scholarly journals Histopathology of Fusarium wilt of staghorn sumac (Rhus typhina) caused by Fusarium oxysporum f. sp. callistephi race 3. II. Characteristics of opaque matter associated with extensive host cell and cell wall alterations

2006 ◽  
Vol 86 (3) ◽  
pp. 175-187 ◽  
Author(s):  
Guillemond B. Ouellette ◽  
Danny Rioux ◽  
Marie Simard
Keyword(s):  
Fusarium Oxysporum ◽  
Wall Layer ◽  
Cell Hyperplasia ◽  
Transmission Electron ◽  
Ray Cells ◽  
Host Origin ◽  
Similar Content ◽  
Fine Structures ◽  
Cell Alterations ◽  
Rhus Typhina

AbstractLight and transmission electron microscopy observations of staghorn sumac plants inoculated or naturally infected withFusarium oxysporumf. sp.callistephiare reported. One aspect of infection was the presence of large intercellular masses of opaque matter (OM) in middle lamellae between ray cells and/or fibres, often bypassing several intercellular areas; similar OM confluent with the intercellular OM also occurred in secondary walls and in the periphery of numerous cells. A gradual increase in the abundance of the OM in host tissues vertically from the inoculation point and then radially was noted over infection time and was related to host wall and cell alterations. In the region of recently deposited tissue, the OM was associated with pronounced cell hyperplasia and hypertrophy. The OM was delimited by thin, compact bands, and when it was less compact, displayed opaque particles and other fine structures. No indications were obtained that it contained or had contained intact or altered organelles. The DNA probe bound to OM in middle lamellae and in cell periplasmic areas, and to material of a similar texture lining vessel walls. Samples fromFusarium-infected plants, incubated on an agar medium before fixing to determine from which elements the pathogens could develop, displayed bodies as the sole elements present in mature xylem cells and in intercellular areas. These bodies were delimited by membranous structures and profiles of a wall layer and contained opaque particles and areas of fine structures. Certain inter- or intracellular fungal cells in the same tissue frequently had similar content. In the light of these observations it is proposed that the OM is primarily of a pathogen rather than of a host origin.

scholarly journals Histopathology of Fusarium wilt of staghorn sumac (Rhus typhina) caused by Fusarium oxysporum f. sp. callistephi race 3. I. Modes of tissue colonization and pathogen peculiarities

2006 ◽  
Vol 86 (3) ◽  
pp. 157-174 ◽  
Author(s):  
Guillemond B. Ouellette ◽  
Mohamed Cherif ◽  
Marie Simard ◽  
Louis Bernier
Keyword(s):  
Fusarium Oxysporum ◽  
Protective Layer ◽  
Wall Layer ◽  
Fungal Cell ◽  
Transmission Electron ◽  
Bordered Pits ◽  
Vessel Walls ◽  
Thin Elements ◽  
Rhus Typhina ◽  
Extracellular Matter

Abstract Light and transmission electron microscope studies of naturally infected or inoculated staghorn sumac plants by Fusarium oxysporum f. sp. callistephi race 3 are reported. Diverse extrinsic material (including latex in some instances) or elements occurred in vessel lumina. Some of this material labelled for pectin, often in association with tyloses, as did other opaque matter in paratracheal cells, related to alterations of their protective layer. Pronounced alterations of pit membranes of bordered pits occurred, with their outer portions disrupted into bodies of opaque matter, strongly labelled for cellulose, and their middle portions as unlabelled shreds. Similarly labelled opaque bodies occasionally occurred on vessel walls and lumina. Direct penetration of host cell secondary walls by the pathogen occurred, but these were degraded to any extent only following intramural invasion. Vessel walls, at all stages of infection, were lined with variously structured matter: in their thinnest forms, by single or paired, equidistant or widely spaced opaque bands, and in their thickest forms as alternating opaque and less opaque layers. Other thin elements, often enclosing opaque material, vesicular structures, or occasionally particles of ribosomal appearance were also delineated by similar but frequently infolded bands. These elements were sometimes observed to be confluent with fungal cells and to label for chitin. Many fungal elements were bound by only a thin or defective lucent wall layer, practically unlabelled for chitin, or by a locally thickened, labelled one; labelling for this substrate was also frequently associated with the fungal cell outer opaque wall layer or with some outer extracellular matter. Fine filamentous structures, connected to fungal cells, to the vessel lining matter, and to these other elements, extended into host walls. The lining itself generally did not label for cellulose or chitin. These observations are discussed in comparison with similar observations made regarding other wilt diseases that we have studied.

