Light and transmission electron microscopy of English oak ectomycorrhizal short roots

1984 ◽  
Vol 62 (7) ◽  
pp. 1327-1335 ◽  
Author(s):  
H. H. Edwards ◽  
R. V. Gessner
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Quercus Robur ◽  
Lipid Droplets ◽  
Apical Meristem ◽  
Fungal Symbiont ◽  
Host Root ◽  
Transmission Electron ◽  
Cell Layers ◽  
English Oak

The incorporation of caffeine in standard transmission electron microscope fixation procedures has allowed good preservation and embedment of ectomycorrhizal short roots of English oak (Quercus robur L.). In the mantle the most conspicuous structures are cystidia which radiate outwards from the surface. These conically shaped cells have knobs at their tips and thickened cell walls. The cystidia and other outer mantle cells contain many cytoplasmic constituents, whereas the inner mantle cells are nearly devoid of cytoplasm. The mantle cells are held together by an intercellular slime network. The Hartig net cells are filled with cytoplasm and contain numerous lipid droplets. Typical dolipore septa separate the cells; however, these cells have irregularly branched shapes. The host root tissue appears little altered by the presence of the fungal symbiont. However, the root cap consists of only a few cell layers. The apical meristem is functional as evidenced by the presence of newly divided cells and microtubules lining enlarging cells.

scholarly journals Comparative structure of the osmophores in the flowers of Stanhopea graveolens Lindley and Cycnoches chlorochilon Klotzsch (Orchidaceae)

2012 ◽  
Vol 65 (2) ◽  
pp. 11-22 ◽  
Author(s):  
Sebastian Antoń ◽  
Magdalena Kamińska ◽  
Małgorzata Stpiczyńska
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Lipid Droplets ◽  
Secretory Cells ◽  
Vascular Bundles ◽  
Scent Glands ◽  
Euglossine Bees ◽  
Dense Cytoplasm ◽  
Transmission Electron ◽  
Comparative Structure

The structure of the osmophores in <i>Stanhopea graveolens</i> and <i>Cycnoches chlorochilon</i> was studied by means of light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The scent glands are located in the basal part of the labellum. The surface of the osmophores is wrinkled or rugose, which increases the area of fragrance emission. On the surface of the epidermis, remnants of secretion are noticeable in <i>S. graveolens</i>, but these are absent in <i>C. chlorochilon</i>. The osmophore tissue is composed of secretory epidermal cells and several layers of subepidermal parenchyma, and it is supplied by vascular bundles that run in ground parenchyma. The secretory cells have large nuclei, a dense cytoplasm with numerous ER profiles, lipid droplets, and plastids with a substantial amount of starch, which are probably involved in the synthesis of volatile substances. In the cell walls of the osmophore cells, numerous pits with plasmodesmata occur that are likely to take part in symplastic transport of the scent compounds. The structure of the osmophores is similar in both investigated species. Both <i>S. graveolens</i> and <i>C. chlorochilon</i> are pollinated by euglossine bees, and such similarity results from adaptation to effective scent emission and attraction of pollinators.

scholarly journals DISTRIBUTION OF PHENOLIC COMPOUNDS, PECTINS AND HEMICELLULOSES IN MATURE PIT MEMBRANES AND ITS VARIATION BETWEEN PIT TYPES IN ENGLISH OAK XYLEM (QUERCUS ROBUR)

IAWA Journal ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 402-419
Author(s):  
Jong Sik Kim ◽  
Geoffrey Daniel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phenolic Compounds ◽  
Quercus Robur ◽  
Transmission Electron ◽  
Pit Membrane ◽  
Bordered Pits ◽  
English Oak ◽  
Pectin Epitopes

