The temporal relationship between the development of intracellular hyphae and haustoria by Physopella zeae in Zea mays

1988 ◽  
Vol 66 (4) ◽  
pp. 742-744 ◽  
Author(s):  
Michèle C. Heath ◽  
M. R. Bonde
Keyword(s):  
Plant Cell ◽  
Mother Cell ◽  
Plant Cell Wall ◽  
Rust Fungus ◽  
Morphological Differentiation ◽  
Adjacent Cell ◽  
Previous Suggestion ◽  
Epidermal Tissue ◽  
Developmental Relationship ◽  
Mother Cells

To investigate the developmental relationship between haustoria and intracellular hyphae, fixed and cleared whole mounts of com leaves infected with the tropical corn rust fungus Physopella zeae (Mains) Cumm. & Ramachar were examined by interference contrast light microscopy. Haustoria were clearly distinguished from intracellular hyphae by their morphological differentiation into a filamentous body and a narrow neck. The latter was encircled by a thin neckband, which appeared to develop in young haustoria at the time when the haustorial body started to expand. Observations made at the colony margins suggested that the fungus grew into uninvaded epidermal tissue in the following sequence: (i) formation of a haustorium from a haustorial mother cell in an adjacent cell, (ii) formation of an intracellular hypha next to the haustorium by the same intracellular hypha that had formed the haustorial mother cell, (iii) growth of the intracellular hypha within the newly invaded plant cell, (iv) formation by the intracellular hyphae of haustorial mother cells against the plant cell wall adjacent to an uninvaded cell, and (v) formation of haustoria in the uninvaded cell. These results support the previous suggestion that the haustorium may induce a state of susceptibility in the plant cell, "paving the way" for invasion by the intracellular hyphae.

Microsurgical isolation of intact plant cell wall appositions for microanalyses

1979 ◽  
Vol 57 (12) ◽  
pp. 1349-1353 ◽  
Author(s):  
Hitoshi Kunoh ◽  
James R. Aist ◽  
Herbert W. Israel
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Analytical Techniques ◽  
Chemical Components ◽  
Specimen Preparation ◽  
Low Frequencies ◽  
Wall Appositions ◽  
Wall Apposition ◽  
Mother Cells

Little is known about the chemical components of the plant cell wall apposition as they relate to its structure and function. The small sizes (5–15 μm diameter) of the appositions, their low frequencies in the cells, and their intimate connections to the cell wall have almost precluded meaningful cytochemical and (or) biochemical analyses. With the development of analytical techniques using the electron microprobe it is now feasible to discover the elemental composition of minute cellular structures, such as the wall apposition, but problems in specimen preparation remain. As a necessary and critical first step in microprobe analysis we have found it best to microsurgically remove fresh wall appositions from their mother cells and then admit them directly into the scanning electron microscope (SEM) after air drying and gold coating. This paper describes the requisite technologies of specimen preparation, microtool fabrication, specimen selection and isolation which are involved. The technique described could find ready application in the microanalyses of many other subcellular structures.

Haustorial mother cell development by Uromyces vignae on collodion membranes

1988 ◽  
Vol 66 (4) ◽  
pp. 736-741 ◽  
Author(s):  
Michèle C. Heath ◽  
C. J. Perumalla
Keyword(s):  
Cell Wall ◽  
Mother Cell ◽  
Rust Fungus ◽  
Potential Binding ◽  
Disulphonic Acid ◽  
Uromyces Vignae ◽  
Mother Cells ◽  
Chloroform Methanol ◽  
Infection Hypha ◽  
Mother Cell Wall

The development of infection structures by the rust fungus Uromyces vignae was observed on oil-containing collodion membranes. About 40% of infection hyphae formed a haustorial mother cell, but this structure commonly senesced and died more rapidly than the infection hypha to which it was attached. These data suggest that the continued development of the haustorial mother cell requires some component normally provided by the host plant. Before they died, many haustorial mother cells apparently formed the thickened region of the wall which normally is traversed by the penetration peg during haustorium formation. Such a peg was observed in the centre of up to 40% of these thickened regions. However, no pegs protruded beyond the haustorial mother cell far enough to be called a haustorial neck. The thickened region of the haustorial mother cell wall could be differentiated from the rest of the wall by its lack of fluorescence under ultraviolet irradiation when mounted in Calcofluor or SITS (4-acetomido-4′-iso-thiocyanatostilbene-2,2′-disulphonic acid). Treatment with alkali, acid, chloroform–methanol, protease, and laminarinase did not affect this differential fluorescence, and the haustorial mother cell wall stained uniformly for proteins, carbohydrates, and chitin. Since Calcofluor normally binds to chitin, these data suggest that the thickened region of the haustorial mother cell wall may physically exclude the dye or may contain potential binding sites that are masked by other wall components.

