Host cell responses in susceptible hard pine tissue infected with Endocronartium harknessii

1988 ◽  
Vol 66 (12) ◽  
pp. 2511-2517 ◽  
Author(s):  
A. A. Hopkin ◽  
J. Reid
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Host Cell ◽  
Pinus Banksiana ◽  
Outer Cortex ◽  
Transmission Electron ◽  
Endocronartium Harknessii ◽  
Host Cell Wall ◽  
Infected Cells ◽  
Hypocotyl Tissue

Compatible interactions between susceptible hypocotyl tissue of Pinus banksiana Lamb, and Endocronartium harknessii (J. P. Moore) Y. Hirat. were studied using light and transmission electron microscopy. Host endoplasmic reticulum was observed to be closely associated with the haustorial body, although staining with silver proteinate failed to show any similarity between the contents of the endoplasmic reticulum and extrahaustorial matrix. The haustorium was also commonly observed to be closely associated with the host nucleus, often indenting the latter, though never in direct contact. Chloroplasts in recently infected cells appeared similar to those in uninfected cells, but in more advanced infections large starch grains were observed in the chloroplasts of the outer cortex; such chloroplasts normally contained little starch. Collars were another common feature of infected cells. Collars were continuous with the host cell wall and reacted to silver proteinate in a similar manner to the cell wall; callose was not evident. Collars were associated with portions of the cell wall that were inwardly displaced by the fungus; however, cytoplasmic vesicles were also observed in association with the collar and possibly contributed to their development.

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.

Ultrastructure of the host–pathogen interface in Arabidopsis thaliana leaves infected by the downy mildew Hyaloperonospora parasitica

2004 ◽  
Vol 82 (7) ◽  
pp. 1001-1008 ◽  
Author(s):  
C W Mims ◽  
E A Richardson ◽  
B F Holt III ◽  
J L Dangl
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Arabidopsis Thaliana ◽  
High Pressure ◽  
Cell Wall ◽  
Host Cell ◽  
Hyaloperonospora Parasitica ◽  
Transmission Electron ◽  
Host Pathogen ◽  
Host Cell Wall

Transmission electron microscopy was used to examine the host–pathogen interface in Arabidopsis thaliana (L.) Heynh. leaves infected by the biotrophic downy mildew pathogen Hyaloperonospora parasitica (Pers.:Fr.) Constant. Both conventionally fixed as well as high-pressure frozen samples were examined. Excellent preservation of the host–pathogen interface was obtained in many of our high-pressure frozen samples and provided information not available in conventionally fixed samples. Mature haustoria of H. parasitica were distinctly pyriform in shape. A small collar of host cell wall material surrounded the neck of each haustorium near the host cell wall penetration site. The presence of callose in collars was demonstrated using immunogold labeling with a monoclonal antibody specific for (1→3)-β-glucans. The body of each haustorium was ensheathed by an invaginated portion of the invaded host-cell plasma membrane known as the extrahaustorial membrane. Lying between this membrane and the haustorial wall was a layer of electron-dense material known as the extrahaustorial matrix (EHM). The EHM typically was thicker at the distal end of a haustorium than at the proximal end. The surface of the EHM covered by the extrahaustorial membrane was highly irregular in outline. Considerable vesicular activity was observed in association with the extrahaustorial membrane.Key words: transmission electron microscopy, high-pressure freezing, haustoria, Peronospora parasitica.

Ultrastructural features of the haustorial apparatus of the white blister fungus Albugo candida

1975 ◽  
Vol 53 (13) ◽  
pp. 1285-1299 ◽  
Author(s):  
Michael D. Coffey
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Host Cell ◽  
Neck Region ◽  
Distal Portion ◽  
Thin Wall ◽  
Fungal Cell ◽  
White Blister ◽  
Host Cell Wall ◽  
Dark Staining

