance seems to be a constitutive species-level trait in Arabidopsis halleri. In order to identify genes potentially implicated in Cd tolerance, a backcross (BC1) segregating population was produced from crosses between A. halleri ssp. halleri and its closest non-tolerant relative A. lyrata ssp. petraea. The most sensitive and tolerant genotypes of the BC1 were analysed on a transcriptome-wide scale by cDNA-amplified fragment length polymorphism (AFLP). A hundred and thirty-four genes expressed more in the root of tolerant genotypes than in sensitive genotypes were identified. Most of the identified genes showed no regulation in their expression when exposed to Cd in a hydroponic culture medium and belonged to diverse functional classes, including reactive oxygen species (ROS) detoxification, cellular repair, metal sequestration, water transport, signal transduction, transcription regulation, and protein degradation, which are discussed. PMID:16916885

  12. Tree age-related effects on seasonal dynamics of carbon reserves in Quercus petraea: an in situ experimental approach

    NASA Astrophysics Data System (ADS)

    Gilson, Angélique; Bazot, Stéphane; Barthes, Laure; Delpierre, Nicolas; Fresneau, Chantal; Audebert, Louise; Dufrêne, Eric

    2013-04-01

    Forest productivity plays an important role in wood production and forest carbon storage capacity. It is well known that forest productivity declines with tree age (Genet et al., 2009). This decline could result from a carbon assimilation decrease and/or a modification of carbon allocation (Ryan et al., 2006 ; Genet, 2009). Relationships between tree age and leaf surface (Bond-Lamberty et al., 2002 ; Louis et al., 2012), light interception (Niinemets et al., 2005) or hydraulic constraint (Bond, 2000 ; Zaehle, 2006) have been widely studied. Yet, studies of relationships between tree age and carbon storage/remobilization processes are scarce in deciduous trees. Therefore in situ experiments appear necessary to have a better understanding of the carbon functioning of deciduous forest ecosystems. Our objective was to compare the seasonal carbon dynamics of different age oak trees classes. We studied three age categories (8, 20, 100 years) of Quercus petraea in the Barbeau national forest (France) over one leafy season. Leaves, 2010 and 2011 twigs, stem, fine and coarse roots were sampled at different key phenological stages (before budburst, at budburst, maximum leaf area index, maximum leaf mass area, summer, yellowing and winter) for determination of starch concentrations. We observed only differences between classes for 2010 twigs and fine roots. After carbon reserves remobilization during budburst, starch concentrations of 2010 twigs for 8 and 20 years old trees don't increase before the end of wood growth (i.e. end of july). Starch concentrations increase occurs just after budburst for the oldest tree category. Starch concentrations in fine roots in the two oldest trees categories are stable throughout the year. On the contrary, juvenile trees present an enhanced starch concentration in autumn. Nevertheless, for oldest tree coarse roots starch concentration increase from summer to yellowing. These first results highlight that starch storage is different between

  13. Molecular approach to characterize ectomycorrhizae fungi from Mediterranean pine stands in Portugal

    PubMed Central

    Ragonezi, Carla; Caldeira, A. Teresa; Martins, M. Rosário; Salvador, Cátia; Santos-Silva, Celeste; Ganhão, Elsa; Klimaszewska, Krystyna; Zavattieri, Amely

    2013-01-01

    Stone pine (Pinus pinea L.), like other conifers, forms ectomycorrhizas (ECM), which have beneficial impact on plant growth in natural environments and forest ecosystems. An in vitro co-culture of stone pine microshoots with pure mycelia of isolated ECM sporocarps was used to overcome the root growth cessation not only in vitro but also to improve root development during acclimation phase. Pisolithus arhizus (Scop.) Rauschert and Lactarius deliciosus (L. ex Fr.) S.F. Gray fungi, were collected, pure cultured and used in in vitro co-culture with stone pine microshoots. Samples of P. arhizus and L. deliciosus for the in vitro co-cultures were collected from the pine stands southwest Portugal. The in situ characterization was based on their morphotypes. To confirm the identity of the collected material, ITS amplification was applied using the pure cultures derived from the sporocarps. Additionally, a molecular profile using PCR based genomic fingerprinting comparison was executed with other genera of Basidiomycetes and Ascomycetes. Our results showed the effectiveness of the techniques used to amplify DNA polymorphic sequences, which enhances the characterization of the genetic profile of ECM fungi and also provides an option to verify the fungus identity at any stage of plant mycorrhization. PMID:24294266

  14. The role of mycorrhization helper bacteria in the establishment and action of ectomycorrhizae associations

    PubMed Central

    Rigamonte, Tatiana Alves; Pylro, Victor Satler; Duarte, Gabriela Frois

    2010-01-01

    More than 95 % short roots of most terrestrial plants are colonized by mycorrhizal fungi as soon as they emerge in the upper soil profiles. The establishment of mycorrhizal association involves profound morphological and physiological changes in root and fungus. It is affected by other rhizospheric microorganisms, specifically by the bacteria. Bacteria may have developed mechanisms of selective interaction with surrounding microorganisms, with neutral or positive effects on mycorrhizal associations, but negative effect on root pathogens in general. Because of the beneficial effect of bacteria on mycorrhizae, the concept of Mycorrhization Helper Bacteria (MHB) was created. Five main actions of MHB on mycorrhizae were proposed: in the receptivity of root to the mycobiont, in root-fungus recognition, in fungal growth, in the modification of rhizospheric soil and in the germination of fungal propagules. MHB appear to develop a gradation of specificity for the mycobiont, but little or no specificity for the host plant in symbiosis. One of the main groups of MHB is the fluorescent Pseudomonas, well represented in diversity and cell density studies of mycorrhizal associations. This review covers the activity of MHB in the establishment of ectomycorrhizae, taking as model the effects of Pseudomonas sp. described in scientific literature. PMID:24031563

  15. Quantitative assessment of the differential impacts of arbuscular and ectomycorrhiza on soil carbon cycling.

    PubMed

    Soudzilovskaia, Nadejda A; van der Heijden, Marcel G A; Cornelissen, Johannes H C; Makarov, Mikhail I; Onipchenko, Vladimir G; Maslov, Mikhail N; Akhmetzhanova, Asem A; van Bodegom, Peter M

    2015-10-01

    A significant fraction of carbon stored in the Earth's soil moves through arbuscular mycorrhiza (AM) and ectomycorrhiza (EM). The impacts of AM and EM on the soil carbon budget are poorly understood. We propose a method to quantify the mycorrhizal contribution to carbon cycling, explicitly accounting for the abundance of plant-associated and extraradical mycorrhizal mycelium. We discuss the need to acquire additional data to use our method, and present our new global database holding information on plant species-by-site intensity of root colonization by mycorrhizas. We demonstrate that the degree of mycorrhizal fungal colonization has globally consistent patterns across plant species. This suggests that the level of plant species-specific root colonization can be used as a plant trait. To exemplify our method, we assessed the differential impacts of AM : EM ratio and EM shrub encroachment on carbon stocks in sub-arctic tundra. AM and EM affect tundra carbon stocks at different magnitudes, and via partly distinct dominant pathways: via extraradical mycelium (both EM and AM) and via mycorrhizal impacts on above- and belowground biomass carbon (mostly AM). Our method provides a powerful tool for the quantitative assessment of mycorrhizal impact on local and global carbon cycling processes, paving the way towards an improved understanding of the role of mycorrhizas in the Earth's carbon cycle. PMID:26011828

  16. Growth of containerized loblolly pine with specific ectomycorrhizae after 2 years on an amended borrow pit

    SciTech Connect

    Ruehle, J.L.

    1980-01-01

    A borrow pit with exposed subsoil in South Carolina was graded level and deep subsoiled. Plots were amended with processed sewage sludge or commercial fertilizer followed by a seeding with fescue. Container-grown loblolly pines colonized with Pisolithus tinctorius, Thelephora terrestris, or no ectomycorrhizae were planted by hand on the plots one year after site preparation. Two years after planting on sludge-amended plots, seedlings initially colonized with Pisolithus had greater height, root-collar diameter, and seedling volume (D/sup 2/H) than Thelephora or control seedlings. The means for these three growth parameters on seedlings planted on fertilized plots were no different between Pisolithus and Thelephora seedlings, but Pisolithus seedlings were greater than controls. There was no difference in survival among mycorrhizal treatments on the sludge plots. Survival and seedling volume were integrated into plot volume indices (PVI). Seedlings on sludge plots had greater PVI than seedlings on fertilized plots. Pisolithus seedlings on sludge plots had 265 and 528% greater PVI after two years than Thelephora or control seedlings. Containerized loblolly seedlings tailored with Pisolithus can be successfully established and rapid growth obtained on a subsoiled borrow pit amended with sewage sludge. This procedure may be applicable to thousands of acres of similar borrow pits left by highway and construction work.

  17. Molecular approach to characterize ectomycorrhizae fungi from Mediterranean pine stands in Portugal.

    PubMed

    Ragonezi, Carla; Caldeira, A Teresa; Martins, M Rosário; Salvador, Cátia; Santos-Silva, Celeste; Ganhão, Elsa; Klimaszewska, Krystyna; Zavattieri, Amely

    2013-01-01

    Stone pine (Pinus pinea L.), like other conifers, forms ectomycorrhizas (ECM), which have beneficial impact on plant growth in natural environments and forest ecosystems. An in vitro co-culture of stone pine microshoots with pure mycelia of isolated ECM sporocarps was used to overcome the root growth cessation not only in vitro but also to improve root development during acclimation phase. Pisolithus arhizus (Scop.) Rauschert and Lactarius deliciosus (L. ex Fr.) S.F. Gray fungi, were collected, pure cultured and used in in vitro co-culture with stone pine microshoots. Samples of P. arhizus and L. deliciosus for the in vitro co-cultures were collected from the pine stands southwest Portugal. The in situ characterization was based on their morphotypes. To confirm the identity of the collected material, ITS amplification was applied using the pure cultures derived from the sporocarps. Additionally, a molecular profile using PCR based genomic fingerprinting comparison was executed with other genera of Basidiomycetes and Ascomycetes. Our results showed the effectiveness of the techniques used to amplify DNA polymorphic sequences, which enhances the characterization of the genetic profile of ECM fungi and also provides an option to verify the fungus identity at any stage of plant mycorrhization. PMID:24294266

  18. Ectomycorrhizas with Paxillus involutus enhance cadmium uptake and tolerance in Populus × canescens.

    PubMed

    Ma, Yonglu; He, Jiali; Ma, Chaofeng; Luo, Jie; Li, Hong; Liu, Tongxian; Polle, Andrea; Peng, Changhui; Luo, Zhi-Bin

    2014-03-01

    Ectomycorrhizas (EMs), which are symbiotic organs formed between tree roots and certain fungi, can mediate cadmium (Cd) tolerance of host plants, but the underlying physiological and molecular mechanisms are not fully understood. To investigate EMs mediated Cd tolerance in woody plants, Populus × canescens was inoculated with Paxillus involutus (strain MAJ) to establish mycorrhizal roots. Mycorrhizal poplars and non-mycorrhizal controls were exposed to 0 or 50 μM CdSO4 . EMs displayed higher net Cd(2+) influx than non-mycorrhizal roots. Net Cd(2+) influx was coupled with net H(+) efflux and inactivation of plasma membrane (PM) H(+) -ATPases reduced Cd(2+) uptake of EMs less than of non-mycorrhizal roots. Consistent with higher Cd(2+) uptake in EMs, in most cases, transcript levels of genes involved in Cd(2+) uptake, transport and detoxification processes were increased in EMs compared to non-mycorrhizal roots. Higher CO2 assimilation, improved nutrient and carbohydrate status, and alleviated oxidative stress were found in mycorrhizal compared to non-mycorrhizal poplars despite higher Cd(2+) accumulation. These results indicate that mycorrhizas increase Cd(2+) uptake, probably by an enlarged root volume and overexpression of genes involved in Cd(2+) uptake and transport, and concurrently enhance Po. × canescens Cd tolerance by increased detoxification, improved nutrient and carbohydrate status and defence preparedness. PMID:23937227

  19. Molecular characterization of pezizalean ectomycorrhizas associated with pinyon pine during drought.

    PubMed

    Gordon, Galena J; Gehring, Catherine A

    2011-07-01

    Recent studies using molecular analysis of ectomycorrhizas have revealed that ascomycete fungi, especially members of the order Pezizales, can be important members of ectomycorrhizal (EM) fungal communities. However, little is known about the ecology and taxonomy of many of these fungi. We used data collected during a wet and a dry period to test the hypothesis that pezizalean EM fungi associated with pinyon pine (Pinus edulis) responded positively to drought stress. We also assessed the phylogenetic relationships among six, unknown pezizalean EM fungi, common to our study sites, using rDNA sequences from the internal transcribed spacer and large subunit (LSU) regions of the ribosomal DNA. Sequences of these fungi were then compared to sequences from known taxa to allow finer-scale identification. Three major findings emerged. First, at two sites, pezizalean EM were 44-95% more abundant during a dry year than a wetter year, supporting the hypothesis that pezizalean EM fungi respond positively to dry conditions. Second, four of the six unknown pezizalean EM fungi associated with P. edulis separated from one another consistently regardless of site or year of collection, suggesting that they represented distinct taxa. Third, comparison with LSU sequences of known members of the Pezizales indicated that these four taxa grouped within the genus Geopora of the family Pyronemataceae. Our results provide further evidence of the importance of pezizalean fungi in the ectomycorrhizal symbiosis and demonstrate high local abundance of members of the genus Geopora in drought-stressed pinyon-juniper woodlands. PMID:21191620

  20. Development of the Poplar-Laccaria bicolor Ectomycorrhiza Modifies Root Auxin Metabolism, Signaling, and Response.

    PubMed

    Vayssières, Alice; Pěnčík, Ales; Felten, Judith; Kohler, Annegret; Ljung, Karin; Martin, Francis; Legué, Valérie

    2015-09-01

    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. PMID:26084921

  1. Headspace solid-phase microextraction with gas chromatography and mass spectrometry in the investigation of volatile organic compounds in an ectomycorrhizae synthesis system.

    PubMed

    Menotta, Michele; Gioacchini, Anna M; Amicucci, Antonella; Buffalini, Michele; Sisti, Davide; Stocchi, Vilberto

    2004-01-01

    Ectomycorrhizae formation represents one of the most significant steps in the truffle life cycle and is determined by a complex molecular signaling between two symbionts. In order to understand the molecular pathway of ectomycorrhiza development, we focused on the signaling interaction between the ectomycorrhizal fungus Tuber borchii Vittad. and the Tilia americana L. plant roots. The medium of a pre-symbiotic (T. americana-T. borchii) in vitro system was analysed by headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry. In total, 73 volatile organic compounds (VOCs) were identified. Twenty-nine of these VOCs were produced only during the interaction phase between the two partners, leading to a hypothesis that these molecules might act as molecular messengers in order to pilot the ectomycorrhizae formation. PMID:14745771

  2. The role of ectomycorrhizae of Arolla pine in mediating soil priming

    NASA Astrophysics Data System (ADS)

    Menyailo, Oleg; Matvienko, Anastasia; Cheng, Chih-Hsin

    2015-04-01

    Ectomycorhizae is playing a vital role in soil C cycle. However, the role is controversial. Mycorrhizae could be a major source of soil C promoting C sequestration. On the other hand, mycorrhizal fungi could compete with soil free-living microorganisms for resources, accelerating their decomposition of soil organic matter, therefore leading to soil C losses. We studied the contribution of ectomycorrhizae of Arolla pine, a popular tree species in Siberia, in soil priming, a short term changes in decomposition of soil organic matter after addition of glucose. We used in-growth mesh collars where mycorrhizal hyphae could or could not grow in. We applied 13C labeled glucose and measured evolution of CO2 thereafter, and determined 13C-CO2 using Picarro 2131 iCO2 analyzer. The CO2 produced from soil was enriched 13C only during the first 48 hours, thereafter the enrichment declined to the natural abundance level. The maximum δ13C-CO2 was observed during the first 20 min after glucose amendment. It is surprising that not more than 3% of applied C-glucose was recovered as C-CO2 suggesting extremely high C use efficiency (97%). The glucose addition caused CO2 flux to increase by 25-30% during the first two days, the amount of primed C-CO2 was 7 times higher than emitted from applied C. The presence of mycorrhizae shifted both CUE and the priming. Mycorrhizae apparently competed with heterotrophs reducing their CUE by factor of 2, and increasing the priming by factor of 1.5. Overall, mycorrhizae could amplify the priming effect increasing C losses. However, the most part of applied C was incorporated into microbial biomass, resulting at least at the short time scale in net C sequestration. Future studies should be directed to understanding of the long-term fate of C incorporated into microbial biomass.

  3. A fungal conserved gene from the basidiomycete Hebeloma cylindrosporum is essential for efficient ectomycorrhiza formation.

    PubMed

    Doré, Jeanne; Marmeisse, Roland; Combier, Jean-Philippe; Gay, Gilles

    2014-10-01

    We used Agrobacterium-mediated insertional mutagenesis to identify genes in the ectomycorrhizal fungus Hebeloma cylindrosporum that are essential for efficient mycorrhiza formation. One of the mutants presented a dramatically reduced ability to form ectomycorrhizas when grown in the presence of Pinus pinaster. It failed to form mycorrhizas in the presence of glucose at 0.5 g liter(-1), a condition favorable for mycorrhiza formation by the wild-type strain. However, it formed few mycorrhizas when glucose was replaced by fructose or when glucose concentration was increased to 1 g liter(-1). Scanning electron microscopy examination of these mycorrhizas revealed that this mutant was unable to differentiate true fungal sheath and Hartig net. Molecular analyses showed that the single-copy disrupting T-DNA was integrated 6,884 bp downstream from the start codon, of an open reading frame potentially encoding a 3,096-amino-acid-long protein. This gene, which we named HcMycE1, has orthologs in numerous fungi as well as different other eukaryotic microorganisms. RNAi inactivation of HcMycE1 in the wild-type strain also led to a mycorrhizal defect, demonstrating that the nonmycorrhizal phenotype of the mutant was due to mutagenic T-DNA integration in HcMycE1. In the wild-type strain colonizing P. pinaster roots, HcMycE1 was transiently upregulated before symbiotic structure differentiation. Together with the inability of the mutant to differentiate these structures, this suggests that HcMycE1 plays a crucial role upstream of the fungal sheath and Hartig net differentiation. This study provides the first characterization of a fungal mutant altered in mycorrhizal ability. PMID:24918768

  4. Ectomycorrhizas naturally established in Nothofagus nervosa seedlings under different cultivation practices in a forest nursery.

    PubMed

    Fernández, Natalia V; Marchelli, Paula; Fontenla, Sonia B

    2013-10-01

    Mycorrhizas are mutualistic associations between soil fungi and plant roots which usually improve water and nutrient uptake, influencing plant fitness. Nothofagus nervosa (Raulí) is an ecologically and economically important species of South American temperate forests. Since this native tree species yields valuable timber, it was overexploited and its natural distribution area was critically reduced, so it is currently included in domestication and conservation programs. Among the factors that should be considered in these programs are the ectomycorrhizas (EcM), which would be important for the successful establishment and survival of outplanted seedlings. The aim of this work was to analyze the abundance and diversity of EcM in N. nervosa nursery-cultivated seedlings assessed by morphotyping, fungal isolation, and DNA sequencing. Arbuscular mycorrhiza (AM) occurrence was also studied. A 2-year trial was conducted following the cultivation conditions used for domestication programs. Seedlings were cultivated under two different cultivation practices (greenhouse and nursery soil) without artificial inoculation of mycorrhizal fungi. Seedlings' roots were examined at different times. It was observed that they developed EcM between 6 and 12 months after germination and AMs were not detected in any plant. The most abundant ectomycorrhizal fungi present in seedlings' roots were Tomentella ellisii (Basidiomycota) and an unidentified fungus named Ascomicetous EcM sp. 1. Abundance and diversity of EcM varied between the two cultivation techniques analyzed in this study, since seedlings that continued growing in the greenhouse had higher colonization values, but those transplanted to the nursery soil were colonized by a higher diversity of fungal taxa. PMID:23636582

  5. Seeing the forest through the trees: comprehensive inference on individual mating patterns in a mixed stand of Quercus robur and Q. petraea

    PubMed Central

    Chybicki, Igor J.; Burczyk, Jaroslaw

    2013-01-01

    Background and Aims Sexual reproduction is one of the most important moments in a life cycle, determining the genetic composition of individual offspring. Controlled pollination experiments often show high variation in the mating system at the individual level, suggesting a persistence of individual variation in natural populations. Individual variation in mating patterns may have significant adaptive implications for a population and for the entire species. Nevertheless, field data rarely address individual differences in mating patterns, focusing rather on averages. This study aimed to quantify individual variation in the different components of mating patterns. Methods Microsatellite data were used from 421 adult trees and 1911 seeds, structured in 72 half-sib families collected in a single mixed stand of Quercus robur and Q. petraea in northern Poland. Using a Bayesian approach, mating patterns were investigated, taking into account pollen dispersal, male fecundity, possible hybridization and heterogeneity in immigrant pollen pools. Key Results Pollen dispersal followed a heavy-tailed distribution (283 m on average). In spite of high pollen mobility, immigrant pollen pools showed strong genetic structuring among mothers. At the individual level, immigrant pollen pools showed highly variable divergence rates, revealing that sources of immigrant pollen can vary greatly among particular trees. Within the stand, the distribution of male fecundity appeared highly skewed, with a small number of dominant males, resulting in a ratio of census to effective density of pollen donors of 5·3. Male fecundity was not correlated with tree diameter but showed strong cline-like spatial variation. This pattern can be attributed to environmental variation. Quercus petraea revealed a greater preference (74 %) towards intraspecific mating than Q. robur (36 %), although mating preferences varied among trees. Conclusions Mating patterns can reveal great variation among individuals

  6. Mycorrhizal fungi and ectomycorrhiza associated bacteria isolated from an industrial desert soil protect pine seedlings against Cd(II) impact.

    PubMed

    Kozdrój, Jacek; Piotrowska-Seget, Zofia; Krupa, Piotr

    2007-08-01

    Effects of mycorrhization with Amanita rubescens or Hebeloma sinapizans and dual inoculation with the fungi and ectomycorrhiza associated bacteria (EMAB) Pseudomonas putida or Bacillus cereus on seedling growth and accumulation of Cd(II) in Pinus sylvestris were studied. Both fungal and bacterial species were isolated from roots of pines growing in an industrial area polluted with high concentrations of heavy metals. During mycorrhization, A. rubescens colonized higher number of pine seedlings than H. sinapizans, especially when EMAB were co-inoculated. In addition, the seedling biometric characteristics (i.e. root and shoot lengths and biomass) were stimulated by treatment with the fungal species alone and dual inoculation with the fungi and EMAB. Amanita rubescens was more efficient in this stimulation than H. sinapizans. The increased growth of pine seedlings was especially seen for co-inoculation with P. putida. Furthermore, elevated accumulation of Cd(II), ranging from 56 microg g(-1) to 72 microg g(-1) dry weight, in underground parts of the inoculated seedlings was found. The seedlings treated with A. rubescens accumulated higher concentrations of the metal than those inoculated with H. sinapizans. Additional treatment of pine seedlings with P. putida resulted in the higher accumulation of Cd(II) in the roots as compared with those inoculated with B. cereus. The results suggest that the growth of pine seedlings in Cd(II)-polluted soil may depend on fungal species forming ectomycorrhizae, species-specific co-inoculation with EMAB and specificity of fungal-EMAB interactions. PMID:17541824

  7. Stable isotope signatures confirm carbon and nitrogen gain through ectomycorrhizas in the ghost orchid Epipogium aphyllum Swartz.

    PubMed

    Liebel, H T; Gebauer, G

    2011-03-01

    Epipogium aphyllum is a rare Eurasian achlorophyllous forest orchid known to associate with fungi that form ectomycorrhizas, while closely related orchids of warm humid climates depend on wood- or litter-decomposer fungi. We conducted (13) C and (15) N stable isotope natural abundance analyses to identify the organic nutrient source of E. aphyllum from Central Norway. These data for orchid shoot tissues, in comparison to accompanying autotrophic plants, document C and N flow from ectomycorrhizal fungi to the orchid. DNA data from fungal pelotons in the orchid root cortex confirm the presence of Inocybe and Hebeloma, which are both fungi that form ectomycorrhizas. The enrichment factors for (13) C and (15) N of E. aphyllum are used to calculate a new overall average enrichment factor for mycoheterotrophic plants living in association with ectomycorrhizal fungi (ε(13) C ± 1 SD of 7.2 ± 1.6 ‰ and ε(15) N ± 1 SD of 12.8 ± 3.9 ‰). These can be used to estimate the fungal contribution to organic nutrient uptake by partially mycoheterotrophic plants where fully mycoheterotrophic plants are lacking. N concentrations in orchid tissue were unusually high and significantly higher than in accompanying autotrophic leaf samples. This may be caused by N gain of E. aphyllum from obligate ectomycorrhizal fungi. We show that E. aphyllum is an epiparasitic mycoheterotrophic orchid that depends on ectomycorrhizal Inocybe and Hebeloma to obtain C and N through a tripartite system linking mycoheterotrophic plants through fungi with forest trees. PMID:21309973

  8. Provenance-specific growth responses to drought and air warming in three European oak species (Quercus robur, Q. petraea and Q. pubescens).

    PubMed

    Arend, Matthias; Kuster, Thomas; Günthardt-Goerg, Madeleine S; Dobbertin, Matthias

    2011-03-01

    Provenance-specific growth responses to experimentally applied drought and air warming were studied in saplings of three European oak species: Quercus robur, Quercus petraea and Quercus pubescens. Four provenances of each species were grown in large open-top chambers and subjected to four climates: control, periodic drought, air warming or their combination in 3 subsequent years. Overall growth responses were found among species and provenances, with drought reducing shoot height growth and stem diameter growth and air warming stimulating shoot height growth but reducing stem diameter growth and root length growth. Differential growth responses in shoots, stems and roots resulted in altered allometric growth relations. Root length growth to shoot height growth increased in response to drought but decreased in response to air warming. Stem diameter growth to shoot height growth decreased in response to air warming. The growth responses in shoots and stems were highly variable among provenances indicating provenance-specific sensitivity to drought and air warming, but this response variability did not reflect local adaptation to climate conditions of provenance origin. Shoot height growth was found to be more sensitive to drought in provenances from northern latitudes than in provenances from southern latitudes, suggesting that genetic factors related to the postglacial immigration history of European oaks might have interfered with selective pressure at provenance origins. PMID:21422189

  9. Anatomical and molecular characterization of Lactarius aff. omphaliformis, Russula alnijorullensis and Cortinarius tucumanensis ectomycorrhizae on Alnus acuminata.

    PubMed

    Becerra, Alejandra; Beenken, Ludwig; Pritsch, Karin; Daniele, Graciela; Schloter, Michael; Agerer, Reinhard

    2005-01-01

    Ectomycorrhizae (ECM) of Lactarius aff. omphaliformis Romagn., Russula alnijorullensis (Sing.) Sing. and Cortinarius tucumanensis Mos. on Andean alder (Alnus acuminata Kunth) were characterized and identified. The identification of the fungal symbionts was achieved by morpho-anatomical observations of mycorrhizae and by comparison of ITS-RFLP patterns obtained from ECM and fruitbodies. L. aff omphaliformis ECM differed in some morphological details such as ramification and mantle type from ECM of the same species on A. glutinosa. L. aff omphaliformis ECM show an orange to ochre mantle containing latex cells, which stain with sulpho-vanillin, emanating hyphae without clamps. R. alnijorullensis ECM represent a typical Russula-type-ECM, light yellow to pinkish, the outer mantle being composed of triangular latex-filled cells staining with sulpho-vanillin, emanating hyphae without clamps. C. tucumanensis ECM exhibit a white (silvery) to yellowish brown mantle covered with soil particles, emanating hyphae with clamps. PMID:16596956

  10. Massively parallel 454-sequencing of fungal communities in Quercus spp. ectomycorrhizas indicates seasonal dynamics in urban and rural sites.

    PubMed

    Jumpponen, Ari; Jones, Kenneth L; David Mattox, J; Yaege, Chulee

    2010-03-01

    We analysed two sites within and outside an urban development in a rural background to estimate the fungal richness, diversity and community composition in Quercus spp. ectomycorrhizas using massively parallel 454-sequencing in combination with DNA-tagging. Our analyses indicated that shallow sequencing ( approximately 150 sequences) of a large number of samples (192 in total) provided data that allowed identification of seasonal trends within the fungal communities: putative root-associated antagonists and saprobes that were abundant early in the growing season were replaced by common ectomycorrhizal fungi in the course of the growing season. Ordination analyses identified a number of factors that were correlated with the observed communities including host species as well as soil organic matter, nutrient and heavy metal enrichment. Overall, our application of the high throughput 454 sequencing provided an expedient means for characterization of fungal communities. PMID:20331769

  11. Repeated Summer Drought and Re-watering during the First Growing Year of Oak (Quercus petraea) Delay Autumn Senescence and Bud Burst in the Following Spring

    PubMed Central

    Vander Mijnsbrugge, Kristine; Turcsán, Arion; Maes, Jorne; Duchêne, Nils; Meeus, Steven; Steppe, Kathy; Steenackers, Marijke

    2016-01-01

    Climate change predicts harsher summer droughts for mid-latitudes in Europe. To enhance our understanding of the putative impacts on forest regeneration, we studied the response of oak seedlings (Quercus petraea) to water deficit. Potted seedlings originating from three locally sourced provenances were subjected to two successive drought periods during the first growing season each followed by a plentiful re-watering. Here, we describe survival and phenological responses after the second drought treatment, applying general linear mixed modeling. From the 441 drought treated seedlings 189 subsisted with higher chances of survival among smaller plants and among single plants per pot compared to doubles. Remarkably, survival was independent of the provenance, although relatively more plants had died off in two provenances compared to the third one with mean plant height being higher in one provenance and standard deviation of plant height being higher in the other. Timing of leaf senescence was clearly delayed after the severe drought treatment followed by re-watering, with two seedlings per pot showing a lesser retardation compared to single plants. This delay can be interpreted as a compensation time in which plants recover before entering the subsequent developmental process of leaf senescence, although it renders seedlings more vulnerable to early autumn frosts because of the delayed hardening of the shoots. Onset of bud flush in the subsequent spring still showed a significant but small delay in the drought treated group, independent of the number of seedlings per pot, and can be considered as an after effect of the delayed senescence. In both phenological models significant differences among the three provenances were detected independent from the treatment. The only provenance that is believed to be local of origin, displayed the earliest leaf senescence and the latest flushing, suggesting an adaptation to the local maritime climate. This provenance also

  12. Pisolithus tinctorius ectomycorrhizae enhance the survival and growth of Pinus taeda on a southern Appalachian coal spoil

    SciTech Connect

    Walker, R.F.; West, D.C.; McLaughlin, S.B.

    1980-01-01

    The significance of Pisolithus tinctorius ectomycorrhizae to the establishment and growth of loblolly pine (Pinus taeda) on sites disturbed in surface-mining operations was studied. Nursery-grown seedlings infected with this fungal symbiont were outplanted on coal spoils in Tennessee. Treatments included seedlings infected with a mycelial inoculum of P. tinctorius and fertilized at the rate of 112/kg/ha NPK, control seedlings without P. tinctorius fertilized at an identical rate, seedlings infected with P. tinctorius but without fertilization, and control seedlings without P. tinctorius or fertilization. Seedlings infected with P. tinctorius survived better than control seedlings, but fertilization during the first growing season reduced survival irrespective of mycorrhizal treatment. Infection by P. tinctorius and fertilization resulted in the best seedling growth whereas unfertilized control seedlings exhibited the least growth. Unfertilized seedlings infected with P. tinctorius and fertilized control seedlings exhibited growth intermediate to that of the other treatments. Apparently, an ectomycorrhizal infection of loblolly pine by P. tinctorius can enhance survival and growth on these adverse sites and reduce the need for fertilization.

  13. Culturable bacterial populations associated with ectomycorrhizae of Norway spruce stands with different degrees of decline in the Czech Republic.

    PubMed

    Avidano, Lorena; Rinaldi, Maurizio; Gindro, Roberto; Cudlín, Pavel; Martinotti, Maria Giovanna; Fracchia, Letizia

    2010-01-01

    The aim of this study was to determine which species of culturable bacteria are associated with ectomycorrhizae (ECM) of Norway spruce (Picea abies (L.) Karst) in the Sudety Mountains, exposed for years to atmospheric pollutants, acid rain, and climatic stress, and to identify particular species that have adapted to those conditions. Biolog identification was performed on bacterial species from ECM of adult spruce trees and seedlings of stands with low, intermediate, and high forest decline. Bacterial diversity in ECM associated with adult spruce trees, seedlings, and seedlings grown on monoliths was calculated; although the expected values appeared to vary widely, no significant differences among sites were observed. Dendrograms based on the identified bacterial species showed that stands with low forest decline clustered separately from the others. Principal component analysis of the normalized data for ECM-associated species showed a clear separation between stands with high forest decline and stands with low forest decline for seedlings and a less evident separation for adult spruce trees. In conclusion, shifts in ECM-associated culturable bacterial populations seem to be associated with forest decline in Norway spruce stands. Some bacterial species were preferentially associated with mycorrhizal roots depending on the degree of forest decline; this was more evident in seedlings where the species Burkholderia cepacia and Pseudomonas fluorescens were associated with, respectively, ECM of the most damaged stands and those with low forest decline. PMID:20130694

  14. Laser microdissection and microarray analysis of Tuber melanosporum ectomycorrhizas reveal functional heterogeneity between mantle and Hartig net compartments.

    PubMed

    Hacquard, Stéphane; Tisserant, Emilie; Brun, Annick; Legué, Valérie; Martin, Francis; Kohler, Annegret

    2013-06-01

    The ectomycorrhizal (ECM) symbiosis, a mutualistic plant-fungus association, plays a fundamental role in forest ecosystems by enhancing plant growth and by providing host protection from root diseases. The cellular complexity of the symbiotic organ, characterized by the differentiation of structurally specialized tissues (i.e. the fungal mantle and the Hartig net), is the major limitation to study fungal gene expression in such specific compartments. We investigated the transcriptional landscape of the ECM fungus Tuber melanosporum during the major stages of its life cycle and we particularly focused on the complex symbiotic stage by combining the use of laser capture microdissection and microarray gene expression analysis. We isolated the fungal/soil (i.e. the mantle) and the fungal/plant (i.e. the Hartig net) interfaces from transverse sections of T. melanosporum/Corylus avellana ectomycorrhizas and identified the distinct genetic programmes associated with each compartment. Particularly, nitrogen and water acquisition from soil, synthesis of secondary metabolites and detoxification mechanisms appear to be important processes in the fungal mantle. In contrast, transport activity is enhanced in the Hartig net and we identified carbohydrate and nitrogen-derived transporters that might play a key role in the reciprocal resources' transfer between the host and the symbiont. PMID:23379715

  15. Upgrading root physiology for stress tolerance by ectomycorrhizas: insights from metabolite and transcriptional profiling into reprogramming for stress anticipation.