Histopathology of Fusarium wilt of staghorn sumac (Rhus typhina) caused by Fusarium oxysporum f. sp. callistephi race 3. III. Host cell and tissue reactions

2006 ◽  
Vol 87 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Guillemond B. Ouellette ◽  
Mohamed Cherif ◽  
Marie Simard
Keyword(s):  
Cell Wall ◽  
Fusarium Oxysporum ◽  
Host Cell ◽  
Cross Wall ◽  
Tissue Proliferation ◽  
Host Cytoplasm ◽  
Transmission Electron ◽  
Host Cell Wall ◽  
Tissue Reactions ◽  
Rhus Typhina

Abstract Various cell reactions occurred in staghorn sumac plants inoculated with Fusarium oxysporum f. sp. callistephi. Light and transmission electron microscopy observations and results of cytochemical tests showed: 1) increased laticifers and latex production in the phloem; 2) tylosis formation; 3) host cell wall modifications, including appositions or other cell wall thickenings; and 4) unusual cross wall formation in some cells, and cell hypertrophy and hyperplasia. Tylosis walls labelled for pectin and cellulose and many displayed inner suberin-like layers. These layers were also noted in cells of the medullary sheath and in many cells with dense content and thickened walls in the barrier zones that had formed. These zones also contained fibres with newly-formed gelatinous-like layers. In the vicinity of these cells, host cell walls were frequently altered, associated with opaque matter. Many small particles present in chains also occurred in some of these cells, which contained only remnants of host cytoplasm. Light microscopy observations showed that pronounced tissue proliferation and aberrant cells occurred in the outer xylem in the infected plants. Unusual neoplasmic tissue also formed from cells surrounding the pith and medullary sheath, and it spanned directly across the pre-existing xylem tissue and burst as large mounds on the stems.

Haustorial development of Peronospora tabacina infecting Nicotiana tabacum

1983 ◽  
Vol 61 (12) ◽  
pp. 3444-3453 ◽  
Author(s):  
R. N. Trigiano ◽  
C. G. Van Dyke ◽  
H. W. Spurr Jr.
Keyword(s):  
Cell Wall ◽  
Toluidine Blue ◽  
Mesophyll Cell ◽  
Wall Layer ◽  
Peronospora Tabacina ◽  
Host Cytoplasm ◽  
Transmission Electron ◽  
Mold Fungus ◽  
Host Cell Wall ◽  
Hyphal Wall

The development of haustoria in tobacco by the blue-mold fungus Peronospora tabacina was examined using light, scanning, and transmission electron microscopy. Electron-lucent, callose-like appositions were observed between the host plasmalemma and the host mesophyll cell wall prior to haustorial penetration. An electron-opaque penetration matrix was present between the apposition and the host cell wall. The intercellular hyphal wall consisted of two layers which differed in staining quality. The haustorial wall was also two layered, but was primarily composed of and continuous with the inner wall layer of the intercellular hypha. Haustoria were either finger-like or branched and were encased with callose-like material. Most encasements were thickened at the proximal regions of haustoria but were thinner along the distal portions. Vesicles were present in host cytoplasm and were occasionally attached to the invaginated host plasmalemma. These vesicles might contribute to the deposition of the encasement material. The encasement stained positively for callose using aniline blue; calcofluor and toluidine blue O tests for cellulose were inconclusive, and lignin was not detected using toluidine blue O or phloroglucinol–HCl.

Immunocytochemical localization of tomato pectinesterase in root cells of tomato plants infected by Fusarium oxysporum f.sp. radicis-lycopersici

1991 ◽  
Vol 69 (6) ◽  
pp. 1265-1274 ◽  
Author(s):  
Hélène Chamberland ◽  
G. B. Ouellette ◽  
F. J. Pauzé ◽  
P. M. Charest
Keyword(s):  
Fusarium Oxysporum ◽  
Polyclonal Antibodies ◽  
Ultrastructural Localization ◽  
Coating Material ◽  
Immunocytochemical Localization ◽  
Intercellular Spaces ◽  
Host Reaction ◽  
Root Cells ◽  
Tomato Plants ◽  
Host Origin