Although there is considerable information on the chemistry of bordered intervessel pit membranes, little is known on the pit membrane chemistry of other pit types in hardwoods. This study investigated distribution of phenolic compounds, pectins and hemicelluloses in different mature pit membranes of English oak xylem using transmission electron microscopy coupled with cytochemistry and immunocytochemistry. Mature bordered intertracheid (vasicentric)- and tracheid-vessel pits showed presence of xyloglucan and heteromannan (hemicelluloses) epitopes across the pit membrane (except for the annulus regions) with differences in amounts of epitopes between earlywood (EW) and latewood (LW). In contrast, pectin epitopes were detected only in the annulus regions of pit membranes. Unlike bordered pits, half-bordered (tracheary-parenchyma pits) and simple (parenchyma pits) pit membranes were rich in pectin epitopes but lacked heteromannan epitopes, indicating difference in pit membrane chemistry between pit types. Distribution of phenolic compounds also differed between pit types and between EW and LW. LW also showed great variations in distribution of phenolic compounds between vessels. Together, this study demonstrates that there are great variations in pit membrane chemistry between pit types and between EW and LW in English oak xylem.

Light and electron microscopic investigations in the Dictyonemataceae (Basidiolichens)

1977 ◽  
Vol 55 (20) ◽  
pp. 2565-2573 ◽  
Author(s):  
Robert D. Slocum ◽  
Gary L. Floyd
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cellular Level ◽  
Fungal Symbiont ◽  
Electron Microscopic ◽  
Basidiomycetous Fungus ◽  
Transmission Electron ◽  
Fungal Symbiosis ◽  
Algal Host ◽  
Microscopic Investigations

The nature of the association between the basidiomycetous mycobiont and the blue-green phycobiont in two species of the tropical basidiolichen Dictyonema was investigated using Nomarski light optics and scanning and transmission electron microscopy. Although members of this family may exhibit either a homoiomerous or heteromerous type of thallus organization, the fungus–alga relationship at the cellular level is remarkably consistent. Scytonema filaments are intimately associated with appressorial hyphae of the mycobiont and with extensive intracellular hyphae, which appear to be unrelated to the basidiomycetous fungal symbiont. This is the first report of a lichen displaying an apparent dual fungal symbiosis with the algal host. Association with the intracellular fungus produces no discernible damage to the phycobiont and apparently does not interfere with the symbiosis involving the basidiomycetous fungus.

TEM and X-Ray Photoelectron Spectroscopic Studies of Wool Fibers after Cuticle Removal

1988 ◽  
Vol 58 (11) ◽  
pp. 640-645 ◽  
Author(s):  
Lyndsay M. Dowling ◽  
Leslie N. Jones ◽  
Ian H. Leaver ◽  
Anthony E. Hughes
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Complete Removal ◽  
Spectroscopic Studies ◽  
Exposed Surface ◽  
X Ray ◽  
Immersion Medium ◽  
Wool Fibers ◽  
Transmission Electron ◽  
Cell Layers

A method is described for cleanly separating the cortex and cuticle of wool fibers using water or an aqueous buffered solution as the immersion medium. Nearly complete removal of cuticle cells can be achieved in 2–3 hours when snippets of wool are vortex-mixed with a suspension containing both glass fiber snippets and glass beads. Examination of treated fibers (transverse sections) by transmission electron microscopy indicates removal of cuticle cell layers (endo- and exocuticle), together with associated membrane intracellular bands ( i-layers). The surface elemental composition of the fiber (determined using x-ray photoelectron spectroscopy) changes appreciably with cuticle removal. The sulfur content of the intracellular cortical proteins at the exposed surface is estimated to be 2%, compared to 9% for the epicuticle proteins at the surface of untreated wool.

Colonization of Sphagnum cells by Lyophyllum palustre

1985 ◽  
Vol 63 (4) ◽  
pp. 757-761 ◽  
Author(s):  
E. Untiedt ◽  
K. Müller
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Host Cell ◽  
Cell Walls ◽  
Transmission Electron ◽  
Scanning Electron

Lyophyllum palustre (Peck) Singer, a basidiomycete (Tricholomataceae) parasitizing Sphagnum, was examined for points of contact between hyphae and Sphagnum cells with the help of light microscopy, scanning electron microscopy, and transmission electron microscopy. Results indicate that the fungus attacks Sphagnum cells by penetrating cell walls and altering host cell protosplasm. In addition, the formation of additional partitioning cell walls in attacked living Sphagnum cells was observed.

