Andrea Polle

Georg-August-Universität Göttingen, Göttingen, Lower Saxony, Germany

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Publications (229)787.05 Total impact

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    ABSTRACT: Overexpression of bacterial γ-glutamylcysteine synthetase in the cytosol of Populus tremula × P. alba produces higher glutathione (GSH) concentrations in leaves, thereby indicating the potential for cadmium (Cd) phytoremediation. However, the net Cd2+ influx in association with H+/Ca2+, Cd tolerance, and the underlying molecular and physiological mechanisms are uncharacterized in these poplars.We assessed net Cd2+ influx, Cd tolerance and the transcriptional regulation of several genes involved in Cd2+ transport and detoxification in wild-type and transgenic poplars.Poplars exhibited highest net Cd2+ influxes into roots at pH 5.5 and 0.1 mM Ca2+. Transgenics had higher Cd2+ uptake rates and elevated transcript levels of several genes involved in Cd2+ transport and detoxification compared with wild-type poplars. Transgenics exhibited greater Cd accumulation in the aerial parts than wild-type plants in response to Cd2+ exposure. Moreover, transgenic poplars had lower concentrations of O2˙− and H2O2; higher concentrations of total thiols, GSH and oxidized GSH in roots and/or leaves; and stimulated foliar GSH reductase activity compared with wild-type plants.These results indicate that transgenics are more tolerant of 100 μM Cd2+ than wild-type plants, probably due to the GSH-mediated induction of the transcription of genes involved in Cd2+ transport and detoxification.
    New Phytologist 09/2014; · 6.74 Impact Factor
  • Andrea Polle, Shaoliang Chen
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    ABSTRACT: Saline and sodic soils that cannot be used for agriculture occur worldwide. Cultivating stress- tolerant trees to obtain biomass from salinised areas has been suggested. Various tree species of economic importance for fruit, fibre and timber production exhibit high salinity tolerance. Little is known about the mechanisms enabling tree crops to cope with high salinity for extended periods. Here, the molecular, physiological and anatomical adjustments underlying salt tolerance in glycophytic and halophytic model tree species, such as Populus euphratica in terrestrial habitats, and mangrove species along coastlines are reviewed. Key mechanisms that have been identified as mediating salt tolerance are discussed at scales from the genetic to the morphological level, including leaf succulence and structural adjustments to wood anatomy. The genetic and transcriptomic bases for physiological salt acclimation are salt sensing and signalling networks that activate target genes; the target genes keep reactive oxygen species under control, maintain the ion balance and restore water status. Evolutionary adaptation includes gene duplication in these pathways. Strategies for and limitations to tree improvement, particularly transgenic approaches for increasing salt tolerance by transforming trees with single and multiple candidate genes, are discussed.
    Plant Cell and Environment 08/2014; · 5.14 Impact Factor
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    ABSTRACT: A greenhouse experiment was conducted to study whether exogenous abscisic acid (ABA) mediates the responses of poplars to excess zinc (Zn). Populus × canescens seedlings were treated with either basal or excess Zn levels and either 0 or 10 μM ABA. Excess Zn led to reduced photosynthetic rates, increased Zn accumulation, induced foliar ABA and salicylic acid (SA), decreased foliar gibberellin (GA3 ) and auxin (IAA), elevated root H2 O2 levels, and increased root ratios of glutathione (GSH) to GSSG and foliar ratios of ascorbate (ASC) to dehydroascorbate (DHA) in poplars. While exogenous ABA decreased foliar Zn concentrations with 7-day treatments, it increased levels of endogenous ABA, GA3 and SA in roots, and resulted in highly increased foliar ASC accumulation and ratios of ASC to DHA. The transcript levels of several genes involved in Zn uptake and detoxification, such as yellow stripe-like family protein 2 (YSL2) and plant cadmium resistance protein 2 (PCR2), were enhanced in poplar roots by excess Zn but repressed by exogenous ABA application. These results suggest that exogenous ABA can decrease Zn concentrations in P. × canescens under excess Zn for 7 days, likely by modulating the transcript levels of key genes involved in Zn uptake and detoxification.
