scholarly journals Accumulation of peroxidase in the cap rays of Acetabularia during the development of gametangia.

1979 ◽  
Vol 27 (6) ◽  
pp. 1003-1010 ◽  
Author(s):  
D Menzel
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Light And Electron Microscopy

Accumulation of peroxidase was demonstrated by light and electron microscopy to occur in Acetabularia in certain regions of the cap rays in relation to the development of the gametangia (cysts). Peroxidase was found to be incorporated into special, cell wall-like obstructions that separate the cap rays from the stalk when the secondary nuclei have settled in the cap rays. It is assumed that peroxidase acts as an anti-microbial protectant of the gametangia.

Initial stages of cell wall formation in the dinoflagellate Peridinium trochoideum

1975 ◽  
Vol 53 (5) ◽  
pp. 483-494 ◽  
Author(s):  
John P. Kalley ◽  
Thana Bisalputra
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Osmotic Pressure ◽  
Fibrous Material ◽  
Light And Electron Microscopy ◽  
Cell Wall Formation ◽  
Vast Number ◽  
Wall Formation ◽  
Marine Dinoflagellate ◽  
Interphase Cells

The formation of the cell wall in the marine dinoflagellate Peridinium trochoideum was studied using light and electron microscopy. In mature, interphase cells, densely staining inclusions termed ‘prothecal bodies’ were found distributed throughout the cytoplasm. Before ecdysis each amorphous prothecal body developed into many vesicles, each of which contained fibrous material in an electron-transparent matrix. The vast number of vesicles so formed may have increased the cell's osmotic pressure enough to initiate ecdysis. At ecdysis the thecal plates and overlying membranes were lost and a new wall was formed by deposition of intact prothecal vesicles at the protoplast surface. The newly formed wall was continuous over the protoplast and no plates existed as such

Production and characterization of monoclonal antibodies to the sapstaining fungus Ophiostoma piceae

1994 ◽  
Vol 40 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Srabani Banerjee ◽  
Judy Little ◽  
Maria Chan ◽  
Brian T. Luck ◽  
Colette Breuil ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Monoclonal Antibodies ◽  
Light And Electron Microscopy ◽  
Cross Reactivity ◽  
Cell Wall Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Enzymatic Modification ◽  
Ophiostoma Piceae

A sensitive immunological tool has been developed to detect the sapstaining fungus Ophiostoma piceae 3871, which plagues the wood industry. Monoclonal antibodies (1F3(1), 4G3(14), 4G2(4), and 2B6(24)) produced against cell wall protein extracts of this fungus were specific. Specificity was estimated by enzyme linked immunosorbent assay, western blotting, and light and electron microscopy using the immunogold technique. Electron microscopy revealed gold particles localized on the outer surface of the cell wall. When screened against 24 biological control fungi the antibodies showed pratically no cross-reactivity (< 4%). When tested against 19 other staining fungi, the antibodies recognized three strains of Ophiostoma piceae, 1F3(1) recognized Phialophora botulispora, and the antibodies showed less than 5% reactivity with the other fungi. Chemical and enzymatic modification of the antigen revealed that the epitopes recognized by the monoclonal antibodies were glycospecific. Although the antibodies were produced against the cell wall protein extracts of the fungus grown in liquid culture, they also recognized the fungus growing in wood and therefore can be employed to investigate wood colonization by this fungus.Key words: Ophiostoma piceae, monoclonal antibodies, glycoprotein.

scholarly journals A CLEM approach to access to the ultrastructure at the graft interface in Arabidopsis thaliana

2021 ◽  
Author(s):  
Clément Chambaud ◽  
Sarah Jane Cookson ◽  
Nathalie Ollat ◽  
Emmanuelle M. F. Bayer ◽  
Lysiane Brocard
Keyword(s):  
Electron Microscopy ◽  
Arabidopsis Thaliana ◽  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Light And Electron Microscopy ◽  
Three Dimensional ◽  
Cellular Events ◽  
Membrane Tethering ◽  
Secondary Plasmodesmata ◽  
Graft Interface