    PubMed

    Luo, Zhi-Bin; Janz, Dennis; Jiang, Xiangning; Göbel, Cornelia; Wildhagen, Henning; Tan, Yupeng; Rennenberg, Heinz; Feussner, Ivo; Polle, Andrea

    2009-12-01

    Ectomycorrhizas (EMs) alleviate stress tolerance of host plants, but the underlying molecular mechanisms are unknown. To elucidate the basis of EM-induced physiological changes and their involvement in stress adaptation, we investigated metabolic and transcriptional profiles in EM and non-EM roots of gray poplar (Populus x canescens) in the presence and absence of osmotic stress imposed by excess salinity. Colonization with the ectomycorrhizal fungus Paxillus involutus increased root cell volumes, a response associated with carbohydrate accumulation. The stress-related hormones abscisic acid and salicylic acid were increased, whereas jasmonic acid and auxin were decreased in EM compared with non-EM roots. Auxin-responsive reporter plants showed that auxin decreased in the vascular system. The phytohormone changes in EMs are in contrast to those in arbuscular mycorrhizas, suggesting that EMs and arbuscular mycorrhizas recruit different signaling pathways to influence plant stress responses. Transcriptome analyses on a whole genome poplar microarray revealed activation of genes related to abiotic and biotic stress responses as well as of genes involved in vesicle trafficking and suppression of auxin-related pathways. Comparative transcriptome analysis indicated EM-related genes whose transcript abundances were independent of salt stress and a set of salt stress-related genes that were common to EM non-salt-stressed and non-EM salt-stressed plants. Salt-exposed EM roots showed stronger accumulation of myoinositol, abscisic acid, and salicylic acid and higher K(+)-to-Na(+) ratio than stressed non-EM roots. In conclusion, EMs activated stress-related genes and signaling pathways, apparently leading to priming of pathways conferring abiotic stress tolerance. PMID:19812185

  16. Patterns in root traits of woody species hosting arbuscular and ectomycorrhizas: implications for the evolution of belowground strategies

    PubMed Central

    Comas, Louise H; Callahan, Hilary S; Midford, Peter E

    2014-01-01

    Root traits vary enormously among plant species but we have little understanding of how this variation affects their functioning. Of central interest is how root traits are related to plant resource acquisition strategies from soil. We examined root traits of 33 woody species from northeastern US forests that form two of the most common types of mutualisms with fungi, arbuscular mycorrhizas (AM) and ectomycorrhizas (EM). We examined root trait distribution with respect to plant phylogeny, quantifying the phylogenetic signal (K statistic) in fine root morphology and architecture, and used phylogenetically independent contrasts (PICs) to test whether taxa forming different mycorrhizal associations had different root traits. We found a pattern of species forming roots with thinner diameters as species diversified across time. Given moderate phylogenetic signals (K = 0.44–0.68), we used PICs to examine traits variation among taxa forming AM or EM, revealing that hosts of AM were associated with lower branching intensity (rPIC = −0.77) and thicker root diameter (rPIC = −0.41). Because EM evolved relatively more recently and intermittently across plant phylogenies, significant differences in root traits and colonization between plants forming AM and EM imply linkages between the evolution of these biotic interactions and root traits and suggest a history of selection pressures, with trade-offs for supporting different types of associations. Finally, across plant hosts of both EM and AM, species with thinner root diameters and longer specific root length (SRL) had less colonization (rPIC = 0.85, −0.87), suggesting constraints on colonization linked to the evolution of root morphology. PMID:25247056

  17. Similar taxonomic richness but different communities of ectomycorrhizas in native forests and non-native plantation forests.

    PubMed

    O'Hanlon, Richard; Harrington, Thomas J

    2012-07-01

    This investigation sought to examine if there was a difference between the ectomycorrhizal (ECM) communities in plots of native oak and introduced Scots pine and Sitka spruce forest. The ECM communities in four plots of each forest type were described, from five soil cores collected in each plot, by morphotyping, internal transcribed spacer (ITS)-restriction fragment length polymorphism matching of mycorrhizas and sporocarps and ITS sequencing. Fifty-one distinct taxa were distinguished; 25 were identified to species level, 11 to genus and 15 remained unidentified. Seventy-one ECM species were recorded as sporocarps from the forest plots; most (43 species) were found in the Sitka spruce plots. The below-ground ECM communities of the different forest types did not differ significantly with respect to species richness of taxa on roots, but differed in species composition. Multivariate analysis produced a clear separation of the communities of the different forest types using below-ground data, but the above-ground sporocarp data did not separate the forest types. Moreover, results of a Mantel test found no relationship between the above- and below-ground similarity matrices. The oak plots had the most distinctive ECM community, with Laccaria amethystina and Elaphomyces granulatus being frequent. The Sitka spruce plots showed the lowest intra-forest type similarity and were often dominated by "nursery type" ectomycorrhizas. There was only 10% similarity between the above- and below-ground ECM species in these plots, different colonisation methods of ectomycorrhizal taxa and insufficient below-ground sampling being possible reasons for this disparity. Our results indicate that plantations of non-native Sitka spruce can support similar levels of ECM diversity as native forests. PMID:21947779

  18. A nitrogen fertilization field study of carbon-13 and nitrogen-15 transfers in ectomycorrhizas of Pinus sabiniana.

    PubMed

    Albarracín, María Victoria; Six, Johan; Houlton, Benjamin Z; Bledsoe, Caroline S

    2013-12-01

    Ectomycorrhizal (EM) fungi form relationships with higher plants; plants transfer C to fungi, and fungi transfer nutrients to their host. While evidence indicates that this interaction is largely mutualistic, less is known about how nutrient supply and EM associates may alter C and nutrient exchanges, especially in intact plant-soil-microbe systems in the field. In a dual-labeling experiment with N fertilization, we used C and N stable isotopes to examine in situ transfers in EM pine trees in a Pinus sabiniana woodland in northern California. We added (15)NH4SO2 and (13)CO2 to track (13)C transfer from pine needles to EM roots and (15)N transfer from soil to EM roots and pine needles. Transfers of (13)C and (15)N differed with EM morphotype and with N fertilization. The brown morphotype received the least C per unit of N transferred (5:1); in contrast red and gold morphotypes gained more C and transferred less N (17:1 and 25:1, respectively). N fertilization increased N retention by ectomycorrhizas (EMs) but did not increase N transfer from EMs to pine needles. Therefore N fertilization positively affected both nutrient and C gains by EMs, increasing net C flows and N retention in EMs. Our work on intact and native trees/EM associations thereby extends earlier conclusions based on pot studies with young plants and culturable EM fungi; our results support the concept that EM-host relationships depend on species-level differences as well as responses to soil resources such as N. PMID:23912260

  19. Patterns in root traits of woody species hosting arbuscular and ectomycorrhizas: implications for the evolution of belowground strategies.

    PubMed

    Comas, Louise H; Callahan, Hilary S; Midford, Peter E

    2014-08-01

    Root traits vary enormously among plant species but we have little understanding of how this variation affects their functioning. Of central interest is how root traits are related to plant resource acquisition strategies from soil. We examined root traits of 33 woody species from northeastern US forests that form two of the most common types of mutualisms with fungi, arbuscular mycorrhizas (AM) and ectomycorrhizas (EM). We examined root trait distribution with respect to plant phylogeny, quantifying the phylogenetic signal (K statistic) in fine root morphology and architecture, and used phylogenetically independent contrasts (PICs) to test whether taxa forming different mycorrhizal associations had different root traits. We found a pattern of species forming roots with thinner diameters as species diversified across time. Given moderate phylogenetic signals (K = 0.44-0.68), we used PICs to examine traits variation among taxa forming AM or EM, revealing that hosts of AM were associated with lower branching intensity (r PIC = -0.77) and thicker root diameter (r PIC = -0.41). Because EM evolved relatively more recently and intermittently across plant phylogenies, significant differences in root traits and colonization between plants forming AM and EM imply linkages between the evolution of these biotic interactions and root traits and suggest a history of selection pressures, with trade-offs for supporting different types of associations. Finally, across plant hosts of both EM and AM, species with thinner root diameters and longer specific root length (SRL) had less colonization (r PIC = 0.85, -0.87), suggesting constraints on colonization linked to the evolution of root morphology. PMID:25247056

  20. Performance of loblolly, Virginia, and shortleaf pine on a reclaimed surface mine as affected by Pisolithus tinctorius ectomycorrhizae and fertilization

    SciTech Connect

    Walker, R.F.; West, D.C.; McLaughlin, S.B.; Amundsen, C.C.

    1985-01-01

    The effects of an induced Pisolithus tinctorius infection and broadcast fertilization were studied on the survival and growth of loblolly (Pinus taeda), Virginia (Pinus virginiana), and shortleaf (Pinus echinata) pine outplanted on a reclaimed east Tennessee coal surface mine site. The study site had been previously regraded and hydroseeded with a mixture of ground cover species. After six years, the survival and growth of loblolly pine with P. tinctorius ectomycorrhizae were signficantly improved in comparison with control loblolly pine infected by other ectomycorrhizal symbionts. The response of the Virginia pine to the infection by P. tinctorius was negligible after five years. Fertilization at outplanting significantly reduced the survival of both loblolly and Virginia pine. Fertilization of the shortleaf pine at the start of the third growing season did not result in the drastic mortality exhibited by the loblolly pine, and to a lesser extent the Virginia pine, in response to fertilization at outplanting, but this treatment was still detrimental to the survival of the shortleaf pine after five years. There was a marginal improvement in the survival and growth of the shortleaf pine in response to the infection by P. tinctorius. The effect of fertilization on the growth of all three species was negligible, and the increase in mortality associated with this treatment appeared to be primarily the result of increased competition with the ground cover species. These results indicate that the magnitude of the response exhibited by pines on harsh sites to an ectomycorrhizal infection by P. tinctorius is species dependent. Also, broadcast fertilization is inefficient on surface-mined sites where a vegetative ground cover has been established. 11 refs., 3 tabs.

  1. Local distribution of ectomycorrhizae-associated basidiomycetes in forest soil correlates with the degree of soil organic matter humification and available electrolytes.

    PubMed

    Gryndler, M; Soukupová, L; Gryndlerová, H; Baldrian, P; Hršelová, H

    2010-09-01

    Spatial distribution of ectomycorrhizae-associated basidiomycetes was determined in oakbirch forest using terminal restriction fragment length polymorphism (T-RFLP) analysis. The data were correlated with actual soil humidity, pH, electric conductivity of the soil extract, absorbance A(465) and A(665) of water and alkali soil extracts and with the ratio A(465)/A(665) (parameter A4/A6). Natural non-homogeneity of the soil parameters was used as experimental gradient. Distance-based redundancy analysis of the T-RFLP data (with soil parameters being taken as environmental parameters) provided significant results when ITS1F-terminanted restriction fragments were analyzed. Among other fungi, a Mycena galericulata related fungus was observed to correlate negatively with A4/A6, indicating its association with highly humified soil organic matter. Positive association of other, unidentified fungi with A4/A6 was also observed. Several other unidentified fungi negatively correlated with electric conductivity of the soil extract. The results may explain nonhomogeneity of the spatial distribution of the fungi associated with ectomycorrhizae as a result of their interaction with non-homogeneous soil environment. PMID:20941580

  2. Quantification of extraradical soil mycelium and ectomycorrhizas of Boletus edulis in a Scots pine forest with variable sporocarp productivity.

    PubMed

    De la Varga, Herminia; Agueda, Beatriz; Martínez-Peña, Fernando; Parladé, Javier; Pera, Joan

    2012-01-01

    concentration of soil mycelium or with the presence or abundance of ectomycorrhizas. PMID:21494822

  3. Ectomycorrhizas in vitro between Tricholoma matsutake, a basidiomycete that associates with Pinaceae, and Betula platyphylla var. japonica, an early-successional birch species, in cool-temperate forests.

    PubMed

    Murata, Hitoshi; Yamada, Akiyoshi; Maruyama, Tsuyoshi; Neda, Hitoshi

    2015-04-01

    Tricholoma matsutake is an ectomycorrhizal basidiomycete that associates with Pinaceae in the Northern Hemisphere and produces prized "matsutake" mushrooms. We questioned whether the symbiont could associate with a birch that is an early-successional species in boreal, cool-temperate, or subalpine forests. In the present study, we demonstrated that T. matsutake can form typical ectomycorrhizas with Betula platyphylla var. japonica; the associations included a Hartig net and a thin but distinct fungal sheath, as well as the rhizospheric mycelial aggregate "shiro" that is required for fruiting in nature. The in vitro shiro also emitted a characteristic aroma. This is the first report of an ectomycorrhizal formation between T. matsutake and a deciduous broad-leaved tree in the boreal or cool-temperate zones that T. matsutake naturally inhabits. PMID:25236465

  4. Time and dose of irrigation impact Tuber melanosporum ectomycorrhiza proliferation and growth of Quercus ilex seedling hosts in young black truffle orchards.

    PubMed

    Olivera, Antoni; Bonet, José Antonio; Oliach, Daniel; Colinas, Carlos

    2014-04-01

    In Mediterranean climate, young truffle-oak orchards are subjected to drought episodes that can compromise the development of Tuber melanosporum. We investigated the responses of T. melanosporum to water supply in three periods: May to July, August to October, and May to October. In each period, five water doses were established: 0, 25, 50, 75, and 100% of the reference evapotranspiration (ETo). Five orchards were planted with Quercus ilex inoculated with T. melanosporum, and in each orchard, we arranged a two-factorial design with irrigation period and irrigation dose as main factors to test their combined effects on the development of both T. melanosporum and Q. ilex after 3 years in the field. Irrigation period significantly interacted with irrigation doses for the absolute presence per seedling of T. melanosporum mycorrhizae. Irrigation in May-July increased significantly T. melanosporum colonization in seedlings irrigated with 50% ETo dose compared to the 0% ETo dose. A similar pattern with smaller differences in means was observed in August-October period, but the irrigation doses did not change T. melanosporum colonization when we watered from May to October. We found ectomycorrhizae different from T. melanosporum in 51% of the seedlings studied, but their presence was marginal. Our results suggest that a moderate irrigation dose promotes seedling growth and number of fine root tips per unit of fine root length, which may be potentially colonized by T. melanosporum. PMID:24310929

  5. The AD-type ectomycorrhizas, one of the most common morphotypes present in truffle fields, result from fungi belonging to the Trichophaea woolhopeia species complex.

    PubMed

    Rubini, Andrea; Belfiori, Beatrice; Passeri, Valentina; Baciarelli Falini, Leonardo; Arcioni, Sergio; Riccioni, Claudia; Paolocci, Francesco

    2011-01-01

    Belowground ectomycorrhizal communities are often species rich. Characterization of the ectomycorrhizas (ECMs) underneath native truffle areas and/or cultivation sites is particularly relevant to identifying fungal species that might interfere with or promote truffle propagation and fruiting. Fungal identification at the genus/species level can now be achieved by combining detailed morphological and anatomical descriptions with molecular approaches. In a survey of the mycorrhizal biodiversity of Tuber melanosporum orchards and inoculated host plants in nurseries, we repeatedly sampled ECMs with morphological features resembling those of the ECMs widely known as the AD type. Despite the fact that the AD type is regarded as one of the most competitive fungal species towards Tuber spp., its taxonomical rank has yet to be resolved. By analyzing the 28S and internal transcribed spacer (ITS) rDNA regions, here, we show that AD-type ECMs result from host plant colonization by the pyronemataceous species Trichophaea woolhopeia. Further to this, the 28S and ITS phylogenetic trees built from the AD-type ECMs analyzed sustain the hypothesis that T. woolhopeia is a species complex. PMID:20349093

  6. Comparing the intra-annual wood formation of three European species (Fagus sylvatica, Quercus petraea and Pinus sylvestris) as related to leaf phenology and non-structural carbohydrate dynamics.

    PubMed

    Michelot, Alice; Simard, Sonia; Rathgeber, Cyrille; Dufrêne, Eric; Damesin, Claire

    2012-08-01

    Monitoring cambial phenology and intra-annual growth dynamics is a useful approach for characterizing the tree growth response to climate change. However, there have been few reports concerning intra-annual wood formation in lowland temperate forests with high time resolution, especially for the comparison between deciduous and coniferous species. The main objective of this study was to determine how the timing, duration and rate of radial growth change between species as related to leaf phenology and the dynamics of non-structural carbohydrates (NSC) under the same climatic conditions. We studied two deciduous species, Fagus sylvatica L. and Quercus petraea (Matt.) Liebl., and an evergreen conifer, Pinus sylvestris L. During the 2009 growing season, we weekly monitored (i) the stem radial increment using dendrometers, (ii) the xylem growth using microcoring and (iii) the leaf phenology from direct observations of the tree crowns. The NSC content was also measured in the eight last rings of the stem cores in April, June and August 2009. The leaf phenology, NSC storage and intra-annual growth were clearly different between species, highlighting their contrasting carbon allocation. Beech growth began just after budburst, with a maximal growth rate when the leaves were mature and variations in the NSC content were low. Thus, beech radial growth seemed highly dependent on leaf photosynthesis. For oak, earlywood quickly developed before budburst, which probably led to the starch decrease quantified in the stem from April to June. For pine, growth began before the needles unfolding and the lack of NSC decrease during the growing season suggested that the substrates for radial growth were new assimilates of the needles from the previous year. Only for oak, the pattern determined from the intra-annual growth measured using microcoring differed from the pattern determined from dendrometer data. For all species, the ring width was significantly influenced by growth duration

  7. Promoter-dependent expression of the fungal transporter HcPT1.1 under Pi shortage and its spatial localization in ectomycorrhiza.

    PubMed

    Garcia, Kevin; Haider, Muhammad Zulqurnain; Delteil, Amandine; Corratgé-Faillie, Claire; Conéjero, Geneviève; Tatry, Marie-Violaine; Becquer, Adeline; Amenc, Laurie; Sentenac, Hervé; Plassard, Claude; Zimmermann, Sabine

    2013-01-01

    Mycorrhizal exchange of nutrients between fungi and host plants involves a specialization and polarization of the fungal plasma membrane adapted for the uptake from the soil and for secretion of nutrient ions towards root cells. In addition to the current progress in identification of membrane transport systems of both symbiotic partners, data concerning the transcriptional and translational regulation of these proteins are needed to elucidate their role for symbiotic functions. To answer whether the formerly described Pi-dependent expression of the phosphate transporter HcPT1.1 from Hebeloma cylindrosporum is the result of its promoter activity, we introduced promoter-EGFP fusion constructs in the fungus by Agrotransformation. Indeed, HcPT1.1 expression in pure fungal cultures quantified and visualized by EGFP under control of the HcPT1.1 promoter was dependent on external Pi concentrations, low Pi stimulating the expression. Furthermore, to study expression and localization of the phosphate transporter HcPT1.1 in symbiotic conditions, presence of transcripts and proteins was analyzed by the in situ hybridization technique as well as by immunostaining of proteins. In ectomycorrhiza, expression of the phosphate transporter was clearly enhanced by Pi-shortage indicating its role in Pi nutrition in the symbiotic association. Transcripts were detected in external hyphae and in the hyphal mantle, proteins in addition also within the Hartig net. Exploiting the transformable fungus H. cylindrosporum, Pi-dependent expression of the fungal transporter HcPT1.1 as result from its promoter activity as well as transcript and protein localization in ectomycorrhizal symbiosis are shown. PMID:23850603

  8. Upgrading Root Physiology for Stress Tolerance by Ectomycorrhizas: Insights from Metabolite and Transcriptional Profiling into Reprogramming for Stress Anticipation1[C][W][OA

    PubMed Central

    Luo, Zhi-Bin; Janz, Dennis; Jiang, Xiangning; Göbel, Cornelia; Wildhagen, Henning; Tan, Yupeng; Rennenberg, Heinz; Feussner, Ivo; Polle, Andrea

    2009-01-01

    Ectomycorrhizas (EMs) alleviate stress tolerance of host plants, but the underlying molecular mechanisms are unknown. To elucidate the basis of EM-induced physiological changes and their involvement in stress adaptation, we investigated metabolic and transcriptional profiles in EM and non-EM roots of gray poplar (Populus × canescens) in the presence and absence of osmotic stress imposed by excess salinity. Colonization with the ectomycorrhizal fungus Paxillus involutus increased root cell volumes, a response associated with carbohydrate accumulation. The stress-related hormones abscisic acid and salicylic acid were increased, whereas jasmonic acid and auxin were decreased in EM compared with non-EM roots. Auxin-responsive reporter plants showed that auxin decreased in the vascular system. The phytohormone changes in EMs are in contrast to those in arbuscular mycorrhizas, suggesting that EMs and arbuscular mycorrhizas recruit different signaling pathways to influence plant stress responses. Transcriptome analyses on a whole genome poplar microarray revealed activation of genes related to abiotic and biotic stress responses as well as of genes involved in vesicle trafficking and suppression of auxin-related pathways. Comparative transcriptome analysis indicated EM-related genes whose transcript abundances were independent of salt stress and a set of salt stress-related genes that were common to EM non-salt-stressed and non-EM salt-stressed plants. Salt-exposed EM roots showed stronger accumulation of myoinositol, abscisic acid, and salicylic acid and higher K+-to-Na+ ratio than stressed non-EM roots. In conclusion, EMs activated stress-related genes and signaling pathways, apparently leading to priming of pathways conferring abiotic stress tolerance. PMID:19812185

  9. Strain-specific bioaccumulation and intracellular distribution of Cd²⁺ in bacteria isolated from the rhizosphere, ectomycorrhizae, and fruitbodies of ectomycorrhizal fungi.

    PubMed

    Hrynkiewicz, Katarzyna; Złoch, Michał; Kowalkowski, Tomasz; Baum, Christel; Niedojadło, Katarzyna; Buszewski, Bogusław

    2015-02-01

    Bioaccumulation of Cd(2+) in soil bacteria might represent an important route of metal transfer to associated mycorrhizal fungi and plants and may have potential as a tool to accelerate Cd(2+) extraction in the bioremediation of contaminated soils. The present study examined the bioaccumulation of Cd(2+) in 15 bacterial strains representing three phyla (Firmicutes, Proteobacteria, and Bacteroidetes) that were isolated from the rhizosphere, ectomycorrhizae, and fruitbody of ectomycorrhizal fungi. The strains Pseudomonas sp. IV-111-14, Variovorax sp. ML3-12, and Luteibacter sp. II-116-7 displayed the highest biomass productivity at the highest tested Cd(2+) concentration (2 mM). Microscopic analysis of the cellular Cd distribution revealed intracellular accumulation by strains Massilia sp. III-116-18, Pseudomonas sp. IV-111-14, and Bacillus sp. ML1-2. The quantities of Cd measured in the interior of the cells ranged from 0.87 to 1.31 weight % Cd. Strains originating from the rhizosphere exhibited higher Cd(2+) accumulation efficiencies than strains from ectomycorrhizal roots or fruitbodies. The high Cd tolerances of Pseudomonas sp. IV-111-16 and Bacillus sp. ML1-2 were attributed to the binding of Cd(2+) as cadmium phosphate. Furthermore, silicate binding of Cd(2+) by Bacillus sp. ML1-2 was observed. The tolerance of Massilia sp. III-116-18 to Cd stress was attributed to a simultaneous increase in K(+) uptake in the presence of Cd(2+) ions. We conclude that highly Cd-tolerant and Cd-accumulating bacterial strains from the genera Massilia sp., Pseudomonas sp., and Bacillus sp. might offer a suitable tool to improve the bioremediation efficiency of contaminated soils. PMID:25231735

  10. The architecture of Norway spruce ectomycorrhizae: three-dimensional models of cortical cells, fungal biomass, and interface for potential nutrient exchange.

    PubMed

    Stögmann, Bernhard; Marth, Andreas; Pernfuß, Barbara; Pöder, Reinhold

    2013-08-01

    Gathering realistic data on actual fungal biomass in ectomycorrhized fine root systems is still a matter of concern. Thus far, observations on architecture of ectomycorrhizae (ECMs) have been limited to analyses of two-dimensional (2-D) images of tissue sections. This unavoidably causes stereometrical problems that lead to inadequate assumptions about actual size of cells and their arrangement within ECM's functional compartments. Based on extensive morphological investigations of field samples, we modeled the architectural components of an average-sized Norway spruce ECM. In addition to our comprehensive and detailed quantitative data on cell sizes, we studied actual shape and size, in vivo arrangement, and potential nutrient exchange area of plant cortical cells (CCs) using computer-aided three-dimensional (3-D) reconstructions based on semithin serial sections. We extrapolated a factual fungal biomass in ECMs (Hartig net (HN) included) of 1.71 t ha(-1) FW (0.36 t ha(-1) DW) for the top 5 cm of soil for an autochthonous, montane, optimum Norway spruce stand in the Tyrolean Alps. The corresponding potential nutrient exchange area in ECMs including main axes of ECM systems, which is defined as the sum of interfaces between plant CCs and the HN, amounts to at least 3.2 × 10(5) m(2) ha(-1). This is the first study that determines the contribution of the HN to the total fungal biomass in ECMs as well as the quantification of its contact area. Our results may stimulate future research on fungal below-ground processes and their impact on the global carbon cycle. PMID:23435714

  11. Identification of quantitative trait loci affecting ectomycorrhizal symbiosis in an interspecific F1 poplar cross and differential expression of genes in ectomycorrhizas of the two parents: Populus deltoides and Populus trichocarpa

    SciTech Connect

    Labbe, Jessy L; Jorge, Veronique; Vion, Patrice; Marcais, Benoit; Bastien, Catherine; Tuskan, Gerald A; Martin, Francis; Le Tacon, F

    2011-01-01

    A Populus deltoides Populus trichocarpa F1 pedigree was analyzed for quantitative trait loci (QTLs) affecting ectomycorrhizal development and for microarray characterization of gene networks involved in this symbiosis. A 300 genotype progeny set was evaluated for its ability to form ectomycorrhiza with the basidiomycete Laccaria bicolor. The percentage of mycorrhizal root tips was determined on the root systems of all 300 progeny and their two parents. QTL analysis identified four significant QTLs, one on the P. deltoides and three on the P. trichocarpa genetic maps. These QTLs were aligned to the P. trichocarpa genome and each contained several megabases and encompass numerous genes. NimbleGen whole-genome microarray, using cDNA from RNA extracts of ectomycorrhizal root tips from the parental genotypes P. trichocarpa and P. deltoides, was used to narrow the candidate gene list. Among the 1,543 differentially expressed genes (p value 0.05; 5.0-fold change in transcript level) having different transcript levels in mycorrhiza of the two parents, 41 transcripts were located in the QTL intervals: 20 in Myc_d1, 14 in Myc_t1, and seven in Myc_t2, while no significant differences among transcripts were found in Myc_t3. Among these 41 transcripts, 25 were overrepresented in P. deltoides relative to P. trichocarpa; 16 were overrepresented in P. trichocarpa. The transcript showing the highest overrepresentation in P. trichocarpa mycorrhiza libraries compared to P. deltoides mycorrhiza codes for an ethylene-sensitive EREBP-4 protein which may repress defense mechanisms in P. trichocarpa while the highest overrepresented transcripts in P. deltoides code for proteins/genes typically associated with pathogen resistance.

  12. Tricholoma vaccinum host communication during ectomycorrhiza formation.

    PubMed

    Wagner, Katharina; Linde, Jörg; Krause, Katrin; Gube, Matthias; Koestler, Tina; Sammer, Dominik; Kniemeyer, Olaf; Kothe, Erika

    2015-11-01

    The genome sequence of Tricholoma vaccinum was obtained to predict its secretome in order to elucidate communication of T. vaccinum with its host tree spruce (Picea abies) in interkingdom signaling. The most prominent protein domains within the 206 predicted secreted proteins belong to energy and nutrition (52%), cell wall degradation (19%) and mycorrhiza establishment (9%). Additionally, we found small secreted proteins that show typical features of effectors potentially involved in host communication. From the secretome, 22 proteins could be identified, two of which showed higher protein abundances after spruce root exudate exposure, while five were downregulated in this treatment. The changes in T. vaccinum protein excretion with first recognition of the partner were used to identify small secreted proteins with the potential to act as effectors in the mutually beneficial symbiosis. Our observations support the hypothesis of a complex communication network including a cocktail of communication molecules induced long before physical contact of the partners. PMID:26449385

  13. Mycorrhization helper bacteria: a case of specificity for altering ectomycorrhiza architecture but not ectomycorrhiza formation.

    PubMed

    Aspray, Thomas J; Frey-Klett, Pascale; Jones, Julie E; Whipps, John M; Garbaye, Jean; Bending, Gary D

    2006-11-01

    Mycorrhization helper bacteria (MHB), isolated from phylogenetically distinct ectomycorrhizal symbioses involving Lactarius rufus, Laccaria bicolor or Suillus luteus, were tested for fungus specificity to enhance L. rufus-Pinus sylvestris or L. bicolor-P. sylvestris mycorrhiza formation. As MHB isolated from the L. rufus and S. luteus mycorrhiza were originally characterised using a microcosm system, we assessed their ability to enhance mycorrhiza formation in a glasshouse system in order to determine the extent to which MHB are system-specific. Paenibacillus sp. EJP73, an MHB for L. rufus in the microcosm, significantly enhanced L. bicolor mycorrhiza formation in the glasshouse, demonstrating that the MHB effect of this bacterium is neither fungus-specific nor limited to the original experimental system. Although the five MHB strains studied were unable to significantly enhance L. rufus mycorrhiza formation, two of them did have a significant effect on dichotomous short root branching by L. rufus. The effect was specific to Paenibacillus sp. EJP73 and Burkholderia sp. EJP67, the two strains isolated from L. rufus mycorrhiza, and was not associated with auxin production. Altered mycorrhiza architecture rather than absolute number of mycorrhizal roots may be an important previously overlooked parameter for defining MHB effects. PMID:16983568

  14. Ectomycorrhizins - symbiosis-specific or artitactual polypeptides from ectomycorrhizas?

    PubMed

    Guttenberger, M; Hampp, R

    1992-08-01

    Fungal mycelium of the fly agaric (Amanita muscaria [L. ex Fr.] Hooker), and inoculated or noninoculated seedlings of Norway spruce (Picea abies [L.] Karst.) were grown aseptically under controlled conditions. In order to detect symbiosis-specific polypeptides ('ectomycorrhizins', see Hubert and Martin, 1988, New Phytol. 110, 339-346) the protein patterns of (i) fungal mycelium, (ii) mycorrhizal, and (iii) non-mycorrhizal root tips were compared by means of one- and twodimensional electrophoresis on a microscale. Because of the sensitivity of these micromethods (50 and 200 ng of protein, respectively), single mycorrhizal root tips and even the minute quantities of extramatrical mycelium growing between the roots of inoculated plants could be analysed. Differences in the protein patterns of root tips could be shown within the root system of an individual plant (mycorrhizal as well as non-mycorrhizal). In addition, the protein pattern of fungal mycelium grown on a complex medium (malt extract and casein hydrolysate) differed from that of extramatrical mycelium collected from the mycorrhiza culture (pure mineral medium). Such differences in protein patterns are obviously due to the composition of the media and/or different developmental stages. Consequently, conventional analyses which use extracts of a large number of root tips, are not suitable for differentiating between these effects and symbiosis-specific differences in protein patterns. In order to detect ectomycorrhizins, it is suggested that roots and mycelium from individual, inoculated plants should be analysed. This approach eliminates the influence of differing media, and at the same time allows a correct discrimination between developmental and symbiosisspecific changes. In our gels we could only detect changes in spot intensity but could not detect any ectomycorrhizins or the phenomenon of polypeptide 'cleansing', which both characterize the Eucalyptus-Pisolithus symbiosis (Martin and Hubert, 1991, Experientia 47, 321-331). We thus suggest that these reported effects either are specific for the Eucalyptus-Pisolithus symbiosis or simply represent artifacts. The latter point of view is strengthened by a comparison of the experimental approaches. PMID:24178209

  15. Ectomycorrhizins - symbiosis-specific or artifactual polypeptides from ectomycorrhizas?

    PubMed

    Guttenberger, M; Hampp, R

    1992-03-01

    Fungal mycelium of the fly agaric (Amanita muscaria [L. ex Fr.] Hooker), and inoculated or noninoculated seedlings of Norway spruce (Picea abies [L.] Karst.) were grown aseptically under controlled conditions. In order to detect symbiosis-specific polypeptides ('ectomycorrhizins', see Hubert and Martin, 1988, New Phytol.110, 339-346) the protein patterns of (i) fungal mycelium, (ii) mycorrhizal, and (iii) non-mycorrhizal root tips were compared by means of one- and twodimensional electrophoresis on a microscale. Because of the sensitivity of these micromethods (50 and 200 ng of protein, respectively), single mycorrhizal root tips and even the minute quantities of extramatrical mycelium growing between the roots of inoculated plants could be analysed. Differences in the protein patterns of root tips could be shown within the root system of an individual plant (mycorrhizal as well as non-mycorrhizal). In addition, the protein pattern of fungal mycelium grown on a complex medium (malt extract and casein hydrolysate) differed from that of extramatrical mycelium collected from the mycorrhiza culture (pure mineral medium). Such differences in protein patterns are obviously due to the composition of the media and/or different developmental stages. Consequently, conventional analyses which use extracts of a large number of root tips, are not suitable for differentiating between these effects and symbiosis-specific differences in protein patterns. In order to detect ectomycorrhizins, it is suggested that roots and mycelium from individual, inoculated plants should be analysed. This approach eliminates the influence of differing media, and at the same time allows a correct discrimination between developmental and symbiosisspecific changes. In our gels we could only detect changes in spot intensity but could not detect any ectomycorrhizins or the phenomenon of polypeptide 'cleansing', which both characterize theEucalyptus-Pisolithus symbiosis (Martin and Hubert, 1991, Experientia47, 321-331). We thus suggest that these reported effects either are specific for theEucalyptus-Pisolithus symbiosis or simply represent artifacts. The latter point of view is strengthened by a comparison of the experimental approaches. PMID:24178210

  16. Endobacteria in some ectomycorrhiza of Scots pine (Pinus sylvestris).

    PubMed

    Izumi, Hironari; Anderson, Ian C; Alexander, Ian J; Killham, Ken; Moore, Edward R B

    2006-04-01

    The diversity of cultivable endobacteria associated with four different ectomycorrhizal morphotypes (Suillus flavidus, Suillus variegatus, Russula paludosa and Russula sp.) of Scots pine (Pinus sylvestris) was analysed by restriction fragment length polymorphism profiling of PCR-amplified rDNA intergenic spacer regions and by sequence analyses of 16S rRNA genes. Ectomycorrhizal root tip surface-sterilization methods were developed and assessed for their efficiencies. Bacterial communities from surface-sterilized ectomycorrhizal root tips were different from those of ectomycorrhizal root tips without surface-sterilization for all the morphotypes studied. Endobacteria belonging to the genera Pseudomonas, Burkholderia and Bacillus were isolated from more than one ectomycorrhizal morphotype, whereas species of Rahnella, Janthinobacterium and Rhodococcus were only isolated from the single morphotypes of S. variegatus, R. paludosa and Russula sp., respectively. Some of the isolated endobacteria utilized fungal sugars more readily than typical plant sugars in carbon utilization assays. PMID:16542403

  17. Response of sessile oak seedlings (Quercus petraea) to flooding: an integrated study.

    PubMed

    Folzer, Hélène; Dat, James F; Capelli, Nicolas; Rieffel, Dominique; Badot, Pierre-Marie

    2006-06-01

    Sessile oak is a species of great ecological and silvicultural importance in Europe; however, increased frequency and severity of flooding of forested areas pose a threat to its regeneration. We monitored water relations, root anatomical changes and the expression of two calmodulin genes (QpCaM) in sessile oak seedlings during a 14-day flooding treatment. The response followed two characteristic sequences. The first phase, in response to between 1 h and 3 days of flooding, was characterized by a dramatic but transient decline in water relations parameters followed by a recovery towards control values with no noticeable change in root cell morphology. During the second phase, in response to 3 to 14 days of flooding, water relations parameters gradually and continuously declined and hypertrophied lenticels developed at the base of the shoot. Concurrently, root cortical cells became larger and less spherical and the root cortex more porous. These cellular changes were accompanied by a transient rise in root transcript levels of QpCaM-2. We conclude that sessile oak seedlings are capable of withstanding a 3-day period of flooding without significant morphological alterations. In contrast, exposure to flooding for more than 3 days resulted in anatomical and morphological changes in the root system. These changes are, however, insufficient to provide sessile oak with long-term tolerance to flooding. PMID:16510391

  18. - A case study for sessile oak (Quercus petraea) distribution - Preliminarly results of a Decision Support System for climate impact analysis

    NASA Astrophysics Data System (ADS)

    Gulyás, Krisztina; Gálos, Borbála; Berki, Imre; Czimber, Kornél

    2014-05-01

    Rainfed sectors of forestry are threatened by projected climate change especially in low-elevation regions in Southeast Europe, where precipitation is the limiting factor of production and ecosystem stability. To initiate preparation for frequency increase of extreme events, disasters and economic losses, a Decision Support System is under development, which provides GIS-supported information about the most important regional and local risks and mitigation options regarding climate change impacts. The case study will focus on the following aspects: • For the time period 1961-2010, precipitation and temperature means and extreme events have been analyzed in the Carpathian basin, using gridded station data from the EU-project CARPATCLIM (http://www.carpatclim-eu.org). • The climate indicators have been identified that characterize and determine the distribution, healty status and vitality of sessile oak. • As a product of the Decision Support System a distribution model is under development, which describes the connection between climate conditions and the distribution of sessile oak. The case study shows, how climate data can be used for impact analyses in the forestry sector. Applying different climate change scenarios, the expected distribution of tree species can be simulated. Acknowledgements: The development of the Decision Support System "Agrárklíma" is supported by TÁMOP-4.2.2.A-11/1/KONV and 4.2.2.B-10/1-2010-0018 "Talentum" joint EU-national research projects. Keywords: climate change, decision support system, distribution model, sessile oak

  19. Nitrogen transport in the ectomycorrhiza association: the Hebeloma cylindrosporum-Pinus pinaster model.

    PubMed

    Müller, Tobias; Avolio, Meghan; Olivi, Martin; Benjdia, Mariam; Rikirsch, Enno; Kasaras, Alexis; Fitz, Michael; Chalot, Michel; Wipf, Daniel

    2007-01-01

    The function of the ectomycorrhizal mutualism depends on the ability of the fungal symbionts to take up nutrients (particularly nitrogen) available in inorganic and/or organic form in the soil and to translocate them (or their metabolites) to the symbiotic roots. A better understanding of the molecular mechanisms underlying nutrient exchanges between fungus and plant at the symbiotic interface is necessary to fully understand the function of the mycorrhizal symbioses. The present review reports the characterization of several genes putatively involved in nitrogen uptake and transfer in the Hebeloma cylindrosporum-Pinus pinaster ectomycorrhizal association. Study of this model system will further clarify the symbiotic nutrient exchange which plays a major role in plant nutrition as well as in resistance of plants against pathogens, heavy metals, drought stress, etc. Ultimately, ecological balance is maintained and/or improved with the help of symbiotic associations, and therefore, warrant further understanding. PMID:17083951

  20. SYNTHESIS OF ECTOMYCORRHIZAE ON NORTHERN RED OAK SEEDLINGS IN MICHIGAN NURSERY

    EPA Science Inventory

    Vegetative inoculum of the ectomycorrhizal fungus Suillus luteus was thoroughly mixed into fumigated nursery soil, and northern red oak seedlings of four families were evaluated one and two years after sowing for ectomycorrhizal development, growth, and nutrition. t the end of ye...