    Plant Cell and Environment 08/2014; · 5.14 Impact Factor
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    ABSTRACT: 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.
    Mycorrhiza 04/2014; · 2.96 Impact Factor
  • 03/2014; 7(4).
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    ABSTRACT: Verticillium longisporum is a soil-borne vascular pathogen causing economic loss in rape. Using the model plant Arabidopsis this study analyzed metabolic changes upon fungal infection in order to identify possible defense strategies of Brassicaceae against this fungus. Metabolite fingerprinting identified infection-induced metabolites derived from the phenylpropanoid pathway. Targeted analysis confirmed the accumulation of sinapoyl glucosides, coniferin, syringin and lignans in leaves from early stages of infection on. At later stages, the amounts of amino acids increased. To test the contribution of the phenylpropanoid pathway, mutants in the pathway were analyzed. The sinapate-deficient mutant fah1-2 showed stronger infection symptoms than wild-type plants, which is most likely due to the lack of sinapoyl esters. Moreover, the coniferin accumulating transgenic plant UGT72E2-OE was less susceptible. Consistently, sinapoyl glucose, coniferyl alcohol and coniferin inhibited fungal growth and melanization in vitro, whereas sinapyl alcohol and syringin did not. The amount of lignin was not significantly altered supporting the notion that soluble derivatives of the phenylpropanoid pathway contribute to defense. These data show that soluble phenylpropanoids are important for the defense response of Arabidopsis against V. longisporum and that metabolite fingerprinting is a valuable tool to identify infection-relevant metabolic markers.
    New Phytologist 01/2014; · 6.74 Impact Factor
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    ABSTRACT: A schematic model showing mediation of K+ homeostasis and cytosolic Ca2+ in the response of Populus euphratica cells to NaCl stress.
    Environmental and Experimental Botany 01/2014; 107:113–124. · 2.58 Impact Factor
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    ABSTRACT: The Paxillus involutus strains MAJ and NAU improve ion homeostasis under salt stress although only strain MAJ forms a functional ectomycorrhiza with poplar roots, whereas strain NAU induces defense reactions. The goal of the present study was to determine whether beneficial effects of MAJ and NAU on root nutrient element fluxes are induced during early stages of fungal-root interaction or require long-term co-culture. Salt-induced flux profiles of H+, Na+, K+, and Ca2+ were examined in the salt-sensitive poplar Populus × canescens after inoculation for 10 d and 20 d with the P. involutus strains, MAJ and NAU and after short-term (24 h) and long-term (7 d) salt stress. Inoculation with P. involutus for 10 d and 20 d increased the capacity of P. × canescens roots to retain K+ after short and long-term exposure to NaCl stress (100 mM). P. involutus-inoculated plants reduced the influx of Na+, especially in the NAU-inoculated roots. The salt-elicited Na+ efflux corresponded with an apparent decline of H+ extrusion in NAU-inoculated roots, which was presumably the result of increased Na+/H+ exchange activity across the plasma membrane. After 10 days of fungal inoculation, P. × canescens roots exhibited an enhanced Ca2+ uptake ability upon salt treatments, whereas a prolonged inoculation time of 20 d caused a marked Ca2+ efflux from P. × canescens roots. The P. involutus-elicited Ca2+ enrichment was probably replaced by Na+ at the later stage of fungal colonization. Ca2+ enrichment is known to mediate K+/Na+ homeostasis in poplar roots under salt stress and therefore both NAU- and MAJ-impeded Na+ accumulation compared with non-inoculated roots. NAU provided greater benefit to the inoculated roots to the maintenance of the K+/Na+ homeostasis because of the pronounced Na+ extrusion during the early stage of fungal colonization when the Ca2+ enrichment was greater than in MAJ-inoculated roots. In accordance with flux data, the whole-plant assessment revealed that inoculation with P. involutus attenuated NaCl-induced leaf damage in P. × canescens. Overall, our results support that the formation of a mature ectomycorrhiza is not required for the amelioration of the protection from salinity stress.