Polyclonal antibodies produced against a purified commercial pectinesterase obtained from tomato plants permitted ultrastructural localization of this enzyme in the roots of young tomato plants infected by Fusarium oxysporum f.sp. radicis-lycopersici Jarvis & Shoemaker. In inoculated susceptible cultivars, gold labeling for pectinesterase was intense over electrondense material in the cortex intercellular spaces, in altered pit membranes in the vascular cylinder, and in the dense coating material deposited along vessel walls. Contrarily, in resistant or uninoculated susceptible plants, which lacked coating material in vessels, labelling was present but nonabundant in the intercellular spaces. The enzyme was not found in the hyphae, indicating that the labelled pectinesterase was probably of host origin. This study suggests the involvement of the tomato pectinesterase in the host reaction against infection by F. oxysporum f.sp. radicis-lycopersici.Key words: pectinesterase, immunocytochemistry, Fusarium oxysporum f.sp. radicis-lycopersici, tomato.

scholarly journals Compensatory lung growth: protein, DNA and RNA lung contents in undernourished trilobectomized rats

2005 ◽  
Vol 20 (3) ◽  
pp. 219-224
Author(s):  
Raul Lopes Ruiz Júnior ◽  
Lídia Raquel de Carvalho ◽  
Antonio José Maria Cataneo
Keyword(s):  
Small Rna ◽  
Left Lung ◽  
Lung Growth ◽  
Cell Hyperplasia ◽  
Adult Rats ◽  
Compensatory Lung Growth ◽  
Dna And Rna ◽  
Male Wistar Rats ◽  
Similar Content ◽  
The Right

PURPOSE: To demonstrate compensatory lung growth (CLG) by lung contents of proteins, DNA, and RNA in undernourished young adult rats, submitted to pulmonary trilobectomy. METHODS: We used 137 male Wistar rats, randomly distributed into 9 groups; they were submitted to three treatments (control, thoracotomy, and trilobectomy), and sacrificed at three different times (7, 30, and 90 days). In trilobectomy we removed the right median, accessory, and caudal lobes. We studied lung proteins, DNA, and RNA contents. RESULTS: In the cranial lobe and left lung, protein content was higher in trilobectomized rats however there was insufficient CLG to make up for the loss. The increase of DNA in the cranial lobe and left lung of trilobectomized rats was sufficient to compensate for this loss, resulting in a similar content to controls. RNA content in trilobectomized rats, was higher in the cranial lobe and left lung, more efficient in the cranial lobe, but less than in the other groups. CONCLUSION: CLG occurred in trilobectomized rats, probably with cell hyperplasia and little hypertrophy, due to the large DNA compensation and small RNA compensation. This was markedly different to well-nourished animals, who had pronounced hypertrophy.

Abnormal Tissue in Swollen Stemwood of Chamaecyparis Obtusa Sieb. ' Zucco

IAWA Journal ◽  
1985 ◽  
Vol 6 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Katsuji Yamanaka
Keyword(s):  
Moisture Stress ◽  
Chamaecyparis Obtusa ◽  
Wall Layer ◽  
Wall Thickening ◽  
Stem Wood ◽  
Ray Cells ◽  
Secondary Wall Thickening ◽  
Abnormal Cells ◽  
Very High ◽  
Abnormal Tissue

Abnormal tissue which was laid down in the boundary between the annual rings in 1973 and 1974 in the swollen stem wood of Chamaecyparis obtusa Sieb. ' Zucco has been studied. The abnormal tissue was an aggregation of polyhederal-shaped thick-walled parenchyma cells containing dark-coloured deposits, and shaped like radially elongated spindles in transverse section. The axial length of these tissues was very high, measuring 50 to 80 mm longitudinally. The thin-walled tracheids adjacent to the abnormal tissue were collapsed in a region over 20 cells wide radially. The formation of the abnormal tissue containing the darkcoloured deposits, tracheids with additional wall layer and trabeculae, indicate the structure to be caused by injury. It is suggested that moisture stress induced the collapse of tracheids during secondary wall thickening, and thus forming radial fissures which are in turn filled with callus tissue arising from a proliferation of growth from the ray cells. The subsequent swelling appears to be a secondary effect caused by the proliferation of abnormal cells.