Wilts caused by Verticillium species. A cytological survey of vascular alterations in leaves

1982 ◽  
Vol 60 (6) ◽  
pp. 825-837 ◽  
Author(s):  
Jane Robb ◽  
Alexandra Smith ◽  
Lloyd Busch
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Sem Analysis ◽  
Disease Symptoms ◽  
Vascular Tissues ◽  
Transmission Electron ◽  
Tem Method ◽  
Cytological Alterations ◽  
Host Parasite ◽  
Leaf Symptoms

Plants that are infected with fungi of the species Verticillium frequently develop foliar disease symptoms which may include one or more of the following: flaccidity, drying, chlorosis leading to necrosis, vascular browning, epinasty, and leaf abscission. A number of ultrastructural and chemical alterations occur in the vascular tissues of such leaves: deposition of brown pigments, coating of xylem vessel walls with abnormal material (i.e., lipid-rich coatings or fibrillar coatings), plugging of xylem vessels with gums, gels or tyloses, degeneration of parenchyma cells, and accumulation of abnormal electron dense materials in primary and secondary cell walls. Different host–parasite combinations exhibit different leaf symptoms and different cytological alterations. The purpose of the present survey was to determine whether the extent of any of the possible vascular alterations in leaves could be correlated with the wilting tendency of the host.Chrysanthemums, snapdragons, eggplants, sunflowers, potatoes, sycamore maples and hedge maples were infected with V. dahliae; alfalfa and hops were infected with V. albo-atrum. When leaf symptoms were well advanced, samples were taken from the major lateral leaf veins and were prepared for light (LM) and transmission electron microscopy (TEM) or scanning electron microscopy (SEM). The various types of alterations in the vascular tissues were identified by a correlated LM–TEM method and (or) SEM analysis and for each sample vein the proportion of vessels affected by each type of alteration was calculated. Four leaf samples, each from different plants, were analysed for each host. The visual symptoms, including vascular browning, were estimated subjectively. The degree of leaf flaccidity was correlated positively with the proportion of lipid-coated vessels and inversely with the degree of vascular browning. No other correlations were observed.

Nectary ultrastructure and secretory modes in three species of Tillandsia (Bromeliaceae) that have different pollinators

Botany ◽  
2013 ◽  
Vol 91 (11) ◽  
pp. 786-798 ◽  
Author(s):  
Stefano Mosti ◽  
Cynthia Ross Friedman ◽  
Ettore Pacini ◽  
Luigi Brighigna ◽  
Alessio Papini
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Lipid Droplets ◽  
Protein Crystals ◽  
Transmission Electron ◽  
Floral Nectaries ◽  
Secretion Product ◽  
Pollination Mode ◽  
Cell Wall Ingrowths ◽  
Holocrine Secretion

The floral nectaries of three Tillandsia L. spp. having different pollinators were investigated with transmission electron microscopy (TEM) to describe the previously unstudied ultrastructure of the nectar-producing tissues (primarily the epidermis) and also to determine if any differences in the ultrastructural features could be correlated to pollination mode. We determined that there were variations in nectaries among the three species, and that these may be linked to pollinator choice. Tillandsia seleriana Mez, which has a strict relationship with ants, had a nectary epithelium characterized by abundant dictyosomes and endoplasmic reticulum (ER), and a final degeneration stage possibly leading to holocrine secretion. The presence of protein crystals in epithelial plastids was correlated to a nectar enriched with amino acids and proteins, likely functioning to provide a protein-enriched diet and possibly defence against pathogens. Epithelial cells of the hummingbird-pollinated Tillandsia juncea (Ruiz et Pav.) Poir. nectary displayed cell wall ingrowths and dictyosomes and also contained cytoplasmic lipid droplets and protein crystals within plastids, both of which would enrich the nectar for hummingbirds. The nectary epithelium and the parenchyma of bat-pollinated Tillandsia grandis Schltdl. possessed a few cubic protein crystals in the plastids and its secretion product appeared electron transparent.