    Environmental and Experimental Botany 01/2014; 108:99–108. · 2.58 Impact Factor
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    ABSTRACT: Roots of forest trees are associated with various ectomycorrhizal (ECM) fungal species that are involved in nutrient exchange between host plant and the soil compartment. The identification of ECM fungi in small environmental samples is difficult. The present study tested the feasibility of attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy followed by hierarchical cluster analysis (HCA) to discriminate in situ collected ECM fungal species. Root tips colonized by distinct ECM fungal species, i.e., Amanita rubescens, Cenococcum geophilum, Lactarius subdulcis, Russula ochroleuca, and Xerocomus pruinatus were collected in mono-specific beech (Fagus sylvatica) and mixed deciduous forests in different geographic areas to investigate the environmental variability of the ECM FTIR signatures. A clear HCA discrimination was obtained for ECM fungal species independent of individual provenance. Environmental variability neither limited the discrimination between fungal species nor provided sufficient resolution to discern species sub-clusters for different sites. However, the de-convoluted FTIR spectra contained site-related spectral information for fungi with wide nutrient ranges, but not for Lactarius subdulcis, a fungus residing only in the litter layer. Specific markers for distinct ECM were identified in spectral regions associated with carbohydrates (i.e., mannans), lipids, and secondary protein structures. The present results support that FTIR spectroscopy coupled with multivariate analysis is a reliable and fast method to identify ECM fungal species in minute environmental samples. Moreover, our data suggest that the FTIR spectral signatures contain information on physiological and functional traits of ECM fungi.
    Frontiers in Plant Science 01/2014; 5:229. · 3.60 Impact Factor
  • Andrea Polle, Zhi-Bin Luo
    Environmental and Experimental Botany 01/2014; 108:1–3. · 2.58 Impact Factor
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    ABSTRACT: Ectomycorrhizas (EMs) are mutualistic associations between certain soil fungi and higher plants. EMs can modulate the cellular, physiological and molecular processes of host plants, resulting in altered responses of the colonized plants to heavy metals. Progress in elucidating the role of EMs in modulating heavy metal tolerance of host trees is reviewed. In the last decade, a number of ectomycorrhizal fungal isolates and host plants have been characterized for their tolerance to heavy metals. Additionally, the cellular processes have been investigated with regard to heavy metal uptake, transport, distribution, toxicity and detoxification by ectomycorrhizal fungi and/or host plants. At the cellular level, mechanisms of heavy metal detoxification include (i) binding of heavy metals to cell wall and extracellular exudates, (ii) decreased uptake and/or pumping metal ions out of cytosol, (iii) chelation of metal ions in cytosol, (iv) compartmentation of metals in vacuoles or other subcellular structures, and (v) repair of damaged biomolecules. The efficiency of these protective measures is often increased by EMs, resulting in improved physiological status and rescued growth. While physiological and cellular responses to heavy metals have been well studied, experimental data on the underlying molecular mechanisms, especially those induced by the interaction of ectomycorrhizal fungi and hosts, are scattered. Progress in genome sequencing of EM partners has revealed the importance of metal transporters in mediating tolerance. A better understanding of the molecular mechanisms is essential for effective application of selected fungal isolates and hosts to improve the efficiency of bioremediation on heavy metal polluted sites.
    Environmental and Experimental Botany 01/2014; 108:47–62. · 2.58 Impact Factor
  • Lara Danielsen, Andrea Polle
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    ABSTRACT: The nutrient status and physiological responses to drought were investigated in young poplar (Populus x canescens) trees, which were either non-mycorrhizal (NM) or colonized with the ectomycorrhizal fungus Paxillus involutus (EM). Stomatal conductance declined rapidly with limited water availability indicating that Populus x canescens is a strongly water-saving tree species. EM trees showed higher stomatal conductance than NM trees but the magnitude of the effect was very small. Nitrogen uptake was traced by 15N. 15N enrichment was higher in EM root tips than in NM root tips. The 15N enrichment in root tips and in roots was significantly linked with stomatal conductance, whereas the enrichment in leaves was correlated with the enrichment in roots, indicating that N uptake is influenced by photosynthetic processes and that the internal translocation to leaves depends on the concentration in the below-ground tissues. Phosphorus and cations, in particular the main osmolyte potassium K, were enriched leaves of EM plants, but not in roots. Under drought, K and Mg increased in roots regardless the EM status, whereas the foliar concentrations increased only in EM plants. A decline in the leaf water content was prevented by increases in both, cations and soluble sugars. EM also delayed root tip mortality compared with NM plants, thus, suggesting transiently positive effects of EM on poplar performance under drought. Under stronger stress at water potentials of about -1.1 MPa, the transcript levels of stress marker genes (aquaporin PIP2.5, ABA-responsive RD26, ammonium transporter AMT3.1) were increased regardless the mycorrhizal status of the trees.