Oxygen Bonding in Bismuth Layered Compounds SrBi2Ta2O9

2007 ◽  
Vol 997 ◽  
Author(s):  
Dong Su ◽  
Nan Jiang ◽  
Jianguo Wen ◽  
Jianshe Liu
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
Local Density ◽  
Layered Compounds ◽  
Density Approximation ◽  
Electron Loss ◽  
Density Of State ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Fine Structures ◽  
Z Contrast

AbstractWith the help of the high resolution Z-contrast scanning transmission electron microscopy (STEM), the near edge fine structures of the electron loss spectroscopy (EELS) arises from different layers are investigated in SBT. The EELS spectra are interpreted by comparing with the calculation using linearnized augment plane wave (LAPW) method within the local density approximation (LDA). The oxygen bonding nature in different layers are discussed. In Bi2O2 layer, oxygen 2p state interacted with the Bi 6p state leads to a high t2g state in density of state while in SrTa2O7 layer, oxygen 2p state hybridized with Ta 5d and Sr 5d, which leads a higher eg state than t2g state.

Cytological studies of the M-haustorium of Endocronartium harknessii: morphology and ontogeny

1988 ◽  
Vol 66 (5) ◽  
pp. 974-988 ◽  
Author(s):  
A. A. Hopkin ◽  
J. Reid
Keyword(s):  
Pinus Banksiana ◽  
Phosphotungstic Acid ◽  
Chromic Acid ◽  
Periodic Acid ◽  
Neck Region ◽  
Wall Layer ◽  
Calcofluor White ◽  
Transmission Electron ◽  
Endocronartium Harknessii ◽  
The Matrix

M-haustoria of the endocyclic rust Endocronartium harknessii (J. P. Moore) Y. Hirat. were examined with light and transmission electron microscopy in infected seedlings of Pinus banksiana Lamb. The haustoria developed from unspecialized cells of the intercellular hyphae, each of which appeared capable of producing several haustoria. The haustoria were distinct from the intercellular hyphae in possessing a narrow septate neck region which terminated in a globose haustorial body. Periodic acid – thiocarbohydrazide – silver proteinate and periodic acid – chromic acid – phosphotungstic acid staining provided evidence of an additional wall layer in the haustorial neck not evident in the intercellular hyphae and suggested that the extra-haustorial matrix contained polysaccharides of mixed linkage as well as lipids. However, cellulase extraction and the use of gold-bound wheat-germ lectin showed that neither cellulose nor chitin, respectively, was a component of the matrix. Both the haustoria and the matrix were separated from the host cytoplasm by the extrahaustorial membrane. This membrane stained positively with periodic acid – chromic acid – phosphotungstic acid, while the noninvaginated portion of the host plasmalemma with which it was continuous usually did not. The matrix fluoresced strongly when stained with aniline blue in an apparently compatible reaction. Other stains such as analinonapthalenesulphonic acid and Calcofluor white showed evidence of protein and polysaccharide in the fungal walls. Light and transmission electron microscope observations showed that penetration pegs formed as narrow tubular evaginations of the haustorial mother cell which caused inward displacement of the host cell wall. They retained their peg-like appearance as they entered the cell lumen, but eventually their distal ends enlarged to form typical globose haustorial bodies.

scholarly journals Effect of household bleach on the structure of the sporocyst wall of Toxoplasma gondii

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 68
Author(s):  
Aurélien Dumètre ◽  
Jitender P. Dubey ◽  
David J.P. Ferguson
Keyword(s):  
Toxoplasma Gondii ◽  
Outer Layer ◽  
Wall Layer ◽  
Cross Link ◽  
Oocyst Wall ◽  
Maclura Pomifera ◽  
Transmission Electron ◽  
Household Bleach ◽  
Sporocyst Wall ◽  
Molecular Nature

Toxoplasma gondii oocysts are responsible for food- and water-borne infections in humans worldwide. They are resistant to common chemical disinfectants, including chlorinated products, presumably due to the structure and molecular nature of the oocyst wall but also the sporocyst wall. In this study, we used fluorescence microscopy and transmission electron microscopy to characterise the structure of both the oocyst and sporocyst walls, exposed to household bleach. Bleach removed the outer layer of the oocyst wall and the outer layer of the wall of sporocysts exposed due to rupture of the oocyst wall. The loss of the outer sporocyst wall layer was associated with a decrease in its autofluorescence, which can be linked to the degradation of dityrosine cross-link proteins, and loss of Maclura pomifera lectin-reactive glycoproteins. This study suggests that the inner layers of the oocyst and sporocyst walls are the main structures responsible for the resistance of the parasite to household bleach.

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