Ultrastructure of the early stages of infection of peanut leaves by the rust fungus Puccinia arachidis

1989 ◽  
Vol 67 (12) ◽  
pp. 3570-3579 ◽  
Author(s):  
C. W. Mims ◽  
J. Taylor ◽  
E. A. Richardson
Keyword(s):  
Host Cell ◽  
Mother Cell ◽  
Primary Infection ◽  
Rust Fungus ◽  
Mitotic Division ◽  
Infection Process ◽  
Rust Disease ◽  
Puccinia Arachidis ◽  
Mother Cells ◽  
Infection Hypha

Peanut rust disease proved to be an excellent system for ultrastructural study of development of infection structures by the fungus Puccinia arachidis. Fungal structures were clearly visible by light microscopy in fixed and embedded samples and could be located either on leaf surfaces or within the large substomatal chambers of peanut leaves. Samples could easily be oriented for thin sectioning. The infection process was a highly orchestrated process involving precisely timed events and highly specialized structures. Infection pegs developed from appressoria over stomata and entered the leaf by growing into the openings between guard cells. Once past the rim formed by the guard cell walls, the infection peg expanded to form a substomatal vesicle in which a synchronous mitotic division of the four nuclei occurred. A primary infection hypha then developed from the vesicle and grew into the mesophyll of the leaf until its tip or side contacted a host cell. A septum then delimited a binucleate or trinucleate terminal haustorial mother cell from the remainder of the infection hypha. The wall of the haustorial mother cell became closely appressed to that of the host cell. Following differentiation of the haustorial mother cell, a penetration peg arose from it and penetrated the host cell wall. The peg invaginated the host cell plasma membrane as it elongated and then expanded at its tip to form the haustorium body into which most of the contents of the haustorial mother cell moved. Meanwhile, the primary infection hypha formed secondary hyphae that gave rise to additional haustorial mother cells and haustoria. Key words: Puccinia arachidis, peanut rust, infection process, ultrastructure.

scholarly journals Targeted Cell Wall Degradation at the Penetration Site of Cowpea Rust Basidiosporelings

1997 ◽  
Vol 10 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Haixin Xu ◽  
Kurt Mendgen
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Rust Fungus ◽  
Wall Material ◽  
Wall Structure ◽  
Polygalacturonic Acid ◽  
Similar Reduction ◽  
Nonhost Plant ◽  
Wall Apposition

Basidiospore germlings of the cowpea rust fungus (Uromyces vignae) penetrate the epidermal cell wall of the nonhost plant Vicia faba. In order to characterize the wall structure of the penetration site, leaves were high pressure frozen, freeze substituted, and embedded in appropriate resins. With antibodies against epitopes present in pectin, polygalacturonic acid, xyloglucan, and callose, we studied the modification of these wall components during infection. The density of epitopes was determined at the penetration site and compared with noninfected areas of the epidermal wall. Along the fungal penetration hypha, a zone of the plant wall, 0.2 μm wide, exhibited a reduced density of pectin and xyloglucan epitopes. A similar reduction of epitope density was also found for xyloglucan after treatment of sections from noninoculated plants with cellulase and xylanase and for pectin after treatment with pectinase. The density of polygalacturonic acid epitopes remained unchanged in the outer layer of the epidermal wall, but increased over the inner layer. A high density of polygalacturonic acid epitopes was found over a collarlike wall apposition produced by the plant cell along the penetration hypha. These results indicate that the fungus degrades the plant cell wall at the penetration site and that the plant cell secretes new wall material into this area to form the wall apposition.

Ultrastructural observations of the rust fungus Physopella zeae in Zea mays

1983 ◽  
Vol 61 (8) ◽  
pp. 2231-2242 ◽  
Author(s):  
Michèle C. Heath ◽  
M. R. Bonde
Keyword(s):  
Plant Cell Wall ◽  
Rust Fungus ◽  
Plant Cells ◽  
Similar Material ◽  
Mesophyll Cells ◽  
Intracellular Location ◽  
Transmission Electron ◽  
The Matrix ◽  
Ultrastructural Characteristics ◽  
Mother Cells

Examination of sporulating uredia of the tropical corn rust fungus, Physopella zeae, with the transmission electron microscope revealed that this fungus possessed most of the distinguishing ultrastructural characteristics reported for temperate zone inhabiting members of the Uredinales. Physopella zeae differed from these latter fungi in the repeated production of urediospores from the same site on the sporogenous cell, and in the intracellular location of most of the mycelium. The intracellular mycelium was differentiated into structurally unspecialized hyphae and structurally distinct haustoria arising from differentiated haustorial mother cells which were located in the neighbouring host cell. Both types of intracellular structures were covered with a matrix, and that around the intracellular hyphae was continuous with similar material lining the plant cell wall. The matrix was thicker and more compact around intracellular hyphae than around the bodies of haustoria. The matrix lining the host walls was thinnest in sections of mesophyll cells containing a ratio of haustoria – intracellular hyphae profiles greater than one. These data suggest that the haustorium may actively inhibit matrix formation in invaded plant cells.

scholarly journals Differentiation of aecidiospore- and uredospore-derived infection structures on cowpea leaves and on artificial surfaces by Uromyces vignae

