Colonization of decomposing Sphagnum moss litter by mycorrhizal roots in two types of peatland ecosystems

2014 ◽  
Vol 10 ◽  
pp. 113-121
Author(s):  
Mateusz Wilk ◽  
Julia Pawłowska ◽  
Marta Wrzosek ◽  
Michał Gorczak ◽  
Małgorzata Suska-Malawska
Keyword(s):  
Molecular Identification ◽  
Decomposition Process ◽  
Sphagnum Moss ◽  
Forest Communities ◽  
Litter Bags ◽  
Poor Fen ◽  
The Poor ◽  
Ectomycorrhizal Roots ◽  
Mycorrhizal Roots ◽  
Ectomycorrhizal Morphotypes

During a 35-month study on the decomposition of Sphagnum moss litter in poor fen and pine bog forest, an intensive colonization of litter-bags by mycorrhizal roots was observed during the decomposition process. Content of mycorrhizal roots in litter-bags, expressed as % mass of roots, was generally increasing during the decomposition in pine bog forest, and fluctuating during decomposition on poor fen, although in both cases the results were statistically insignificant. Two morphotypes of ericoid roots and two morphotypes of ectomycorrhizal roots were recorded from litter-bags on poor fen during the decomposition experiment, while in pine bog forest one morphotype of ericoid and nine morphotypes of ectomycorrhizal roots were recorded. Molecular identification of mycorrhizal roots succeeded only in the case of one ericoid and six putatively ectomycorrhizal morphotypes. Most morphotypes were recorded only once during the whole 35-month decomposition period, and only one ericoid and one ectomycorrhizal morphotypes were shared between the poor fen and pine bog forest communities.

scholarly journals Metabolomics and transcriptomics to decipher molecular mechanisms underlying ectomycorrhizal root colonization of an oak tree

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Sebastiana ◽  
A. Gargallo-Garriga ◽  
J. Sardans ◽  
M. Pérez-Trujillo ◽  
F. Monteiro ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Positive Impact ◽  
Ectomycorrhizal Fungus ◽  
Cork Oak ◽  
Mycorrhizal Symbiosis ◽  
Gamma Aminobutyric Acid ◽  
Ectomycorrhizal Symbiosis ◽  
Ectomycorrhizal Roots ◽  
Oak Tree ◽  
Mycorrhizal Roots

AbstractMycorrhizas are known to have a positive impact on plant growth and ability to resist major biotic and abiotic stresses. However, the metabolic alterations underlying mycorrhizal symbiosis are still understudied. By using metabolomics and transcriptomics approaches, cork oak roots colonized by the ectomycorrhizal fungus Pisolithus tinctorius were compared with non-colonized roots. Results show that compounds putatively corresponding to carbohydrates, organic acids, tannins, long-chain fatty acids and monoacylglycerols, were depleted in ectomycorrhizal cork oak colonized roots. Conversely, non-proteogenic amino acids, such as gamma-aminobutyric acid (GABA), and several putative defense-related compounds, including oxylipin-family compounds, terpenoids and B6 vitamers were induced in mycorrhizal roots. Transcriptomic analysis suggests the involvement of GABA in ectomycorrhizal symbiosis through increased synthesis and inhibition of degradation in mycorrhizal roots. Results from this global metabolomics analysis suggest decreases in root metabolites which are common components of exudates, and in compounds related to root external protective layers which could facilitate plant-fungal contact and enhance symbiosis. Root metabolic pathways involved in defense against stress were induced in ectomycorrhizal roots that could be involved in a plant mechanism to avoid uncontrolled growth of the fungal symbiont in the root apoplast. Several of the identified symbiosis-specific metabolites, such as GABA, may help to understand how ectomycorrhizal fungi such as P. tinctorius benefit their host plants.

Aggregation of Lepidostomatidae in small mesh size litter-bags: implication to the leaf litter decomposition process

2008 ◽  
Vol 17 (4) ◽  
pp. 417-421 ◽  
Author(s):  
Aung Nanda ◽  
Takashi Asaeda ◽  
Takeshi Fujino ◽  
Kian Siong ◽  
Takashi Nakajima
Keyword(s):  
Leaf Litter ◽  
Litter Decomposition ◽  
Mesh Size ◽  
Decomposition Process ◽  
Leaf Litter Decomposition ◽  
Litter Bags

scholarly journals Soil and vegetation characteristics of a peatland near Lake Édouard in Mauricie National Park, Québec, Canada

2014 ◽  
Vol 61 (1) ◽  
pp. 37-43
Author(s):  
Pierre Milette ◽  
Denis Fontaine ◽  
Miroslav V. Grandtner
Keyword(s):  
National Park ◽  
Myrica Gale ◽  
Carex Stricta ◽  
New Associations ◽  
Calamagrostis Canadensis ◽  
Poor Fen ◽  
The Poor ◽  
Quality Of Water ◽  
Carex Rostrata