Despite recent progress in our understanding of the graft union formation, we still know little about the cellular events underlying the grafting process. This is partially due to the difficulty of reliably targeting the graft interface in electron microscopy to study its ultrastructure and three-dimensional architecture. To overcome this technological bottleneck, we developed a correlative light electron microscopy approach (CLEM) to study the graft interface with high ultrastructural resolution. Grafting hypocotyls of Arabidopsis thaliana lines expressing YFP or mRFP in the endoplasmic reticulum allowed the efficient targeting of the grafting interface for under light and electron microscopy. To explore the potential of our method to study sub-cellular events at the graft interface, we focused on the formation of secondary plasmodesmata (PD) between the grafted partners. We showed that 4 classes of PD were formed at the interface and that PD introgression into the call wall was initiated equally by both partners. Moreover, the success of PD formation appeared not systematic with a third of PD not spanning the cell wall entirely. Characterizing the ultrastructural characteristics of these failed PD gives us insights into the process of secondary PD biogenesis. We showed that the thinning of the cell wall and the endoplasmic reticulum-plasma membrane tethering seem to be required for the establishment of symplastic connections between the scion and the rootstock. The resolution reached in this work shows that our CLEM method offer a new scale to the study for biological processes requiring the combination of light and electron microscopy.

scholarly journals Localization of chitin in algal and fungal cell walls by light and electron microscopy.

1978 ◽  
Vol 26 (10) ◽  
pp. 782-791 ◽  
Author(s):  
N L Pearlmutter ◽  
C A Lembi
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Acetic Acid ◽  
Electron Microscope ◽  
Cell Walls ◽  
Potassium Hydroxide ◽  
Light And Electron Microscopy ◽  
Fungal Cell ◽  
Blastocladiella Emersonii ◽  
Fungal Cell Walls

Chitin was visualized in cell walls after hydrolysis with potassium hydroxide and subsequent postfixation of the deacetylated polysaccharide (chitosan) in OsO4. Areas of chitin deposition appeared dark borwn by light microscopy and electron dense in the electron microscope. With this method, the presence of chitin was demonstrated in the cell walls of the green alga Pithophora oedogonia (Montagne) Wittrock and two fungi, Ceratocystis ulmi Buism. (C. Moreau) and Blastocladiella emersonii Cantino and Hyatt. Most of the chitin in P. oedogonia ws found in the crosswall disk and small amounts occurred in the outer longitudinal walls. The septal disk of C. ulmi also contained chitin, but significant amounts were present in the inner and outer regions of longitudinal walls as well. Chitin was present throughout the walls of B. emersonii. Small amounts of chitin were not easily demonstrated by this technique, but removal of chitosan by exposure to dilute acetic acid before osmium fixation disrupted cell wall integrity, suggesting that small amounts of the structural polysaccharide had been removed.

Light and electron microscopy studies on the infection of tomato fruits by Botrytis cinerea

1980 ◽  
Vol 58 (12) ◽  
pp. 1394-1404 ◽  
Author(s):  
F.H. J. Rijkenberg ◽  
G. T. N. De Leeuw ◽  
K. Verhoeff
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Host Cell ◽  
Botrytis Cinerea ◽  
Light And Electron Microscopy ◽  
Microscopy Study ◽  
Wall Material ◽  
Wall Thickening ◽  
Cell Organelles ◽  
Tomato Fruits

A light microscopy study of the host–parasite relationship of Botrytis cinerea on immature tomato fruits was combined with an electron microscopy examination. Both techniques indicate that the cuticle is dissolved enzymatically rather than ruptured mechanically. Inter- and intracellular hyphae have no apparent effect on the cuticle, but do break down wall material. If the penetration tube development is arrested after emerging from the cuticle into the wall, wall discolouration and wall thickening become evident and a considerable increase in host cell organelles below the penetration site is observed. A papilla is also apposited. At successful penetration, when the hypha emerges from the cell wall into the host cell, little cell wall discolouration at the infection site is evident, but the cytoplasm becomes degenerate. Further hyphal extension then occurs in the epidermis, killing more epidermal cells, and leading to collapse, but not penetration, of underlying tissue.

Microscopie de la mycoflore des aiguilles de sapin (Abies alba). II. Lophodermium piceae

1986 ◽  
Vol 64 (1) ◽  
pp. 102-107 ◽  
Author(s):  
François Gourbière ◽  
Régis Pépin ◽  
Dominique Bernillon
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Light And Electron Microscopy ◽  
Abies Alba ◽  
Living Cells

Colonization of Abies alba Mill, needles by Lophodermium piceae (Fckl.) Höhn. (Ascomycetes, Hypodermataceae) was studied by light and electron microscopy. Internal mycelium is at first extracellular and invades all the tissues of the needle; thereafter hyphae may penetrate all cells. Cytoplasm and walls of living cells (parenchyma, phloem, cellulosic transfusion tissues) are then lysed. Hyphae also invade thick-walled and lignified cells (epidermis, hypodermis, xylem, tracheids, and fibers of transfusion tissues) without major degradation of the cell wall. Ascomatal development is intraepidermic. Colonization of the needles is limited by black areas (the diaphragms), the structure of which is described. Lophodermium piceae is a primary saprophyte. Needles are colonized during senescence but ascomata appear only on fallen needles. There are about 230 ascomata per gram of needles. The ecology of this fungus is compared with that of Thysanophora penicillioides (Roum.) Kendrick on Abies needles and with that of Lophodermium pinastri (Schrad.) Chev. on Pinus needles.