The small spherical haustorium of the white blister fungus is connected to the much larger haustorial mother cell by a slender cylindrical neck. The haustorium contains mitochondria with tubular cristae as well as ribosomes and occasional cisternae of rough endoplasmic reticulum. Nuclei and perinuclear dictyosomes are found in the mother cells but are absent from haustoria. No discontinuity is found in the fungal cell wall in the haustorial neck. Immediately adjacent to the fungal wall and extending through the penetration site to a point about midway along the neck is a dark-staining layer continuous with the host cell wall. A collar consisting of fibrillar material, also continuous with the host cell wall, is commonly found around the proximal portion of the neck external to this dark-staining layer. An electron-dense sheath surrounds the thin wall of the haustorial body but is absent from the neck region. A series of tubules is continuous with the invaginated host plasmalemma which surrounds the haustorial body. These tubules contain an electron-dense core similar in appearance to, and continuous with, the sheath matrix. No evidence was obtained for the involvement of host dictyosomes and their secretory vesicles in the formation of the haustorial sheath. A constant feature of the haustorial apparatus is the association of flattened cisternae of host endoplasmic reticulum with the distal portion of the haustorial neck. The significance of this finding is discussed in relation to the endomembrane concept.

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.

scholarly journals Comparative Transcriptomic Analysis of Race 1 and Race 4 of Fusarium oxysporum f. sp. cubense Induced with Different Carbon Sources

2017 ◽  
Vol 7 (7) ◽  
pp. 2125-2138 ◽  
Author(s):  
Shiwen Qin ◽  
Chunyan Ji ◽  
Yunfeng Li ◽  
Zhenzhong Wang
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Fusarium Oxysporum ◽  
Host Cell ◽  
Expression Profiles ◽  
Cell Wall Polysaccharide ◽  
Host Cell Wall ◽  
Race 1 ◽  
Race 4 ◽  
Banana Cultivar

Abstract The fungal pathogen Fusarium oxysporum f. sp. cubense causes Fusarium wilt, one of the most destructive diseases in banana and plantain cultivars. Pathogenic race 1 attacks the “Gros Michel” banana cultivar, and race 4 is pathogenic to the Cavendish banana cultivar and those cultivars that are susceptible to Foc1. To understand the divergence in gene expression modules between the two races during degradation of the host cell wall, we performed RNA sequencing to compare the genome-wide transcriptional profiles of the two races grown in media containing banana cell wall, pectin, or glucose as the sole carbon source. Overall, the gene expression profiles of Foc1 and Foc4 in response to host cell wall or pectin appeared remarkably different. When grown with host cell wall, a much larger number of genes showed altered levels of expression in Foc4 in comparison with Foc1, including genes encoding carbohydrate-active enzymes (CAZymes) and other virulence-related genes. Additionally, the levels of gene expression were higher in Foc4 than in Foc1 when grown with host cell wall or pectin. Furthermore, a great majority of genes were differentially expressed in a variety-specific manner when induced by host cell wall or pectin. More specific CAZymes and other pathogenesis-related genes were expressed in Foc4 than in Foc1 when grown with host cell wall. The first transcriptome profiles obtained for Foc during degradation of the host cell wall may provide new insights into the mechanism of banana cell wall polysaccharide decomposition and the genetic basis of Foc host specificity.

scholarly journals Extracellular Polysaccharides from Xanthomonas axonopodis pv. manihotis Interact with Cassava Cell Walls During Pathogenesis

1997 ◽  
Vol 10 (7) ◽  
pp. 803-811 ◽  
Author(s):  
B. Boher ◽  
M. Nicole ◽  
M. Potin ◽  
J. P. Geiger
Keyword(s):  
Cell Wall ◽  
Monoclonal Antibodies ◽  
Host Cell ◽  
Cell Walls ◽  
Plant Cell Wall ◽  
Infection Process ◽  
Extracellular Polysaccharides ◽  
Xanthomonas Axonopodis ◽  
Cassava Leaves ◽  
Host Cell Wall

The location of lipopolysaccharides produced by Xanthomonas axonopodis pv. manihotis during pathogenesis on cassava (Manihot esculenta) was determined by fluorescence and electron microscopy immunolabeling with monoclonal antibodies. During the early stages of infection, pathogen lipopolysaccharides were detected on the outer surface of the bacterial envelope and in areas of the plant middle lamellae in the vicinity of the pathogen. Later in the infection process, lipopolysaccharide-specific antibodies bound to areas where the plant cell wall was heavily degraded. Lipopolysaccharides were not detected in the fibrillar matrix filling intercellular spaces of infected cassava leaves. Monoclonal antibodies specific for the exopolysaccharide xanthan side chain labeled the bacteria, the fibrillar matrix, and portions of the host cell wall. The association of Xanthomonas lipopolysaccharides with host cell walls during plant infection is consistent with a role of these bacterial extracellular polysaccharides in the infection process.