The majority of plant communities within the peatland near Lake Édouard belongs to the poor fen group. They are containing poor fen species such as <i>Myrica gale</i>, <i>Carex rostrata</i>, <i>Glyceria canadensis</i>, <i>Calamagrostis canadensis</i>, <i>Carex canescens</i>, <i>Carex stricta</i>, <i>Alnus rugosa</i> and <i>Sphagnum subsecundum</i>. Members of these taxa grow in association with a group of marsh species and with <i>Chamaedaphne calyculata</i> and <i>Sphagnum majus</i>, species characteristic of bogs. The soil are of the humisol great group, being well decomposed and relatively rich in nutrient elements but ranging from extremely to strongly acidic. Four new associations are noted: <i>Sphagno-Juncetum brevicaudati</i>, <i>Sphagno-Hypericetum boreale</i>, <i>Sphagno-Glycerietum canadensis</i> and <i>Carici canescenti</i>-<i>Sphagnetum maji</i>. The distribution of vegetation appears dependent on ground relief and, consequently, on the level and quality of water in the peatland.

Nowe stanowisko Salix myrtilloides (Salicaceae) w Kampinoskim Parku Narodowym

2019 ◽  
pp. 168-170
Author(s):  
Karol Torzewski
Keyword(s):  
Environmental Conditions ◽  
National Park ◽  
Poor Fen ◽  
The Poor

In April 2014, a new locality of Salix myrtilloides was found in the eastern part of Kampinos National Park in the abandoned village of Wyględy Górne (Leszno municipality, Warszawa Zachód District; GPS: 52°17′35.4″N, 20°41′41.5″E). The population consisted of 17 stems scattered in an area of 30 m2 within a poor fen that developed between small dunes. The main threat to the species at this locality is the poor quantity of these plants, which makes the population susceptible to sudden changes in environmental conditions. Another threat is biocenotic succession and the associated increase in shading from shrubs and perennials.

MEASUREMENT OF HYDRAULIC CONDUCTIVITY OF PEATS

1973 ◽  
Vol 53 (1) ◽  
pp. 21-26 ◽  
Author(s):  
T. S. DAI ◽  
J. H. SPARLING
Keyword(s):  
Hydraulic Conductivity ◽  
Darcy’S Law ◽  
Vertical Component ◽  
Darcy's Law ◽  
Horizontal Component ◽  
Chamber Length ◽  
Poor Fen ◽  
The Poor

The measurement of hydraulic conductivity of peats in a northeastern Ontario peatland is described. Several sizes of piezometer were tested and revealed little effect on the hydraulic conductivity. Various lengths of piezometer chamber were used to measure both vertical and horizontal components of hydraulic conductivity at a number of sites. Open bog sites had a higher vertical component of hydraulic conductivity than the poor fen site. The poor fen site exhibited a greater dependence of the hydraulic conductivity on piezometer chamber length than the open bog site, indicating a greater horizontal component of the hydraulic conductivity. A significant correlation between the differential heads and hydraulic conductivity is demonstrated. This indicates a deviation of Darcian flow in the peatland. The ratios of differential heads in piezometer are constant, however, and therefore the proportionality of Darcy's Law is exhibited by the piezometer method.

scholarly journals Warming and leaf litter functional diversity, not litter quality, drive decomposition in a freshwater ecosystem

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gustavo H. Migliorini ◽  
Gustavo Q. Romero
Keyword(s):  
Litter Decomposition ◽  
Functional Diversity ◽  
Litter Quality ◽  
Joint Effect ◽  
Freshwater Ecosystems ◽  
Decomposition Process ◽  
Freshwater Ecosystem ◽  
Litter Bags ◽  
Litter Traits ◽  
Underlying Mechanisms

AbstractEnvironment, litter composition and decomposer community are known to be the main drivers of litter decomposition in aquatic ecosystems. However, it remains unclear whether litter quality or functional diversity prevails under warming conditions. Using tank bromeliad ecosystems, we evaluated the combined effects of warming, litter quality and litter functional diversity on the decomposition process. We also assessed the contribution of macroinvertebrates and microorganisms in explaining litter decomposition patterns using litter bags made with different mesh sizes. Our results showed that litter decomposition was driven by litter functional diversity and was increasingly higher under warming, in both mesh sizes. Decomposition was explained by increasing litter dissimilarities in C and N. Our results highlight the importance of considering different aspects of litter characteristics (e.g., quality and functional diversity) in order to predict the decomposition process in freshwater ecosystems. Considering the joint effect of warming and litter traits aspects allow a more refined understanding of the underlying mechanisms of climate change and biodiversity shifts effects on ecosystem functioning.