    Environmental and Experimental Botany 01/2014; · 2.58 Impact Factor
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    ABSTRACT: Populus × euramericana (Pe) displays higher stable carbon isotope composition (δ(13) C) and intrinsic water use efficiency (WUEi ) than P. cathayana (Pc) under unlimited water conditions, rendering us to hypothesize that Pe is better acclimated to water deficiency than Pc. To examine this hypothesis, saplings of Pc and Pe were exposed to drought and subsequently re-watered. Pc and Pe exhibited distinct anatomical, physiological and transcriptional responses in acclimation to drought and re-watering, mainly due to stronger responsiveness of transcriptional regulation of genes encoding plasma membrane intrinsic proteins (PIPs), higher starch accumulation, δ(13) C, stable nitrogen isotope composition (δ(15) N) and WUEi , and lower reactive oxygen species (ROS) accumulation and scavenging in Pe. In acclimation to drought, both poplar genotypes demonstrated altered anatomical properties, declined height growth, differential expression of PIPs, activation of ABA signaling pathway, decreased total soluble sugars and starch, increased δ(13) C, δ(15) N and WUEi , and shifted homeostasis of ROS production and scavenging, and these changes can be recovered upon re-watering. These data indicate that Pe is more tolerant to drought than Pc, and that anatomical, physiological and transcriptional acclimation to drought and re-watering is essential for poplars to survive and grow under projected dry climate scenarios in the future.
    Physiologia Plantarum 12/2013; · 3.66 Impact Factor
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    ABSTRACT: Populus euphratica is a salt-tolerant tree species that develops leaf succulence after a prolonged period of salinity stress. In the present study, a putative xyloglucan endotransglucosylase/hydrolase gene (PeXTH) from P. euphratica was isolated and transferred to tobacco plants. PeXTH localized exclusively to the endoplasmic reticulum and cell wall. Plants overexpressing PeXTH were more salt tolerant than wild-type tobacco with respect to root and leaf growth, and survival. The increased capacity for salt tolerance was due mainly to the anatomical and physiological alterations caused by PeXTH overexpression. Compared with the wild type, PeXTH-transgenic plants contained 36% higher water content per unit area and 39% higher ratio of fresh weight to dry weight, a hallmark of leaf succulence. However, the increased water storage in the leaves in PeXTH-transgenic plants was not accompanied by greater leaf thickness but was due to highly packed palisade parenchyma cells and fewer intercellular air spaces between mesophyll cells. In addition to the salt dilution effect in response to NaCl, these anatomical changes increased leaf water-retaining capacity, which lowered the increase of salt concentration in the succulent tissues and mesophyll cells. Moreover, the increased number of mesophyll cells reduced the intercellular air space, which improved carbon economy and resulted in a 47-78% greater net photosynthesis under control and salt treatments (100-150mM NaCl). Taken together, the results indicate that PeXTH overexpression enhanced salt tolerance by the development of succulent leaves in tobacco plants without swelling.
    Journal of Experimental Botany 10/2013; · 5.24 Impact Factor
  • Rodica Pena, Andrea Polle
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    ABSTRACT: 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.