  1. Ectomycorrhizae of Tuber huidongense and T. liyuanum with Castanea mollissima and Pinus armandii.

    PubMed

    Wan, Shan-Ping; Yu, Fu-Qiang; Tang, Li; Wang, Ran; Wang, Yun; Liu, Pei-Gui; Wang, Xiang-Hua; Zheng, Yi

    2016-04-01

    Tuber huidongense and T. liyuanum are common commercial white truffles in China that belong to the Rufum and Puberulum groups of the genus Tuber, respectively. Their mycorrhizae were successfully synthesized with two native trees--Castanea mollissima and Pinus armandii--under greenhouse conditions. The identities of the mycorrhizae were confirmed through internal transcribed spacer (ITS) sequence analyses, and their morphological characteristics were described. All of the obtained mycorrhizae have an interlocking pseudoparenchymatous mantle, which is a typical feature of truffle mycorrhizae. The mycorrhizae of T. huidongense on the two trees have hyaline branched emanating hyphae, similar to the documented mycorrhizae of the Rufum group. The unramified, spiky, and hyaline cystidia on the mycorrhizae of T. liyuanum with both C. mollissima and P. armandii further confirmed that this characteristic is constant for the mycorrhizae of the Puberulum group. The successful mycorrhizal syntheses on the two nut-producing trees will be of economic importance in the cultivation of the two truffles. PMID:26452572

  2. Ectomycorrhizae influences on CO/sub 2/ exchange and carbon allocation in Pinus

    SciTech Connect

    Kidd, F.A.

    1983-01-01

    Although the importance of mycorrhizal fungi in nutrient ion absorption is relatively well documented, little is known concerning the energy cost required of the host plant for the maintenance of the nurient-absorbing area provided by the mycorrhizae. The objective of this research was to gain further knowledge on how the basic physiological processes of photosynthesis and respiration, as well as allocation of carbon compounds, may be stimulated in host Pinus seedlings through source-sink relationships resulting from mycorrhizae. Seedlings of four Pinus species with 50-75% short root infection by three mycorrhizae species had a rate of net photosynthesis 3X as great as that of noninfected plants. The increase in CO/sub 2/ fixation appeared linear with respect to fungal infection as percentage short root infection increased from zero to 75%. When other parameters of seedling growth and morphology, i.e. shoot and root dry weight, dark respiration rates, and foliar concentration of nitrogen, were correlated with net photosynthetic rate, only mycorrhizae infection demonstrated a statistically significant (P < 0.05) influence on increasing host CO/sub 2/ exchange. Partitioning of current photosynthate was examined by pulse-labeling Pinus taeda L. with /sup 14/CO/sub 2/ at each of six time intervals. Although the stimulation of photosynthesis and allocation of current photosynthate to the root system by mycorrhizae formation was consistent with the source-sink concept of sink demand, foliar N and P concentrations were also greater in mycorrhizal plants.

  3. Final Report: Exudation by Poplar Ectomycorrhizas: Qualitative and Quantitative Assessment of C Sequestration

    SciTech Connect

    Cumming, J R

    2012-11-12

    Study 1. We compared mycorrhizal Populus tremuloides inoculated with Laccaria bicolor and nonmycorrhizal (NM) P. tremuloides seedlings grown under different levels of P nutrition. Decreasing concentrations of P significantly increased the activity of reactive oxygen scavenging enzymes. In addition, phosphoenolpyruvate carboxylase activity increased under P limitation. P deficiency also increased organic acid exudation and total organic carbon exudation. Colonization by L. bicolor reduced the P concentration thresholds where these physiological changes occurred. Study 2. We assessed the influences of ectomycorrhizal colonization on phosphate limitation responses of trembling aspen. Photosynthetic CO2 uptake was reduced in NM poplar, but not in plants colonized by L. bicolor or P. involutus. Reductions in shoot and root biomass in NM plants were substantially greater than reductions in plants colonized by either ectomycorrhizal fungi. Leaf starch and sugar concentrations declined with Pi limitation across mycorrhizal treatments, but were higher in plants colonized by L. bicolor and P. involutus. In roots, starch concentrations were greater in NM plants with Pi limitation. In roots, sugars were significantly higher in NM plants compared to mycorrhizal plants and increased significantly in NM plants under Pi limitation. Concentrations were unaffected by Pi limitation in plants colonized by L. bicolor or P. involutus. Study 3. We analyzed proteins that were differentially expressed during the mycorrhizal association. A comparison of global protein expression elucidated broad differences in protein profiles between NM plants and plants colonized by ectomycorrhizal (ECM) or arbuscular mycorrhizal (AM) fungi as well as differences between the ECM fungi L. bicolor and P. involutus. Plants colonized by P. involutus and G. intraradices exhibited unique patterns of up/down-regulated proteins compared to NM plants, whereas plants colonized by L. bicolor exhibited patterns of protein expression more aligned with NM plants. The greatest change in protein expression was in the areas of energy production and the TCA cycle. Among these proteins, fructose-bisphosphate and glyceraldehyde-3-phosphate dedydrogenase were notably up-regulated due to mycorrhizal colonization of aspen by L. bicolor. Pyruvate dehydrogenase, aldehyde dehydrogenase, and aconitate hydratase were up-regulated due to mycorrhizal colonized by P. involutus. Malate dehydrogenase, cinnamyl-alcohol dehydrogenase, and NADH-ubiquinone oxidoreductase proteins were up-regulated due to mycorrhizal colonization of aspen by G. intraradices. Study 4. Eight hybrid crosses of P. trichocarpa, P. deltoides and P. nigra were exposed to Al in solution culture. Resistance to Al varied by genotype and hybrid cross, with P. trichocarpa P. deltoides crosses being most resistant, P. trichocarpa P. nigra being intermediate and P. deltoides P. nigra being most sensitive to Al. Total root Al accumulation was not a good indicator of Al resistance/sensitivity. However, differences in sensitivity among genotypes were associated with Al uptake into the symplasm. Aluminum treatment increased callose and pectin concentrations of root tips more prominently in Al sensitive genotypes/hybrids. In Al sensitive genotypes, higher levels of symplastic Al accumulation correlated with elevated concentrations of citrate, malate, succinate or formate in root tips, whereas organic acid accumulation was not as pronounced in Al resistant genotypes. These findings suggest that exclusion of Al from the symplast is associated with Al resistance. Study 5. We assessed patterns of exudation in Al-resistant and Al-sensitive Populus hybrid crosses. Exposure to Al in solution induced the exudation of citrate and malate from the roots of both hybrid genotypes and altered the contributions of other organic acids to the exudation profiles. Citrate exudation was about 8-times greater in DTAC-7 (resistant) than OP-367 (sensitive). The analysis of total and cationic Al in solution indicated that the amount of bound Al in solution

  4. Ectomycorrhiza succession patterns in Pinus sylvestris forests after stand-replacing fire in the Central Alps.

    PubMed

    Kipfer, Tabea; Moser, Barbara; Egli, Simon; Wohlgemuth, Thomas; Ghazoul, Jaboury

    2011-09-01

    Fires shape fundamental properties of many forest ecosystems and climate change will increase their relevance in regions where fires occur infrequently today. In ecosystems that are not adapted to fire, post-fire tree recruitment is often sparse, a fact that might be attributed to a transient lack of mycorrhizae. Ectomycorrhizal (EcM) fungi play an important role for recruitment by enhancing nutrient and water uptake of their hosts. The questions arise whether and for how long the EcM community is transformed by fire. We investigated the resistance and resilience of EcM fungal communities on a chronosequence of 12 Pinus sylvestris stands in Valais (Switzerland) and Val d'Aosta (Italy) affected by fire between 1990 and 2006. Soil samples from burnt and non-burnt forests were analyzed with respect to EcM fungi by means of a bioassay. The number of EcM species was significantly lower in samples from recently (2-5 years) burnt sites than non-burnt forest, and increased with time since fire reaching levels of adjacent forests after 15-18 years. Community composition changed after fire but did not converge to that of non-burnt sites over the 18 year period. Only Rhizopogon roseolus and Cenococcum geophilum were abundant in both burnt sites and adjacent forest. Our data indicate fire resistance of some EcM fungal species as well as rapid resilience in terms of species number, but not in species composition. As long as the function of different EcM species for seedling establishment is unknown, the consequences of long-term shifts in EcM community composition for tree recruitment remain unclear. PMID:21468664

  5. Influence of zygomycete-derived D'orenone on IAA signalling in Tricholoma-spruce ectomycorrhiza.

    PubMed

    Wagner, Katharina; Krause, Katrin; David, Anja; Kai, Marco; Jung, Elke-Martina; Sammer, Dominik; Kniemeyer, Olaf; Boland, Wilhelm; Kothe, Erika

    2016-09-01

    Despite the rising interest in microbial communication, only few studies relate to mycorrhization and the pool of potential morphogenic substances produced by the surrounding soil community. Here, we investigated the effect exerted by the C18 - ketone β-apo-13-carotenone, D'orenone, on the ectomycorrhizal basidiomycete Tricholoma vaccinum and its symbiosis with the economically important host tree, spruce (Picea abies). D'orenone is an early intermediate in the biosynthesis of morphogens in sexual development of mucoromycetes, the trisporoids. In the ectomycorrhizal fungus T. vaccinum, D'orenone increased the production and/or release of the phytohormone indole-3-acetic acid (IAA) which had been proposed to be involved in the mutual symbiosis. The induced expression of the fungal aldehyde dehydrogenase, Ald5 is associated with IAA synthesis and excretion. In the host tree, D'orenone modulated root architecture by increasing lateral root length and hypertrophy of root cortex cells, likely via changed IAA concentrations and flux. Thus, we report for the first time on carotenoid metabolites from soil fungi affecting both ectomycorrhizal partners. The data imply a complex network of functions for secondary metabolites which act in an inter-kingdom signalling in soil. PMID:26636983

  6. Hartig' net formation of Tricholoma vaccinum-spruce ectomycorrhiza in hydroponic cultures.

    PubMed

    Henke, Catarina; Jung, Elke-Martina; Kothe, Erika

    2015-12-01

    For re-forestation of metal-contaminated land, ectomycorrhizal trees may provide a solution. Hence, the study of the interaction is necessary to allow for comprehensive understanding of the mutually symbiotic features. On a structural level, hyphal mantle and the Hartig' net formed in the root apoplast are essential for plant protection and mycorrhizal functioning. As a model, we used the basidiomycete Tricholoma vaccinum and its host spruce (Picea abies). Using an optimized hydroponic cultivation system, both features could be visualized and lower stress response of the tree was obtained in non-challenged cultivation. Larger spaces in the apoplasts could be shown with high statistical significance. The easy accessibility will allow to address metal stress or molecular responses in both partners. Additionally, the proposed cultivation system will enable for other experimental applications like addressing flooding, biological interactions with helper bacteria, chemical signaling, or other biotic or abiotic challenges relevant in the natural habitat. PMID:25791268

  7. ASSESSING ABUNDANCE DISTRIBUTIONS IN NATURAL COMMUNITIES OF ECTOMYCORRHIZAS ALONG AN ENVIRONMENTAL GRADIENT

    EPA Science Inventory

    Alpha diversity indices often fail to distinguish between natural populations that a more detailed investigation of the distribution of ramets among types would show are quite different. We studied the effectiveness of applying SHE analyses to morphotype classifications of ectom...

  8. Mitigation of antagonistic effects on plant growth due to root co-colonization by dark septate endophytes and ectomycorrhiza.

    PubMed

    Reininger, Vanessa; Sieber, Thomas N

    2013-12-01

    Dark septate endophytes (DSE) are very common root colonizers of woody plant species. Ascomycetes of the Phialocephala fortinii s.l.-Acephala applanata species complex (PAC) are the main representatives of DSE fungi in forest ecosystems. PAC and mycorrhizal fungi share the same habitat, but interactions among PAC, mycorrhizal fungi and plants are poorly understood. We compared the effects of single and dual inoculation of Norway spruce seedlings with PAC and the ectomycorrhizal (ECM) fungus Hebeloma crustuliniforme on host growth, degree of mycorrhization and density of endophytic PAC biomass. Single colonization by H. crustuliniforme or PAC significantly reduced plant biomass. Dual colonization reduced or neutralized plant growth depression caused by single fungal colonization. The degree of mycorrhization was independent on PAC colonization, and mycorrhization significantly reduced endophytic PAC biomass. Plant biomass of dually colonized plants positively correlated with PAC biomass. These results demonstrate the ability of dual inoculation of PAC and H. crustuliniforme to neutralize plant growth depression caused by single fungal inoculation. Our explanations of enhanced plant growth in dually inoculated plants are the inhibition of PAC during root colonization by the ECM mantle and ECM-mediated access to plant growth-promoting nutrients resulting from the mineralization of the potting medium by PAC. PMID:24249297

  9. Diversity of culturable bacterial populations associated to Tuber borchii ectomycorrhizas and their activity on T. borchii mycelial growth.

    PubMed

    Sbrana, Cristiana; Agnolucci, Monica; Bedini, Stefano; Lepera, Annamaria; Toffanin, Annita; Giovannetti, Manuela; Nuti, Marco P

    2002-06-01

    Isolation and physiological and molecular characterisation of culturable bacterial strains belonging to actinomycetes, pseudomonads and aerobic spore-forming bacteria were carried out on mycorrhizal root tips of Quercus robur var. peduncolata infected by Tuber borchii. Cellular density of the three bacterial groups in ectomycorrhizal root tips was estimated to be 1.3+/-0.11 x 10(6) cfu g(-1) dry weight for total heterotrophic bacteria and 1.08+/-0.6 x 10(5) (mean+/-S.E.), 1.3+/-0.3 x 10(5) and 1.4+/-0.2 x 10(5) cfu g(-1) dry weight for pseudomonads, actinomycetes and spore-forming bacteria respectively. Identification of pseudomonads by the Biolog system indicated, besides the most represented species Pseudomonas fluorescens (biotypes B, F and G), the occurrence of strains belonging to Pseudomonas corrugata. Amplified ribosomal DNA restriction analysis of actinomycetes and spore formers revealed at least three and six different groups of patterns, respectively. Many bacterial isolates were able to induce variations in growth rates of T. borchii mycelium; among these, 101 strains showed antifungal activity, whereas 17 isolates, belonging to spore formers, were able to increase mycelial growth up to 78% when compared to uninoculated mycelial growth. The potential role of these populations in the development and establishment of mycorrhizas is discussed. PMID:12076812

  10. The Microbiome of Pinus muricata Ectomycorrhizae: Community Assemblages, Fungal Species Effects, and Burkholderia as Important Bacteria in Multipartnered Symbioses.

    PubMed

    Nguyen, Nhu H; Bruns, Thomas D

    2015-05-01

    Bacteria have been observed to grow with fungi, and those that associate with ectomycorrhizal fungi have often been thought of as symbionts that may either increase or decrease ectomycorrhizal formation rate or provide other unaccounted benefits. To explore this symbiosis from a community ecology perspective, we sampled ectomycorrhizal root tips over a 3-year period and used 454 pyrosequencing to identify the bacteria that live inside the ectomycorrhizal root tips. The results showed that fungal community composition within the same soil core and fungal taxonomic identity had a stronger effect on bacterial community composition than sample year or site. Members of the Burkholderiales and Rhizobiales were most highly represented, reflecting many previous reports of these bacteria in association with fungi. The repeated occurrences of these two bacterial orders suggest that they may be symbiotic with their fungal hosts, although the nature of such mechanisms, be it symbiotic diazotrophy or otherwise, remains to be thoroughly tested. PMID:25687126

  11. Expression analysis of Clavata1-like and Nodulin21-like genes from Pinus sylvestris during ectomycorrhiza formation.

    PubMed

    Heller, Gregory; Lundén, Karl; Finlay, Roger D; Asiegbu, Frederick O; Elfstrand, Malin

    2012-05-01

    The ecology and physiology of ectomycorrhizal (EcM) symbiosis with conifer trees are well documented. In comparison, however, very little is known about the molecular regulation of these associations. In an earlier study, we identified three EcM-regulated Pinus expressed sequence tags (EST), two of which were identified as homologous to the Medicago truncatula nodulin MtN21. The third EST was a homologue to the receptor-like kinase Clavata1. We have characterized the expression patterns of these genes and of auxin- and mycorrhiza-regulated genes after induction with indole-3-butyric acid in Pinus sylvestris and in a time course experiment during ectomycorrhizal initiation with the co-inoculation of 2,3,5-triiodobenzoic acid, an auxin transport inhibitor. Our results suggest that different P. sylvestris nodulin homologues are associated with diverse processes in the root. The results also suggest a potential role of the Clv1-like gene in lateral root initiation by the ectomycorrhizal fungus. PMID:21751039

  12. Two species of the Asian endemic genus Keteleeria form ectomycorrhizas with diverse fungal symbionts in southwestern China.

    PubMed

    Ge, Zai-Wei; Smith, Matthew E; Zhang, Qing-Ying; Yang, Zhu L

    2012-07-01

    The ectomycorrhizal status of Keteleeria species is reported for the first time based on morphological and molecular analyses of root tips from southwestern China. Based on internal transcribed spacer rDNA sequences, we detected 26 ectomycorrhizal (ECM) fungal species on roots of Keteleeria evelyniana and Keteleeria davidiana collected from natural sites and a botanical garden in Kunming, China. These ECM symbionts represent six fungal lineages, including /russula-lactarius, /inocybe, /sebacina, /tomentella-thelephora, /wilcoxina, and /cenococcum. Our results provide the first evidence of ECM formation by Keteleeria and also supply ecologically important information for conservation and restoration efforts to recover populations of Keteleeria. PMID:21997220

  13. Liming in a beech forest results in more mineral elements stored in the mantle of Lactarius subdulcis ectomycorrhizas.

    PubMed

    Rineau, François; Rose, Christophe; Le Thiec, Didier; Garbaye, Jean

    2010-01-01

    Liming is a forest practice used to counteract forest decline induced by soil acidification. It consists of direct Ca and Mg input in forest soil and restores tree mineral nutrition, but also causes drastic changes in nutrient availability in soil. Ectomycorrhizal (ECM) fungi significantly contribute in nutrient uptake by trees, and can recover them through organic acid secretion or through enzymatic degradation of organic matter. The symbiotic fungi use their extraradical mycelium for nutrient uptake, and then store them into the ECM mantle. In this study we measured how liming influences element contents in the mantle of Lactarius subdulcis ECMs, an abundant and particularly active in oxalate and laccase secretion in beech stands. For this purpose we used SEM observation coupled with energy- (EDX) and wavelength-dispersive-X-ray microanalyses (WDX). Results showed that ECM mantles of this species presented significantly higher Ca, Mg, Mn, K, Si, Al and Fe contents in limed plots. The nutrient amounts of L. subdulcis ECMs were significantly different between individuals for all the elements, showing a differential storage ability between individuals. The storage role of the ECM mantle can be interpreted in two different ways: i) a detoxification role for Al or heavy metals and ii) an increased potential nutrient resource by the fungus, which can benefit the tree. PMID:21036345

  14. Patterns in root traits of woody species hosting arbuscular and ectomycorrhizas: implications for the evolution of belowground strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite large variation in root traits among species, we have limited understanding of how traits are related to diverse soil resource acquisition strategies. We examined root trait variation among 33 species co-existing in Northeastern US forests that form the two most common mutualisms with mycorr...

  15. Local adaptation in migrated interior Douglas-fir seedlings is mediated by ectomycorrhizas and other soil factors.

    PubMed

    Pickles, Brian J; Twieg, Brendan D; O'Neill, Gregory A; Mohn, William W; Simard, Suzanne W

    2015-08-01

    Separating edaphic impacts on tree distributions from those of climate and geography is notoriously difficult. Aboveground and belowground factors play important roles, and determining their relative contribution to tree success will greatly assist in refining predictive models and forestry strategies in a changing climate. In a common glasshouse, seedlings of interior Douglas-fir (Pseudotsuga menziesii var. glauca) from multiple populations were grown in multiple forest soils. Fungicide was applied to half of the seedlings to separate soil fungal and nonfungal impacts on seedling performance. Soils of varying geographic and climatic distance from seed origin were compared, using a transfer function approach. Seedling height and biomass were optimized following seed transfer into drier soils, whereas survival was optimized when elevation transfer was minimised. Fungicide application reduced ectomycorrhizal root colonization by c. 50%, with treated seedlings exhibiting greater survival but reduced biomass. Local adaptation of Douglas-fir populations to soils was mediated by soil fungi to some extent in 56% of soil origin by response variable combinations. Mediation by edaphic factors in general occurred in 81% of combinations. Soil biota, hitherto unaccounted for in climate models, interacts with biogeography to influence plant ranges in a changing climate. PMID:25757098

  16. Interactive and Single Effects of Ectomycorrhiza Formation and Bacillus cereus on Metallothionein MT1 Expression and Phytoextraction of Cd and Zn by Willows.

    PubMed

    Hrynkiewicz, Katarzyna; Dabrowska, Grazyna; Baum, Christel; Niedojadlo, Katarzyna; Leinweber, Peter

    2012-03-01

    Single and joint ectomycorrhizal (+ Hebeloma mesophaeum) and bacterial (+ Bacillus cereus) inoculations of willows (Salix viminalis) were investigated for their potential and mode of action in the promotion of cadmium (Cd) and zinc (Zn) phytoextraction. Dual fungal and bacterial inoculations promoted the biomass production of willows in contaminated soil. Single inoculations either had no effect on the plant growth or inhibited it. All inoculated willows showed increased concentrations of nutritional elements (N, P, K and Zn) and decreased concentrations of Cd in the shoots. The lowest biomass production and concentration of Cd in the willows (+ B. cereus) were combined with the strongest expression of metallothioneins. It seems that biotic stress from bacterial invasion increased the synthesis of these stress proteins, which responded in decreased Cd concentrations. Contents of Cd and Zn in the stems of willows were combination-specific, but were always increased in dual inoculated plants. In conclusion, single inoculations with former mycorrhiza-associated B. cereus strains decreased the phytoextraction efficiency of willows by causing biotic stress. However, their joint inoculation with an ectomycorrhizal fungus is a very promising method for promoting the phytoextraction of Cd and Zn through combined physiological effects on the plant. PMID:22389535

  17. Carbon cycling and carbon metabolism by soil fungi in a boreal forest: impacts of wildfire and permafrost on functional genes, isotope signatures, and ectomycorrhizae

    NASA Astrophysics Data System (ADS)

    Waldrop, M. P.; Harden, J. W.

    2006-12-01

    Understanding the mechanisms that control the stabilization and destabilization of soil carbon within boreal forest ecosystems is of great importance to the global carbon budget. Much is currently known about boreal soil carbon dynamics in relation to biophysical and landscape variables such as temperature, moisture, wildfire intensity, and stand age. We have less information regarding the controls on decomposition at the molecular scale, where interactions between microbial communities, their genetic `potential' for decomposition, functional genes, enzyme synthesis, and organic matter transformations occur. We have entered an age in which these connections can be made at the molecular scale, but what form do they take, and can they scale up to affect carbon dynamics at the level of the ecosystem? We examined these molecular scale processes in mature boreal forest soils and soils that had been impacted by wildfire near Delta Junction, Alaska. We also examined the interactive effect of permafrost presence, which reduces soil drainage, with wildfire. We focused on three themes: linking microbial communities and laccase functional genes to soil laccase enzyme activity and lignin decomposition, assessing substrate availability using the natural abundance δ13C isotope ratios of microbial biomass, and the influence of ectomycorrhizal mats on decomposition. Wildfire reduced fungal biomass, laccase functional gene abundance, laccase activity, and δ13C-lignin decomposition. Relationships between gene abundance and microbial activity were significant and logarithmic in form. Soil drainage, which is mediated by the presence of permafrost, had little effect on the abundance of fungi, functional genes, or potential process rates. Microbial biomass δ13C was always enriched relative to soil organic matter, and this difference was greater in control soils compared to wildfire-affected soils, indicating that ÄΔδ13C MB-SOIL may indicate the level of bioavailability of soil carbon for microbial metabolism. Ectomycorrhizal mats occurred only in control soils and increased fungal biomass, functional gene abundance, enzyme activities and process rates compared to non-mat soils. Taken together these results indicate that linkages can be made between the distribution of soil microbial communities, molecular scale information, and soil carbon dynamics.

  18. LIFETIME AND TEMPORAL OCCURRENCE OF ECTOMYCORRHIZAE ON PONDEROSA PINE (PINUS PONDEROSA LAWS.) SEEDLINGS GROWN UNDER VARIED ATMOSPHERIC CO-2 AND NITROGEN LEVELS

    EPA Science Inventory

    Climate change(elevated atmospheric CO-2,and altered air temperatures,precipitation amounts and seasonal patterns)may affect ecosystem processes by altering carbon allocation in plants,and carbon flux from plants to soil.Mycorrhizal fungi,as carbon sinks, are among the first soil...

  19. Small-scale soil water repellency in pine rizhosphere associated with ectomycorrhiza is affected by nutrient patchiness: a soil microcosms study

    NASA Astrophysics Data System (ADS)

    Lozano, Elena; Hallett, Paul; Johnson, David; Moore, Lucy; Mataix-Solera, Jorge; Jiménez-Pinilla, Patricia; Arcenegui, Victoria

    2014-05-01

    Soil water repellency (SWR) or hydrophobicity has been commonly related to organic compounds released from the roots or decomposition of different plant species (Doerr et al., 2000). In addition, fungi and microorganisms that are associated with specific plants, could also influence SWR through the production of exudates or cellular material that form hydrophobic coatings on soil surfaces (Feeney et al., 2004; Hallett and Young, 1999) or act as surfactants. Nutrient availability, microbial biomass, organic matter and specific exudates have all been associated with the development of SWR. In terms of plant productivity, these impacts can be significant as their interaction with pore structure changes at the root-soil interface regulates both water transport and storage (Sperry et al., 1998). In boreal forests, basidiomycetous fungi are known to have a large impact on the development of SWR. These fungi are important degraders of organic material and symbionts forming ectomycorrhizal fungi (EF) associations with trees. Although many researchers have suggested a strong positive impact of EF on the ability of plants to capture water from soils, their impact on SWR at the root-soil interface and spatially within soil with a patchy nutrient distribution has not yet been investigated. This study used microcosms with mycelia systems of the EF extending from Pinus sylvestris host plants. Each microcosm was incubated during 15 days and contained plastic cup with 33P under the roots. The transfer of P from the mycelium to the host plant was monitored using a radioactive tracers and a non-destructive electronic autoradiography system in another study (data not published). SWR was measured using different approaches; as repellency index, R using a microinfiltrometer with a contact radius of 0.1 mm (modified from Hallet et al., 2002) and with the water drop penetration time test (WDPT). Sorptivity and SWR were measured between 40-50 points/microcosms. Results obtained with both approaches were correlated (Spearmans' rho correlation coefficient = 0.698*). Most of the points measured along the microcosms showed hydrophobicity. Preliminary results indicate that the presence/absence in each point of visual roots along the microcosms was not related with a higher hydrophobicity (P>0.05). However, the distance from each point to the cups of 33P was significant (P

  20. Temporal changes of bacterial communities in the Tuber melanosporum ectomycorrhizosphere during ascocarp development.

    PubMed

    Deveau, Aurélie; Antony-Babu, Sanjay; Le Tacon, François; Robin, Christophe; Frey-Klett, Pascale; Uroz, Stéphane

    2016-07-01

    Ectomycorrhizae create a multitrophic ecosystem formed by the association between tree roots, mycelium of the ectomycorrhizal fungus, and a complex microbiome. Despite their importance in the host tree's physiology and in the functioning of the ectomycorrhizal symbiosis, detailed studies on ectomycorrhiza-associated bacterial community composition and their temporal dynamics are rare. Our objective was to investigate the composition and dynamics of Tuber melanosporum ectomycorrhiza-associated bacterial communities from summer to winter seasons in a Corylus avellana tree plantation. We used 16S ribosomal RNA (rRNA)-based pyrosequencing to compare the bacterial community structure and the richness in T. melanosporum's ectomycorrhizae with those of the bulk soil. The T. melanosporum ectomycorrhizae harbored distinct bacterial communities from those of the bulk soil, with an enrichment in Alpha- and Gamma-proteobacteria. In contrast to the bacterial communities of truffle ascocarps that vastly varies in composition and richness during the maturation of the fruiting body and to those from the bulk soil, T. melanosporum ectomycorrhiza-associated bacterial community composition stayed rather stable from September to January. Our results fit with a recent finding from the same experimental site at the same period that a continuous supply of carbohydrates and nitrogen occurs from ectomycorrhizae to the fruiting bodies during the maturation of the ascocarps. We propose that this creates a stable niche in the ectomycorrhizosphere although the phenology of the tree changes. PMID:26781750

  1. Survival and growth of seedlings of 10 half-sib families of loblolly pine with three ectomycorrhizal conditions on an upland site in South Carolina

    SciTech Connect

    Marx, D.H.

    1981-01-01

    Seedlings of 10 families from plots artificially infested with Pisolithus tinctorius (Pt), Thelephora terrestries (Tt), or naturally inoculated (NI) were grown in the IMRD nursery in Athens, lifted (February 1980), and graded by size and ectomycorrhizal development. Graded seedlings from Pt plots have 70% of all their feeder roots with ectomycorrhizae and in which eight-tenths of these were formed by Pt. Seedlings from Tt plots also had 70% of all feeder roots with ectomycorrhizae in which eight-tenths were formed by Tt. The NI seedlings had 35% of all feeder roots with ectomycorrhizae all of which were formed by naturally occurring Tt and other fungi. The latter seedlings have ectomycorrhizae comparable to routine nursery-run seedlings.

