PIXE analysis to estimate the elemental composition of ectomycorrhizal rhizomorphs grown in contact with different minerals in forest soil

Wallander, HÃ¥kan; Johansson, Leif; Pallon, Jan

doi:10.1111/j.1574-6941.2002.tb00916.x

Cited by 53 publications

(43 citation statements)

References 35 publications

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“…On the other hand, our carbon to nutrient ratios used for microbes (C : N = 18 and C : P = 250) may be high. Reported values of fungal C : P range from 70 to 632 (BEEVER and BURNS, 1980;WALLANDER et al, 2002;OLSSON et al, 2008), though none of the data are for aquatic hyphomycetes. Bacteria probably have higher phosphorus content (lower C : P) than fungi (STERNER and ELSER, 2002, suggested C : P < 27 for bacteria based on various reported studies), so a realistic C : P for the assemblage of microbes on decaying leaves is probably lower than that of fungi and generally lower than that of decaying leaves.…”

Section: Is There a Net Retention Or A Net Mineralization Of Nutrientmentioning

confidence: 99%

Nutrient Uptake and Mineralization during Leaf Decay in Streams – a Model Simulation

Webster

Newbold

Thomas

et al. 2009

International Review of Hydrobiology

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We developed a stoichiometrically explicit computer model to examine how heterotrophic uptake of nutrients and microbial mineralization occurring during the decay of leaves in streams may be important in modifying nutrient concentrations. The simulations showed that microbial uptake can substantially decrease stream nutrient concentrations during the initial phases of decomposition, while mineralization may produce increases in concentrations during later stages of decomposition. The simulations also showed that initial nutrient content of the leaves can affect the stream nutrient concentration dynamics and determine whether nitrogen or phosphorus is the limiting nutrient. Finally, the simulations suggest a net retention (uptake > mineralization) of nutrients in headwater streams, which is balanced by export of particulate organic nutrients to downstream reaches. Published studies support the conclusion that uptake can substantially change stream nutrient concentrations. On the other hand, there is little published evidence that mineralization also affects nutrient concentrations. Also, there is little information on direct microbial utilization of nutrients contained in the decaying leaves themselves. Our results suggest several directions for research that will improve our understanding of the complex relationship between leaf decay and nutrient dynamics in streams.

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Section: Is There a Net Retention Or A Net Mineralization Of Nutrientmentioning

confidence: 99%

Nutrient Uptake and Mineralization during Leaf Decay in Streams – a Model Simulation

Webster

Newbold

Thomas

et al. 2009

International Review of Hydrobiology

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“…K accumulations of 5-10 µm would correspond to 0.1-0.2 mg K per g cells. K accumulations of this range and even higher have been shown for mycorrhizal fungi (Wallander et al, 2002(Wallander et al, , 2003. The estimated weight of the inoculum is 15 mg.…”

Section: Discussionmentioning

confidence: 93%

Laboratory Tools to Quantify Biogenic Dissolution of Rocks and Minerals: A Model Rock Biofilm Growing in Percolation Columns

et al. 2016

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Sub-aerial biofilms (SAB) are ubiquitous, self-sufficient microbial ecosystems found on mineral surfaces at all altitudes and latitudes. SABs, which are the principal causes of weathering on exposed terrestrial surfaces, are characterized by patchy growth dominated by associations of algae, cyanobacteria, fungi and heterotrophic bacteria. A recently developed in vitro system to study colonization of rocks exposed to air included two key SAB participants -the rock-inhabiting ascomycete Knufia petricola (CBS 123872) and the phototrophic cyanobacterium Nostoc punctiforme ATCC29133. Both partners are genetically tractable and we used them here to study weathering of granite, K-feldspar and plagioclase. Small fragments of the various rocks or minerals (1-6 mm) were packed into flow-through columns and incubated with 0.1% glucose and 10 µM thiamine-hydrochloride (90 µL min −1 ) to compare weathering with and without biofilms. Dissolution of the minerals was followed by: (i) analysing the degradation products in the effluent from the columns via Inductively Coupled Plasma Spectroscopy and (ii) by studying polished sections of the incubated mineral fragments/grains using scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analyses. K. petricola/N. punctiforme stimulated release of Ca, Na, Mg and Mn. Analyses of the polished sections confirmed depletion of Ca, Na and K near the surface of the fragments. The abrupt decrease in Ca concentration observed in peripheral areas of plagioclase fragments favored a dissolution-reprecipitation mechanism. Percolation columns in combination with a model biofilm can thus be used to study weathering in closed systems. Columns can easily be filled with different minerals and biofilms, the effluent as well as grains can be collected after long-term exposure under axenic conditions and easily analyzed.