    The ISME Journal 09/2013; · 8.95 Impact Factor
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    ABSTRACT: Temperature-induced lipocalins (TIL) have been invoked in the defense from heat, cold and oxidative stress. Here we document a function of TIL for basal protection from salinity stress. Heterologous expression of TIL from the salt resistant poplar Populus euphratica did not rescue growth but prevented chlorophyll b destruction in salt-exposed Arabidopsis thaliana. The protein was localized to the plasma membrane but was re-translocated to the symplast under salt stress. The A. thaliana knock out and knock down lines Attil1-1 and Attil1-2 showed stronger stress symptoms and stronger chlorophyll b degradation than the wildtype (WT) under excess salinity. They accumulated more chloride and sodium in chloroplasts than the WT. Chloroplast chloride accumulation was found even in the absence of salt stress. Since lipocalins are known to bind regulatory fatty acids of channel proteins as well as iron, we suggest that the salt-induced trafficking of TIL may be required for protection of chloroplasts by affecting ion homeostasis.
    Journal of plant physiology 09/2013; · 2.50 Impact Factor
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    ABSTRACT: To investigate N metabolism of two contrasting Populus species in acclimation to low N availability, saplings of slow-growing species (Populus popularis, Pp) and a fast-growing species (Populus alba × Populus glandulosa, Pg) were exposed to 10, 100, or 1000 μM NH4NO3. Despite greater root biomass and fine root surface area in Pp, lower net influxes of NH4 (+) and NO3 (-) at the root surface were detected in Pp compared to those in Pg, corresponding well to lower NH4 (+) and NO3 (-) content and total N concentration in Pp roots. Meanwhile, higher stable N isotope composition (δ(15)N) in roots and stronger responsiveness of transcriptional regulation of 18 genes involved in N metabolism were found in roots and leaves of Pp compared to those of Pg. These results indicate that the N metabolism of Pp is more sensitive to decreasing N availability than that of Pg. In both species, low N treatments decreased net influxes of NH4 (+) and NO3 (-), root NH4 (+) and foliar NO3 (-) content, root NR activities, total N concentration in roots and leaves, and transcript levels of most ammonium (AMTs) and nitrate (NRTs) transporter genes in leaves and genes involved in N assimilation in roots and leaves. Low N availability increased fine root surface area, foliar starch concentration, δ(15)N in roots and leaves, and transcript abundance of several AMTs (e.g. AMT1;2) and NRTs (e.g. NRT1;2 and NRT2;4B) in roots of both species. These data indicate that poplar species slow down processes of N acquisition and assimilation in acclimation to limiting N supply.
    Journal of Experimental Botany 08/2013; · 5.24 Impact Factor
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    ABSTRACT: 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 nonmycorrhizal controls were exposed to 0 or 50 μM CdSO4 . EMs displayed higher net Cd(2+) influx than nonmycorrhizal 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 nonmycorrhizal 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 nonmycorrhizal roots. Higher CO2 assimilation, improved nutrient and carbohydrate status, and alleviated oxidative stress were found in mycorrhizal compared to nonmycorrhizal 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 P. × canescens Cd tolerance by increased detoxification, improved nutrient and carbohydrate status and defense preparedness.
    Plant Cell and Environment 08/2013; · 5.14 Impact Factor
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    ABSTRACT: We labeled tree saplings of beech and ash with 15N and 13C in a greenhouse. Carbon (C) was applied as 13CO2 to plants and nitrogen (N) was added as 15NH415NO3 to the soil. We hypothesized that C will be transferred from plants to the rhizosphere, subsequently in beech to ectomycorrhiza (EM), in ash to arbuscular mycorrhiza (AM) and finally to soil animals. We expected the C signal to be more effectively transferred to soil animals in EM as compared to AM systems since EM forms more extensive extramatrical mycelia as compared to AM. For 15N we hypothesized that it will be taken up by both saprotrophic microorganisms and mycorrhizal fungi and then channeled to soil animals. After five month, δ13C and δ15N signatures of soil animals, EM and fine roots of beech and ash were measured. Litter and soil were hardly enriched in 15N whereas fine roots of beech and ash were highly enriched suggesting that nitrogen in 15NH415NO3 was predominantly taken up by plants and mycorrhizal fungi but little by saprotrophic microorganisms. Roots of beech and ash were highly enriched in 13C with maximum values in EM proving that 13C was translocated into roots and mycorrhizal fungi. Soil animals were a priori assigned to primary decomposers, secondary decomposers and predators. Generally, signatures of soil animals did not significantly vary between beech and ash and therefore were pooled. Primary decomposers had low δ13C and δ15N signatures similar to litter and soil confirming that rhizosphere C and microbial N are of limited importance for primary decomposer taxa. δ13C and δ15N signatures of secondary decomposers were higher than those of primary decomposers and spanned a large gradient indicating that certain secondary decomposers rely on root derived C and microbial N, however, none of the secondary decomposers had signatures pointing to exclusive feeding on EM. Unexpectedly, δ13C and δ15N signatures were highest in predators suggesting that they heavily preyed on secondary decomposer species such as the litter dwelling Collembola species Lepidocyrtus cyaneus and species not captured by the heat extraction procedure used for capturing prey taxa, presumably predominantly root associated nematodes. Overall, the results highlight that in particular higher trophic levels rely on carbon originating from other resources than litter with these resources channeled to dominant predators via litter dwelling Collembola species.
