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.

Light and electron microscopy of a host–fungus interaction in the roots of some epiphytic ferns from Costa Rica

1995 ◽  
Vol 73 (7) ◽  
pp. 991-996 ◽  
Author(s):  
E. Schmid ◽  
F. Oberwinkler ◽  
L. D. Gómez
Keyword(s):  
Electron Microscopy ◽  
Costa Rica ◽  
Matrix Material ◽  
Light And Electron Microscopy ◽  
Root Hairs ◽  
Host Cells ◽  
Cortical Cells ◽  
Host Fungus ◽  
Hyphal Coils ◽  
Uniform Diameter

The roots of 11 epiphytic fern species from the genera Elaphaglossum, Peltapteris, Hymenophyllum, Grammitis, and Lellingeria were studied by means of light and electron microscopy. All species showed a similar association with an ascomycete that traversed the root hairs and formed intracellular hyphal coils within cytoplasmic epidermal and outer cortical cells. The unbranched fungal hyphae were of a uniform diameter. They were surrounded by a flocculent matrix material and by the host plasmalemma. Cytoplasmic hyphae also occurred within degenerated host cells. The host–fungus interaction showed similarities to Ericoid mycorrhizae. Key words: ferns, mycorrhiza, ascomycete, ultrastructure, Costa Rica.

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.

The development and zoospore ultrastructure of a polycentric chytridiomycete gut fungus, Orpinomyces joyonii comb.nov.

1991 ◽  
Vol 69 (3) ◽  
pp. 580-589 ◽  
Author(s):  
Jinliang Li ◽  
I. Brent Heath ◽  
K.-J. Cheng
Keyword(s):  
Electron Microscopy ◽  
Distribution Pattern ◽  
Key Words ◽  
Light And Electron Microscopy ◽  
General Morphology ◽  
Organelle Distribution ◽  
Central Nuclei

Orpinomyces bovis, a polycentric gut fungus isolated from a steer, was examined with both light and electron microscopy and renamed Orpinomyces joyonii comb.nov. on the basis of its general morphology and zoospore ultrastructure. The multinucleate rhizomycelium is extensively branched, and sporangia form exogenously on branched or unbranched sporangiophores. The organelles in the zoospores have a distribution pattern typical of other gut fungi, i.e., anterior ribosomal aggregates, central nuclei, and posterior presumptive hydrogenosomes. The perikinetosomal apparatus in O. joyonii is comparable to that in monocentric gut fungi but with minor variations. New details of the posterior dome are described. It contains highly ordered specialized lamellae, peripheral granules, and megatubules. Microtubules intersect the dome predominantly at approximately right angles to its surface; this differs from monocentric gut fungi, in which microtubules form a posterior fan running parallel to the dome. We suggest that both monocentric and polycentric gut fungi are monophyletic, since both have a similar, distinctive perikinetosomal apparatus, posterior dome, and organelle distribution pattern. Key words: Orpinomyces joyonii, gut fungi, ultrastructure, posterior dome, perikinetosomal apparatus.

Electron microscopy of two nematode-destroying fungi, Meristacrum asterospermum and Zygnemomyces echinulatus (Meristacraceae, Entomophthorales)

1997 ◽  
Vol 75 (5) ◽  
pp. 762-768 ◽  
Author(s):  
Masatoshi Saikawa ◽  
Masami Oguchi ◽  
Rafael F. Castañeda Ruiz
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Key Words ◽  
Septal Wall ◽  
Apical Portion ◽  
Key Words Infection ◽  
Ultrathin Sections

Infection of nematodes by Meristacrum asterospermum and Zygnemomyces echinulatus was initiated by conidia adhering to the nematode's cuticle. Each conidium developed an infection peg to penetrate the nematode after adhesion. In M. asterospermum, an infection peg just under the penetration was found in ultrathin sections, in which the peg's cell wall was broken into several lobes that were covered entirely with an amorphous mass of electron-opaque substance. Septa formed in the apical portion of aerial conidiophore under conidiation. The septal wall was nonperforate and often contained electron-opaque inclusions. Vegetative hyphae of Z. echinulatus had typical bifurcate septa, but septa at both ends of the pedicel of conidia were often slightly deformed. Key words: infection of nematodes, Meristacrum asterospermum, septum, Zygnemomyces echinulatus.

Microtubular configurations during endosperm development in Phaseolus vulgaris

1994 ◽  
Vol 72 (10) ◽  
pp. 1489-1495 ◽  
Author(s):  
X. XuHan ◽  
A. A. M. Van Lammeren
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Phaseolus Vulgaris ◽  
Key Words ◽  
Cell Walls ◽  
Endosperm Development ◽  
Initial Cell ◽  
Related Cell ◽  
Cellular Endosperm ◽  
Cell Shaping

Microtubular cytoskeletons in nuclear, alveolar, and cellular endosperm of bean (Phaseolus vulgaris) were analyzed immunocytochemically and by electron microscopy to reveal their function during cellularization. Nuclear endosperm showed a fine network of microtubules between the wide-spaced nuclei observed towards the chalazal pole. Near the embryo, where nuclei were densely packed, bundles of microtubules radiated from nuclei. They were formed just before alveolus formation and functioned in spacing nuclei and in forming internuclear, phragmoplast-like structures that gave rise to nonmitosis-related cell plates. During alveolus formation cell plates extended and fused with other newly formed walls, thus forming the walls of alveoli. Growing wall edges of cell plates exhibited arrays of microtubules perpendicular to the plane of the wall, initially. When two growing walls were about to fuse, microtubules of both walls interacted, and because of the interaction of microtubules, the cell walls changed their position. When a growing wall was about to fuse with an already existing wall, such interactions between microtubules were not observed. It is therefore concluded that interactions of microtubules of fusing walls influence shape and position of walls. Thus microtubules control the dynamics of cell wall positioning and initial cell shaping. Key words: cell wall, cellularization, endosperm, microtubule, Phaseolus vulgaris.

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.

Development of wheat (Triticum aestivum) pollen wall before and after effect of a gametocide

1990 ◽  
Vol 68 (11) ◽  
pp. 2509-2516 ◽  
Author(s):  
Gamal A. El-Ghazaly ◽  
William A. Jensen
Keyword(s):  
Electron Microscopy ◽  
Triticum Aestivum ◽  
Key Words ◽  
Light And Electron Microscopy ◽  
Pollen Grains ◽  
Pollen Wall ◽  
Seed Plants ◽  
Before And After ◽  
After Effect

Light and electron microscopy studies show that pollen wall development in plants treated with the gametocide RH0007 and untreated plants was similar until the stage at which sporopollenin is normally deposited on the wall. At this stage, the pollen wall of treated plants is 80% thinner than that of the control. Shortly after this stage, the pollen grains in the treated plants collapse and abort. We conclude that the gametocide clearly acts through the inhibition of sporopollenin formation, which results in pollen death. As sporopollenin is found only in the pollen wall of seed plants and the spores of nonseed plants, harm to other parts of the plant is not expected to occur. Key words: pollen wall development, Triticum aestivum, gametocide.

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.

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