  2. Ectomycorrhizal fungal communities of pedunculate and sessile oak seedlings from bare-root forest nurseries.

    PubMed

    Leski, Tomasz; Pietras, Marcin; Rudawska, Maria

    2010-03-01

    In this study, we present the detailed molecular investigation of the ectomycorrhizal (ECM) community of Quercus petraea and Quercus robur seedlings grown in bare-root forest nurseries. In all tested oak samples, mycorrhizal colonization was nearly 100%. Morphological observation and molecular investigations (sequencing of fungal ITS rDNA) revealed a total of 23 mycorrhizal taxa. The most frequent and abundant fungal taxa were Hebeloma sacchariolens, Tuber sp., and Peziza sp.; from the detected fungal taxa, 20 were noted for Q. petraea and 23 for Q. robur. Depending on the nursery, the species richness of identified ECM fungal taxa for both oak species ranged from six to 11 taxa. The mean species richness for all nurseries was 5.36 and 5.82 taxa per Q. petraea and Q. robur sample, respectively. According to the analysis of similarity, ECM fungal communities were similar for Q. petraea and Q. robur (R = 0.019; p = 0.151). On the other hand, detected fungal communities were significantly different between nurseries (R = 0.927; p < 0.0001). Using the Spearman rank correlation, it was determined that the ectomycorrhizal diversity (in terms of richness, the Shannon diversity, evenness, and Simpson dominance indices) is significantly related to the soil parameters of each nursery. We conclude that individual nursery may be considered as separate ecological niches that strongly discriminate diversity of ECM fungi. PMID:19756776

  3. Comparative Pollen Morphological Analysis and Its Systematic Implications on Three European Oak (Quercus L., Fagaceae) Species and Their Spontaneous Hybrids

    PubMed Central

    Danielewicz, Władysław; Bocianowski, Jan; Maliński, Tomasz; Janyszek, Magdalena

    2016-01-01

    Pollen morphology of three parental Quercus species (Q. robur L., Q. petraea (Matt) Liebl, Q. pubescens Willd.) and two spontaneous hybrids of these species (Q. ×calvescens Vuk. = Q. petraea × Q. pubescens and Q. ×rosacea Bechst. = Q. robur × Q. petraea) was investigated in this study. The pollen originated from 18 natural oak sites and 67 individuals (oak trees). Each individual was represented by 30 pollen grains. In total, 2010 pollen grains were measured. They were analysed for nine quantitative and four qualitative features. Pollen size and shape were important features to diagnosing Quercus parental species and hybrids. On the basis of exine ornamentation, it was possible to identify only Q. pubescens, while the remaining species and hybrids did not differ significantly with respect to this feature. The determination of the diagnostic value of endoaperture features requires further palynological studies. On the basis of pollen size and shape Q. robur × Q. petraea was clearly separated. Grouping of 67 oak trees on the basis of pollen grain features has shown that individuals from different as well as same taxa occurred in the same groups. Likewise, with respect to natural sites, oak trees originating from the same places as well as from geographically distant ones, grouped together. Pollen morphological features allow to distinguish a part of the studied Quercus taxa. Therefore, it can be used as an auxiliary feature in the taxonomy. PMID:27564015

  4. Comparative Pollen Morphological Analysis and Its Systematic Implications on Three European Oak (Quercus L., Fagaceae) Species and Their Spontaneous Hybrids.

    PubMed

    Wrońska-Pilarek, Dorota; Danielewicz, Władysław; Bocianowski, Jan; Maliński, Tomasz; Janyszek, Magdalena

    2016-01-01

    Pollen morphology of three parental Quercus species (Q. robur L., Q. petraea (Matt) Liebl, Q. pubescens Willd.) and two spontaneous hybrids of these species (Q. ×calvescens Vuk. = Q. petraea × Q. pubescens and Q. ×rosacea Bechst. = Q. robur × Q. petraea) was investigated in this study. The pollen originated from 18 natural oak sites and 67 individuals (oak trees). Each individual was represented by 30 pollen grains. In total, 2010 pollen grains were measured. They were analysed for nine quantitative and four qualitative features. Pollen size and shape were important features to diagnosing Quercus parental species and hybrids. On the basis of exine ornamentation, it was possible to identify only Q. pubescens, while the remaining species and hybrids did not differ significantly with respect to this feature. The determination of the diagnostic value of endoaperture features requires further palynological studies. On the basis of pollen size and shape Q. robur × Q. petraea was clearly separated. Grouping of 67 oak trees on the basis of pollen grain features has shown that individuals from different as well as same taxa occurred in the same groups. Likewise, with respect to natural sites, oak trees originating from the same places as well as from geographically distant ones, grouped together. Pollen morphological features allow to distinguish a part of the studied Quercus taxa. Therefore, it can be used as an auxiliary feature in the taxonomy. PMID:27564015

  5. Effects of root dips of benomyl and captan on seedling response and mycorrhizal development of outplanted longleaf, sand, and loblolly pines

    SciTech Connect

    Hatchell, G.E.

    1981-01-01

    Longleaf pine seedlings inoculated with Pisolithus tinctorius (Pt) on naturally inoculated (NI) were grown at densities of 7-1/2 or 15 per square feet. Seedlings were graded by size and ectomycorrhizal development. The Pt group at 7-1/2 per square feet had 50% ectomycorrhiza with 70% formed by Pt. In the Pt-15 per square foot group, 65% had ectomycorrhiza, 90% of which were Pt. The NI-7-1/2 per square foot group had 20% feeder root with ectomycorrhiza and the NI-15 per square foot had ectomycorrhiza in 30% of the feeder roots. A split-plot design was used to isolate Pt and NI treatments on major plots and 12 minor plots within each were represented by 25 seedlings. One experiment will determine the effect of removal of ectomycorrhiza (stripping) on seedling performance in the field. Preliminary observations indicate that stripping 50% or more of the mycorrhizae substantially reduces survival. Another experiment will test the effects of benomyl and captan as dips of fungicide/clay slurries on mycorrhizal development and seedling response. 2 tables. (MF)

  6. Ecological and evolutionary significance of mycorrhizal symbioses in vascular plants (A Review)

    PubMed Central

    Malloch, D. W.; Pirozynski, K. A.; Raven, P. H.

    1980-01-01

    Mycorrhizae, the symbioses between fungi and plant roots, are nearly universal in terrestrial plants and can be classified into two major types: endomycorrhizae and ectomycorrhizae. About four-fifths of all land plants form endomycorrhizae, whereas several groups of trees and shrubs, notably Pinaceae, some Cupressaceae, Fagaceae, Betulaceae, Salicaceae, Dipterocarpaceae, and most Myrtaceae form ectomycorrhizae. Among legumes, Papilionoideae and Mimosoideae have endomycorrhizae and usually form bacterial nodules. The members of the third subfamily, Caesalpinioideae, rarely form nodules, and one of the included groups, the two large, pantropical, closely related tribes Amherstieae and Detarieae, regularly form ectomycorrhizae. Nodules and ectomycorrhizae may well be alternative means of supplying organic nitrogen to the plants that form them. Those plants having endomycorrhizae usually occur in forests of high species richness, whereas those with ectomycorrhizae usually occur in forests of low species richness. The roots of ectomycorrhizal trees, however, support a large species richness of fungal symbionts, probably amounting to more than 5000 species worldwide, whereas those of endomycorrhizal trees have low fungal species richness, with only about 30 species of fungi known to be involved worldwide. Ectomycorrhizal forests are generally temperate or occur on infertile soils in the tropics. They apparently have expanded in a series of ecologically important events through the course of time from the Middle Cretaceous onward at the expense of endomycorrhizal forests. PMID:16592806

  7. Molecular studies on terricolous microfungi reveal novel anamorphs of two Tuber species.

    PubMed

    Urban, Alexander; Neuner-Plattner, Isabell; Krisai-Greilhuber, Irmgard; Haselwandter, Kurt

    2004-07-01

    This study reports novel terricolous mitosporic fungal morphs nested in the genus Tuber according to molecular phylogenetic analysis. Fungal DNA was amplified directly from field-collected anamorph samples. Nuclear ribosomal DNA (nrDNA) sequences including the ITS regions and the D1 and D2 domains of the LSU identify the anamorphs as mitosporic Tuber borchii and Tuber oligospermum. The link of the novel anamorphs to the genus Tuber is confirmed by the comparative analysis of five collections from four sampling sites. Ectomycorrhizas with characteristic features of Tuber borchii ectomycorrhizas were found in the soil volume collected with one of the mitosporic T. borchii collections. A nrDNA sequence amplified from these ectomycorrhizae is identical with the corresponding anamorph sequence. The possible role of the newly discovered anamorphs in the Tuber life-cycle and the potential significance of anamorphs for the propagation of ectomycorrhizal fungi are discussed. PMID:15446707

  8. Four new species of Andricus Hartig oak gallwasp from Turkey (Hymenoptera: Cynipidae, Cynipini).

    PubMed

    Mutun, Serap; Dinç, Serdar; Bozsó, Miklós; Melika, George

    2014-01-01

    Four new species of oak gallwasps, Andricus ahmeti, A. anatolicus, A. bakrachus and A. turcicus (Hymenoptera: Cynipidae: Cynipini) are described from Turkey. All four species are known only from asexual females and induce galls on twigs and young shoots on Q. infectoria, Q. macranthera and Q. petraea. Data on the diagnosis, distribution and biology of the four new species are given. Andricus stonei and Aphelonyx kordestanica are listed for the first time for the Turkish oak gallwasp fauna. PMID:24870080

  9. Characterisation of bacteria from Pinus sylvestris-Suillus luteus mycorrhizas and their effects on root-fungus interactions and plant growth.

    PubMed

    Bending, Gary D; Poole, Elizabeth J; Whipps, John M; Read, David J

    2002-03-01

    Bacteria from Pinus sylvestris-Suillus luteus mycorrhizas were isolated, characterised, and their effects on P. sylvestris-S. luteus interactions and plant growth investigated in vitro. The isolates formed five distinct phenotypic and physiological groups. Two of the groups, accounting for 34 of the 55 isolates, consisted of Bacillus spp., with three subgroups represented. The other groups contained Burkholderia spp., Serratia spp. and Pseudomonas spp. Representatives from each bacterial group were used in microcosm experiments to investigate bacterial effects on P. sylvestris-S. luteus interactions. Most Bacillus isolates stimulated growth of S. luteus along the P. sylvestris root, while isolates of Pseudomonas and Serratia inhibited root colonisation by the fungus. Burkholderia and Serratia isolates inhibited ectomycorrhiza formation by 97 and 41% respectively, while a single Bacillus isolate doubled the formation of first order ectomycorrhizal roots. There were no clear relationships between effects of the bacteria on root colonisation by the fungus after 4 weeks, and chitinase production or subsequent ectomycorrhiza formation. However, isolates that inhibited ectomycorrhiza formation appeared to associate preferentially with ectomycorrhizal roots. Several isolates enhanced plant growth substantially, although these effects were unrelated to either root colonisation by the fungus or ectomycorrhiza formation. PMID:19709201

  10. Three-way interactions among ectomycorrhizal mutualists, scale insects, and resistant and susceptible pinyon pines.

    PubMed

    Gehring, C A; Cobb, N S; Whitham, T G

    1997-05-01

    Herbivores and mycorrhizal fungi are important associates of most plants, but little is known about how these organisms interact. In a 9-yr experiment, we examined how the pinyon needle scale (Matsucoccus acalyptus) affects and is affected by the ectomycorrhizal mutualists found on the roots of scale-resistant and -susceptible pinyon pines (Pinus edulis). Three major results emerged. First, removal experiments demonstrated that scales negatively affected ectomycorrhiza. Second, although ectomycorrhiza could either positively or negatively influence scale performance by improving plant vigor or increasing plant investment in antiherbivore defenses, we found no ectomycorrhizal effect on scale mortality when we experimentally enhanced levels of ectomycorrhiza. This represented the first test of whether ectomycorrhiza promote plant resistance and contrasted with studies showing that arbuscular mycorrhiza negatively affected herbivores. Third, pinyon resistance to scales mediated the asymmetrical interaction between fungal mutualists and scale herbivores. High scale densities suppressed ectomycorrhizal colonization, but only on trees susceptible to scales. Similarities between mycorrhiza-herbivore interactions and competitive interactions among herbivores suggest broader generalities in the way aboveground herbivores interact with belowground plant associates. However, because mycorrhiza are mutualists, mycorrhiza-herbivore interactions do not fit within traditional competition paradigms. The widespread occurrence and importance of both herbivores and mycorrhiza argue for incorporating their interactions into ecological theory. PMID:18811251

  11. Morphological and molecular identification of the ectomycorrhizal association of Lactarius fumosibrunneus and Fagus grandifolia var. mexicana trees in eastern Mexico.

    PubMed

    Garay-Serrano, Edith; Bandala, Victor Manuel; Montoya, Leticia

    2012-11-01

    A population of Fagus grandifolia var. mexicana (covering ca. 4.7 ha) is established in a montane cloud forest refuge at Acatlan Volcano in eastern Mexico (Veracruz State), and it represents one of only ten populations of this species known to occur in the country (each stand covers ca. 2-35 ha in extension) and one of the southernmost in the continent. Sporocarps of several ectomycorrhizal macrofungi have been observed in the area, and among them, individuals of the genus Lactarius are common in the forest. However, the morphological and molecular characterization of ectomycorrhizae is still in development. Currently, two species of Lactarius have been previously documented in the area. Through the phylogenetic analysis of the internal transcribed spacer (ITS) region from basidiomes and ectomycorrhizae, we identified the Lactarius fumosibrunneus ectomycorrhiza. The host, F. grandifolia var. mexicana, was determined comparing the amplified ITS sequence from ectomycorrhizal root tips in the GenBank database with Basic Local Alignment Search Tool. The mycorrhizal system of L. fumosibrunneus is monopodial-pyramidal, characterized by its shiny, white to silver and pruinose surface, secreting a white latex when damaged, composed of three plectenchymatous mantle layers, with diverticulated terminal elements at the outer mantle. It lacks emanating hyphae, rhizomorphs, and sclerotia. A detailed morphological and anatomical description, illustrations, and photographs of the ectomycorrhiza are presented. The comparison of L. fumosibrunneus and other Lactarius belonging to subgenus Plinthogalus is presented. PMID:22402818

  12. Mycorrhization of pecan trees (Carya illinoinensis) with commercial truffle species: Tuber aestivum Vittad. and Tuber borchii Vittad.

    PubMed

    Benucci, Gian Maria Niccolò; Bonito, Gregory; Baciarelli Falini, Leonardo; Bencivenga, Mattia

    2012-07-01

    Pecan (Carya illinoinensis) is an economically important nut tree native to the Mississippi basin and cultivated worldwide. In North America, species of truffles are regularly found fruiting in productive pecan orchards and the truffle genus Tuber appears to be abundant in pecan ectomycorrhizal (EM) communities. As an initial step to determine the feasibility of co-cropping European truffle species with pecan, we evaluated whether mycorrhizae of highly esteemed European truffle species (Tuber aestivum Vittad. T. borchii and T. macrosporum) could be formed on pecan seedlings. Seedlings were inoculated with truffle spores and were grown in a greenhouse for 10 months. Levels of EM colonization were estimated visually and quantified by counting EM tips. Ectomycorrhizae were identified both morphologically and molecularly with species-specific amplification and by sequencing of the ITS region of the nuclear ribosomal DNA (nrDNA). Both T. borchii and T. aestivum spores produced well-formed ectomycorrhizae on pecan seedlings with average root colonization levels of about 62% and 42%, respectively, whereas no ectomycorrhizae of T. macrosporum were formed. The anatomy and morphology of these truffle ectomycorrhizae on pecan was characterized. The co-cropping of T. aestivum and T. borchii may hold promise as an additional stream of revenue to pecan growers, although, further studies are needed to assess whether this symbiosis is maintained after planting in the field and whether truffle production can be supported by this host species. PMID:21986799

  13. A quest for indigenous truffle helper prokaryotes.

    PubMed

    Gryndler, Milan; Soukupová, Lucie; Hršelová, Hana; Gryndlerová, Hana; Borovička, Jan; Streiblová, Eva; Jansa, Jan

    2013-06-01

    Tuber aestivum is the most common European truffle with significant commercial exploitation. Its production originates from natural habitats and from artificially inoculated host tree plantations. Formation of Tuber ectomycorrhizae in host seedling roots is often inefficient. One possible reason is the lack of indigenous associative microbes. Here we aimed at metagenetic characterization and cultivation of indigenous prokaryotes associated with T. aestivum in a field transect cutting through the fungus colony margin. Several operational taxonomic units (OTUs) showed close association with the T. aestivum in the ectomycorrhizae and in the soil, but there was no overlap between the associative prokaryotes in the two different habitats. Among those positively associated with the ectomycorrhizae, we identified several bacterial genera belonging to Pseudonocardineae. Extensive isolation efforts yielded many cultures of ectomycorrhizae-associative bacteria belonging to Rhizobiales and Streptomycineae, but none belonging to the Pseudonocardineae. The specific unculturable Tuber-associated prokaryotes are likely to play important roles in the biology of these ectomycorrhizal fungi, including modulation of competition with other symbiotic and saprotrophic microbes, facilitation of root penetration and/or accessing mineral nutrients in the soil. However, the ultimate proof of this hypothesis will require isolation of the microbes for metabolic studies, using novel cultivation approaches. PMID:23754715

  14. Functional profiling and distribution of the forest soil bacterial communities along the soil mycorrhizosphere continuum.

    PubMed

    Uroz, S; Courty, P E; Pierrat, J C; Peter, M; Buée, M; Turpault, M P; Garbaye, J; Frey-Klett, P

    2013-08-01

    An ectomycorrhiza is a multitrophic association between a tree root, an ectomycorrhizal fungus, free-living fungi and the associated bacterial communities. Enzymatic activities of ectomycorrhizal root tips are therefore result of the contribution from different partners of the symbiotic organ. However, the functional potential of the fungus-associated bacterial communities remains unknown. In this study, a collection of 80 bacterial strains randomly selected and isolated from a soil-ectomycorrhiza continuum (oak-Scleroderma citrinum ectomycorrhizas, the ectomycorrhizosphere and the surrounding bulk soil) were characterized. All the bacterial isolates were identified by partial 16S rRNA gene sequences as members of the genera Burkholderia, Collimonas, Dyella, Mesorhizobium, Pseudomonas, Rhizobium and Sphingomonas. The bacterial strains were then assayed for β-xylosidase, β-glucosidase, N-acetyl-hexosaminidase, β-glucuronidase, cellobiohydrolase, phosphomonoesterase, leucine-aminopeptidase and laccase activities, chitin solubilization and auxin production. Using these bioassays, we demonstrated significant differences in the functional distribution of the bacterial communities living in the different compartments of the soil-ectomycorrhiza continuum. The surrounding bulk soil was significantly enriched in bacterial isolates capable of hydrolysing cellobiose and N-acetylglucosamine. In contrast, the ectomycorrhizosphere appeared significantly enriched in bacterial isolates capable of hydrolysing glucopyranoside and chitin. Notably, chitinase and laccase activities were found only in bacterial isolates belonging to the Collimonas and Pseudomonas genera. Overall, the results suggest that the ectomycorrhizal fungi favour specific bacterial communities with contrasting functional characteristics from the surrounding soil. PMID:23455431

  15. A RAPID DNA EXTRACTION METHOD IS SUCCESSFULLY APPLIED TO ITS-RFLP ANALYSIS OF MYCORRHIZAL ROOT TIPS

    EPA Science Inventory

    A rapid method for extracting DNA from intact, single root tips using a Xanthine solution was developed to handle very large numbers of analyses of ectomycorrhizas. By using an extraction without grinding we have attempted to bias the extraction towards the fungal DNA in the man...

  16. Piracy in the high trees: ectomycorrhizal fungi from an aerial 'canopy soil' microhabitat.

    PubMed

    Orlovich, David A; Draffin, Suzy J; Daly, Robert A; Stephenson, Steven L

    2013-01-01

    The mantle of dead organic material ("canopy soil") associated with the mats of vascular and nonvascular epiphytes found on the branches of trees in the temperate rainforests along the southwestern coast of the South Island of New Zealand were examined for evidence of ectomycorrhizal fungi. DNA sequencing and cluster analysis were used to identify the taxa of fungi present in 74 root tips collected from the canopy soil microhabitat of three old growth Nothofagus menziesii trees in the South West New Zealand World Heritage Area. A diverse assemblage of ectomycorrhizal fungi was found to infect an extensive network of adventitious canopy roots of Nothofagus menziesii in this forest, including 14 phylotypes from nine genera of putative ectomycorrhizal fungi. Seven of the genera identified previously were known to form ectomycorrhizas with terrestrial roots of Nothofagus: Cortinarius, Russula, Cenococcum, Thelephora/Tomentella, Lactarius and Laccaria; two, Clavulina and Leotia, previously have not been reported forming ectomycorrhizas with Nothofagus. Canopy ectomycorrhizas provide an unexpected means for increased host nutrition that may have functional significance in some forest ecosystems. Presumably, canopy ectomycorrhizas on host adventitious roots circumvent the tree-ground-soil nutrient cycle by accessing a wider range of nutrients directly in the canopy than would be possible for non-mycorrhizal or arbuscular mycorrhizal canopy roots. In this system, both host and epiphytes would seem to be in competition for the same pool of nutrients in canopy soil. PMID:22778170

  17. PtSRR1, a putative Pisolithus tinctorius symbiosis related receptor gene is expressed during the first hours of mycorrhizal interaction with Castanea sativa roots

    PubMed Central

    Acioli-Santos, B.; Malosso, E.; Calzavara-Silva, C.E.; Lima, C.E.P.; Figueiredo, A.; Sebastiana, M.; Pais, M.S.

    2009-01-01

    PtSRR1 EST was previously identified in the first hours of Pisolithus tinctorius and Castanea sativa interaction. QRT-PCR confirmed PtSRR1 early expression and in silico preliminary translated peptide analysis indicated a strong probability that PtSRR1 be a transmembrane protein. These data stimulate the PtSRR1 gene research during ectomycorrhiza formation. PMID:24031360

  18. Three-way interactions among ectomycorrhizal mutualists, scale insects, and resistant and susceptible pinyon pines

    SciTech Connect

    Gehring, C.A.; Cobb, N.S.; Whitham, T.G.

    1997-05-01

    Herbivores and mycorrhizal fungi are important associates of most plants, but little is known about how these organisms interact. In a 9-yr experiment, we examined how the pinyon needle scale (Matsucoccus acalyptus) affects and is affected by the ectomycorrhizal mutualists found on the roots of scale-resistant and -susceptible pinyon pines (Pinus edulis). Three major results emerged. First, removal experiments demonstrated that scales negatively affected ectomycorrhiza. Second, although ectomycorrhiza could either positively or negatively influence scale performance by improving plant vigor or increasing plant investment in antiherbivore defenses, we found no ectomycorrhizal effect on scale mortality when we experimentally enhanced levels of ectomycorrhiza. This represented the first test of whether ectomycorrhiza promote plant resistance and contrasted with studies showing that arbuscular mycorrhiza negatively affected herbivores. Third, pinyon resistance to scales mediated the asymmetrical interaction between fungal mutualists and scale herbivores. High scale densities suppressed ectomycorrhizal colonization, but only on trees susceptible to scales. Similarities between mycorrhiza-herbivore interactions and competitive interactions among herbivores suggest broader generalities in the way aboveground herbivores interact with belowground plant associates. However, because mycorrhiza are mutualists, mycorrhiza-herbivore interactions do not fit within traditional competition paradigms. The widespread occurrence and importance of both herbivores and mycorrhiza argue for incorporating their interactions into ecological theory. 53 refs., 4 figs.

  19. Pisolithus tinctorius, a gasteromycete, associated with Jeffrey and Sierra lodgepole pine on acid mine spoils in the Sierra Nevada

    SciTech Connect

    Walker, R.F. )

    1989-01-31

    Basidiocarps of Pisolithus tinctorius, a gasteromycetous fungus adapted to harsh sites, were observed in association with Jeffrey and Sierra lodgepole pine on acid mine spoils in northeastern California. Subterranean mycelial strands were traced from these basidiocarps to the root systems of the two pine species, which had ectomycorrhizae characteristic of those formed by this fungus in symbiotic relationships with conifer hosts.

  20. Patterns of contemporary hybridization inferred from paternity analysis in a four-oak-species forest

    PubMed Central

    2009-01-01

    Background Few studies address the issue of hybridization in a more than two-species context. The species-rich Quercus complex is one of the systems which can offer such an opportunity. To investigate the contemporary pattern of hybridization we sampled and genotyped 320 offspring from a natural mixed forest comprising four species of the European white oak complex: Quercus robur, Q. petraea, Q. pubescens, and Q. frainetto. Results A total of 165 offspring were assigned unambiguously to one of the pollen donors within the study plot. The minimum amount of effective pollen originating from outside the plot varied markedly among the seed parents, ranging from 0.18 to 0.87. The majority of the successful matings (64.1%) occurred between conspecific individuals indicating the existence of reproductive barriers between oak species. However, the isolation was not complete since we found strong evidence for both first-generation (8.4%) and later-generation hybrids (27.5%). Only two out of eight seed parents, belonging to Q. petraea and Q. robur, showed a high propensity to hybridize with Q. pubescens and Q. petraea, respectively. Significant structure of the effective pollen pools (Φpt = 0.069, P = 0.01) was detected in our sample. However, no support was found for the isolation by distance hypothesis. The proportion of hybrids was much higher (79%) in the seed generation when compared to the adult tree generation. Conclusion First-generation hybrids were observed only between three out of six possible species combinations. Hybrids between one pair of species preferred to mate with one of their parental species. The observation of first and later-generation hybrids in higher frequency in acorns than in adults might be explained by selection against hybrid genotypes, the history of this uneven-aged forest or past introgression between species. PMID:19968862

  1. Tree litter and forest understorey vegetation: a conceptual framework to understand the effects of tree litter on a perennial geophyte, Anemone nemorosa

    PubMed Central

    Baltzinger, Marie; Archaux, Frédéric; Dumas, Yann

    2012-01-01

    Background and Aims Litter is a key factor in structuring plant populations, through positive or negative interactions. The litter layer forms a mechanical barrier that is often strongly selective against individuals lacking hypocotyle plasticity. Litter composition also interacts with plant growth by providing beneficial nutrients or, inversely, by allowing harmful allelopathic leaching. As conspicuous litter fall accumulation is often observed under deciduous forests, interactions between tree litter and understorey plant populations are worthy of study. Methods In a 1-year ex-situ experiment, the effects of tree litter on the growth of Anemone nemorosa, a small perennial forest geophyte, were investigated. Three ‘litter quantity’ treatments were defined, representative of forest floor litter (199, 356·5 and 514 g m−2), which were crossed with five ‘litter composition’ treatments (Quercus petraea, Fagus sylvatica, Carpinus betulus, Q. petraea + F. sylvatica and Q. petraea + C. betulus), plus a no-litter control. Path analysis was then used to investigate the pathways linking litter characteristics and components of adult plant growth. Key Results As expected, the heavier the litter, the longer the petiole; rhizome growth, however, was not depreciated by the litter-induced petiole lengthening. Both rhizome mass increment and number of initiated buds marginally increased with the amount of litter. Rhizome mass increment was in fact determined primarily by leaf area and leaf life span, neither of which was unequivocally correlated with any litter characteristics. However, the presence of litter significantly increased leafing success: following a late frost event, control rhizomes growing in the absence of litter experienced higher leaf mortality before leaf unfolding. Conclusions The study questions the role of litter as a physical or chemical barrier to ground vegetation; to better understand this role, there is a need for ex-situ, longer

  2. Complex climate controls on 20th century oak growth in Central-West Germany.

    PubMed

    Friedrichs, Dagmar A; Büntgen, Ulf; Frank, David C; Esper, Jan; Neuwirth, Burkhard; Löffler, Jörg

    2009-01-01

    We analyze interannual to multi-decadal growth variations of 555 oak trees from Central-West Germany. A network of 13 pedunculate oak (Quercus robur L.) and 33 sessile oak (Quercus petraea (Matt.) Liebl.) site chronologies is compared with gridded temperature, precipitation, cloud-cover, vapor pressure and drought (i.e., Palmer Drought Severity Index, PDSI) fluctuations. A hierarchic cluster analysis identifies three groups for each oak species differentiated by ecologic settings. When high precipitation is primarily a characteristic for one Q. robur and one Q. petraea cluster, the other clusters are more differentiated by prevailing temperature conditions. Correlation analysis with precipitation and vapor pressure reveals statistically significant (P < or = 0.05) correlations for June (r = 0.51) and annual (r = 0.43) means. Growth of both species at dry sites correlates strongly with PDSI (r = 0.39, P < or = 0.05), and weakly with temperature and cloud-cover. In natural stands, Q. robur responds more strongly to water depletion than Q. petraea. Twenty-one-year moving correlations show positive significant growth response to both PDSI and precipitation throughout the 20th century, except for the 1940s - an anomalously warm decade during which all oak sites are characterized by an increased growth and an enhanced association with vapor pressure and temperature. We suggest that the wider oak rings that are exhibited during this period may be indicative of a nonlinear or threshold-induced growth response to drought and vapor pressure, and run counter to the general response of oak to drought and precipitation that normally would result in suppressed growth in a warmer and drier environment. As the wide rings are formed during the severe drought period of the 20th century, a complex model seems to be required to fully explain the widespread oak growth. Our results indicate uncertainty in estimates of future growth trends of Central European oak forests in a warming and

  3. Characterization of Tuber borchii and Arbutus unedo mycorrhizas.

    PubMed

    Lancellotti, Enrico; Iotti, Mirco; Zambonelli, Alessandra; Franceschini, Antonio

    2014-08-01

    For the first time, arbutoid mycorrhizas established between Tuber borchii and Arbutus unedo were described. Analyzed mycorrhizas were from one T. borchii natural truffle ground, dominated by Pinus pinea, as well as synthesized in greenhouse conditions. A. unedo mycorrhizas presented some typical characteristics of ectomycorrhizas of T. borchii. However, as in arbutoid mycorrhizas, ramification was cruciform and intracellular colonization in epidermal cells was present. The ability of T. borchii to form ectomycorrhizas with A. unedo opens up the possibility to also use this fruit plant for truffle cultivation. This represents an important economic opportunity in Mediterranean areas by combining both the cultivation of precious truffles and the production of edible fruits which are used fresh or in food delicacies. PMID:24535602

  4. Ectomycorrhizal specificity patterns in a mixed Pinus contorta and Picea engelmannii forest in Yellowstone National Park

    NASA Technical Reports Server (NTRS)

    Cullings, K. W.; Vogler, D. R.; Parker, V. T.; Finley, S. K.

    2000-01-01

    We used molecular genetic methods to test two hypotheses, (i) that host plant specificity among ectomycorrhizal fungi would be common in a closed-canopy, mixed Pinus contorta-Picea engelmannii forest in Yellowstone National Park and (ii) that specificity would be more common in the early successional tree species, P. contorta, than in the invader, P. engelmannii. We identified 28 ectomycorrhizal fungal species collected from 27 soil cores. The proportion of P. engelmannii to P. contorta ectomycorrhizae was nearly equal (52 and 48%, respectively). Of the 28 fungal species, 18 composed greater than 95% of the fungal community. No species was associated exclusively with P. contorta, but four species, each found in only one core, and one species found in two cores were associated exclusively with P. engelmannii. These fungi composed less than 5% of the total ectomycorrhizae. Thus, neither hypothesis was supported, and hypothesized benefits of ectomycorrhizal specificity to both trees and fungi probably do not exist in this system.

  5. Assessment of ectomycorrhizal fungal communities in the natural habitats of Tuber magnatum (Ascomycota, Pezizales).

    PubMed

    Leonardi, M; Iotti, M; Oddis, M; Lalli, G; Pacioni, G; Leonardi, P; Maccherini, S; Perini, C; Salerni, E; Zambonelli, A

    2013-07-01

    The ectomycorrhizal (ECM) fungal communities of four natural Tuber magnatum truffle grounds, located in different Italian regions (Abruzzo, Emilia-Romagna, Molise, and Tuscany), were studied. The main objective of this study was to characterize and compare the ECM fungal communities in the different regions and in productive (where T. magnatum ascomata were found) and nonproductive points. More than 8,000 (8,100) colonized root tips were counted in 73 soil cores, and 129 operational taxonomic units were identified using morphological and molecular methods. Although the composition of the ECM fungal communities studied varied, we were able to highlight some common characteristics. The most plentiful ECM fungal taxa belong to the Thelephoraceae and Sebacinaceae families followed by Inocybaceae and Russulaceae. Although several ectomycorrhizas belonging to Tuber genus were identified, no T. magnatum ectomycorrhizas were found. The putative ecological significance of some species is discussed. PMID:23299664

  6. Morphological characterization of mycorrhizae formed between three Terfezia species (desert truffles) and several Cistaceae and Aleppo pine.

    PubMed

    Zitouni-Haouar, Fatima El-Houaria; Fortas, Zohra; Chevalier, Gerard

    2014-07-01

    Six Cistaceae species, Helianthemum ledifolium, Helianthemum lippii, Fumana procumbens, Cistus albidus, Cistus incanus, Cistus salvifolius, and Pinus halepensis (Aleppo pine) were inoculated with three mycorrhizal desert truffles, Terfezia leptoderma, Terfezia boudieri, and Terfezia claveryi under greenhouse conditions, on soil originating from desert truffle natural habitat in Algeria. The syntheses have led to the formation of typical endomycorrhizae in annual Cistaceae (H. ledifolium) and perennial ones (H. lippii and F. procumbens) and an ectomycorrhiza with a less developed sheath in Cistus species and Aleppo pine. These results demonstrate the plasticity of Terfezia species to form different mycorrhizal types. The formation of an endomycorrhiza with H. ledifolium and F. procumbens and a sheathing ectomycorrhiza with P. halepensis inoculated by T. leptoderma in in vivo culture conditions was obtained for the first time. PMID:24384787

  7. Characterisation of seven Inocybe ectomycorrhizal morphotypes from a semiarid woody steppe.

    PubMed

    Seress, Diána; Dima, Bálint; Kovács, Gábor M

    2016-04-01

    Ectomycorrhizas (ECM) of Inocybe species (Inocybaceae, Basidiomycota) formed by three host plant species (Populus alba, Salix rosmarinifolia and Pinus nigra) in a semiarid woody steppe of Hungary were studied. To identify the fungal partners, we performed phylogenetic analyses of nucleotide sequences for the internal transcribed spacer region of nuclear DNA (nrDNA ITS) together with sequences gained from public databases. Seven Inocybe ectomycorrhiza morphotypes were morpho-anatomically characterised. Five morphotypes were identified (I. phaeoleuca, I. psammophila, I. semifulva, I. splendens and I. subporospora), whereas two morphotypes represented unidentified Inocybe species. Differences were discernible among the morphotypes, and they showed general anatomical characteristics of Inocybe ECM, such as the slightly organised plectenchymatic mantle (types A, B and E and the gelatinous C). The ECM of I. subporospora and I. phaeoleuca were detected from the introduced Pinus nigra. These two fungi are probably native to the area but capable of forming a novel ectomycorrhizal association with the invasive host. PMID:26403243

  8. Structure elucidation of auxofuran, a metabolite involved in stimulating growth of fly agaric, produced by the mycorrhiza helper bacterium Streptomyces AcH 505.

    PubMed

    Keller, Simone; Schneider, Kathrin; Süssmuth, Roderich D

    2006-12-01

    Mycorrhiza helper bacterium Streptomyces strain AcH 505 stimulates ectomycorrhiza formation between spruce and fly agaric by supporting fungal growth whereas growth of pathogenic fungi is suppressed. A fungal growth promoting substance was isolated and the chemical structure elucidated by mass spectrometry and NMR spectroscopy. The absolute configuration of the novel fungal growth promoting compound auxofuran (1) was deduced from NMR data with the help of Mosher esters. PMID:17323648

  9. New species of Tomentella (Thelephorales) from the Patagonian Andes forests.

    PubMed

    Kuhar, Francisco; Barroetaveña, Carolina; Rajchenberg, Mario

    2016-01-01

    The genus Tomentella forms abundant ectomycorrhizae in coniferous and deciduous forests worldwide. Molecular identification of root tips suggests undescribed species in the Nothofagus forests of Patagonia, Argentina. Tomentella tenuissima, T. pulvinulata and T. patagonica are described here as new to science based on morphological and molecular analyses. Their host range is addressed using available soil sequences. The identity of previous records of T. galzinii and T. radiosa are discussed with morphological and molecular evidence. PMID:27091385

  10. A 5.8S nuclear ribosomal RNA gene sequence database: applications to ecology and evolution

    NASA Technical Reports Server (NTRS)

    Cullings, K. W.; Vogler, D. R.