Ultrastructure of compatible and incompatible reactions of sunflower to Plasmopara halstedii

1979 ◽  
Vol 57 (4) ◽  
pp. 315-323 ◽  
Author(s):  
Glenn Wehtje ◽  
Larry J. Littlefield ◽  
David E. Zimmer
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Host Cell ◽  
Epidermal Cell ◽  
Cortical Cell ◽  
Hypersensitive Reaction ◽  
Host Cells ◽  
Plasmopara Halstedii ◽  
Host Cell Wall ◽  
Host Plasma Membrane

Penetration of sunflower, Heliantluis animus, root epidermal cells by zoospores of Plasmopara halstedii is preceded by formation of a papilla on the inner surface of the host cell wall that invaginates the host plasma membrane. Localized degradation and penetration of the host cell wall by the pathogen follow. The invading fungus forms an allantoid primary infection vesicle in the penetrated epidermal cell. The host plasma membrane invaginates around the infection vesicle but its continuity is difficult to follow. Upon exit from the epidermal cell the fungus may grow intercellularly, producing terminal haustorial branches which extend into adjacent host cells. The fungus may grow through one or two cortical cell is after growing from the epidermal cell before it becomes intercellular. Host plasma membrane is not penetrated by haustoria. Intercellular hyphae grow toward the apex of the plant and ramify the seedling tissue. Resistance in an immune cultivar is hypersensitive and is triggered upon contact of the host cell with the encysting zoospore before the host cell wall is penetrated. Degeneration of zoospore cytoplasm accompanies the hypersensitive reaction of the host. Zoospores were often parasitized by bacteria and did not germinate unless penicillin and streptomycin were added to the inoculum suspension.

Host cell wall synthesis and its role in resistance to a mycoparasite

1982 ◽  
Vol 20 (2) ◽  
pp. 157-164 ◽  
Author(s):  
M.S. Manocha ◽  
Lori L. Graham
Keyword(s):  
Cell Wall ◽  
Host Cell ◽  
Cell Wall Synthesis ◽  
Host Cell Wall

Interrelations between the Parasitophorous Vacuole ofToxoplasma gondiiand Host Cell Organelles

2005 ◽  
Vol 11 (2) ◽  
pp. 166-174 ◽  
Author(s):  
Rodrigo Cardoso Magno ◽  
Lorian Cobra Straker ◽  
Wanderley de Souza ◽  
Marcia Attias
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Host Cell ◽  
Fluorescent Probes ◽  
Parasitophorous Vacuole ◽  
Laser Scanning Microscopy ◽  
Cell Organelles ◽  
Apical Side ◽  
Transmission Electron

Toxoplasma gondii, the causative agent of toxoplasmosis, is capable of actively penetrating and multiplying in any nucleated cell of warm-blooded animals. Its survival strategies include escape from fusion of the parasitophorous vacuole with host cell lysosomes and rearrangement of host cell organelles in relation to the parasitophorous vacuole. In this article we report the rearrangement of host cell organelles and elements of the cytoskeleton of LLCMK2 cells, a lineage derived from green monkey kidney epithelial cells, in response to infection byT. gondiitachyzoites. Transmission electron microscopy made on flat embedded monolayers cut horizontally to the apical side of the cells or field emission scanning electron microscopy of monolayers scraped with scotch tape before sputtering showed that association of mitochondria to the vacuole is much less frequent than previously described. On the other hand, all parasitophorous vacuoles were surrounded by elements of the endoplasmic reticulum. These data were complemented by observations by laser scanning microscopy using fluorescent probes from mitochondria and endoplasmic reticulum and reinforced by three-dimensional reconstruction from serial sections observed by transmission electron microscopy and labeling of mitochondria and endoplasmic reticulum by fluorescent probes.

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