Electron microscopy in diagnostic virology

1984 ◽  
Vol 42 ◽  
pp. 70-73
Author(s):  
S. E. Miller
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Molecular Identification ◽  
Point Of View ◽  
Negative Stain ◽  
Viral Diagnosis ◽  
Electron Microscopist ◽  
Diagnostic Virology

The techniques for detecting viruses are many and varied including FAT, ELISA, SPIRA, RPHA, SRH, TIA, ID, IEOP, GC (1); CF, CIE (2); Tzanck (3); EM, IEM (4); and molecular identification (5). This paper will deal with viral diagnosis by electron microscopy and will be organized from the point of view of the electron microscopist who is asked to look for an unknown agent--a consideration of the specimen and possible agents rather than from a virologist's view of comparing all the different viruses. The first step is to ascertain the specimen source and select the method of preparation, e. g. negative stain or embedment, and whether the sample should be precleared by centrifugation, concentrated, or inoculated into tissue culture. Also, knowing the type of specimen and patient symptoms will lend suggestions of possible agents and eliminate some viruses, e. g. Rotavirus will not be seen in brain, nor Rabies in stool, but preconceived notions should not prejudice the observer into missing an unlikely pathogen.

High-Resolution, Low-Voltage SEM of Cell Wall Regeneration of Yeast Shizosaccharomyces Pombe Protoplasts

1988 ◽  
Vol 46 ◽  
pp. 208-211
Author(s):  
M. Osumi ◽  
N. Yamada ◽  
T. Nagatani
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Low Voltage ◽  
Cell Wall Regeneration ◽  
The Past ◽  
The Poor ◽  
Probe Size ◽  
Beam Damage ◽  
Biological Field ◽  
Scanning Electron

Even though many early workers had suggested the use of lower voltages to increase topographic contrast and to reduce specimen charging and beam damage, we did not usually operate in the conventional scanning electron microscope at low voltage because of the poor resolution, especially of bioligical specimens. However, the development of the “in-lens” field emission scanning electron microscope (FESEM) has led to marked inprovement in resolution, especially in the range of 1-5 kV, within the past year. The probe size has been cumulated to be 0.7nm in diameter at 30kV and about 3nm at 1kV. We have been trying to develop techniques to use this in-lens FESEM at low voltage (LVSEM) for direct observation of totally uncoated biological specimens and have developed the LVSEM method for the biological field.

Artefacts in the x-ray microanalysis of frozen-hydrated biological samples

1987 ◽  
Vol 45 ◽  
pp. 658-659
Author(s):  
Patrick Echlin
Keyword(s):  
Electron Scattering ◽  
Biological Samples ◽  
Fracture Face ◽  
Detailed Structure ◽  
X Ray ◽  
Morphological Appearance ◽  
The Poor ◽  
Freeze Dried

A number of papers have appeared recently which purport to have carried out x-ray microanalysis on fully frozen hydrated samples. It is important to establish reliable criteria to be certain that a sample is in a fully hydrated state. The morphological appearance of the sample is an obvious parameter because fully hydrated samples lack the detailed structure seen in their freeze dried counterparts. The electron scattering by ice within a frozen-hydrated section and from the surface of a frozen-hydrated fracture face obscures cellular detail. (Fig. 1G and 1H.) However, the morphological appearance alone can be quite deceptive for as Figures 1E and 1F show, parts of frozen-dried samples may also have the poor morphology normally associated with fully hydrated samples. It is only when one examines the x-ray spectra that an assurance can be given that the sample is fully hydrated.

Influence of the Acoustic Reflex on Vowel Recognition

1986 ◽  
Vol 29 (3) ◽  
pp. 420-424 ◽  
Author(s):  
Michael Dorman ◽  
Ingrid Cedar ◽  
Maureen Hannley ◽  
Marjorie Leek ◽  
Julie Mapes Lindholm
Keyword(s):  
Auditory System ◽  
Sound Pressure ◽  
Dynamic Range ◽  
Recognition Accuracy ◽  
Pressure Level ◽  
Acoustic Reflex ◽  
The Poor ◽  
Stapedial Reflex ◽  
Vowel Recognition ◽  
High Sound

Computer synthesized vowels of 50- and 300-ms duration were presented to normal-hearing listeners at a moderate and high sound pressure level (SPL). Presentation at the high SPL resulted in poor recognition accuracy for vowels of a duration (50 ms) shorter than the latency of the acoustic stapedial reflex. Presentation level had no effect on recognition accuracy for vowels of sufficient duration (300 ms) to elicit the reflex. The poor recognition accuracy for the brief, high intensity vowels was significantly improved when the reflex was preactivated. These results demonstrate the importance of the acoustic reflex in extending the dynamic range of the auditory system for speech recognition.

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