    1998-01-01

    We complied a 5.8S nuclear ribosomal gene sequence database for animals, plants, and fungi using both newly generated and GenBank sequences. We demonstrate the utility of this database as an internal check to determine whether the target organism and not a contaminant has been sequenced, as a diagnostic tool for ecologists and evolutionary biologists to determine the placement of asexual fungi within larger taxonomic groups, and as a tool to help identify fungi that form ectomycorrhizae.

  11. The ectomycorrhizal morphotype Pinirhiza sclerotia is formed by Acephala macrosclerotiorum sp. nov., a close relative of Phialocephala fortinii.

    PubMed

    Münzenberger, Babette; Bubner, Ben; Wöllecke, Jens; Sieber, Thomas N; Bauer, Robert; Fladung, Matthias; Hüttl, Reinhard F

    2009-09-01

    Relatively few ectomycorrhizal fungal species are known to form sclerotia. Usually, sclerotia are initiated at the extraradical mycelium. In this study, we present anatomical and ultrastructural evidence for the formation of sclerotia directly in the hyphal mantle of the mycorrhizal morphotype Pinirhiza sclerotia. A dark-pigmented fungal strain was isolated from Pinirhiza sclerotia and identified by molecular tools as Acephala macrosclerotiorum sp. nov., a close relative of Phialocephala fortinii s.l. As dark septate fungi are known to be mostly endophytic, resyntheses with Pinus sylvestris and A. macrosclerotiorum as well as Populus tremula x Populus tremuloides and A. macrosclerotiorum or P. fortinii s.l. were performed under axenic conditions. No mycorrhizas were found when hybrid aspen was inoculated with A. macrosclerotiorum or P. fortinii. However, A. macrosclerotiorum formed true ectomycorrhizas in vitro with P. sylvestris. Anatomical and ultrastructural features of this ectomycorrhiza are presented. The natural and synthesized ectomycorrhizal morphotypes were identical and characterized by a thin hyphal mantle that bore sclerotia in a later ontogenetic stage. The Hartig net was well-developed and grew up to the endodermis. To our knowledge, this is the first evidence at the anatomical and ultrastructural level that a close relative of P. fortinii s.l. forms true ectomycorrhizas with a coniferous host. PMID:19415343

  12. Molecular and morphological analyses confirm Rhizopogon verii as a widely distributed ectomycorrhizal false truffle in Europe, and its presence in South America.

    PubMed

    Sulzbacher, Marcelo A; Grebenc, Tine; García, Miguel Á; Silva, Bianca D; Silveira, Andressa; Antoniolli, Zaida I; Marinho, Paulo; Münzenberger, Babette; Telleria, M Teresa; Baseia, Iuri G; Martín, María P

    2016-07-01

    The genus Rhizopogon includes species with hypogeous or subepigeus habit, forming ectomycorrhizae with naturally occurring or planted pines (Pinaceae). Species of the genus Rhizopogon can be distinguished easily from the other hypogeous basidiomycetes by their lacunose gleba without columella and their smooth elliptical spores; however, the limit between species is not always easy to establish. Rhizopogon luteolus, the type species of the genus, has been considered one of the species that are more abundant in Europe, as well as it has been cited in pine plantation of North and South America, different parts of Africa, Australia, and New Zealand. However, in this study, based on molecular analyses of the ITS nuclear ribosomal DNA (nrDNA) sequences (19 new sequences; 37 sequences from GenBank/UNITE, including those from type specimens), we prove that many GenBank sequences under R. luteolus were misidentified and correspond to Rhizopogon verii, a species described from Tunisia. Also, we confirm that basidiomes and ectomycorrhizae recently collected in Germany under Pinus sylvestris, as well as specimens from South of Brazil under Pinus taeda belong to R. verii. Thanks to the numerous ectomycorrhizal tips collected in Germany, a complete description of R. verii/P. sylvestris ectomycorrhiza is provided. Moreover, since in this paper the presence of R. verii in South America is here reported for the first time, a short description of basidiomes collected in Brazil, compared with collections located in different European herbaria, is included. PMID:26763005

  13. Effect of poplar genotypes on mycorrhizal infection and secreted enzyme activities in mycorrhizal and non-mycorrhizal roots.

    PubMed

    Courty, P E; Labbé, J; Kohler, A; Marçais, B; Bastien, C; Churin, J L; Garbaye, J; Le Tacon, F

    2011-01-01

    The impact of ectomycorrhiza formation on the secretion of exoenzymes by the host plant and the symbiont is unknown. Thirty-eight F(1) individuals from an interspecific Populus deltoides (Bartr.)×Populus trichocarpa (Torr. & A. Gray) controlled cross were inoculated with the ectomycorrhizal fungus Laccaria bicolor. The colonization of poplar roots by L. bicolor dramatically modified their ability to secrete enzymes involved in organic matter breakdown or organic phosphorus mobilization, such as N-acetylglucosaminidase, β-glucuronidase, cellobiohydrolase, β-glucosidase, β-xylosidase, laccase, and acid phosphatase. The expression of genes coding for laccase, N-acetylglucosaminidase, and acid phosphatase was studied in mycorrhizal and non-mycorrhizal root tips. Depending on the genes, their expression was regulated upon symbiosis development. Moreover, it appears that poplar laccases or phosphatases contribute poorly to ectomycorrhiza metabolic activity. Enzymes secreted by poplar roots were added to or substituted by enzymes secreted by L. bicolor. The enzymatic activities expressed in mycorrhizal roots differed significantly between the two parents, while it did not differ in non-mycorrhizal roots. Significant differences were found between poplar genotypes for all enzymatic activities measured on ectomycorrhizas except for laccases activity. In contrast, no significant differences were found between poplar genotypes for enzymatic activities of non-mycorrhizal root tips except for acid phosphatase activity. The level of enzymes secreted by the ectomycorrhizal root tips is under the genetic control of the host. Moreover, poplar heterosis was expressed through the enzymatic activities of the fungal partner. PMID:20881013

  14. Effect of poplar genotypes on mycorrhizal infection and secreted enzyme activities in mycorrhizal and non-mycorrhizal roots

    PubMed Central

    Courty, P. E.; Labbé, J.; Kohler, A.; Marçais, B.; Bastien, C.; Churin, J. L.; Garbaye, J.; Le Tacon, F.

    2011-01-01

    The impact of ectomycorrhiza formation on the secretion of exoenzymes by the host plant and the symbiont is unknown. Thirty-eight F1 individuals from an interspecific Populus deltoides (Bartr.)×Populus trichocarpa (Torr. & A. Gray) controlled cross were inoculated with the ectomycorrhizal fungus Laccaria bicolor. The colonization of poplar roots by L. bicolor dramatically modified their ability to secrete enzymes involved in organic matter breakdown or organic phosphorus mobilization, such as N-acetylglucosaminidase, β-glucuronidase, cellobiohydrolase, β-glucosidase, β-xylosidase, laccase, and acid phosphatase. The expression of genes coding for laccase, N-acetylglucosaminidase, and acid phosphatase was studied in mycorrhizal and non-mycorrhizal root tips. Depending on the genes, their expression was regulated upon symbiosis development. Moreover, it appears that poplar laccases or phosphatases contribute poorly to ectomycorrhiza metabolic activity. Enzymes secreted by poplar roots were added to or substituted by enzymes secreted by L. bicolor. The enzymatic activities expressed in mycorrhizal roots differed significantly between the two parents, while it did not differ in non-mycorrhizal roots. Significant differences were found between poplar genotypes for all enzymatic activities measured on ectomycorrhizas except for laccases activity. In contrast, no significant differences were found between poplar genotypes for enzymatic activities of non-mycorrhizal root tips except for acid phosphatase activity. The level of enzymes secreted by the ectomycorrhizal root tips is under the genetic control of the host. Moreover, poplar heterosis was expressed through the enzymatic activities of the fungal partner. PMID:20881013

  15. Changes in the dynamics of foliar N metabolites in oak saplings by drought and air warming depend on species and soil type.

    PubMed

    Hu, Bin; Simon, Judy; Günthardt-Goerg, Madeleine S; Arend, Matthias; Kuster, Thomas M; Rennenberg, Heinz

    2015-01-01

    Climate change poses direct or indirect influences on physiological mechanisms in plants. In particular, long living plants like trees have to cope with the predicted climate changes (i.e. drought and air warming) during their life span. The present study aimed to quantify the consequences of simulated climate change for foliar N metabolites over a drought-rewetting-drought course. Saplings of three Central European oak species (i.e. Quercus robur, Q. petraea, Q. pubescens) were tested on two different soil types (i.e. acidic and calcareous). Consecutive drought periods increased foliar amino acid-N and soluble protein-N concentrations at the expense of structural N in all three oak species. In addition, transient effects on foliar metabolite dynamics were observed over the drought-rewetting-drought course. The lowest levels of foliar soluble protein-N, amino acid-N and potassium cation with a minor response to drought and air warming were found in the oak species originating from the driest/warmest habitat (Q. pubescens) compared to Q. robur and Q. petraea. Higher foliar osmolyte-N and potassium under drought and air warming were observed in all oak species when grown on calcareous versus acidic soil. These results indicate that species-specific differences in physiological mechanisms to compensate drought and elevated temperature are modified by soil acidity. PMID:25961713

  16. Natural forest expansion on reclaimed coal mines in Northern Spain: the role of native shrubs as suitable microsites.

    PubMed

    Alday, Josu G; Zaldívar, Pilar; Torroba-Balmori, Paloma; Fernández-Santos, Belén; Martínez-Ruiz, Carolina

    2016-07-01

    The characterization of suitable microsites for tree seedling establishment and growth is one of the most important tasks to achieve the restoration of native forest using natural processes in disturbed sites. For that, we assessed the natural Quercus petraea forest expansion in a 20-year-old reclaimed open-cast mine under sub-Mediterranean climate in northern Spain, monitoring seedling survival, growth, and recruitment during 5 years in three contrasting environments (undisturbed forest, mine edge, and mine center). Seedling density and proportion of dead branches decreased greatly from undisturbed forest towards the center of the mine. There was a positive effect of shrubs on Q. petraea seedling establishment in both mine environments, which increase as the environment undergoes more stress (from the mine edge to the center of the mine), and it was produced by different shrub structural features in each mine environment. Seedling survival reduction through time in three environments did not lead to a density reduction because there was a yearly recruitment of new seedlings. Seedling survival, annual growth, and height through time were greater in mine sites than in the undisturbed forest. The successful colonization patterns and positive neighbor effect of shrubs on natural seedlings establishment found in this study during the first years support the use of shrubs as ecosystem engineers to increase heterogeneity in micro-environmental conditions on reclaimed mine sites, which improves late-successional Quercus species establishment. PMID:26517999

  17. Changes in the Dynamics of Foliar N Metabolites in Oak Saplings by Drought and Air Warming Depend on Species and Soil Type

    PubMed Central

    Hu, Bin; Simon, Judy; Günthardt-Goerg, Madeleine S.; Arend, Matthias; Kuster, Thomas M.; Rennenberg, Heinz

    2015-01-01

    Climate change poses direct or indirect influences on physiological mechanisms in plants. In particular, long living plants like trees have to cope with the predicted climate changes (i.e. drought and air warming) during their life span. The present study aimed to quantify the consequences of simulated climate change for foliar N metabolites over a drought-rewetting-drought course. Saplings of three Central European oak species (i.e. Quercus robur, Q. petraea, Q. pubescens) were tested on two different soil types (i.e. acidic and calcareous). Consecutive drought periods increased foliar amino acid-N and soluble protein-N concentrations at the expense of structural N in all three oak species. In addition, transient effects on foliar metabolite dynamics were observed over the drought-rewetting-drought course. The lowest levels of foliar soluble protein-N, amino acid-N and potassium cation with a minor response to drought and air warming were found in the oak species originating from the driest/warmest habitat (Q. pubescens) compared to Q. robur and Q. petraea. Higher foliar osmolyte-N and potassium under drought and air warming were observed in all oak species when grown on calcareous versus acidic soil. These results indicate that species-specific differences in physiological mechanisms to compensate drought and elevated temperature are modified by soil acidity. PMID:25961713

  18. Arabidopsis hybrid speciation processes

    PubMed Central

    Schmickl, Roswitha; Koch, Marcus A.

    2011-01-01

    The genus Arabidopsis provides a unique opportunity to study fundamental biological questions in plant sciences using the diploid model species Arabidopsis thaliana and Arabidopsis lyrata. However, only a few studies have focused on introgression and hybrid speciation in Arabidopsis, although polyploidy is a common phenomenon within this genus. More recently, there is growing evidence of significant gene flow between the various Arabidopsis species. So far, we know Arabidopsis suecica and Arabidopsis kamchatica as fully stabilized allopolyploid species. Both species evolved during Pleistocene glaciation and deglaciation cycles in Fennoscandinavia and the amphi-Beringian region, respectively. These hybrid studies were conducted either on a phylogeographic scale or reconstructed experimentally in the laboratory. In our study we focus at a regional and population level. Our research area is located in the foothills of the eastern Austrian Alps, where two Arabidopsis species, Arabidopsis arenosa and A. lyrata ssp. petraea, are sympatrically distributed. Our hypothesis of genetic introgression, migration, and adaptation to the changing environment during the Pleistocene has been confirmed: We observed significant, mainly unidirectional gene flow between the two species, which has given rise to the tetraploid A. lyrata. This cytotype was able to escape from the narrow ecological niche occupied by diploid A. lyrata ssp. petraea on limestone outcrops by migrating northward into siliceous areas, leaving behind a trail of genetic differentiation. PMID:21825128

  19. Using isotopic patterns of ectomycorrhizal and saprotrophic fungi to elucidate fungal sources of carbon and nitrogen in a Norway spruce stand

    NASA Astrophysics Data System (ADS)

    Chen, Janet; Rinne-Garmston, Katja; Penttilä, Reijo; Hobbie, Erik; Mäkipää, Raisa

    2016-04-01

    To predict effects of global change on fungal community structure and the consequential effects on carbon (C) and nitrogen (N) cycling, we first need to understand different fungal sources of C and N. We determined sources of C and N by measuring δ15N and δ13C of an extensive collection of ectomycorrhizal and saprotrophic sporocarps and their potential substrates from Norway spruce (Picea abies) stands in southern Finland. The substrates included organic soil, roots in organic soil, mineral soil, roots in mineral soil, moss, needles, needles in litter, branches, twigs in litter, wood and decay wood from stages I-V. Notably, δ15N and δ13C analysis of wood in decay stages I-V was a novel measurement, as were our associations between wood decay fungi and the decay stage of trees. Decay stage of wood significantly correlated with the δ15N and δ13C of associated saprotrophic wood decay fungi species. Fungi were lower in δ15N by 0.3-0.7‰ when associated with decay wood in stages II and III compared to I and IV and higher in δ13C by 0.9-1.2‰ when associated with decay stage I compared to decay stages II-IV. The ectomycorrhizal fungi, Piloderma fallax, was significantly correlated with 15N enrichment of decay wood upon its introduction in decay stages III and IV that continued to the later decay stage V, with δ15N of decay stage V 1.5‰ higher than decay stage IV. These results indicate that wood decay fungi rely on C and N from various wood decay stages and influence C and N pools of wood as well. Litter decay fungi were lower in δ13C than wood decay fungi by 1.9‰ and higher in δ15N by 3‰ and isotopically tracked their C and N sources. Calocera viscosa, Gymnopus acervatus, and Leotia lubrica were highly 15N-enriched compared to other saprotrophic fungi and they had δ15N values similar to fungi with hydrophobic ectomycorrhizae indicating function more similar to ectomycorrhizal fungi or N sources similar to this functional group. Similar to other

  20. Tree diversity and the role of non-host neighbour tree species in reducing fungal pathogen infestation

    PubMed Central

    Hantsch, Lydia; Bien, Steffen; Radatz, Stine; Braun, Uwe; Auge, Harald; Bruelheide, Helge

    2014-01-01

    The degree to which plant pathogen infestation occurs in a host plant is expected to be strongly influenced by the level of species diversity among neighbouring host and non-host plant species. Since pathogen infestation can negatively affect host plant performance, it can mediate the effects of local biodiversity on ecosystem functioning. We tested the effects of tree diversity and the proportion of neighbouring host and non-host species with respect to the foliar fungal pathogens of Tilia cordata and Quercus petraea in the Kreinitz tree diversity experiment in Germany. We hypothesized that fungal pathogen richness increases while infestation decreases with increasing local tree diversity. In addition, we tested whether fungal pathogen richness and infestation are dependent on the proportion of host plant species present or on the proportion of particular non-host neighbouring tree species. Leaves of the two target species were sampled across three consecutive years with visible foliar fungal pathogens on the leaf surface being identified macro- and microscopically. Effects of diversity among neighbouring trees were analysed: (i) for total fungal species richness and fungal infestation on host trees and (ii) for infestation by individual fungal species. We detected four and five fungal species on T. cordata and Q. petraea, respectively. High local tree diversity reduced (i) total fungal species richness and infestation of T. cordata and fungal infestation of Q. petraea and (ii) infestation by three host-specialized fungal pathogen species. These effects were brought about by local tree diversity and were independent of host species proportion. In general, host species proportion had almost no effect on fungal species richness and infestation. Strong effects associated with the proportion of particular non-host neighbouring tree species on fungal species richness and infestation were, however, recorded. Synthesis. For the first time, we experimentally

  1. Drought and air warming affect the species-specific levels of stress-related foliar metabolites of three oak species on acidic and calcareous soil.

    PubMed

    Hu, Bin; Simon, Judy; Rennenberg, Heinz

    2013-05-01

    Climate change as projected for Central Europe will lead to prolonged periods of summer drought and enhanced air temperature. Thus, forest management practices are required to take into account how species performance is adapted to cope with these climate changes. Oak trees may play a major role in future forests because of their relative drought-tolerance compared with other species like beech. Therefore, this study investigated the stress responses (i.e., anti-oxidants, free amino acids) in the leaves of three widely distributed oak species in Central Europe (i.e., Quercus robur L., Q. petraea [Matt.] Libel., Q. pubescens Willd.) to drought, air warming and the combination of drought plus air warming under controlled conditions after periods of spring drought, a short rewetting and summer drought. We quantified foliar levels of thiols, ascorbate, and free amino compounds in Q robur, Q. petraea and Q. pubescens. Our study showed that oak saplings had increased levels of γ-glutamylcysteine and total glutathione and proline with drought and air warming. Foliar ascorbate, glutathione disulfide and dehydroascorbic acid levels were not affected. The comparison of stress responses to drought and/or air warming between the three species showed higher foliar thiol levels in Q. robur and Q. pubescens compared with Q. petraea. For total and reduced ascorbic acid and γ-aminobutyric acid, the highest levels were found in Q. robur. In conclusion, our study showed that foliar anti-oxidant and free amino acid levels were significantly affected by drought plus air warming; however, this effect was species-dependent with the drought-tolerant species of Q. pubescens having the highest reactive oxygen species scavenging capacity among three tested oak species. Furthermore, stress responses as shown by increased levels of foliar anti-oxidants and free amino acids differ between calcareous and acidic soil indicating that the capacities of anti-oxidative defense and osmotic stress

  2. The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis

    SciTech Connect

    Martin, F.; Aerts, A.; Ahren, D.; Brun, A.; Danchin, E. G. J.; Duchaussoy, F.; Gibon, J.; Kohler, A.; Lindquist, E.; Peresa, V.; Salamov, A.; Shapiro, H. J.; Wuyts, J.; Blaudez, D.; Buee, M.; Brokstein, P.; Canback, B.; Cohen, D.; Courty, P. E.; Coutinho, P. M.; Delaruelle, C.; Detter, J. C.; Deveau, A.; DiFazio, S.; Duplessis, S.; Fraissinet-Tachet, L.; Lucic, E.; Frey-Klett, P.; Fourrey, C.; Feussner, I.; Gay, G.; Grimwood, J.; Hoegger, P. J.; Jain, P.; Kilaru, S.; Labbe, J.; Lin, Y. C.; Legue, V.; Le Tacon, F.; Marmeisse, R.; Melayah, D.; Montanini, B.; Muratet, M.; Nehls, U.; Niculita-Hirzel, H.; Secq, M. P. Oudot-Le; Peter, M.; Quesneville, H.; Rajashekar, B.; Reich, M.; Rouhier, N.; Schmutz, J.; Yin, T.; Chalot, M.; Henrissat, B.; Kues, U.; Lucas, S.; Van de Peer, Y.; Podila, G. K.; Polle, A.; Pukkila, P. J.; Richardson, P. M.; Rouze, P.; Sanders, I. R.; Stajich, J. E.; Tunlid, A.; Tuskan, G.; Grigoriev, I. V.

    2007-08-10

    Mycorrhizal symbioses the union of roots and soil fungi are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants 1, 2. Boreal, temperate and montane forests all depend on ectomycorrhizae1. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features, most notably a battery of effector-type small secreted proteins (SSPs) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific SSPs probably have a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell wall polysaccharides, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem to perform vital functions in the carbon and nitrogen cycles that are

  3. The Genome of Laccaria Bi color Provides Insights into Mycorrhizal Symbiosis

    SciTech Connect

    Martin, F; Aerts, A.; Ahren, D; Brun, A; Duchaussoy, F; Gibon, J; Kohler, A; Lindquist, E; Pereda, V; Salamov, A.; Shapiro, HJ; Wuyts, J; Blaudez, D; Buee, M; Brokstein, P; Canbeck, B; Cohen, D; Courty, PE; Coutinho, PM; Danchin, E; Delaruelle, C; Detter, J C; Deveau, A; DiFazio, Stephen P; Duplessis, S; Fraissinet-Tachet, L; Lucic, E; Frey-Klett, P; Fourrey, C; Feussner, I; Gay, G; Grimwood, Jane; Hoegger, P J; Jain, P; Kilaru, S; Labbe, J; Lin, Y C; Legue, V; Le Tacon, F; Marmeisse, R; Melayah, D; Montanini, B; Muratet, M; Nehls, U; Niculita-Hirzel, H; Oudot-Le Secq, M P; Peter, M; Quesneville, H; Rajashekar, B; Reich, M; Rouhler, N; Schmutz, Jeremy; Yin, Tongming; Chalot, M; Henrissat, B; Kues, U; Lucas, S; Van de Peer, Y; Podila, G; Polle, A; Pukkila, P J; Richardson, P M; Rouze, P; Sanders, I R; Stajich, J E; Tunlid, A; Tuskan, Gerald A; Grigoriev, I.

    2008-01-01

    Mycorrhizal symbioses the union of roots and soil fungi are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants1,2. Boreal, temperate and montane forests all depend on ectomycorrhizae1. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features, most notably a battery of effector-type small secreted proteins (SSPs) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific SSPs probably have a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell wall polysaccharides, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem to perform vital functions in the carbon and

  4. The genome of Laccaria bicolor provides insights into

    SciTech Connect

    Martin, F; Aerts, A.; Ahren, D; Brun, A; Danchin, E; Duchaussoy, F; Gibon, J; Kohler, A; Lindquist, E; Pereda, V; Salamov, A.; Shapiro, HJ; Wuyts, J; Blaudez, D.; Buee, M; Brokstein, P; Canbeck, B; Cohen, D; Courty, PE; Coutinho, PM; Delaruelle, C; Detter, J C; Deveau, A; DiFazio, Stephen P; Duplessis, S; Fraissinet-Tachet, L; Lucic, E; Frey-Klett, P; Fourrey, C; Feussner, I; Gay, G; Grimwood, Jane; Hoegger, P J; Jain, P; Kilaru, S; Labbe, J; Lin, Y C; Legue, V; Le Tacon, F; Marmeisse, R; Melayah, D; Montanini, B; Muratet, M; Nehls, U; Niculita-Hirzel, H; Oudot-Le Secq, M P; Peter, M; Quesneville, H; Rajashekar, B; Reich, M; Rouhler, N; Schmutz, Jeremy; Yin, Tongming; Tuskan, Gerald A; Chalot, M; Henrissat, B; Kues, U; Lucas, S; Van de Peer, Y; Podila, G; Polle, A; Pukkila, P J; Richardson, P M; Rouze, P; Sanders, I R; Stajich, J E; Tunlid, A; Grigoriev, I.

    2008-01-01

    Mycorrhizal symbioses the union of roots and soil fungi are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants1,2. Boreal, temperate and montane forests all depend on ectomycorrhizae1. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features, most notably a battery of effector-type small secreted proteins (SSPs) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific SSPs probably have a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell wall polysaccharides, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem to perform vital functions in the carbon and nitrogen cycles that are

  5. The Potential of Dark Septate Endophytes to Form Root Symbioses with Ectomycorrhizal and Ericoid Mycorrhizal Middle European Forest Plants

    PubMed Central

    Lukešová, Tereza; Kohout, Petr; Větrovský, Tomáš; Vohník, Martin

    2015-01-01

    The unresolved ecophysiological significance of Dark Septate Endophytes (DSE) may be in part due to existence of morphologically indistinguishable cryptic species in the most common Phialocephala fortinii s. l.—Acephala applanata species complex (PAC). We inoculated three middle European forest plants (European blueberry, Norway spruce and silver birch) with 16 strains of eight PAC cryptic species and other DSE and ectomycorrhizal/ericoid mycorrhizal fungi and focused on intraradical structures possibly representing interfaces for plant-fungus nutrient transfer and on host growth response. The PAC species Acephala applanata simultaneously formed structures resembling ericoid mycorrhiza (ErM) and DSE microsclerotia in blueberry. A. macrosclerotiorum, a close relative to PAC, formed ectomycorrhizae with spruce but not with birch, and structures resembling ErM in blueberry. Phialocephala glacialis, another close relative to PAC, formed structures resembling ErM in blueberry. In blueberry, six PAC strains significantly decreased dry shoot biomass compared to ErM control. In birch, one A. macrosclerotiorum strain increased root biomass and the other shoot biomass in comparison with non-inoculated control. The dual mycorrhizal ability of A. macrosclerotiorum suggested that it may form mycorrhizal links between Ericaceae and Pinaceae. However, we were unable to detect this species in Ericaceae roots growing in a forest with presence of A. macrosclerotiorum ectomycorrhizae. Nevertheless, the diversity of Ericaceae mycobionts was high (380 OTUs) with individual sites often dominated by hitherto unreported helotialean and chaetothyrialean/verrucarialean species; in contrast, typical ErM fungi were either absent or low in abundance. Some DSE apparently have a potential to form mycorrhizae with typical middle European forest plants. However, except A. applanata, the tested representatives of all hitherto described PAC cryptic species formed typical DSE colonization without

  6. The potential of Dark Septate Endophytes to form root symbioses with ectomycorrhizal and ericoid mycorrhizal middle European forest plants.

    PubMed

    Lukešová, Tereza; Kohout, Petr; Větrovský, Tomáš; Vohník, Martin

    2015-01-01

    The unresolved ecophysiological significance of Dark Septate Endophytes (DSE) may be in part due to existence of morphologically indistinguishable cryptic species in the most common Phialocephala fortinii s. l.--Acephala applanata species complex (PAC). We inoculated three middle European forest plants (European blueberry, Norway spruce and silver birch) with 16 strains of eight PAC cryptic species and other DSE and ectomycorrhizal/ericoid mycorrhizal fungi and focused on intraradical structures possibly representing interfaces for plant-fungus nutrient transfer and on host growth response. The PAC species Acephala applanata simultaneously formed structures resembling ericoid mycorrhiza (ErM) and DSE microsclerotia in blueberry. A. macrosclerotiorum, a close relative to PAC, formed ectomycorrhizae with spruce but not with birch, and structures resembling ErM in blueberry. Phialocephala glacialis, another close relative to PAC, formed structures resembling ErM in blueberry. In blueberry, six PAC strains significantly decreased dry shoot biomass compared to ErM control. In birch, one A. macrosclerotiorum strain increased root biomass and the other shoot biomass in comparison with non-inoculated control. The dual mycorrhizal ability of A. macrosclerotiorum suggested that it may form mycorrhizal links between Ericaceae and Pinaceae. However, we were unable to detect this species in Ericaceae roots growing in a forest with presence of A. macrosclerotiorum ectomycorrhizae. Nevertheless, the diversity of Ericaceae mycobionts was high (380 OTUs) with individual sites often dominated by hitherto unreported helotialean and chaetothyrialean/verrucarialean species; in contrast, typical ErM fungi were either absent or low in abundance. Some DSE apparently have a potential to form mycorrhizae with typical middle European forest plants. However, except A. applanata, the tested representatives of all hitherto described PAC cryptic species formed typical DSE colonization without

  7. Restriction fragment length polymorphism species-specific patterns in the identification of white truffles.

    PubMed

    Bertini, L; Potenza, L; Zambonelli, A; Amicucci, A; Stocchi, V

    1998-07-15

    A molecular method for the identification of ectomycorrhizae belonging to five species of white truffle is described. The polymerase chain reaction (PCR) and universal primers were used to amplify internal transcribed spacers and 5.8S rDNA, target sequences present in a high number of copies. The amplified products were digested with restriction enzymes in order to detect interspecific polymorphisms. Species-specific restriction fragment length polymorphism patterns were determined for all five species. The use of PCR in conjunction with restriction enzymes provides a sensitive and efficient tool for use in distinguishing ectomycorrhizal species and monitoring inoculated seedlings or field mycorrhizal populations. PMID:9682488

  8. Managing coarse woody debris in forests of the Rocky Mountains. Forest Service research paper

    SciTech Connect

    Graham, R.T.; Harvey, A.E.; Jurgensen, M.F.; Jain, T.B.; Tonn, J.R.

    1994-09-01

    Recommendations for managing coarse woody debris after timber harvest were developed for 14 habitat types, ranging from ponderosa pine (Pinus ponderosa) habitat types of Arizona to subalpine fir (Abis lasiocarpa) habitat types of western Montana. Ectomycorrhizae were used as a bioindicator of health, productive forest soils. Undisturbed stands were studied to determine the optimum amounts of organic material for ectomycorrhizal activity. The management recommendations are intentionally conservative to ensure that enough organic matter is left after timber harvest to maintain long-term forest productivity.

  9. A revision of the Alpova diplophloeus complex in North America.

    PubMed

    Hayward, Jeremy; Tourtellot, Samuel G; Horton, Thomas R

    2014-01-01

    Alpova diplophloeus (Boletales, Paxillaceae) is the only currently recognized Alpova in North America with a brownish peridium, large gleba chambers and which forms ectomycorrhizas with Alnus. However, A. diplophloeus as currently circumscribed is a polyphyletic species, with at least three distinct genetic entities. Using a combination of molecular and morphological characters, we examined the type collections of A. diplophloeus, as well as species synonymized with it, including A. cinnamomeus and Rhizopogon parvisporus. We also examined several other collections of A. diplophloeus complex basidiomata. We describe A. diplophloeus sensu stricto; we also resurrect A. cinnamomeus, synonymized with R. parvisporus and describe a new species, A. concolor, from the complex. PMID:24891419

  10. Ectomycorrhizal association of three Lactarius species with Carpinus and Quercus trees in a Mexican montane cloud forest.

    PubMed

    Lamus, Valentina; Montoya, Leticia; Aguilar, Carlos J; Bandala, Victor M; Ramos, David

    2012-01-01

    Ectomycorrhizal (EM) fungi are being monitored in the Santuario del Bosque de Niebla in the central region of Veracruz (eastern Mexico). Based on the comparison of DNA sequences (ITS rDNA) of spatiotemporally co-occurring basidiomes and EM root tips, we discovered the EM symbiosis of Lactarius indigo, L. areolatus and L. strigosipes with Carpinus caroliniana, Quercus xalapensis and Quercus spp. The host of the EM tips was identified by comparison of the large subunit of the ribulose-bisphosphate carboxylase gene (rbcL). Descriptions coupled with photographs of ectomycorrhizas and basidiomes are presented. PMID:22675052

  11. Microevolution of European temperate oaks in response to environmental changes.

    PubMed

    Kremer, Antoine

    2016-01-01

    This review reconstructs microevolutionary processes that allowed long-lived species as temperate oaks (Quercus petraea and Q. robur) to cope with climate change since the last glacial maximum, by assembling insights from complementary synchronic and allochronic approaches. Paleobotanical and genetic investigations show that oaks migrated at larger velocities than expected, thanks to long-distance rare events and most likely human interferences. Hybridization was a key mechanism accelerating migration and enhancing species succession. Common garden experiments and genome wide association studies demonstrated that diversifying selection across large environmental gradients contributed to rapid local adaptation. Finally the review explores how lessons taken from past evolutionary scenarios may help to predict future responses of oaks to ongoing climate change. PMID:27263361

  12. Antioxidant Characterization of Oak Extracts Combining Spectrophotometric Assays and Chemometrics

    PubMed Central

    Popović, Boris M.; Štajner, Dubravka; Orlović, Saša; Galić, Zoran

    2013-01-01

    Antioxidant characteristics of leaves, twigs, and acorns from two Serbian oak species Quercus robur L. and Quercus petraea L. from Vojvodina province (northern Serbia) were investigated. 80% ethanol (in water) extracts were used for antiradical power (ARP) determinations against DPPH•, •NO, and O2•− radicals, ferric reducing antioxidant power (FRAP), total phenol, tannin, flavonoid, and proanthocyanidin contents. Permanganate reducing antioxidant capacity (PRAC) was determined using water extracts. Beside, mentioned parameters, soluble proteins, lipid peroxidation (LP), pigments and proline contents were also determined. The data of different procedures were compared and analyzed by multivariate techniques (correlation matrix calculation and principal component analysis (PCA)). PCA found that investigated organs of two different oak tree species possess similar antioxidant characteristics. The superior antioxidant characteristics showed oak leaves over twigs and acorns and seem to be promising source of antioxidants with possible use in industry and pharmacy. PMID:24453789

  13. High-density linkage mapping and distribution of segregation distortion regions in the oak genome.

    PubMed

    Bodénès, Catherine; Chancerel, Emilie; Ehrenmann, François; Kremer, Antoine; Plomion, Christophe

    2016-04-01

    We developed the densest single-nucleotide polymorphism (SNP)-based linkage genetic map to date for the genus Quercus An 8k gene-based SNP array was used to genotype more than 1,000 full-sibs from two intraspecific and two interspecific full-sib families of Quercus petraea and Quercus robur A high degree of collinearity was observed between the eight parental maps of the two species. A composite map was then established with 4,261 SNP markers spanning 742 cM over the 12 linkage groups (LGs) of the oak genome. Nine genomic regions from six LGs displayed highly significant distortions of segregation. Two main hypotheses concerning the mechanisms underlying segregation distortion are discussed: genetic load vs. reproductive barriers. Our findings suggest a predominance of pre-zygotic to post-zygotic barriers. PMID:27013549

  14. The influence of nitrogen in stemflow and precipitation on epiphytic bryophytes, Isothecium myosuroides Brid., Dicranum scoparium Hewd. and Thuidium tamariscinum (Hewd.) Schimp of Atlantic oakwoods.