Origin of the Inner Intine in Pollen of Canna

1974 ◽  
Vol 32 ◽  
pp. 84-85 ◽  
Author(s):  
John R. Rowley ◽  
John J. Skvarla
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Surface ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Amorphous Matrix ◽  
Light And Electron Microscopy ◽  
Pollen Wall ◽  
Cytoplasmic Surface ◽  
Canna Generalis

Observations of development in the nonaperaturate pollen of Canna generalis Bailey, based upon light and electron microscopy, indicate that the inner intine of this species is initiated by plasmalemmasomes originating at widely separated areas of the cell surface.The intine is that part of the pollen wall located between the sporopollenin exine and the cytoplasmic surface. It is often interbedded with the exine but is not itself composed of sporopollenin. In appearance and composition, the intine is comparable with the primary plant cell wall and has been characterized by Roland as an amorphous matrix of pectins with infrequent microfibrils.

Light and electron microscopy of the host–fungus interaction in the achlorophyllous gametophyte of Botrychium lunaria

1994 ◽  
Vol 72 (2) ◽  
pp. 182-188 ◽  
Author(s):  
E. Schmid ◽  
F. Oberwinkler
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Key Words ◽  
Host Cell ◽  
Matrix Material ◽  
Light And Electron Microscopy ◽  
Thick Layer ◽  
Fungal Endophyte ◽  
Host Fungus ◽  
Translucent Material

The host–fungus interaction between the achlorophyllous gametophyte of Botrychium lunaria and its fungal endophyte was studied by means of light and electron microscopy. Aseptate hyphae with a multilayered cell wall formed intracellular coils. The interface consisted of a thick layer of fibrillar matrix material, an electron-translucent zone, and the host plasmalemma. Several vesicles that show different stages of development and degeneration occurred within one host cell. Degenerating vesicles were encased by large amounts of an electron-translucent material. Arbuscules were not observed. The fungus did not infect the young sporophyte but degenerated within intact gametophyte cells. Key words: Botrychium lunaria, gametophyte, mycorrhiza, ultrastructure.

The Morphology of Vacuolated Cells in the Liver Following Administration of Vitamin A.

1973 ◽  
Vol 31 ◽  
pp. 408-409
Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo ◽  
Fawzia Batti
Keyword(s):  
Electron Microscopy ◽  
Body Weight ◽  
Vitamin A ◽  
Light And Electron Microscopy ◽  
Liver Cells ◽  
Prominent Feature ◽  
Vascular Space ◽  
Vacuolated Cell ◽  
Vacuolated Cells ◽  
Vacuolated Cytoplasm

Vacuolated cells in the liver of young rats were studied by light and electron microscopy following the administration of vitamin A (200 units per gram of body weight). Their characteristics were compared with similar cells found in untreated animals.In rats given vitamin A, cells with vacuolated cytoplasm were a prominent feature. These cells were found mostly in a perisinusoidal location, although some appeared to be in between liver cells (Fig. 1). Electron microscopy confirmed their location in Disse's space adjacent to the sinusoid and in recesses between liver cells. Some appeared to be bordering the lumen of the sinusoid, but careful observation usually revealed a tenuous endothelial process separating the vacuolated cell from the vascular space. In appropriate sections, fenestrations in the thin endothelial processes were noted (Fig. 2, arrow).

Control of Autogenous Vein Grafts Prior to Reimplantation, By Electron Microscopy

1972 ◽  
Vol 30 ◽  
pp. 106-107
Author(s):  
John H. L. Watson ◽  
John L. Swedo ◽  
M. Vrandecic
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Physiological Saline ◽  
Experimental Conditions ◽  
Vein Grafts ◽  
Arterial Blood ◽  
Saphenous Veins ◽  
Autogenous Vein ◽  
Control Of Parameters ◽  
Post Implantation

The ambient temperature and the nature of the storage fluids may well have significant effects upon the post-implantation behavior of venus autografts. A first step in the investigation of such effects is reported here. Experimental conditions have been set which approximate actual operating room procedures. Saphenous veins from dogs have been used as models in the experiments. After removal from the dogs the veins were kept for two hours under four different experimental conditions, viz at either 4°C or 23°C in either physiological saline or whole canine arterial blood. At the end of the two hours they were prepared for light and electron microscopy. Since no obvious changes or damage could be seen in the veins by light microscopy, even with the advantage of tissue specific stains, it was essential that the control of parameters for successful grafts be set by electron microscopy.

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