    Soil Biology and Biochemistry 07/2013; 62:76–81. · 4.41 Impact Factor
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    ABSTRACT: 16S rRNA genes and transcripts of Acidobacteria were investigated in 57 grassland and forest soils of three different geographic regions. Acidobacteria contributed 9-31% of bacterial 16S rRNA genes whereas the relative abundances of the respective transcripts were 4-16%. The specific cellular 16S rRNA content (determined as molar ratio of rRNA : rRNA genes) ranged between 3 and 80, indicating a low in situ growth rate. Correlations with flagellate numbers, vascular plant diversity and soil respiration suggest that biotic interactions are important determinants of Acidobacteria 16S rRNA transcript abundances in soils. While the phylogenetic composition of Acidobacteria differed significantly between grassland and forest soils, high throughput denaturing gradient gel electrophoresis and terminal restriction fragment length polymorphism fingerprinting detected 16S rRNA transcripts of most phylotypes in situ. Partial least squares regression suggested that chemical soil conditions such as pH, total nitrogen, C : N ratio, ammonia concentrations and total phosphorus affect the composition of this active fraction of Acidobacteria. Transcript abundance for individual Acidobacteria phylotypes was found to correlate with particular physicochemical (pH, temperature, nitrogen or phosphorus) and, most notably, biological parameters (respiration rates, abundances of ciliates or amoebae, vascular plant diversity), providing culture-independent evidence for a distinct niche specialization of different Acidobacteria even from the same subdivision.
    Environmental Microbiology 06/2013; · 6.24 Impact Factor

Publication Stats

5k Citations
787.05 Total Impact Points


  • 1970–2014
    • Georg-August-Universität Göttingen
      • • Department of Forest Botany and Tree Physiology
      • • Buesgen Institute
      Göttingen, Lower Saxony, Germany
  • 2007–2013
    • Beijing Forestry University
      Peping, Beijing, China
    • Xinjiang University
      Hsin-chien, Jiangxi Sheng, China
  • 2010
    • Karlsruhe Institute of Technology
      • Institut für Meteorologie und Klimaforschung
      Karlsruhe, Baden-Wuerttemberg, Germany
    • University of Applied Science and Arts Dortmund
      Dortmund, North Rhine-Westphalia, Germany
    • Technische Universität Braunschweig
      • Institut für Pflanzenbiologie
      Braunschweig, Lower Saxony, Germany
  • 1994–2010
    • University of Freiburg
      • Institute of Forest Botany and Tree Physiology
      Freiburg, Baden-Wuerttemberg, Germany
  • 2009
    • French National Institute for Agricultural Research
      Lutetia Parisorum, Île-de-France, France
    • Gesellschaft für wissenschaftliche Datenverarbeitung mbH Göttingen
      Göttingen, Lower Saxony, Germany
  • 2008
    • Shanghai Institute of Landscape Gardening
      Shanghai, Shanghai Shi, China
  • 2004
    • Lampung University
      Bandarlampung, Lampung, Indonesia
  • 1983
    • University of Cologne
      • Botanical Institute
      Köln, North Rhine-Westphalia, Germany