    PubMed

    Leith, I D; Mitchell, R J; Truscott, A-M; Cape, J N; van Dijk, N; Smith, R I; Fowler, D; Sutton, M A

    2008-09-01

    The spatial relationship between the concentration and deposition of the major ions in precipitation and stemflow and their influence on the tissue nitrogen concentration of three epiphytic bryophytes on Quercus petraea (Matt) Liebl. and Q. robur L. was investigated at seven UK Atlantic oak woodland sites with a range of total N deposition of 55-250 mmol m(-2). The main driver of change in tissue N concentrations of three epiphytic bryophytes (Isothecium myosuroides Brid. (Eurhynchium myosuroides (Brid.) Schp.), Dicranum scoparium Hewd. and Thuidium tamariscinum (Hewd.) Schimp.) was total N deposition in stemflow, dominated by ammonium deposition. The three epiphytic species also showed strong relationships between tissue N concentration and total N deposition in rainfall but a poor correlation with total N ion concentration in rainfall. This study shows that epiphytic bryophytes utilise stemflow N and thus increase their risk from inputs of total N deposition compared to terricolous species at the same site. PMID:18343004

  15. High-density linkage mapping and distribution of segregation distortion regions in the oak genome

    PubMed Central

    Bodénès, Catherine; Chancerel, Emilie; Ehrenmann, François; Kremer, Antoine; Plomion, Christophe

    2016-01-01

    We developed the densest single-nucleotide polymorphism (SNP)-based linkage genetic map to date for the genus Quercus. An 8k gene-based SNP array was used to genotype more than 1,000 full-sibs from two intraspecific and two interspecific full-sib families of Quercus petraea and Quercus robur. A high degree of collinearity was observed between the eight parental maps of the two species. A composite map was then established with 4,261 SNP markers spanning 742 cM over the 12 linkage groups (LGs) of the oak genome. Nine genomic regions from six LGs displayed highly significant distortions of segregation. Two main hypotheses concerning the mechanisms underlying segregation distortion are discussed: genetic load vs. reproductive barriers. Our findings suggest a predominance of pre-zygotic to post-zygotic barriers. PMID:27013549

  16. Tree mineral nutrition is deteriorating in Europe.

    PubMed

    Jonard, Mathieu; Fürst, Alfred; Verstraeten, Arne; Thimonier, Anne; Timmermann, Volkmar; Potočić, Nenad; Waldner, Peter; Benham, Sue; Hansen, Karin; Merilä, Päivi; Ponette, Quentin; de la Cruz, Ana C; Roskams, Peter; Nicolas, Manuel; Croisé, Luc; Ingerslev, Morten; Matteucci, Giorgio; Decinti, Bruno; Bascietto, Marco; Rautio, Pasi

    2015-01-01

    The response of forest ecosystems to increased atmospheric CO2 is constrained by nutrient availability. It is thus crucial to account for nutrient limitation when studying the forest response to climate change. The objectives of this study were to describe the nutritional status of the main European tree species, to identify growth-limiting nutrients and to assess changes in tree nutrition during the past two decades. We analysed the foliar nutrition data collected during 1992-2009 on the intensive forest monitoring plots of the ICP Forests programme. Of the 22 significant temporal trends that were observed in foliar nutrient concentrations, 20 were decreasing and two were increasing. Some of these trends were alarming, among which the foliar P concentration in F. sylvatica, Q. Petraea and P. sylvestris that significantly deteriorated during 1992-2009. In Q. Petraea and P. sylvestris, the decrease in foliar P concentration was more pronounced on plots with low foliar P status, meaning that trees with latent P deficiency could become deficient in the near future. Increased tree productivity, possibly resulting from high N deposition and from the global increase in atmospheric CO2, has led to higher nutrient demand by trees. As the soil nutrient supply was not always sufficient to meet the demands of faster growing trees, this could partly explain the deterioration of tree mineral nutrition. The results suggest that when evaluating forest carbon storage capacity and when planning to reduce CO2 emissions by increasing use of wood biomass for bioenergy, it is crucial that nutrient limitations for forest growth are considered. PMID:24920268

  17. Expanding leaves of mature deciduous forest trees rapidly become autotrophic.

    PubMed

    Keel, Sonja G; Schädel, Christina

    2010-10-01

    Emerging leaves in evergreen tree species are supplied with carbon (C) from the previous year's foliage. In deciduous trees, no older leaves are present, and the early phase of leaf development must rely on C reserves from other tissues. How soon developing leaves become autotrophic and switch from being C sinks to sources has rarely been studied in mature forest trees, and simultaneous comparisons of species are scarce. Using a canopy crane and a simple (13)CO(2)-pulse-labelling technique, we demonstrate that young leaves of mature trees in three European deciduous species (Fagus sylvatica L., Quercus petraea (Matt.) Liebl., Tilia platyphyllos Scop.) start assimilating CO(2) at a very early stage of development (10-50% expanded). One month after labelling, all leaves were still strongly (13)C enriched, suggesting that recent photosynthates had been incorporated into slow turnover pools such as cellulose or lignin and thus had contributed to leaf growth. In line with previous studies performed at the same site, we found stronger incorporation of recent photosynthates into growing tissues of T. platyphyllos compared with F. sylvatica and Q. petraea. Non-structural carbohydrate (NSC) concentrations analysed for one of the three study species (F. sylvatica) showed that sugar and starch pools rapidly increased during leaf development, suggesting that newly developed leaves soon produce more NSC than can be used for growth. In conclusion, our findings indicate that expanding leaves of mature deciduous trees become C autonomous at an early stage of development despite the presence of vast amounts of mobile carbohydrate reserves. PMID:20688879

  18. Wood anatomical responses of oak saplings exposed to air warming and soil drought.

    PubMed

    Fonti, P; Heller, O; Cherubini, P; Rigling, A; Arend, M

    2013-01-01

    Water is vital for plant performance and survival. Its scarcity, induced by a seasonal decline in soil water availability or an increase of evaporative demand, can cause failures of the water conducting system. An adequate tolerance to drought and the ability to acclimate to changing hydraulic conditions are important features for the survival of long-lived woody plants in dry environments. In this study we examine secondary growth and xylem anatomical acclimation of 6 year old saplings of three European oak species (Quercus robur, Q. petraea, Q. pubescens) during the third consecutive year of exposure to soil drought and/or air warming (from 2007 to 2009). Intra-annual pinning was applied to mark the development of the formation of the annual ring 2009. Vessel size, parenchyma cell density and fiber size produced at different time of the growing season 2009 were compared between drought and warming treatments and species. Drought reduced secondary growth and induced changes in xylem structure while air warming had little effect on wood anatomical traits. Results indicate that drought-exposed saplings adjust their xylem structure to improve resistance and repairing abilities after cavitation. All species show a significant radial growth reduction, a reduced vessel size with diminished conductivity and a slightly increased density of parenchyma cells. Comparisons between species fostered our understanding of the relationship between the inter-specific xylem hydraulic plasticity and the ecological response to drought. The stronger changes observed for Q. robur and Q. petraea indicate a lower drought tolerance than Q. pubescens. PMID:22612857

  19. A Major Quantitative Trait Locus for Cadmium Tolerance in Arabidopsis halleri Colocalizes with HMA4, a Gene Encoding a Heavy Metal ATPase1[OA

    PubMed Central

    Courbot, Mikael; Willems, Glenda; Motte, Patrick; Arvidsson, Samuel; Roosens, Nancy; Saumitou-Laprade, Pierre; Verbruggen, Nathalie

    2007-01-01

    Cadmium (Cd) tolerance seems to be a constitutive species-level trait in Arabidopsis halleri sp. halleri. Therefore, an interspecific cross was made between A. halleri and its closest nontolerant interfertile relative, Arabidopsis lyrata sp. petraea, and a first-generation backcross population (BC1) was used to map quantitative trait loci (QTL) for Cd tolerance. Three QTL were identified, which explained 43%, 24%, and 16% of the phenotypic variation in the mapping population. Heavy metal transporting ATPases4 (HMA4), encoding a predicted heavy metal ATPase, colocalized with the peak of the major QTL Cdtol-1 and was consequently further studied. HMA4 transcripts levels were higher in the roots and the shoots of A. halleri than in A. lyrata sp. petraea. Furthermore, HMA4 was also more highly expressed in all BC1 genotypes harboring the HMA4 A. halleri allele at the QTL Cdtol-1, independently of the presence of an A. halleri allele at the two other QTL. Overexpression of AhHMA4 in yeast (Saccharomyces cerevisiae) supported a role of HMA4 in zinc (Zn) and Cd transport by reducing the Cd and Zn contents of the yeast cells. In epidermal tobacco (Nicotiana tabacum) cells, AhHMA4:green fluorescent protein was clearly localized in the plasma membrane. Taken together, all available data point to the elevated expression of HMA4 P1B-type ATPase as an efficient mechanism for improving Cd/Zn tolerance in plants under conditions of Cd/Zn excess by maintaining low cellular Cd2+ and Zn2+ concentrations in the cytoplasm. PMID:17434989

  20. Forms of zinc accumulated in the hyperaccumulator Arabidopsis halleri.

    PubMed

    Sarret, Géraldine; Saumitou-Laprade, Pierre; Bert, Valérie; Proux, Olivier; Hazemann, Jean-Louis; Traverse, Agnès; Marcus, Matthew A; Manceau, Alain

    2002-12-01

    The chemical forms of zinc (Zn) in the Zn-tolerant and hyperaccumulator Arabidopsis halleri and in the non-tolerant and nonaccumulator Arabidopsis lyrata subsp. petraea were determined at the molecular level by combining chemical analyses, extended x-ray absorption spectroscopy (EXAFS), synchrotron-based x-ray microfluorescence, and muEXAFS. Plants were grown in hydroponics with various Zn concentrations, and A. halleri specimens growing naturally in a contaminated site were also collected. Zn speciation in A. halleri was independent of the origin of the plants (contaminated or non-contaminated) and Zn exposure. In aerial parts, Zn was predominantly octahedrally coordinated and complexed to malate. A secondary organic species was identified in the bases of the trichomes, which contained elevated Zn concentrations, and in which Zn was tetrahedrally coordinated and complexed to carboxyl and/or hydroxyl functional groups. This species was detected thanks to the good resolution and sensitivity of synchrotron-based x-ray microfluorescence and muEXAFS. In the roots of A. halleri grown in hydroponics, Zn phosphate was the only species detected, and is believed to result from chemical precipitation on the root surface. In the roots of A. halleri grown on the contaminated soil, Zn was distributed in Zn malate, Zn citrate, and Zn phosphate. Zn phosphate was present in both the roots and aerial part of A. lyrata subsp. petraea. This study illustrates the complementarity of bulk and spatially resolved techniques, allowing the identification of: (a) the predominant chemical forms of the metal, and (b) the minor forms present in particular cells, both types of information being essential for a better understanding of the bioaccumulation processes. PMID:12481065

  1. Mycorrhizal symbionts of Pisonia grandis and P. sechellarum in Seychelles: identification of mycorrhizal fungi and description of new Tomentella species.

    PubMed

    Suvi, Triin; Tedersoo, Leho; Abarenkov, Kessy; Beaver, Katy; Gerlach, Justin; Kõljalg, Urmas

    2010-01-01

    Nyctaginaceae includes species that are predominantly non-mycorrhizal or form arbuscular or ectomycorrhiza. Root-associated fungi were studied from P. grandis and P. sechellarum roots collected respectively on the islands of Cousin and Silhouette in Seychelles. In addition fungal sporocarps were collected from the sampling area. Fungal symbionts were identified from the roots by anatomotyping and rDNA sequencing; sporocarps collected were examined microscopically and sequenced. Three distantly related ectomycorrhizal fungal species belonging to Thelephoraceae were identified from the roots of P. grandis. Sporocarps also were found for two symbionts and described as new Tomentella species. In addition Tomentella species collected from other Seychelles islands were studied and described as new species if there was no close resemblance to previously established species. P. sechellarum was determined to be an arbuscular mycorrhizal plant; three arbuscular mycorrhizal fungal species were detected from the roots. P. grandis is probably associated only with species of Thelephoraceae throughout its area. Only five Tomentella species are known to form ectomycorrhiza with P. grandis and they never have been found to be associated with another host, suggesting adaptation of these fungi to extreme environmental conditions in host's habitat. PMID:20524585

  2. The ectomycorrhizal community in natural Tuber borchii grounds.

    PubMed

    Iotti, Mirco; Lancellotti, Enrico; Hall, Ian; Zambonelli, Alessandra

    2010-05-01

    Although Tuber borchii is a commercially valuable truffle, its habitat has been virtually ignored. Here, we examine the ectomycorrhizal fungal communities in natural T. borchii grounds. Ectomycorrhizas under T. borchii ascomata and up to 1 m away were collected and morphologically assigned to pine or oak host plants. They were then morphotyped and molecular typed using internal transcribed spacer regions. Seventy ectomycorrhizal taxa were identified, many of which were rare. Tuber borchii dominated, forming 20% of ectomycorrhizas, with Thelephoraceae, Inocybaceae and Sebacinaceae being the other main species. Species composition was markedly affected by the host plant, although community structure and composition was also influenced by the location from which the soil cores were collected. Tuber dryophilum, an edible truffle, but without commercial value, shared the habitat with T. borchii. Its mycorrhizas were never found together with those of T. borchii. Tuber borchii was present on both oaks and pines, but was more abundant in soil cores where the roots of both hosts were present. It is suggested that the presence of young oaks contributed to the maintenance of T. borchii colonization on pines. PMID:20199569

  3. Solid-phase microextraction gas chromatography/ion trap mass spectrometry and multistage mass spectrometry experiments in the characterization of germacrene D.

    PubMed

    Gioacchini, A M; Menotta, M; Polidori, E; Giomaro, G; Stocchi, V

    2002-12-01

    Germacrene D is a vegetable pheromone utilized in interactions among organisms belonging to different species. For the first time, using solid-phase microextraction/gas chromatography/ion trap mass spectrometry, the presence of this compound was detected in an in vitro mycorrhizal synthesis system where the mycelium of the ectomycorrhizal fungus Tuber borchii Vittad. interacts with the plant Tilia Americana L. From this symbiosis, a new structure, called ectomycorrhiza, is formed where the two symbionts exchange nutrients and metabolites. It seems that only after this interaction can the mycelium develop the fruitbody, commonly known as truffle. The results obtained allowed us to ascertain that germacrene D was synthesized by the plant exclusively in the presence of T. borchii. The originality of these data prompted us to hypothesize that this compound could be involved in the first step of ectomycorrhiza formation, as it is able to stimulate specific fungi receptors. In fact, plants release hundreds of secondary metabolites that are important in their interactions with other organisms. PMID:12489082

  4. Beech carbon productivity as driver of ectomycorrhizal abundance and diversity.

    PubMed

    Druebert, Christine; Lang, Christa; Valtanen, Kerttu; Polle, Andrea

    2009-08-01

    We tested the hypothesis that carbon productivity of beech (Fagus sylvatica) controls ectomycorrhizal colonization, diversity and community structures. Carbon productivity was limited by long-term shading or by girdling. The trees were grown in compost soil to avoid nutrient deficiencies. Despite severe limitation in photosynthesis and biomass production by shading, the concentrations of carbohydrates in roots were unaffected by the light level. Shade-acclimated plants were only 10% and sun-acclimated plants were 74% colonized by ectomycorrhiza. EM diversity was higher on roots with high than at roots with low mycorrhizal colonization. Evenness was unaffected by any treatment. Low mycorrhizal colonization had no negative effects on plant mineral nutrition. In girdled plants mycorrhizal colonization and diversity were retained although (14)C-leaf feeding showed almost complete disruption of carbon transport from leaves to roots. Carbohydrate storage pools in roots decreased upon girdling. Our results show that plant carbon productivity was the reason for and not the result of high ectomycorrhizal diversity. We suggest that ectomycorrhiza can be supplied by two carbon routes: recent photosynthate and stored carbohydrates. Storage pools may be important for ectomycorrhizal survival when photoassimilates were unavailable, probably feeding preferentially less carbon demanding EM species as shifts in community composition were found. PMID:19344334

  5. Profiling functions of ectomycorrhizal diversity and root structuring in seedlings of Norway spruce (Picea abies) with fast- and slow-growing phenotypes.

    PubMed

    Velmala, Sannakajsa M; Rajala, Tiina; Heinonsalo, Jussi; Taylor, Andy F S; Pennanen, Taina

    2014-01-01

    We studied the role of taxonomical and functional ectomycorrhizal (ECM) fungal diversity in root formation and nutrient uptake by Norway spruce (Picea abies) seedlings with fast- and slow-growing phenotypes. Seedlings were grown with an increasing ECM fungal diversity gradient from one to four species and sampled before aboveground growth differences between the two phenotypes were apparent. ECM fungal colonization patterns were determined and functional diversity was assayed via measurements of potential enzyme activities of eight exoenzymes probably involved in nutrient mobilization. Phenotypes did not vary in their receptiveness to different ECM fungal species. However, seedlings of slow-growing phenotypes had higher fine-root density and thus more condensed root systems than fast-growing seedlings, but the potential enzyme activities of ectomycorrhizas did not differ qualitatively or quantitatively. ECM species richness increased host nutrient acquisition potential by diversifying the exoenzyme palette. Needle nitrogen content correlated positively with high chitinase activity of ectomycorrhizas. Rather than fast- and slow-growing phenotypes exhibiting differing receptiveness to ECM fungi, our results suggest that distinctions in fine-root structuring and in the belowground growth strategy already apparent at early stages of seedling development may explain later growth differences between fast- and slow-growing families. PMID:24117652

  6. An overview of Cistus ectomycorrhizal fungi.

    PubMed

    Comandini, O; Contu, M; Rinaldi, A C

    2006-09-01

    The genus Cistus comprises a group of about 20 shrub species found in wide areas throughout the whole Mediterranean region to the Caucasus. Being one of the main constituents of the Mediterranean-type maquis, this plant genus is peculiar in that it has developed a range of specific adaptations to resist summer drought and frequent disturbance events, such as fire and grazing. In addition, it can form both ectomycorrhizas and arbuscular mycorrhizas. In this paper, we review the information available on the ectomycorrhizal fungi of Cistus across its entire geographic range, as gathered and critically sifted from both published literature sources and personal observations. Although the resulting data matrix was based primarily on accounts of sporocarp inventories in the field, existing knowledge on the features of Cistus natural and synthesized ectomycorrhizas was also included and discussed. In total, more than 200 fungal species belonging to 40 genera have been reported so far to be associated with Cistus. An analysis of the pattern of ectomycorrhizal diversity and host specificity revealed that members of the Cortinariaceae and Russulaceae make the most of both Cistus-aspecific and Cistus-specific mycobionts. Further studies are needed to expand our preliminary knowledge of the mycorrhizal ecology and biology of Cistus and its fungal associates, focusing on topics such as mycobiont diversity, host specificity, fungal succession, mycorrhizal influence on stress tolerance, and impact of disturbances, while comparing the findings with those from other ecosystems. PMID:16896800

  7. The alpha-tubulin gene AmTuba1: a marker for rapid mycelial growth in the ectomycorrhizal basidiomycete Amanita muscaria.

    PubMed

    Tarkka, Mika T; Schrey, Silvia; Nehls, Uwe

    2006-05-01

    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 alpha-tubulin gene from the ectomycorrhizal basidiomycete Amanita muscaria (AmTuba1). The phylogenetic analysis of protein sequences revealed the existence of two subgroups of alpha-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 alpha-tubulin proteins are promising tools for the classification of fungi. PMID:16447071

  8. Eucalypt NADP-Dependent Isocitrate Dehydrogenase1

    PubMed Central

    Boiffin, Vincent; Hodges, Michael; Gálvez, Susana; Balestrini, Raffaella; Bonfante, Paola; Gadal, Pierre; Martin, Francis

    1998-01-01

    NADP-dependent isocitrate dehydrogenase (NADP-ICDH) activity is increased in roots of Eucalyptus globulus subsp. bicostata ex Maiden Kirkp. during colonization by the ectomycorrhizal fungus Pisolithus tinctorius Coker and Couch. To investigate the regulation of the enzyme expression, a cDNA (EgIcdh) encoding the NADP-ICDH was isolated from a cDNA library of E. globulus-P. tinctorius ectomycorrhizae. The putative polypeptide sequence of EgIcdh showed a high amino acid similarity with plant NADP-ICDHs. Because the deduced EgICDH protein lacks an amino-terminal targeting sequence and shows highest similarity to plant cytosolic ICDHs, it probably represents a cytoplasmic isoform. RNA analysis showed that the steady-state level of EgIcdh transcripts was enhanced nearly 2-fold in ectomycorrhizal roots compared with nonmycorrhizal roots. Increased accumulation of NADP-ICDH transcripts occurred as early as 2 d after contact and likely led to the observed increased enzyme activity. Indirect immunofluorescence microscopy indicated that NADP-ICDH was preferentially accumulated in the epidermis and stele parenchyma of nonmycorrhizal and ectomycorrhizal lateral roots. The putative role of cytosolic NADP-ICDH in ectomycorrhizae is discussed. PMID:9662536

  9. Evolutionary history of Serpulaceae (Basidiomycota): molecular phylogeny, historical biogeography and evidence for a single transition of nutritional mode

    PubMed Central

    2011-01-01

    Background The fungal genus Serpula (Serpulaceae, Boletales) comprises several saprotrophic (brown rot) taxa, including the aggressive house-infecting dry rot fungus Serpula lacrymans. Recent phylogenetic analyses have indicated that the ectomycorrhiza forming genera Austropaxillus and Gymnopaxillus cluster within Serpula. In this study we use DNA sequence data to investigate phylogenetic relationships, historical biogeography of, and nutritional mode transitions in Serpulaceae. Results Our results corroborate that the two ectomycorrhiza-forming genera, Austropaxillus and Gymnopaxillus, form a monophyletic group nested within the saprotrophic genus Serpula, and that the Serpula species S. lacrymans and S. himantioides constitute the sister group to the Austropaxillus-Gymnopaxillus clade. We found that both vicariance (Beringian) and long distance dispersal events are needed to explain the phylogeny and current distributions of taxa within Serpulaceae. Our results also show that the transition from brown rot to mycorrhiza has happened only once in a monophyletic Serpulaceae, probably between 50 and 22 million years before present. Conclusions This study supports the growing understanding that the same geographical barriers that limit plant- and animal dispersal also limit the spread of fungi, as a combination of vicariance and long distance dispersal events are needed to explain the present patterns of distribution in Serpulaceae. Our results verify the transition from brown rot to ECM within Serpulaceae between 50 and 22 MyBP. PMID:21816066

  10. Ectomycorrhizal fungal diversity in orchards of cultivated pecan (Carya illinoinensis; Juglandaceae).

    PubMed

    Bonito, Gregory; Brenneman, Timothy; Vilgalys, Rytas

    2011-10-01

    Carya illinoinensis (pecan) belongs to the Juglandaceae (walnut family) and is a major economic nut crop in the southern USA. Although evidence suggests that some species in the Juglandaceae are ectomycorrhizal, investigations on their ectomycorrhizal fungal symbionts are quite limited. Here we assessed the ectomycorrhizal fungal diversity in cultivated orchards of C. illinoinensis. Five pecan orchards in southern Georgia, USA, were studied, three of which were known to fruit the native edible truffle species Tuber lyonii. We sequenced rDNA from single ectomycorrhizal root tips sampled from a total of 50 individual trees. Mycorrhizae were identified by ITS and LSU rDNA sequence-based methods. Forty-four distinct ectomycorrhizal taxa were detected. Sequestrate taxa including Tuber and Scleroderma were particularly abundant. The two most abundant sequence types belonged to T. lyonii (17%) and an undescribed Tuber species (~20%). Because of our interest in the ecology of T. lyonii, we also conducted greenhouse studies to determine whether this species would colonize and form ectomycorrhizae on roots of pecan, oak, or pine species endemic to the region. T. lyonii ectomycorrhizae were formed on pecan and oak seedlings, but not pine, when these were inoculated with spores. That oak and pecan seedling roots were receptive to truffle spores indicates that spore slurry inoculation could be a suitable method for commercial use and that, ecologically, T. lyonii may function as a pioneer ectomycorrhizal species for these hosts. PMID:21369784

  11. Independent, specialized invasions of ectomycorrhizal mutualism by two nonphotosynthetic orchids

    PubMed Central

    Taylor, D. Lee; Bruns, Thomas D.

    1997-01-01

    We have investigated the mycorrhizal associations of two nonphotosynthetic orchids from distant tribes within the Orchidaceae. The two orchids were found to associate exclusively with two distinct clades of ectomycorrhizal basidiomycetous fungi over wide geographic ranges. Yet both orchids retained the internal mycorrhizal structure typical of photosynthetic orchids that do not associate with ectomycorrhizal fungi. Restriction fragment length polymorphism and sequence analysis of two ribosomal regions along with fungal isolation provided congruent, independent evidence for the identities of the fungal symbionts. All 14 fungal entities that were associated with the orchid Cephalanthera austinae belonged to a clade within the Thelephoraceae, and all 18 fungal entities that were associated with the orchid Corallorhiza maculata fell within the Russulaceae. Restriction fragment length polymorphism and single-strand conformational polymorphism analysis of ectomycorrhizal tree roots collected adjacent to Cephalanthera showed that (i) the fungi associated internally with Cephalanthera also form typical external ectomycorrhizae and that (ii) ectomycorrhizae formed by other Basidiomycetes were abundant where the orchid grows but these fungi did not associate with the orchid. This is the first proof of ectomycorrhizal epiparasitism in nature by an orchid. We argue that these orchids are cheaters because they do not provide fixed carbon to associated fungi. This view suggests that mycorrhizae, like other ancient mutualisms, are susceptible to cheating. The extreme specificity in these orchids relative to other ectomycorrhizal plants agrees with trends seen in more conventional parasites. PMID:9114020

  12. Ectomycorrhizal Influence on Particle Size, Surface Structure, Mineral Crystallinity, Functional Groups, and Elemental Composition of Soil Colloids from Different Soil Origins

    PubMed Central

    Li, Yanhong; Wang, Huimei; Wang, Wenjie; Yang, Lei; Zu, Yuangang

    2013-01-01

    Limited data are available on the ectomycorrhizae-induced changes in surface structure and composition of soil colloids, the most active portion in soil matrix, although such data may benefit the understanding of mycorrhizal-aided soil improvements. By using ectomycorrhizae (Gomphidius viscidus) and soil colloids from dark brown forest soil (a good loam) and saline-alkali soil (heavily degraded soil), we tried to approach the changes here. For the good loam either from the surface or deep soils, the fungus treatment induced physical absorption of covering materials on colloid surface with nonsignificant increases in soil particle size (P > 0.05). These increased the amount of variable functional groups (O–H stretching and bending, C–H stretching, C=O stretching, etc.) by 3–26% and the crystallinity of variable soil minerals (kaolinite, hydromica, and quartz) by 40–300%. However, the fungus treatment of saline-alkali soil obviously differed from the dark brown forest soil. There were 12–35% decreases in most functional groups, 15–55% decreases in crystallinity of most soil minerals but general increases in their grain size, and significant increases in soil particle size (P < 0.05). These different responses sharply decreased element ratios (C : O, C : N, and C : Si) in soil colloids from saline-alkali soil, moving them close to those of the good loam of dark brown forest soil. PMID:23766704

  13. Fine-scale diversity and distribution of ectomycorrhizal fungal mycelium in a Scots pine forest.

    PubMed

    Anderson, Ian C; Genney, David R; Alexander, Ian J

    2014-03-01

    Ectomycorrhizal (ECM) mycelium is a key component of the ectomycorrhizal symbiosis, yet we know little regarding the fine-scale diversity and distribution of mycelium in ECM fungal communities. We collected four 20 × 20 × 2-cm(3) (800-cm(3)) slices of Scots pine (Pinus sylvestris) forest soil and divided each into 100 2 × 2 × 2-cm(3) (8-cm(3)) cubes. The presence of mycelium of ECM fungi was determined using an internal transcribed spacer (ITS) database terminal restriction fragment length polymorphism (T-RFLP) approach. As expected, many more ECM fungi were detected as mycelium than as ectomycorrhizas in a cube or slice. More surprisingly, up to one-quarter of the 43 species previously detected as ectomycorrhizas over an area of 400 m(2) could be detected in a single 8-cm(3) cube, and up to three-quarters in a single 800-cm(3) slice. ECM mycelium frequency decreased markedly with depth and there were distinct 'hotspots' of mycelium in the moss/F1 layer. Our data demonstrate a high diversity of ECM mycelium in a small (8-cm(3) ) volume of substrate, and indicate that the spatial scale at which ECM species are distributed as mycelium may be very different from the spatial scale at which they are distributed as tips. PMID:24345261

  14. Significance of various soil amendments to borrow pit reclamation with loblolly pine and fescue

    SciTech Connect

    Berry, C.R.; Marx, D.H.

    1980-01-01

    Loblolly pine seedlings with ectomycorrhizae formed by Pisolithus tinctorius (Pt) or naturally occurring Thelephora terrestris (Tt) were planted on a borrow pit in South Carolina in plots with no amendment; with fertilizer plus dolomitic limestone alone and with pine bark or bottom ash or bark and ash together; or with dried sewage sludge alone and with bark or ash or bark and ash together. All plots were subsoiled, disked, and seeded to fescue grass before planting pine seedlings. Naturally occurring Pt formed abundant ectomycorrhizae on all Tt seedlings by the end of the first season, precluding any specific ectomycorrhizal fungus effect for the duration of the study. Sewage sludge alone or with bark or ash amendments dramatically improved pine seedling growth and grass biomass in comparison with other soil treatments. Mean seedling volume (D/sup 2/H) was 28 times greater and grass biomass was five times greater in the sludge plots than on nonsludge plots. Generally, soil amended with sludge contained more N, P, organic matter, and had a higher cation exchange capacity than soil of other treatments. Foliage of pine seedlings in sludge-amended soil also contained more N and less Ca than other seedlings. The significance of these results to reclamation of borrow pits is discussed.

  15. Belowground legacies of Pinus contorta invasion and removal result in multiple mechanisms of invasional meltdown

    PubMed Central

    Dickie, Ian A.; St John, Mark G.; Yeates, Gregor W.; Morse, Chris W.; Bonner, Karen I.; Orwin, Kate; Peltzer, Duane A.

    2013-01-01

    Plant invasions can change soil biota and nutrients in ways that drive subsequent plant communities, particularly when co-invading with belowground mutualists such as ectomycorrhizal fungi. These effects can persist following removal of the invasive plant and, combined with effects of removal per se, influence subsequent plant communities and ecosystem functioning. We used field observations and a soil bioassay with multiple plant species to determine the belowground effects and post-removal legacy caused by invasion of the non-native tree Pinus contorta into a native plant community. Pinus facilitated ectomycorrhizal infection of the co-occurring invasive tree, Pseudotsuga menziesii, but not conspecific Pinus (which always had ectomycorrhizas) nor the native pioneer Kunzea ericoides (which never had ectomycorrhizas). Pinus also caused a major shift in soil nutrient cycling as indicated by increased bacterial dominance, NO3-N (17-fold increase) and available phosphorus (3.2-fold increase) in soils, which in turn promoted increased growth of graminoids. These results parallel field observations, where Pinus removal is associated with invasion by non-native grasses and herbs, and suggest that legacies of Pinus on soil nutrient cycling thus indirectly promote invasion of other non-native plant species. Our findings demonstrate that multi-trophic belowground legacies are an important but hitherto largely unconsidered factor in plant community reassembly following invasive plant removal. PMID:25228312

  16. Attributing functions to ectomycorrhizal fungal identities in assemblages for nitrogen acquisition under stress

    PubMed Central

    Pena, Rodica; Polle, Andrea

    2014-01-01

    Mycorrhizal fungi have a key role in nitrogen (N) cycling, particularly in boreal and temperate ecosystems. However, the significance of ectomycorrhizal fungal (EMF) diversity for this important ecosystem function is unknown. Here, EMF taxon-specific N uptake was analyzed via 15N isotope enrichment in complex root-associated assemblages and non-mycorrhizal root tips in controlled experiments. Specific 15N enrichment in ectomycorrhizas, which represents the N influx and export, as well as the exchange of 15N with the N pool of the root tip, was dependent on the fungal identity. Light or water deprivation revealed interspecific response diversity for N uptake. Partial taxon-specific N fluxes for ectomycorrhizas were assessed, and the benefits of EMF assemblages for plant N nutrition were estimated. We demonstrated that ectomycorrhizal assemblages provide advantages for inorganic N uptake compared with non-mycorrhizal roots under environmental constraints but not for unstressed plants. These benefits were realized via stress activation of distinct EMF taxa, which suggests significant functional diversity within EMF assemblages. We developed and validated a model that predicts net N flux into the plant based on taxon-specific 15N enrichment in ectomycorrhizal root tips. These results open a new avenue to characterize the functional traits of EMF taxa in complex communities. PMID:24030593

  17. Identification of genes differentially expressed in ectomycorrhizal roots during the Pinus pinaster-Laccaria bicolor interaction.