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“…Esses valores encontram-se dentro da faixa de concentração desse elemento em rizomorfos de Rhizopogon sp. associado a Pinus muricata (Wallander et al, 2002). O Ca é um dos principais elementos encontrados em rizomorfos e hifas dos fungos ectomicorrízicos (Malajczuk & Cromack, 1982;Wallander et al, 2002).…”

Section: Resultsunclassified

“…As ectomicorrizas contribuem efetivamente para absorção de Ca, K, Mg e micronutrientes pela planta hospedeira em razão do menor diâmetro das hifas, as quais podem explorar pequenos poros inacessíveis às raízes (Wallander et al, 2002).…”

Section: Introductionunclassified

“…A superfície das hifas fúngicas e os rizomorfos contêm quantidades expressivas de Ca e K, sobretudo na forma de cristais de oxalato (Malajczuk & Cromack, 1982;Costa, 2002). A excreção de ácidos orgânicos, principalmente o ácido oxálico, capaz de solubilizar minerais primários, demonstra que os fungos ectomicorrízicos podem ter papel importante na pedogênese e, assim, contribuir para disponibilização desses nutrientes de fontes inorgânicas (Wallander, 2000b;Wallander et al, 2002;Hagerberg, 2003).…”

Section: Introductionunclassified

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Formação de ectomicorrizas por monocários e dicários de Pisolithus sp. e interações nutricionais em Eucalyptus grandis

Silva

Costa²,

Rocha³

et al. 2007

Rev. Bras. Ciênc. Solo

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RESUMOA germinação de basidiósporos de Pisolithus spp. dá origem a monocários, caracterizados por possuírem um único núcleo haplóide por célula. No campo, o eucalipto associa-se a micélios dicarióticos de Pisolithus spp., não havendo relatos sobre a capacidade dos monocários em estabelecer a associação ectomicorrízica com a planta hospedeira nessas condições. Embora os monocários de Pisolithus sp. sejam capazes de formar a associação ectomicorrízica in vitro, nada se sabe sobre a capacidade dessas estirpes em promover a absorção de nutrientes e o crescimento do eucalipto. O objetivo deste trabalho foi estudar a formação de ectomicorrizas por isolados monocarióticos e dicarióticos de Pisolithus sp. em Eucalyptus grandis, sob condições de casa de vegetação, bem como investigar as relações entre o estabelecimento da associação e o crescimento e a absorção de P, Ca, Mg, K, Cu e Zn pelas plantas. Caracterizou-se, também, a produção de massa seca micelial e a absorção de nutrientes pelos isolados fúngicos in vitro. Os isolados monocarióticos e dicarióticos testados variaram na produção de massa seca micelial e na capacidade de absorção de nutrientes. Em geral, os monocários apresentaram maiores índices de eficiência de utilização de nutrientes do que os dicários. Todos os isolados monocarióticos e dicarióticos formaram ectomicorrizas típicas quando associados com E. grandis. A presença dos isolados fúngicos monocarióticos associados às raízes laterais resultou em aumento do diâmetro radial das células da epiderme radicular, característico das ectomicorrizas de eucalipto, indicando que os monocários, à semelhança dos dicários, são capazes de produzir reguladores de crescimento. As médias de percentagem de colonização das raízes pelos isolados monocarióticos e dicarióticos variaram de 12 a 76 %. A absorção de Ca, Mg e K foi estimulada de forma expressiva pela presença das ectomicorrizas, com aumentos de até 760 vezes, demonstrando a relevância dessa associação no suprimento desses macronutrientes, especialmente o Ca. Alguns isolados monocarióticos são tão eficientes quanto os dicários na colonização radicular e na absorção de nutrientes. A caracterização dos monocários de Pisolithus sp. é necessária para se estabelecer a seleção e o cruzamento dos isolados com características desejáveis, visando ao

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PIXE analysis to estimate the elemental composition of ectomycorrhizal rhizomorphs grown in contact with different minerals in forest soil

Cited by 53 publications

References 35 publications

Nutrient Uptake and Mineralization during Leaf Decay in Streams – a Model Simulation

Nutrient Uptake and Mineralization during Leaf Decay in Streams – a Model Simulation

Laboratory Tools to Quantify Biogenic Dissolution of Rocks and Minerals: A Model Rock Biofilm Growing in Percolation Columns

Formação de ectomicorrizas por monocários e dicários de Pisolithus sp. e interações nutricionais em Eucalyptus grandis

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