Immunolocalization of a proteinase of the sap-staining fungus Ophiostoma piceae using antibodies to proteinase K

1995 ◽  
Vol 73 (10) ◽  
pp. 1604-1610 ◽  
Author(s):  
C. Hoffert ◽  
S. Gharibian ◽  
C. Breuil ◽  
D. L. Brown
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Walls ◽  
Polyclonal Antibodies ◽  
Immunogold Labelling ◽  
Proteinase K ◽  
Igg Antibodies ◽  
Extracellular Proteinase ◽  
Ophiostoma Piceae ◽  
Transmission Electron

Polyclonal antibodies were raised against proteinase K and were used to immunolocalize the major extracellular proteinase of the sap-staining fungus Ophiostoma piceae (Münch) H. and P. Sydow. Immunodot blotting showed that the IgG antibodies recognized both enzymes but reacted more strongly with proteinase K than with the O. piceae proteinase. Immunogold labelling and transmission electron microscopy revealed that the O. piceae proteinase was localized in the cell walls of O. piceae grown either in liquid media or wood. Key words: Ophiostoma piceae, proteinase, immunogold labelling, transmission electron microscopy, antibody, proteinase K.

Ultrastructure of hyperparasitism of Coniothyrium minitans on sclerotia of Sclerotinia sclerotiorum

1987 ◽  
Vol 65 (12) ◽  
pp. 2483-2489 ◽  
Author(s):  
H. C. Huang ◽  
E. G. Kokko
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Sclerotinia Sclerotiorum ◽  
Cell Walls ◽  
Chemical Activity ◽  
Coniothyrium Minitans ◽  
Medullary Tissue ◽  
Transmission Electron

Transmission electron microscopy revealed that hyphae of the hyperparasite Coniothyrium minitans invade sclerotia of Sclerotinia sclerotiorum, resulting in the destruction and disintegration of the sclerotium tissues. The dark-pigmented rind tissue is more resistant to invasion by the hyperparasite than the unpigmented cortical and medullary tissues. Evidence from cell wall etching at the penetration site suggests that chemical activity is required for hyphae of C. minitans to penetrate the thick, melanized rind walls. The medullary tissue infected by C. minitans shows signs of plasmolysis, aggregation, and vacuolization of cytoplasm and dissolution of the cell walls. While most of the hyphal cells of C. minitans in the infected sclerotium tissue are normal, some younger hyphal cells in the rind tissue were lysed and devoid of normal contents.

Ultrastructure of the digestive system and experimental study of feeding in the monogenean skin and fin parasite Macrogyrodactylus congolensis

2013 ◽  
Vol 58 (4) ◽  
Author(s):  
Safaa Arafa ◽  
Mohammed El-Naggar ◽  
Graham Kearn
Keyword(s):  
Electron Microscopy ◽  
Lipid Droplets ◽  
Digestive System ◽  
Intestinal Lumen ◽  
Luminal Surface ◽  
Brown Colour ◽  
Transmission Electron ◽  
Large Particles ◽  
H 30 ◽  
Macrogyrodactylus Congolensis

AbstractIn the present study, transmission electron microscopy (TEM) has been used to study the ultrastructure of the digestive system, namely the pharynx, oesophageal glands and intestine, of the monogenean skin and fin parasite Macrogyrodactylus congolensis. The pharynx consists of an anterior highly muscular region and a posterior mainly glandular syncytial region. The anterior region is provided with six pharyngeal papillae, the centre of each of which is occupied by electron dense secretory bodies, identical with those in the posterior region of the pharynx. The intestine has an uninterrupted syncytial gastrodermis and the luminal surface is provided with many unbranched lamellae. The intestine of living specimens contains large and small granules which give it a reddish brown colour. Large particles, presumed to be lipid droplets, and small granules, presumed to be melanin granules, were found in the gastrodermis and in the intestinal lumen. Parasites were induced to feed and then preserved for TEM at the following intervals: just after feeding, 30 min after feeding, 1 h 30 min after feeding and 2 h after feeding. The specimens were then processed for TEM and sections cut through the intestine of each specimen were examined with the transmission electron microscope. Three types of vacuoles (V1, V2, V3) were detected in the gastrodermis. Vacuoles V1 have thick walls and are likely to be endocytotic, enclosing luminal contents at the surface of the gastrodermis. V2 vacuoles may be lysosomes that fuse with V1 vacuoles. V3 vacuoles may serve to dispose of residual digestive material into the lumen.

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