    PubMed

    Flores-Monterroso, Aranzazu; Canales, Javier; de la Torre, Fernando; Ávila, Concepción; Cánovas, Francisco M

    2013-06-01

    Ectomycorrhizal associations are of major ecological importance in temperate and boreal forests. The development of a functional ectomycorrhiza requires many genetic and biochemical changes. In this study, suppressive subtraction hybridization was used to identify differentially expressed genes in the roots of maritime pine (Pinus pinaster Aiton) inoculated with Laccaria bicolor, a mycorrhizal fungus. A total number of 200 unigenes were identified as being differentially regulated in maritime pine roots during the development of mycorrhiza. These unigenes were classified into 10 categories according to the function of their homologues in the GenBank database. Approximately, 40 % of the differentially expressed transcripts were genes that coded for unknown proteins in the databases or that had no homology to known genes. A group of these differentially expressed genes was selected to validate the results using quantitative real-time PCR. The transcript levels of the representative genes were compared between the non-inoculated and inoculated plants at 1, 5, 15 and 30 days after inoculation. The observed expression patterns indicate (1) changes in the composition of the wall cell, (2) tight regulation of defence genes during the development of mycorrhiza and (3) changes in carbon and nitrogen metabolism. Ammonium excess or deficiency dramatically affected the stability of ectomycorrhiza and altered gene expression in maritime pine roots. PMID:23543110

  18. The aquaporin gene family of the ectomycorrhizal fungus Laccaria bicolor: lessons for symbiotic functions.

    PubMed

    Dietz, Sandra; von Bülow, Julia; Beitz, Eric; Nehls, Uwe

    2011-06-01

    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. PMID:21352231

  19. Belowground legacies of Pinus contorta invasion and removal result in multiple mechanisms of invasional meltdown.

    PubMed

    Dickie, Ian A; St John, Mark G; Yeates, Gregor W; Morse, Chris W; Bonner, Karen I; Orwin, Kate; Peltzer, Duane A

    2014-01-01

    Plant invasions can change soil biota and nutrients in ways that drive subsequent plant communities, particularly when co-invading with belowground mutualists such as ectomycorrhizal fungi. These effects can persist following removal of the invasive plant and, combined with effects of removal per se, influence subsequent plant communities and ecosystem functioning. We used field observations and a soil bioassay with multiple plant species to determine the belowground effects and post-removal legacy caused by invasion of the non-native tree Pinus contorta into a native plant community. Pinus facilitated ectomycorrhizal infection of the co-occurring invasive tree, Pseudotsuga menziesii, but not conspecific Pinus (which always had ectomycorrhizas) nor the native pioneer Kunzea ericoides (which never had ectomycorrhizas). Pinus also caused a major shift in soil nutrient cycling as indicated by increased bacterial dominance, NO3-N (17-fold increase) and available phosphorus (3.2-fold increase) in soils, which in turn promoted increased growth of graminoids. These results parallel field observations, where Pinus removal is associated with invasion by non-native grasses and herbs, and suggest that legacies of Pinus on soil nutrient cycling thus indirectly promote invasion of other non-native plant species. Our findings demonstrate that multi-trophic belowground legacies are an important but hitherto largely unconsidered factor in plant community reassembly following invasive plant removal. PMID:25228312

  20. Fungal functioning in a pine forest: evidence from a ¹⁵N-labeled global change experiment.

    PubMed

    Hobbie, Erik A; van Diepen, Linda T A; Lilleskov, Erik A; Ouimette, Andrew P; Finzi, Adrien C; Hofmockel, Kirsten S

    2014-03-01

    • We used natural and tracer nitrogen (N) isotopes in a Pinus taeda free air CO₂ enrichment (FACE) experiment to investigate functioning of ectomycorrhizal and saprotrophic fungi in N cycling. • Fungal sporocarps were sampled in 2004 (natural abundance and (15) N tracer) and 2010 (tracer) and δ(15)N patterns were compared against litter and soil pools. • Ectomycorrhizal fungi with hydrophobic ectomycorrhizas (e.g. Cortinarius and Tricholoma) acquired N from the Oea horizon or deeper. Taxa with hydrophilic ectomycorrhizas acquired N from the Oi horizon (Russula and Lactarius) or deeper (Laccaria, Inocybe, and Amanita). (15)N enrichment patterns for Cortinarius and Amanita in 2010 did not correspond to any measured bulk pool, suggesting that a persistent pool of active organic N supplied these two taxa. Saprotrophic fungi could be separated into those colonizing pine cones (Baeospora), wood, litter (Oi), and soil (Ramariopsis), with δ(15)N of taxa reflecting substrate differences. (15)N enrichment between sources and sporocarps varied across taxa and contributed to δ(15)N patterns. • Natural abundance and (15)N tracers proved useful for tracking N from different depths into fungal taxa, generally corresponded to literature estimates of fungal activity within soil profiles, and provided new insights into interpreting natural abundance δ(15)N patterns. PMID:24304469

  1. Carbon and nitrogen fluxes between beech and their ectomycorrhizal assemblage.

    PubMed

    Valtanen, Kerttu; Eissfeller, Verena; Beyer, Friderike; Hertel, Dietrich; Scheu, Stefan; Polle, Andrea

    2014-11-01

    To determine the exchange of nitrogen and carbon between ectomycorrhiza and host plant, young beech (Fagus sylvatica) trees from natural regeneration in intact soil cores were labelled for one growing season in a greenhouse with (13)CO2 and (15)NO3 (15)NH4. The specific enrichments of (15)N and (13)C were higher in ectomycorrhizas (EMs) than in any other tissue. The enrichments of (13)C and (15)N were also higher in the fine-root segments directly connected with the EM (mainly second-order roots) than that in bulk fine or coarse roots. A strict, positive correlation was found between the specific (15)N enrichment in EM and the attached second-order roots. This finding indicates that strong N accumulators provide more N to their host than low N accumulators. A significant correlation was also found for the specific (13)C enrichment in EM and the attached second-order roots. However, the specific enrichments for (15)N and (13)C in EM were unrelated showing that under long-term conditions, C and N exchange between host and EMs are uncoupled. These findings suggest that EM-mediated N flux to the plant is not the main control on carbon flux to the fungus, probably because EMs provide many different services to their hosts in addition to N provision in their natural assemblages. PMID:24756632

  2. Identity and specificity of the fungi forming mycorrhizas with the rare mycoheterotrophic orchid Rhizanthella gardneri.

    PubMed

    Bougoure, Jeremy; Ludwig, Martha; Brundrett, Mark; Grierson, Pauline

    2009-10-01

    Fully subterranean Rhizanthella gardneri (Orchidaceae) is obligately mycoheterotrophic meaning it is nutritionally dependent on the fungus it forms mycorrhizas with. Furthermore, R. gardneri purportedly participates in a nutrient sharing tripartite relationship where its mycorrhizal fungus simultaneously forms ectomycorrhizas with species of Melaleuca uncinata s.l. Although the mycorrhizal fungus of R. gardneri has been morphologically identified as Thanatephorus gardneri (from a single isolate), this identification has been recently questioned. We sought to clarify the identification of the mycorrhizal fungus of R. gardneri, using molecular methods, and to identify how specific its mycorrhizal relationship is. Fungal isolates taken from all sites where R. gardneri is known to occur shared almost identical ribosomal DNA (rDNA) sequences. The fungal isolate rDNA most closely matched that of other Ceratobasidiales species, particularly within the Ceratobasidium genus. However, interpretation of results was difficult as we found two distinct ITS sequences within all mycorrhizal fungal isolates of R. gardneri that we assessed. All mycorrhizal fungal isolates of R. gardneri readily formed ectomycorrhizas with a range of M. uncinata s.l. species. Consequently, it is likely that R. gardneri can form a nutrient sharing tripartite relationship where R. gardneri is connected to autotrophic M. uncinata s.l. by a common mycorrhizal fungus. These findings have implications for better understanding R. gardneri distribution, evolution and the ecological significance of its mycorrhizal fungus, particularly in relation to nutrient acquisition. PMID:19619652

  3. Attributing functions to ectomycorrhizal fungal identities in assemblages for nitrogen acquisition under stress.

    PubMed

    Pena, Rodica; Polle, Andrea

    2014-02-01

    Mycorrhizal fungi have a key role in nitrogen (N) cycling, particularly in boreal and temperate ecosystems. However, the significance of ectomycorrhizal fungal (EMF) diversity for this important ecosystem function is unknown. Here, EMF taxon-specific N uptake was analyzed via (15)N isotope enrichment in complex root-associated assemblages and non-mycorrhizal root tips in controlled experiments. Specific (15)N enrichment in ectomycorrhizas, which represents the N influx and export, as well as the exchange of (15)N with the N pool of the root tip, was dependent on the fungal identity. Light or water deprivation revealed interspecific response diversity for N uptake. Partial taxon-specific N fluxes for ectomycorrhizas were assessed, and the benefits of EMF assemblages for plant N nutrition were estimated. We demonstrated that ectomycorrhizal assemblages provide advantages for inorganic N uptake compared with non-mycorrhizal roots under environmental constraints but not for unstressed plants. These benefits were realized via stress activation of distinct EMF taxa, which suggests significant functional diversity within EMF assemblages. We developed and validated a model that predicts net N flux into the plant based on taxon-specific (15)N enrichment in ectomycorrhizal root tips. These results open a new avenue to characterize the functional traits of EMF taxa in complex communities. PMID:24030593

  4. Diversity of ectomycorrhizal Thelephoraceae in Tuber melanosporum-cultivated orchards of Northern Spain.

    PubMed

    De Miguel, Ana María; Águeda, Beatriz; Sáez, Raimundo; Sánchez, Sergio; Parladé, Javier

    2016-04-01

    Truffles are edible hypogeous ascomycetes highly appreciated worldwide, especially the black truffle (Tuber melanosporum Vittad.). In recent decades, the cultivation of the black truffle has expanded across the Mediterranean climate regions in and outside its native range. Members of the Thelephoraceae (Thelephorales, Agaricomycetes, Basidiomycota) are commonly found in truffle plantations, but their co-occurrence with Tuber species and other members of the fungal community has been scarcely reported. Thelephoraceae is one of the most represented families of the ectomycorrhizal fungal community in boreal and Mediterranean forests. To reveal the diversity of these fungi in T. melanosporum-cultivated plantations, ten orchards located in the Navarra region (Northern Spain) were surveyed for 2 years. Morphological and molecular approaches were used to detect and identify the Thelephoraceae ectomycorrhizas present in those plantations. Ten different mycorrhizal types were detected and described. Four of them were morphologically identified as Tomentella galzinii, Quercirhiza cumulosa, Q. squamosa, and T39 Thelephoraceae type. Molecular analyses revealed 4-6 operational taxonomic units (OTUs), depending on the nucleotide database used, but similarities remained under 95 % and no clear species assignments could be done. The results confirm the diversity and abundance of this fungal family in the ectomycorrhizal community of black truffle plantations, generally established in Mediterranean areas. The occurrence and relative abundance of Thelephoraceae ectomycorrhizas is discussed in relation to their possible influence on truffle production. PMID:26458929

  5. Comparison of the carbon stock in forest soil of sessile oak and beech forests

    NASA Astrophysics Data System (ADS)

    Horváth, Adrienn; Bene, Zsolt; Bidló, András

    2016-04-01

    Forest ecosystems are the most important carbon sinks. The forest soils play an important role in the global carbon cycle, because the global climate change or the increase of atmospheric CO2 level. We do not have enough data about the carbon stock of soils and its change due to human activities, which have similar value to carbon content of biomass. In our investigation we measured the carbon stock of soil in 10 stands of Quercus petraea and Fagus sylvatica. We took a 1.1 m soil column with soil borer and divided to 11 samples each column. The course organic and root residues were moved. After evaluation, we compared our results with other studies and the carbon stock of forests to each other. Naturally, the amount of SOC was the highest in the topsoil layers. However, we found significant difference between forest stands which stayed on the same homogenous bedrock, but very close to each other (e.g. distance was 1 or 2 km). We detected that different forest utilizations and tree species have an effect on the forest carbon as the litter as well (amount, composition). In summary, we found larger amount (99.1 C t/ha on average) of SOC in soil of stands, where sessile oak were the main stand-forming tree species. The amount of carbon was the least in turkey oak-sessile oak stands (85.4 C t/ha on average). We found the highest SOC (118.3 C t/ha) in the most mixed stand (silver lime-beech-red oak). In the future, it will be very important: How does climate change affect the spread of tree species or on carbon storage? Beech is more sensitive, but even sessile oak. These species are expected to replace with turkey oak, which is less sensitive to drought. Thus, it is possible in the future that we can expect to decrease of forest soil carbon stock capacity, which was confirmed by our experiment. Keywords: carbon sequestration, mitigation, Fagus sylvatica, Quercus petraea, litter Acknowledgements: Research is supported by the "Agroclimate.2" (VKSZ_12-1-2013-0034) EU

  6. Planting sentinel European trees in eastern Asia as a novel method to identify potential insect pest invaders.

    PubMed

    Roques, Alain; Fan, Jian-Ting; Courtial, Béatrice; Zhang, Yan-Zhuo; Yart, Annie; Auger-Rozenberg, Marie-Anne; Denux, Olivier; Kenis, Marc; Baker, Richard; Sun, Jiang-Hua

    2015-01-01

    Quarantine measures to prevent insect invasions tend to focus on well-known pests but a large proportion of the recent invaders were not known to cause significant damage in their native range, or were not even known to science before their introduction. A novel method is proposed to detect new potential pests of woody plants in their region of origin before they are introduced to a new continent. Since Asia is currently considered to be the main supplier of insect invaders to Europe, sentinel trees were planted in China during 2007-2011 as an early warning tool to identify the potential for additional Asian insect species to colonize European trees. Seedlings (1-1.5 m tall) of five broadleaved (Quercus petraea, Q. suber, Q. ilex, Fagus sylvatica, and Carpinus betulus) and two conifer species (Abies alba and Cupressus sempervirens) were planted in blocks of 100 seedlings at two widely separated sites (one in a nursery near Beijing and the other in a forest environment near Fuyang in eastern China), and then regularly surveyed for colonization by insects. A total of 104 insect species, mostly defoliators, were observed on these new hosts, and at least six species were capable of larval development. Although a number of the insects observed were probably incidental feeders, 38 species had more than five colonization events, mostly infesting Q. petraea, and could be considered as being capable of switching to European trees if introduced to Europe. Three years was shown to be an appropriate duration for the experiment, since the rate of colonization then tended to plateau. A majority of the identified species appeared to have switched from agricultural crops and fruit trees rather than from forest trees. Although these results are promising, the method is not appropriate for xylophagous pests and other groups developing on larger trees. Apart from the logistical problems, the identification to species level of the specimens collected was a major difficulty. This

  7. Is growth reduction in defoliated trees a consequence of prioritized carbon allocation to reserves?

    NASA Astrophysics Data System (ADS)

    Hoch, Guenter; Schmid, Sandra; Palacio, Sara

    2015-04-01

    Tissue concentrations of carbon reserve compounds are frequently used as proxies for the carbon balance of trees, but the mechanisms regulating the formation of carbon reserves are still under debate. It is often assumed that carbon storage in trees is largely a consequence of surplus carbon supply (reserve accumulation). In contrast, carbon storage might also occur against prevailing carbon demand from other sink activities, like growth (reserve formation), in which case carbon reserve pools might increase even at carbon limitation, and thus, cannot be used as indicators for a tree's carbon supply status. Such a situation might be severe defoliation by herbivores. Especially in evergreen tree species, it has been shown that natural and experimental defoliation leads to a reduction of growth that is proportional to the lost leaf area. Compared to this strong effect on growth, carbon reserve pools (i.e. sugars, starch and storage lipids) of defoliated trees often exert only a temporary decrease immediately after defoliation, while tissue concentrations of carbon reserves return to those of undefoliated trees by the end of the growing season. Within a recent experiment, we investigated, if the growth decline in trees following early season defoliation is the consequence of prioritized carbon allocation to carbon reserves over growth. To test this hypothesis we grew seedlings of evergreen Quecus ilex and deciduous Quercus petraea trees under low (140 ppm), medium (280 ppm) and high (560 ppm) CO2 concentrations and completely defoliated half of the seedlings in each CO2 treatment at the beginning of the growing season. In undefoliated control trees, CO2 had a significant positive effect on the seasonal growth in both species. Defoliation had a strong negative impact on growth in the evergreen Q. illex, but less in the deciduous Q. petraea. In both species, the growth reduction after defoliation relative to undefoliated controls was very similar at all three CO2

  8. The denitrification properties of soils under three different shelterbelts and in adjoining cultivated fields

    NASA Astrophysics Data System (ADS)

    Szajdak, L.; Augustin, J.; Gaca, W.; Meysner, T.; Styla, K.

    2009-04-01

    The investigations were carried out in Agroecological Landscape Park in Turew (40 km South-West of Poznań). Intensively agricultural is observed in this region. Characteristic features of this landscape are shelterbelts created in the XIX century by general Dezydery Chlapowski. All shelterbelts and adjoining cultivated fields were introduced on Hapludalfs soils. Three shelterbelts and adjoining cultivated fields were selected for this experiment. Two of them were created approximately 200 years ago. The first shelterbelt consists mainly of Robinia pseudoacacia and small admixture Quercus robur and Quercus petraea. The second one consists of Crataegus monogyna. The third one - a young shelterbelt was created in 1993 and consists of several species of plants such as: Quercus petraea and Quercus robur, Larix deciduas, Pinus sylvestris, Sorbus aucuparia, Sorbus intermedia, Tilia cordata and some other tree species. On soils were determinated: activity of nitrate reductase, activity of peroxidase, activity of urease and activity of xantine oxidase, total iron, Fe+3, Fe+2, total nitrogen, N-NH4+, N-NO3-, total organic carbon (TOC), dissolved organic carbon (DOC), current N2O, N2 and CH4 flux rates, and pH (in 1M KCl). The contents of total organic carbon, dissolved organic carbon, total nitrogen, N-NO3- and N-NH4+ were higher in the soil under old shelterbelts (Robinia pseudoacacia and Crataegus monogyna) than under young one. It points out the highest accumulation of organic matter in soils under two old shelterbelts. The same also applied to the current N2O and N2 fluxes. Unlike this CH4exchange was just low everywhere. Nitrate reductase, urease, xantine oxidase and peroxidase activities participates in the cycle of nitrogen and are sensitive on redox potential in soil. The highest activity of nitrate reductase and xantine oxidase activity were observed in young shelterbelt. Activity of urease and activity of peroxidase were higher under two old shelterbelts Robinia

  9. Planting Sentinel European Trees in Eastern Asia as a Novel Method to Identify Potential Insect Pest Invaders

    PubMed Central

    Roques, Alain; Fan, Jian-ting; Courtial, Béatrice; Zhang, Yan-zhuo; Yart, Annie; Auger-Rozenberg, Marie-Anne; Denux, Olivier; Kenis, Marc; Baker, Richard; Sun, Jiang-hua

    2015-01-01

    Quarantine measures to prevent insect invasions tend to focus on well-known pests but a large proportion of the recent invaders were not known to cause significant damage in their native range, or were not even known to science before their introduction. A novel method is proposed to detect new potential pests of woody plants in their region of origin before they are introduced to a new continent. Since Asia is currently considered to be the main supplier of insect invaders to Europe, sentinel trees were planted in China during 2007-2011 as an early warning tool to identify the potential for additional Asian insect species to colonize European trees. Seedlings (1-1.5 m tall) of five broadleaved (Quercus petraea, Q. suber, Q. ilex, Fagus sylvatica, and Carpinus betulus) and two conifer species (Abies alba and Cupressus sempervirens) were planted in blocks of 100 seedlings at two widely separated sites (one in a nursery near Beijing and the other in a forest environment near Fuyang in eastern China), and then regularly surveyed for colonization by insects. A total of 104 insect species, mostly defoliators, were observed on these new hosts, and at least six species were capable of larval development. Although a number of the insects observed were probably incidental feeders, 38 species had more than five colonization events, mostly infesting Q. petraea, and could be considered as being capable of switching to European trees if introduced to Europe. Three years was shown to be an appropriate duration for the experiment, since the rate of colonization then tended to plateau. A majority of the identified species appeared to have switched from agricultural crops and fruit trees rather than from forest trees. Although these results are promising, the method is not appropriate for xylophagous pests and other groups developing on larger trees. Apart from the logistical problems, the identification to species level of the specimens collected was a major difficulty. This

  10. Novel findings on the role of signal exchange in arbuscular and ectomycorrhizal symbioses.

    PubMed

    Raudaskoski, Marjatta; Kothe, Erika

    2015-05-01

    The availability of genome sequences from both arbuscular and ectomycorrhizal fungi and their hosts has, together with elegant biochemical and molecular biological analyses, provided new information on signal exchange between the partners in mycorrhizal associations. The progress in understanding cellular processes has been more rapid in arbuscular than ectomycorrhizal symbiosis due to its similarities of early processes with Rhizobium-legume symbiosis. In ectomycorrhiza, the role of auxin and ethylene produced by both fungus and host plant is becoming understood at the molecular level, although the actual ligands and receptors leading to ectomycorrhizal symbiosis have not yet been discovered. For both systems, the functions of small effector proteins secreted from the respective fungus and taken up into the plant cell may be pivotal in understanding the attenuation of host defense. We review the subject by comparing cross-talk between fungal and plant partners during formation and establishment of arbuscular and ectomycorrhizal symbioses. PMID:25260351

  11. Heavy metal distribution in Suillus luteus mycorrhizas - as revealed by micro-PIXE analysis

    NASA Astrophysics Data System (ADS)

    Turnau, K.; Przybyłowicz, W. J.; Mesjasz-Przybyłowicz, J.

    2001-07-01

    Suillus luteus/Pinus sylvestris mycorrhizas, collected from zinc wastes in Southern Poland, were selected as potential biofilters on the basis of earlier studies carried out with energy dispersive spectrometry (EDS) microanalytical system coupled to scanning electron microscope (SEM) and transmission electron microscope (TEM). Using the National Accelerator Centre (NAC) nuclear microprobe, elemental concentrations in the ectomycorrhiza parts were for the first time estimated quantitatively. Micro-proton-induced X-ray emission (PIXE) true elemental maps from freeze-dried and chemically fixed mycorrhizas revealed strong accumulation of Ca, Fe, Zn and Pb within the fungal mantle and in the rhizomorph. Vascular tissue was enriched with P, S and K, while high concentrations of Si and Cl were present in the endodermis. Cu was the only element showing elevated concentrations in the cortex region. Elemental losses and redistributions were found in mycorrhizas prepared by chemical fixation. Some problems related to elemental imaging are discussed.

  12. Phylogenetic and microscopic studies in the genus Lactifluus (Basidiomycota, Russulales) in West Africa, including the description of four new species.

    PubMed

    Maba, Dao Lamèga; Guelly, Atsu K; Yorou, Nourou S; Verbeken, Annemieke; Agerer, Reinhard

    2015-06-01

    Despite the crucial ecological role of lactarioid taxa (Lactifluus, Lactarius) as common ectomycorrhiza formers in tropical African seasonal forests, their current diversity is not yet adequately assessed. During the last few years, numerous lactarioid specimens have been sampled in various ecosystems from Togo (West Africa). We generated 48 ITS sequences and aligned them against lactarioid taxa from other tropical African ecozones (Guineo-Congolean evergreen forests, Zambezian miombo). A Maximum Likelihood phylogenetic tree was inferred from a dataset of 109 sequences. The phylogenetic placement of the specimens, combined with morpho-anatomical data, supported the description of four new species from Togo within the monophyletic genus Lactifluus: within subgen. Lactifluus (L. flavellus), subgen. Russulopsis (L. longibasidius and L. pectinatus), and subgen. Edules (L. melleus). This demonstrates that the current species richness of the genus is considerably higher than hitherto estimated for African species and, in addition, a need to redefine the subgenera and sections within it. PMID:26203413

  13. Transformation of the mycorrhizal fungus Laccaria bicolor using Agrobacterium tumefaciens.

    PubMed

    Kemppainen, Minna J; Pardo, Alejandro G

    2011-01-01

    Most boreal and temperate forest trees form a mutualistic symbiosis with soil borne fungi called ectomycorrhiza (ECM). In this association both partners benefit due to nutrient exchange at the symbiotic interface. Laccaria bicolor is the first mycorrhizal fungus with its genome sequenced thus making possible for the first time to analyze genome scale gene expression profiles of a mutualistic fungus. However, in order to be able to take full advantage of the genome sequence, reverse genetic tools are needed. Among them a high throughput transformation system is crucial. Herein we present a detailed protocol for genetic transformation of L. bicolor by means of Agrobacterium tumefaciens with emphasis on critical steps affecting the success and efficiency of the approach. PMID:21636986

  14. Characterization and complementation of a Fus3/Kss1 type MAPK from Tuber borchii, TBMK.

    PubMed

    Menotta, M; Pierleoni, R; Amicucci, A; Sisti, D; Cerasi, A; Millo, E; Chiarantini, L; Stocchi, V

    2006-08-01

    Mitogen-activated protein kinases (MAPK) are used by organisms to transduce extra cellular signals from the environment in cellular events such as proliferation and differentiation. In the present study, we have characterized the first MAPK from the ectomycorrhizal fungus Tuber borchii (TBMK) which belongs to the YERK1 (yeast extra cellular regulated kinase) subfamily. TBMK is present as a single copy in the genome and the codified protein was phosphorylated during the interaction with the host plant, Tilia americana. Complementation studies showed that TBMK restores pheromone signaling in Saccharomyces cerevisiae and partially restores invasive growth of Fusarium oxysporum that lack the fmk1 gene. This suggests a protein kinase activity and its involvement in the infection processes. Hence, TBMK could play an important role during the pre-symbiotic phase of T. borchii with its host plant in the modulation of genes necessary for the establishment of symbiosis leading to the synthesis of functional ectomycorrhizae. PMID:16705420

  15. Molecular characterisation of a Tuber borchii Smt3 gene.

    PubMed

    Zeppa, S; Guidi, C; Barbieri, E; Guescini, M; Polidori, E; Agostini, D; Stocchi, V

    2006-01-01

    Tbsmt3 gene from the ectomychorrizal fungus Tuber borchii was identified and sequenced. The Tbsmt3 gene encodes for a protein sharing significant amino acid homology with the yeast SMT3, a ubiquitin-like protein that is post-translationally attached to several proteins involved in many cellular processes. The comparison between the Tbsmt3 genomic and cDNA sequences established that the encoding sequence is interrupted by an intron of 312 bp. Southern blot analysis revealed only one copy of Tbsmt3 gene in the T. borchii genome. Tbsmt3 is expressed in all phases of T. borchii life cycle: mycelium, ectomycorrhiza and ascoma. However, the Tbsmt3 mRNA decreased during fruit body maturation. PMID:17023169

  16. Morphological and molecular analyses of ectomycorrhizal diversity in a man-made T. melanosporum plantation: description of novel truffle-like morphotypes.

    PubMed

    Baciarelli-Falini, Leonardo; Rubini, Andrea; Riccioni, Claudia; Paolocci, Francesco

    2006-10-01

    Below-ground ectomycorrhizal communities are often species-rich, and monitoring their dynamics is important to understand the conditions that promote truffle fructification. Characterization of the different ectomycorrhizas (ECM) at the species level can now be achieved by combining detailed morphological and anatomical descriptions with molecular approaches. Following this strategy, we have characterized ectomycorrhizal biodiversity in an artificial Tuber melanosporum plantation. Although the plantation was unproductive, T. melanosporum mycorrhizas were the most present and two Tuber-like mycorrhizal morphotypes, named ECMm1 and ECMm3, showing distinctive features were found. Internal transcribed spacer (ITS) phylogenetic analysis demonstrated that ECMm3 is related to the Tuber rufum/Tuber ferrugineum species complex, whereas ECMm1 shows the highest ITS similarity with Tuber scruposum and fungi-colonizing Epipactis roots. The results presented here provide more insights into genetic variability, mycorrhizal morphology, and below-ground distribution of fungi associated with artificial truffle plantations. PMID:16909286

  17. An ectomycorrhizal nitrogen economy facilitates monodominance in a neotropical forest.

    PubMed

    Corrales, Adriana; Mangan, Scott A; Turner, Benjamin L; Dalling, James W

    2016-04-01

    Tropical forests are renowned for their high diversity, yet in many sites a single tree species accounts for the majority of the individuals in a stand. An explanation for these monodominant forests remains elusive, but may be linked to mycorrhizal symbioses. We tested three hypotheses by which ectomycorrhizas might facilitate the dominance of the tree, Oreomunnea mexicana, in montane tropical forest in Panama. We tested whether access to ectomycorrhizal networks improved growth and survival of seedlings, evaluated whether ectomycorrhizal fungi promote seedling growth via positive plant-soil feedback, and measured whether Oreomunnea reduced inorganic nitrogen availability. We found no evidence that Oreomunnea benefits from ectomycorrhizal networks or plant-soil feedback. However, we found three-fold higher soil nitrate and ammonium concentrations outside than inside Oreomunnea-dominated forest and a correlation between soil nitrate and Oreomunnea abundance in plots. Ectomycorrhizal effects on nitrogen cycling might therefore provide an explanation for the monodominance of ectomycorrhizal tree species worldwide. PMID:26833573

  18. Convergence in Multispecies Interactions.

    PubMed

    Bittleston, Leonora S; Pierce, Naomi E; Ellison, Aaron M; Pringle, Anne

    2016-04-01

    The concepts of convergent evolution and community convergence highlight how selective pressures can shape unrelated organisms or communities in similar ways. We propose a related concept, convergent interactions, to describe the independent evolution of multispecies interactions with similar physiological or ecological functions. A focus on convergent interactions clarifies how natural selection repeatedly favors particular kinds of associations among species. Characterizing convergent interactions in a comparative context is likely to facilitate prediction of the ecological roles of organisms (including microbes) in multispecies interactions and selective pressures acting in poorly understood or newly discovered multispecies systems. We illustrate the concept of convergent interactions with examples: vertebrates and their gut bacteria; ectomycorrhizae; insect-fungal-bacterial interactions; pitcher-plant food webs; and ants and ant-plants. PMID:26858111

  19. [Resource and ecological distribution of ectomycorrhizal fungi under pine forests of Huangshan Mountain district].

    PubMed

    Ke, Lixia; Liu, Birong

    2005-03-01

    Pinus massoniana and Pinus taiwanensis are the most common and important tree species in the Huangshan Mountain district, and ectomycorrhizae plays an important role in their forestation. Our investigations in 1998-2003 showed that under the pine forests of this district, there were 43 species of ectomycorrhizal fungi belonging to 10 families and 17 genera, of which, 43 were under Pinus massoniana forest, and 12 under Pinus taiwanensis forest. Only a few species were found under young Pinus massoniana forest, with the dominant of Pisolithus tinctorius (Pers.) Coken and Rhizopogon spp., but under mature Pinus massoniana forest, there were plentiful species, with the dominant of Russulaceae, Amanitaceae, Boletaceae and Canthurellaceae. The relationships between woody species and ectomycorrhizal fungi, and between fungi distribution and temperature, moisture and soil condition were discussed in this paper, which would benefit to the further studies on the effects of different ectomyrrhizal fungi to Pinus massoniana and Pinus taiwanensis forests. PMID:15943356

  20. New evidence for the symbiosis between Tuber aestivum and Picea abies.

    PubMed

    Stobbe, Ulrich; Stobbe, Annika; Sproll, Ludger; Tegel, Willy; Peter, Martina; Büntgen, Ulf; Egli, Simon

    2013-11-01

    The Burgundy truffle (Tuber aestivum Vittad.), an ectomycorrhizal fungus living in association with host plants, is one of the most exclusive delicacies. The symbiosis with deciduous oak, beech, and hazel dominates our concept of truffle ecophysiology, whereas potential conifer hosts have rarely been reported. Here, we present morphological and molecular evidence of a wildlife T. aestivum symbiosis with Norway spruce (Picea abies Karst.) and an independent greenhouse inoculation experiment, to confirm our field observation in southwest Germany. A total of 27 out of 50 P. abies seedlings developed T. aestivum ectomycorrhizae with a mean mycorrhization rate of 19.6 %. These findings not only suggest P. abies to be a productive host species under suitable biogeographic conditions but also emphasize the broad ecological amplitude and great symbiotic range of T. aestivum. While challenging common knowledge, this study demonstrates a significant expansion of the species' cultivation potential to the central European regions, where P. abies forests occur on calcareous soils. PMID:23674121

  1. Suillus quiescens, a new species commonly found in the spore bank in California and Oregon.

    PubMed

    Bruns, Thomas D; Grubisha, Lisa C; Trappe, James M; Kerekes, Jennifer F; Vellinga, Else C

    2010-01-01

    Suillus quiescens sp. nov. is common under Pinus muricata on Santa Cruz and Santa Rosa Islands in the northern Channel Islands of California, and we subsequently found it fruiting at Point Reyes National Seashore on the central coast of California. Sequences from the internal transcribed spacer region show that it is distinct from all 44 species of Suillus tested, and features of its morphology separate it from all other unsequenced species. Suillus quiescens has a broader distribution than coastal California because it also was encountered as ectomycorrhizae on roots of pine seedlings from the eastern Sierra Nevada, coastal Oregon and the southern Cascade Mountains. The reason it had not been identified from these areas might be due to its resemblance to S. brevipes at maturity or it might be a rare fruiter that persists in the spore bank. PMID:20361510

  2. Shift in ectomycorrhizal community composition in Scots pine (Pinus sylvestris L.) seedling roots as a response to nickel deposition and removal of lichen cover.

    PubMed

    Markkola, A M; Ahonen-Jonnarth, U; Roitto, M; Strömmer, R; Hyvärinen, M

    2002-01-01

    Scots pine seedlings were exposed to wet-deposited nickel (Ni) and removal of lichen cover in a dry heath Scots pine forest. Ni deposition affected the colonization of roots by indigenous ectomycorrhizal fungi in contrasting ways in intact and skimmed quadrats. Highest frequencies of tubercle morphotypes of ectomycorrhiza were found in quadrats exposed to 100 mg m(-2) year(-1) Ni in lichen covered treatment, while in skimmed quadrats these peaked after the treatment with 10 mg Ni m(-2) year(-1). Removal of the lichen layer increased the value of diversity index (H') of ectomycorrhizal fungal community, probably due to the increase in the evenness of the morphotype distribution. Lichen removal seemed also to improve the condition of the short roots, as the frequencies of poor and senescent short roots were decreased by the removal. PMID:12442803

  3. Evolution of mycorrhiza systems

    NASA Astrophysics Data System (ADS)

    Cairney, J. W. G.

    Most terrestrial plants live in mutualistic symbiosis with root-infecting mycorrhizal fungi. Fossil records and molecular clock dating suggest that all extant land plants have arisen from an ancestral arbuscular mycorrhizal condition. Arbuscular mycorrhizas evolved concurrently with the first colonisation of land by plants some 450-500 million years ago and persist in most extant plant taxa. Ectomycorrhizas (about 200million years ago) and ericoid mycorrhizas (about 100million years ago) evolved subsequently as the organic matter content of some ancient soils increased and sclerophyllous vegetation arose as a response to nutrient-poor soils respectively. Mycorrhizal associations appear to be the result of relatively diffuse coevolutionary processes. While early events in the evolution of mycorrhizal symbioses may have involved reciprocal genetic changes in ancestral plants and free-living fungi, available evidence points largely to ongoing parallel evolution of the partners in response to environmental change.

  4. Nitrogen availability is a primary determinant of conifer mycorrhizas across complex environmental gradients.

    PubMed

    Cox, Filipa; Barsoum, Nadia; Lilleskov, Erik A; Bidartondo, Martin I

    2010-09-01

    Global environmental change has serious implications for functional biodiversity in temperate and boreal forests. Trees depend on mycorrhizal fungi for nutrient uptake, but predicted increases in nitrogen availability may alter fungal communities. To address a knowledge gap regarding the effects of nitrogen availability on mycorrhizal communities at large scales, we examine the relationship between nitrogen and ectomycorrhizas in part of a European biomonitoring network of pine forest plots. Our analyses show that increased nitrogen reduces fungal diversity and causes shifts in mycorrhizal community composition across plots, but we do not find strong evidence that within-plot differences in nitrogen availability affect ectomycorrhizal communities. We also carry out exploratory analyses to determine the relative importance of other environmental variables in structuring mycorrhizal communities, and discuss the potential use of indicator species to predict nitrogen-induced shifts in fungal communities. PMID:20545731

  5. Evolution of tree nutrition.

    PubMed

    Raven, John A; Andrews, Mitchell

    2010-09-01

    Using a broad definition of trees, the evolutionary origins of trees in a nutritional context is considered using data from the fossil record and molecular phylogeny. Trees are first known from the Late Devonian about 380 million years ago, originated polyphyletically at the pteridophyte grade of organization; the earliest gymnosperms were trees, and trees are polyphyletic in the angiosperms. Nutrient transporters, assimilatory pathways, homoiohydry (cuticle, intercellular gas spaces, stomata, endohydric water transport systems including xylem and phloem-like tissue) and arbuscular mycorrhizas preceded the origin of trees. Nutritional innovations that began uniquely in trees were the seed habit and, certainly (but not necessarily uniquely) in trees, ectomycorrhizas, cyanobacterial, actinorhizal and rhizobial (Parasponia, some legumes) diazotrophic symbioses and cluster roots. PMID:20581011

  6. Linking mycorrhizas to sporocarps: a new species, Geopora cercocarpi, on Cercocarpus ledifolius (Rosaceae).

    PubMed

    Southworth, Darlene; Frank, Jonathan L

    2011-01-01

    Mycorrhizal assemblages characterized by molecular data frequently differ from collections of mycorrhizal sporocarps at the same site. Geopora species are frequent mycobionts of ectomycorrhizal roots, but except for G. cooperi they are rarely identified to species by molecular methods. Among the mycobionts of ectomycorrhizas with Cercocarpus ledifolius (Rosaceae) was a fungal species with a 91% BLAST match to G. arenicola. To determine the species of Geopora we surveyed for hypogeous sporocarps under C. ledifolius at sites in southern Oregon where the Geopora mycorrhizas had been collected and identified by DNA sequences of the ITS region. We found sporocarps of a Geopora species with 100% BLAST match to the mycorrhizas. Morphological characters of a white hymenium, inrolled entire margin and large spores, along with a hypogeous habit and a mycorrhizal host of C. ledifolius, distinguished these specimens from previously described species. Here we describe a new species, Geopora cercocarpi. PMID:21700635

  7. Membranomyces species are common ectomycorrhizal symbionts in Northern Hemisphere forests.

    PubMed

    Uehling, Jessie K; Henkel, Terry W; Vilgalys, Rytas; Smith, Matthew E

    2012-10-01

    Membranomyces (Clavulinaceae, Cantharellales) Jülich consists of two described species of resupinate (crust-like) basidiomycetes. Previous studies indicated that Membranomyces falls within the Clavulinaceae, but the phylogenetic position of the genus has not been fully resolved. Membranomyces species were thought to be saprotrophic until 2003 when Tedersoo et al. detected Membranomyces delectabilis on ectomycorrhizal roots of Populus and Picea. Membranomyces was previously known only from collections made in eastern Canada and Europe. We recently sequenced the ITS rDNA barcode region from Scandinavian herbarium specimens identified as M. delectabilis and Membranomyces spurius. Phylogenetic analyses of these sporocarp sequences and similar environmental sequences indicated that Membranomyces is more diverse than previously thought and forms ectomycorrhizas with hosts from a diverse range of plant families in many north temperate ecosystems. PMID:22847636

  8. Evolution of mycorrhiza systems.

    PubMed

    Cairney, J W

    2000-11-01

    Most terrestrial plants live in mutualistic symbiosis with root-infecting mycorrhizal fungi. Fossil records and molecular clock dating suggest that all extant land plants have arisen from an ancestral arbuscular mycorrhizal condition. Arbuscular mycorrhizas evolved concurrently with the first colonisation of land by plants some 450-500 million years ago and persist in most extant plant taxa. Ectomycorrhizas (about 200 million years ago) and ericoid mycorrhizas (about 100 million years ago) evolved subsequently as the organic matter content of some ancient soils increased and sclerophyllous vegetation arose as a response to nutrient-poor soils respectively. Mycorrhizal associations appear to be the result of relatively diffuse coevolutionary processes. While early events in the evolution of mycorrhizal symbioses may have involved reciprocal genetic changes in ancestral plants and free-living fungi, available evidence points largely to ongoing parallel evolution of the partners in response to environmental change. PMID:11151665

  9. New North American truffles (Tuber spp.) and their ectomycorrhizal associations.

    PubMed

    Guevara, Gonzalo; Bonito, Gregory; Trappe, James M; Cázares, Efren; Williams, Gwendolyn; Healy, Rosanne A; Schadt, Christopher; Vilgalys, Rytas

    2013-01-01

    Recent surveys of belowground fungal biodiversity in México and USA have revealed many undescribed truffle species, including many in the genus Tuber. Here we describe seven new species: Tuber beyerlei, T. castilloi, T. guevarai, T. lauryi, T. mexiusanum, T. miquihuanense and T. walkeri. Phylogenetic analyses place these species within the Maculatum group, an understudied clade of small truffles with little apparent economic value. These species are among the more taxonomically challenge-ing in the genus. We collected Tuber castilloi, T. mexiusanum and T. guevarai as fruit bodies and ectomycorrhizae on Quercus spp. in forests of eastern México. Tuber mexiusanum has a particularly broad geographic range, being collected in eastern USA under Populus deltoides and in Minnesota and Iowa in mixed hardwood forests. T. walkeri is described from the upper midwestern USA, and T. lauryi and T. beyerlei occur in the western USA. PMID:22962353

  10. Belowground carbon trade among tall trees in a temperate forest.

    PubMed

    Klein, Tamir; Siegwolf, Rolf T W; Körner, Christian

    2016-04-15

    Forest trees compete for light and soil resources, but photoassimilates, once produced in the foliage, are not considered to be exchanged between individuals. Applying stable carbon isotope labeling at the canopy scale, we show that carbon assimilated by 40-meter-tall spruce is traded over to neighboring beech, larch, and pine via overlapping root spheres. Isotope mixing signals indicate that the interspecific, bidirectional transfer, assisted by common ectomycorrhiza networks, accounted for 40% of the fine root carbon (about 280 kilograms per hectare per year tree-to-tree transfer). Although competition for resources is commonly considered as the dominant tree-to-tree interaction in forests, trees may interact in more complex ways, including substantial carbon exchange. PMID:27081070

  11. Mycorrhizal synthesis of Lactarius indigo (Schw.) Fr. with five Neotropical pine species.

    PubMed

    Flores, R; Díaz, G; Honrubia, M

    2005-11-01

    This paper describes for the first time the ectomycorrhiza synthesized between two Guatemalan strains of Lactarius indigo (Schw.) Fr. and the Neotropical species Pinus ayacahuite var. ayacahuite Ehren, P. hartwegii Lindl., P. oocarpa Schiede ex Schltdl. var oocarpa, P. pseudostrobus Lindl. and P. rudis Endl. The synthesis was carried out in a controlled growth chamber using plastic containers with peat moss-vermiculite substrate and mycelial inoculum. Mycorrhiza were obtained 25 days after inoculation. A description of the morphology, appearance and structure of mantle and Hartig net is given for each combination. Mycorrhiza were saffron to cinnamon greenish with age, with a net of saffron laticifers visible through outer mantle; orange latex secreted when injured. Cystidia-like emanating hyphae were observed on the mantle surface of young mycorrhiza. Plectenchymatous mantle with abundant interhyphal gelatinous material. PMID:16133250

  12. Genomic and transcriptomic analysis of Laccaria bicolor CAZome reveals insights into polysaccharides remodelling during symbiosis establishment.

    PubMed

    Veneault-Fourrey, Claire; Commun, Carine; Kohler, Annegret; Morin, Emmanuelle; Balestrini, Raffaella; Plett, Jonathan; Danchin, Etienne; Coutinho, Pedro; Wiebenga, Ad; de Vries, Ronald P; Henrissat, Bernard; Martin, Francis

    2014-11-01

    Ectomycorrhizal fungi, living in soil forests, are required microorganisms to sustain tree growth and productivity. The establishment of mutualistic interaction with roots to form ectomycorrhiza (ECM) is not well known at the molecular level. In particular, how fungal and plant cell walls are rearranged to establish a fully functional ectomycorrhiza is poorly understood. Nevertheless, it is likely that Carbohydrate Active enZymes (CAZyme) produced by the fungus participate in this process. Genome-wide transcriptome profiling during ECM development was used to examine how the CAZome of Laccaria bicolor is regulated during symbiosis establishment. CAZymes active on fungal cell wall were upregulated during ECM development in particular after 4weeks of contact when the hyphae are surrounding the root cells and start to colonize the apoplast. We demonstrated that one expansin-like protein, whose expression is specific to symbiotic tissues, localizes within fungal cell wall. Whereas L. bicolor genome contained a constricted repertoire of CAZymes active on cellulose and hemicellulose, these CAZymes were expressed during the first steps of root cells colonization. L. bicolor retained the ability to use homogalacturonan, a pectin-derived substrate, as carbon source. CAZymes likely involved in pectin hydrolysis were mainly expressed at the stage of a fully mature ECM. All together, our data suggest an active remodelling of fungal cell wall with a possible involvement of expansin during ECM development. By contrast, a soft remodelling of the plant cell wall likely occurs through the loosening of the cellulose microfibrils by AA9 or GH12 CAZymes and middle lamella smooth remodelling through pectin (homogalacturonan) hydrolysis likely by GH28, GH12 CAZymes. PMID:25173823

  13. Characterization of a Pinus pinaster cDNA encoding an auxin up-regulated putative peroxidase in roots.

    PubMed

    Charvet-Candela, V; Hitchin, S; Reddy, M S; Cournoyer, B; Marmeisse, R; Gay, G

    2002-03-01

    As part of a study to identify host plant genes regulated by fungal auxin during ectomycorrhiza formation, we differentially screened a cDNA library constructed from roots of auxin-treated Pinus pinaster (Ait.) Sol. seedlings. We identified three cDNAs up-regulated by auxin. Sequence analysis of one of these cDNAs, PpPrx75, revealed the presence of an open reading frame of 216 amino acids with the characteristic consensus sequences of plant peroxidases. The deduced amino acid sequence showed homology with Arabidopsis thaliana (L.) Heynh., Arachis hypogaea L. and Stylosanthes humilis HBK cationic peroxidases. Amino acid sequence identities in the conserved domains of plant peroxidases ranged from 60 to 100%. In PpPrx75, there are five cysteine residues and one histidine residue that are found at conserved positions among other peroxidases. A potential glycosylation site (NTS) is present in the deduced sequence. Phylogenetic analysis showed that PpPrx75 is closely related to two A. thaliana peroxidases. The PpPrx75 cDNA was induced by active auxins, ethylene, abscisic acid and quercetin, a flavonoid possibly involved in plant-microorganism interactions. Transcript accumulation was detected within 3 h following root induction by auxin, and the amount of mRNA increased over the following 24 h. The protein synthesis inhibitor cycloheximide did not inhibit indole-3-acetic acid-induced transcript accumulation, suggesting that PpPrx75 induction is a primary (direct) response to auxin. This cDNA can be used to study expression of an auxin-regulated peroxidase during ectomycorrhiza formation. PMID:11874719

  14. Effects of soil-applied lead on seedling growth and ectomycorrhizal colonization of loblolly pine.

    PubMed

    Chappelka, A H; Kush, J S; Runion, G B; Meier, S; Kelley, W D

    1991-01-01

    Six-month-old loblolly pine (Pinus taeda) were grown for 15 weeks in two native soils amended with 0, 30, 60, 120, 240 or 480 mg kg(-1) Pb as PbCl2. Ectomycorrhizae were quantified, by morphotype, as the total number of tips per centimeter, and as the number of tips for each morphotype and for Cenococcum geophilum. Total numbers of non-ectomycorrhizal short roots and necrotic tips were recorded. Total height and biomass exhibited a non-linear response to soil-applied lead. Growth generally was greatest in the controls and higher treatments, and least in the intermediate treatments. In both soils, Pb concentrations in roots increased linearly with increasing levels of soil-applied Pb. Neither foliage nor stems exhibited significant increases in Pb concentrations with increasing levels of Pb. Significant linear decreases in total numbers of ectomycorrhizal tips and significant linear increases in non-ectomycorrhizal short roots and necrotic tips occurred with increasing levels of Pb in the soil. The majority of individual morphotypes decreased with increasing Pb. However, the number of ectomycorrhizal tips formed by C. geophilium increased with increasing soil Pb levels after 15 weeks of treatment. These results indicate that short-term loblolly pine seedling growth is not inhibited by increasing Pb levels. Ectomycorrhizal formation decreased, and alterations in species composition occurred as a result of increasing concentrations of soil-applied Pb. These effects on ectomycorrhizae may cause long-term changes in nutrient and water balances, which could reduce tree vigor. PMID:15092097

  15. Effect of raw humus under two adult Scots pine stands on ectomycorrhization, nutritional status, nitrogen uptake, phosphorus uptake and growth of Pinus sylvestris seedlings.

    PubMed

    Schulz, Horst; Schäfer, Tina; Storbeck, Veronika; Härtling, Sigrid; Rudloff, Renate; Köck, Margret; Buscot, François

    2012-01-01

    Ectomycorrhiza (EM) formation improves tree growth and nutrient acquisition, particularly that of nitrogen (N). Few studies have coupled the effects of naturally occurring EM morphotypes to the nutrition of host trees. To investigate this, pine seedlings were grown on raw humus substrates collected at two forest sites, R2 and R3. Ectomycorrhiza morphotypes were identified, and their respective N uptake rates from organic (2-(13)C, (15)N-glycine) and inorganic ((15)NH(4)Cl, Na(15)NO(3), (15)NH(4)NO(3), NH(4)(15)NO(3)) sources as well as their phosphate uptake rates were determined. Subsequently, the growth and nutritional status of the seedlings were analyzed. Two dominant EM morphotypes displayed significantly different mycorrhization rates in the two substrates. Rhizopogon luteolus Fr. (RL) was dominant in R2 and Suillus bovinus (Pers.) Kuntze (SB) was dominant in R3. (15)N uptake of RL EM was at all times higher than that of SB EM. Phosphate uptake rates by the EM morphotypes did not differ significantly. The number of RL EM correlated negatively and the number of SB EM correlated positively with pine growth rate. Increased arginine concentrations and critical P/N ratios in needles indicated nutrient imbalances of pine seedlings from humus R2, predominantly mycorrhizal with RL. We conclude that different N supply in raw humus under Scots pine stands can induce shifts in the EM frequency of pine seedlings, and this may lead to EM formation by fungal strains with different ability to support tree growth. PMID:22184278

  16. Ectomycorrhizal fungal communities of native and non-native Pinus and Quercus species in a common garden of 35-year-old trees.

    PubMed

    Trocha, Lidia K; Kałucka, Izabela; Stasińska, Małgorzata; Nowak, Witold; Dabert, Mirosława; Leski, Tomasz; Rudawska, Maria; Oleksyn, Jacek

    2012-02-01

    Non-native tree species have been widely planted or have become naturalized in most forested landscapes. It is not clear if native trees species collectively differ in ectomycorrhizal fungal (EMF) diversity and communities from that of non-native tree species. Alternatively, EMF species community similarity may be more determined by host plant phylogeny than by whether the plant is native or non-native. We examined these unknowns by comparing two genera, native and non-native Quercus robur and Quercus rubra and native and non-native Pinus sylvestris and Pinus nigra in a 35-year-old common garden in Poland. Using molecular and morphological approaches, we identified EMF species from ectomycorrhizal root tips and sporocarps collected in the monoculture tree plots. A total of 69 EMF species were found, with 38 species collected only as sporocarps, 18 only as ectomycorrhizas, and 13 both as ectomycorrhizas and sporocarps. The EMF species observed were all native and commonly associated with a Holarctic range in distribution. We found that native Q. robur had ca. 120% higher total EMF species richness than the non-native Q. rubra, while native P. sylvestris had ca. 25% lower total EMF species richness than non-native P. nigra. Thus, across genera, there was no evidence that native species have higher EMF species diversity than exotic species. In addition, we found a higher similarity in EMF communities between the two Pinus species than between the two Quercus species. These results support the naturalization of non-native trees by means of mutualistic associations with cosmopolitan and novel fungi. PMID:21573837

  17. Ectomycorrhizal fungus diversity and community structure with natural and cultivated truffle hosts: applying lessons learned to future truffle culture.

    PubMed

    De Miguel, Ana María; Águeda, Beatriz; Sánchez, Sergio; Parladé, Javier

    2014-04-01

    Since the first truffle plantations were established in France, Italy and other parts in the world, many studies have been carried out to improve their productivity and sustainability. Success of plantations is clearly related to the mycorrhizal status of the host trees over the years, from inoculated seedlings to truffle-producing trees. The experience gained in monitoring the ectomycorrhizal fungus status in cultivated truffle grounds has allowed us to develop an extensive catalogue of the ectomycorrhizal fungi present in truffle plantations. Herein, we summarize fungal community data from 85 references that represent different truffle studies in natural habitats and plantations. Approximately 25% of the ectomycorrhizae reported in the 85 references are common to most of the studies. In general, more fungal species are detected in productive plantations than in the non-productive ones. Truffle plantations display a diverse ectomycorrhizal fungal community, in which species of the genus Tuber are well represented. Tuber rufum and some members of Boletales are typically restricted to productive truffle plots. On the other hand, Hebeloma, Laccaria and Russula species are mostly associated with unproductive plots. Ectomycorrhizae belonging to Thelephoraceae are frequently found in mature truffle orchards but do not seem to affect sporocarp production. Several biotic and abiotic factors affect the ectomycorrhizal fungus communities associated with truffle orchards. Among them are plantation age, host species and its growth, the surrounding environment (particularly the presence of other ectomycorrhizal hosts), and plantation management. Understanding the ectomycorrhizal fungal communities inhabiting different plantations may give us clues about the dynamics of the targeted truffles and the possibility of identifying mycorrhizal fungal species that are good indicators of successful truffle plantations. PMID:24424507

  18. Tree height growth indicating drought and nitrogen deposition

    NASA Astrophysics Data System (ADS)

    Gulyás, Krisztina; Berki, Imre

    2016-04-01

    Several studies have been reported the increasing trends of forest growth in Europe in the last decades. Sites, where the water is not limiting factor, the increasing carbon dioxide (CO2) concentration and high nitrogen deposition influenced accelerated tree height growth. However few researches show that the drying climate conditions and water deficit cause slow/not definite trend of tree height growth in forests. The aim of our study presents the effects of drying climate and surplus nitrogen on height growth of sessile oak (Quercus petraea). Almost 50 sessile oak stands (with zonal site condition) have been measured along a humid-arid climatic transect in Hungary. Top heights of the trees are the best dendrometric parameter for indicating the changing site conditions. Observed top heights dates were compared with 50-years climate condition along the humid-arid climatic transect. Tree height growth in the dry and mesic section of climatic gradient slowed at the last 4 decades, because of the increasing frequency of dry periods. Accelerated height growth were measured in the mesic and humid section of transect, where the nitrogen deposition due to local air pollution were higher than the background deposition. These results draw attention to the importance of the drying climate and surplus nitrogen in the global changes. Keywords: climate change impacts, drought periods, surplus deposition, tree height growth Acknowledgements: Research is supported by the "Agroclimate.2" (VKSZ_12-1-2013-0034) EU-national joint funded research project.

  19. Comparison of Different EO Sensors for Mapping Tree Species- A Case Study in Southwest Germany

    NASA Astrophysics Data System (ADS)

    Enβle, Fabian; Kattenborn, Teja; Koch, Barbara

    2014-11-01

    The variety of different remote sensing sensors and thus the types of data specifications which are available is increasing continuously. Especially the differences in geometric, radiometric and temporal resolutions of different platforms affect their ability for the mapping of forests. These differences hinder the comparability and application of uniform methods of different remotely sensed data across the same region of interest. The quality and quantity of retrieved forest parameters is directly dependent on the data source, and therefore the objective of this project is to analyse the relationship between the data source and its derived parameters. A comparison of different optical EO-data (e.g. spatial resolution and spectral resolution of specific bands) will help to define the optimum data sets to produce a reproducible method to provide additional inputs to the Dragon cooperative project, specifically to method development for woody biomass estimation and biodiversity assessment services. This poster presents the first results on tree species mapping in a mixed temperate forest by satellite imagery taken from four different sensors. Tree species addressed in this pilot study are: Scots pine (Pinus sylvestris), sessile oak (Quercus petraea) and red oak (Quercus rubra). The spatial resolution varies from 2m to 30m and the spectral resolutions range from 8bands up to 155bands.

  20. Bacterial succession on decomposing leaf litter exhibits a specific occurrence pattern of cellulolytic taxa and potential decomposers of fungal mycelia.

    PubMed

    Tláskal, Vojtěch; Voříšková, Jana; Baldrian, Petr

    2016-11-01

    The decomposition of dead plant biomass contributes to the carbon cycle and is one of the key processes in temperate forests. While fungi in litter decomposition drive the chemical changes occurring in litter, the bacterial community appears to be important as well, especially later in the decomposition process when its abundance increases. In this paper, we describe the bacterial community composition in live Quercus petraea leaves and during the subsequent two years of litter decomposition. Members of the classes Alpha-, Beta- and Gammaproteobacteria and the phyla Actinobacteria, Bacteroidetes and Acidobacteria were dominant throughout the experiment. Bacteria present in the oak phyllosphere were rapidly replaced by other taxa after leaf senescence. There were dynamic successive changes in community composition, in which the early-stage (months 2-4), mid-stage (months 6-8) and late-stage (months 10-24) decomposer communities could be distinguished, and the diversity increased with time. Bacteria associated with dead fungal mycelium were important during initial decomposition, with sequence relative abundances of up to 40% of the total bacterial community in months 2 and 4 when the highest fungal biomass was observed. Cellulose-decomposing bacteria were less frequent, with abundance ranging from 4% to 15%. The bacterial community dynamics reflects changes in the availability of possible resources either of the plant or microbial origin. PMID:27543318

  1. A Phenological Timetable of Oak Growth under Experimental Drought and Air Warming

    PubMed Central

    Kuster, Thomas M.; Dobbertin, Matthias; Günthardt-Goerg, Madeleine S.; Schaub, Marcus; Arend, Matthias

    2014-01-01

    Climate change is expected to increase temperature and decrease summer precipitation in Central Europe. Little is known about how warming and drought will affect phenological patterns of oaks, which are considered to possess excellent adaptability to these climatic changes. Here, we investigated bud burst and intra-annual shoot growth of Quercus robur, Q. petraea and Q. pubescens grown on two different forest soils and exposed to air warming and drought. Phenological development was assessed over the course of three growing seasons. Warming advanced bud burst by 1–3 days °C−1 and led to an earlier start of intra-annual shoot growth. Despite this phenological shift, total time span of annual growth and shoot biomass were not affected. Drought changed the frequency and intensity of intra-annual shoot growth and advanced bud burst in the subsequent spring of a severe summer drought by 1–2 days. After re-wetting, shoot growth recovered within a few days, demonstrating the superior drought tolerance of this tree genus. Our findings show that phenological patterns of oaks are modified by warming and drought but also suggest that ontogenetic factors and/or limitations of water and nutrients counteract warming effects on the biomass and the entire span of annual shoot growth. PMID:24586988

  2. Quantification of Fungal Hyphae in Leaves of Deciduous Trees by Automated Image Analysis

    PubMed Central

    Daniel, O.; Schonholzer, F.; Zeyer, J.

    1995-01-01

    An optical method to quantify the fungal hyphae within decomposing leaves of deciduous trees was developed. The plant matrix was partially destroyed under hydrolytic conditions, and fungal hyphae and cellulose residues within the leaves were stained with Calcofluor M2R. Cellulose residues were subsequently depolymerized by cellulase, and fungal hyphae were separated from the remaining plant matrix with a pressurized air-water mixture. An image analysis program to quantify the fungal hyphae was written. The program included the recognition of fungal hyphae, the elimination of stomata from the images, and the measuring of lengths of fungal hyphae. The optical method was verified by a chemical method relying on glucosamine as an indicator of fungal biomass. The fungal biomass in leaves of Fagus silvatica and Quercus petraea at early states of decomposition was 0.2 to 0.4% of the leaf weight. The biomass reached a maximum within 2 to 4 weeks (optical method, 0.5 to 0.7%; chemical method, 1 to 1.4% of the initial leaf weight) and decreased thereafter. PMID:16535160

  3. The influence of mature oak stands and spruce plantations on soil-dwelling click beetles in lowland plantation forests.

    PubMed

    Loskotová, Tereza; Horák, Jakub

    2016-01-01

    Most European forests have been converted into forest plantations that are managed for timber production. The main goal of this paper was to determine the difference between mature native sessile oak (Quercus petraea) stands and non-indigenous Norway spruce (Picea abies) plantations, with respect to communities of Athous click beetles in approximately 6,500 ha of lowland plantation forest area in the Czech Republic. Athous subfuscus was the most abundant and widespread species, followed by A. zebei and A. haemorrhoidalis, while A. vittatus was considered rare. Spatial analysis of environmental variables inside studied patches showed that the species composition of Athous beetles best responded to a 20 m radius surrounding traps. The species' responses to the environment showed that A. vittatus and A. haemorrhoidalis preferred oak stands, while A. zebei and A. subfuscus were associated with spruce plantations. In addition, oak stands showed higher diversity of beetle communities. The studied species are important for their ecosystem services (e.g. predation on pests or bioturbation) and seem to tolerate certain degrees of human disturbances, which is especially beneficial for forest plantations managed for timber production. PMID:26793425

  4. Stem CO2 efflux in six co-occurring tree species: underlying factors and ecological implications.

    PubMed

    Rodríguez-Calcerrada, Jesús; López, Rosana; Salomón, Roberto; Gordaliza, Guillermo G; Valbuena-Carabaña, María; Oleksyn, Jacek; Gil, Luis

    2015-06-01

    Stem respiration plays a role in species coexistence and forest dynamics. Here we examined the intra- and inter-specific variability of stem CO2 efflux (E) in dominant and suppressed trees of six deciduous species in a mixed forest stand: Fagus sylvatica L., Quercus petraea [Matt.] Liebl, Quercus pyrenaica Willd., Prunus avium L., Sorbus aucuparia L. and Crataegus monogyna Jacq. We conducted measurements in late autumn. Within species, dominants had higher E per unit stem surface area (Es ) mainly because sapwood depth was higher than in suppressed trees. Across species, however, differences in Es corresponded with differences in the proportion of living parenchyma in sapwood and concentration of non-structural carbohydrates (NSC). Across species, Es was strongly and NSC marginally positively related with an index of drought tolerance, suggesting that slow growth of drought-tolerant trees is related to higher NSC concentration and Es . We conclude that, during the leafless period, E is indicative of maintenance respiration and is related with some ecological characteristics of the species, such as drought resistance; that sapwood depth is the main factor explaining variability in Es within species; and that the proportion of NSC in the sapwood is the main factor behind variability in Es among species. PMID:25292455

  5. Variation at range margins across multiple spatial scales: environmental temperature, population genetics and metabolomic phenotype

    PubMed Central

    Kunin, William E.; Vergeer, Philippine; Kenta, Tanaka; Davey, Matthew P.; Burke, Terry; Ian Woodward, F.; Quick, Paul; Mannarelli, Maria-Elena; Watson-Haigh, Nathan S.; Butlin, Roger

    2009-01-01

    Range margins are spatially complex, with environmental, genetic and phenotypic variations occurring across a range of spatial scales. We examine variation in temperature, genes and metabolomic profiles within and between populations of the subalpine perennial plant Arabidopsis lyrata ssp. petraea from across its northwest European range. Our surveys cover a gradient of fragmentation from largely continuous populations in Iceland, through more fragmented Scandinavian populations, to increasingly widely scattered populations at the range margin in Scotland, Wales and Ireland. Temperature regimes vary substantially within some populations, but within-population variation represents a larger fraction of genetic and especially metabolomic variances. Both physical distance and temperature differences between sites are found to be associated with genetic profiles, but not metabolomic profiles, and no relationship was found between genetic and metabolomic population structures in any region. Genetic similarity between plants within populations is the highest in the fragmented populations at the range margin, but differentiation across space is the highest there as well, suggesting that regional patterns of genetic diversity may be scale dependent. PMID:19324821

  6. Potential of ultrasonic pulse velocity for evaluating the dimensional stability of oak and chestnut wood.

    PubMed

    Dündar, Türker; Wang, Xiping; As, Nusret; Avcı, Erkan

    2016-03-01

    The objective of this study was to examine the potential of ultrasonic velocity as a rapid and nondestructive method to predict the dimensional stability of oak (Quercus petraea (Mattuschka) Lieblein) and chestnut (Castanea sativa Mill.) that are commonly used in flooring industry. Ultrasonic velocity, specific gravity, and radial, tangential and volumetric shrinkages were measured on seventy-four 20×20×30-mm(3) specimens obtained from freshly cut oak and chestnut stems. The ultrasonic velocities of the specimens decreased with increasing moisture content (MC). We found that specific gravity was not a good predictor of the transverse shrinkages as indicated by relatively weak correlations. Ultrasonic velocity, on the other hand, was found to be a significant predictor of the transverse shrinkages for both oak and chestnut. The best results for prediction of shrinkages of oak and chestnut were obtained when the ultrasonic velocity and specific gravity were used together. The multiple regression models we developed in this study explained 77% of volumetric shrinkages in oak and 72% of volumetric shrinkages in chestnut. It is concluded that ultrasonic velocity coupled with specific gravity can be employed as predicting parameters to evaluate the dimensional stability of oak and chestnut wood during manufacturing process. PMID:26678790

  7. Investigating the effects of topography and clonality on genetic structuring within a large Norwegian population of Arabidopsis lyrata

    PubMed Central

    Lundemo, Sverre; Stenøien, Hans K.; Savolainen, Outi

    2010-01-01

    Background and Aims The gene flow through pollen or seeds governs the extent of spatial genetic structure in plant populations. Another factor that can contribute to this pattern is clonal growth. The perennial species Arabidopsis lyrata ssp. petraea (Brassicaceae) is a self-incompatible, clonal species found in disjunctive populations in central and northern Europe. Methods Fourteen microsatellite markers were employed to study the level of kinship and clonality in a high-altitude mountain valley at Spiterstulen, Norway. The population has a continuous distribution along the banks of the River Visa for about 1·5 km. A total of 17 (10 m × 10 m) squares were laid out in a north–south transect following the river on both sides. Key Results It is shown that clonal growth is far more common than previously shown in this species, although the overall size of the genets is small (mean diameter = 6·4 cm). Across the whole population there is no indication of isolation by distance, and spatial genetic structure is only visible on fine spatial scales. In addition, no effect of the river on the spatial distribution of genotypes was found. Conclusions Unexpectedly, the data show that populations of small perennials like A. lyrata can behave like panmictic units across relatively large areas at local sites, as opposed to earlier findings in central Europe. PMID:20519240

  8. Impacts of local adaptation of forest trees on associations with herbivorous insects: implications for adaptive forest management.

    PubMed

    Sinclair, Frazer H; Stone, Graham N; Nicholls, James A; Cavers, Stephen; Gibbs, Melanie; Butterill, Philip; Wagner, Stefanie; Ducousso, Alexis; Gerber, Sophie; Petit, Rémy J; Kremer, Antoine; Schönrogge, Karsten

    2015-12-01

    Disruption of species interactions is a key issue in climate change biology. Interactions involving forest trees may be particularly vulnerable due to evolutionary rate limitations imposed by long generation times. One mitigation strategy for such impacts is Climate matching - the augmentation of local native tree populations by input from nonlocal populations currently experiencing predicted future climates. This strategy is controversial because of potential cascading impacts on locally adapted animal communities. We explored these impacts using abundance data for local native gallwasp herbivores sampled from 20 provenances of sessile oak (Quercus petraea) planted in a common garden trial. We hypothesized that non-native provenances would show (i) declining growth performance with increasing distance between provenance origin and trial site, and (ii) phenological differences to local oaks that increased with latitudinal differences between origin and trial site. Under a local adaptation hypothesis, we predicted declining gallwasp abundance with increasing phenological mismatch between native and climate-matched trees. Both hypotheses for oaks were supported. Provenance explained significant variation in gallwasp abundance, but no gall type showed the relationship between abundance and phenological mismatch predicted by a local adaptation hypothesis. Our results show that climate matching would have complex and variable impacts on oak gall communities. PMID:26640522

  9. Development of Molecular Markers for Determining Continental Origin of Wood from White Oaks (Quercus L. sect. Quercus).

    PubMed

    Schroeder, Hilke; Cronn, Richard; Yanbaev, Yulai; Jennings, Tara; Mader, Malte; Degen, Bernd; Kersten, Birgit

    2016-01-01

    To detect and avoid illegal logging of valuable tree species, identification methods for the origin of timber are necessary. We used next-generation sequencing to identify chloroplast genome regions that differentiate the origin of white oaks from the three continents; Asia, Europe, and North America. By using the chloroplast genome of Asian Q. mongolica as a reference, we identified 861 variant sites (672 single nucleotide polymorphisms (SNPs); 189 insertion/deletion (indel) polymorphism) from representative species of three continents (Q. mongolica from Asia; Q. petraea and Q. robur from Europe; Q. alba from North America), and we identified additional chloroplast polymorphisms in pools of 20 individuals each from Q. mongolica (789 variant sites) and Q. robur (346 variant sites). Genome sequences were screened for indels to develop markers that identify continental origin of oak species, and that can be easily evaluated using a variety of detection methods. We identified five indels and one SNP that reliably identify continent-of-origin, based on evaluations of up to 1078 individuals representing 13 white oak species and three continents. Due to the size of length polymorphisms revealed, this marker set can be visualized using capillary electrophoresis or high resolution gel (acrylamide or agarose) electrophoresis. With these markers, we provide the wood trading market with an instrument to comply with the U.S. and European laws that require timber companies to avoid the trade of illegally harvested timber. PMID:27352242

  10. Impacts of local adaptation of forest trees on associations with herbivorous insects: implications for adaptive forest management

    PubMed Central

    Sinclair, Frazer H; Stone, Graham N; Nicholls, James A; Cavers, Stephen; Gibbs, Melanie; Butterill, Philip; Wagner, Stefanie; Ducousso, Alexis; Gerber, Sophie; Petit, Rémy J; Kremer, Antoine; Schönrogge, Karsten

    2015-01-01

    Disruption of species interactions is a key issue in climate change biology. Interactions involving forest trees may be particularly vulnerable due to evolutionary rate limitations imposed by long generation times. One mitigation strategy for such impacts is Climate matching – the augmentation of local native tree populations by input from nonlocal populations currently experiencing predicted future climates. This strategy is controversial because of potential cascading impacts on locally adapted animal communities. We explored these impacts using abundance data for local native gallwasp herbivores sampled from 20 provenances of sessile oak (Quercus petraea) planted in a common garden trial. We hypothesized that non-native provenances would show (i) declining growth performance with increasing distance between provenance origin and trial site, and (ii) phenological differences to local oaks that increased with latitudinal differences between origin and trial site. Under a local adaptation hypothesis, we predicted declining gallwasp abundance with increasing phenological mismatch between native and climate-matched trees. Both hypotheses for oaks were supported. Provenance explained significant variation in gallwasp abundance, but no gall type showed the relationship between abundance and phenological mismatch predicted by a local adaptation hypothesis. Our results show that climate matching would have complex and variable impacts on oak gall communities. PMID:26640522