1993 ◽  
Vol 71 (9) ◽  
pp. 1236-1242 ◽  
Author(s):  
M. Stark-Urnau ◽  
K. Mendgen
Keyword(s):  
Key Words ◽  
Mother Cell ◽  
Host Plants ◽  
Rust Fungus ◽  
Host Cells ◽  
In Planta ◽  
Infection Structures ◽  
Artificial Surfaces ◽  
Uromyces Vignae ◽  
Mother Cells

Aecidiospores and uredospores are the two dikaryotic spore forms of the cowpea rust fungus Uromyces vignae. After germination they can be induced to develop a series of infection structures including appressoria, infection hyphae, and haustorial mother cells. Haustoria are then formed within host cells. The differentiation of infection structures was compared on polystyrene membranes with defined topographies, on scratched polyethylene membranes, and in planta. On polystyrene membranes with defined topographies both sporelings showed highest rates of differentiation on ridges 0.3 μm high but aecidiosporelings responded less efficiently to this stimulus than uredosporelings. On scratched polyethylene membranes, almost 90% of both sporelings differentiated appressoria, but only 10% formed haustorial mother cells; haustoria were not observed. On the host plant, by contrast, only 50% of the sporelings differentiated appressoria, but most of these formed haustorial mother cells and haustoria. In planta haustorial mother cell development occurred approximately 6 h earlier than on inductive membranes. Infection structures formed on artificial membranes and on host plants were similar in morphology and nuclear condition. Key words: cowpea rust fungus, nucleus, appressorium.

In vitro formation of haustoria of the cowpea rust fungus Uromyces vignae in the absence of a living plant cell. II. Electron microscopy

1990 ◽  
Vol 68 (2) ◽  
pp. 278-287 ◽  
Author(s):  
Michèle C. Heath
Keyword(s):  
Plant Cell ◽  
Rust Fungus ◽  
Periodic Acid ◽  
Outer Wall ◽  
Wall Layer ◽  
Living Plant ◽  
Uromyces Vignae ◽  
Mother Cells ◽  
Extrahaustorial Matrix

The ultrastructure of infection hyphae, haustorial mother cells, and haustoria of Uromyces vignae formed on collodion membranes is described after conventional preparation and after treatment with periodic acid – thiocarbonhydrazide – silver proteinate or periodic acid – chromic acid – phosphotungstic acid treatments. Infection hyphae and haustorial mother cells developed normally in vitro but lacked an outer wall layer present in older infections in the host plant. Haustorium formation in vitro was accompanied by the development of elaborations of the plasmalemma along the infection hypha side of the haustorial mother cell septum, but their contents did not show identical staining responses to the haustorial neck wall as reported for other rust fungus species. Haustorial necks, and to a lesser extent haustorial bodies, were coated with a fibrillar material, the staining characteristics of which were similar to material normally considered part of the extrahaustorial matrix in infected plants. The restriction of this material to the haustorium suggests that it may play an important role in the interaction between the haustorium and the plant cell.

Cytochemical studies on Puccinia graminis f. sp. tritici in a compatible wheat host. I. Walls of intercellular hyphal cells and haustorium mother cells

1985 ◽  
Vol 63 (10) ◽  
pp. 1713-1724 ◽  
Author(s):  
J. Chong ◽  
D. E. Harder ◽  
R. Rohringer
Keyword(s):  
Concanavalin A ◽  
Mother Cell ◽  
Cell Walls ◽  
Lectin Binding ◽  
Rust Fungus ◽  
Hydroxyl Groups ◽  
Protease Treatment ◽  
Wheat Leaves ◽  
Formed Part ◽  
Mother Cells

Walls of intercellular hyphae and haustorium mother cells of the stem rust fungus in wheat leaves were studied cytochemically using lectin probes, periodate – thiocarbohydrazide – silver proteinate or periodate–chromate–phosphotungstate staining, and protease treatment. Up to six possible layers in the haustorium mother cell walls and four in the hyphal walls were resolved. Three outer layers of the haustorium mother cell walls were continuous with the three outer layers of the hyphal walls. The two innermost layers of the haustorium mother cell walls were not continuous with the hyphal walls but formed part of the septum. These two layers differed from the other layers of the haustorium mother cell walls in having no affinity to concanavalin A. In both hyphal and haustorium mother cell walls, components with an affinity for concanavalin A were extractable with protease treatment. Wheat-germ lectin binding occurred throughout the fungal walls except in the two outermost layers. Periodate-sensitive glycosubstances were also common, but the amounts varied among layers. Although some of these glycosubstances were confirmed as polysaccharides containing sugars with vicinal hydroxyl groups, much of the glycosubstances present in the walls was sensitive to protease treatment, indicating a possible glycoprotein composition.

An ultrastructural comparison of monokaryotic and dikaryotic haustoria formed by the fusiform rust fungus Cronartium quercuum f.sp. fusiforme

1982 ◽  
Vol 60 (12) ◽  
pp. 2914-2922 ◽  
Author(s):  
D. J. Gray ◽  
H. V. Amerson ◽  
C. G. Van Dyke
Keyword(s):  
Cell Wall ◽  
Host Cell ◽  
Pinus Taeda ◽  
Mother Cell ◽  
Rust Fungus ◽  
Neck Region ◽  
Cronartium Quercuum ◽  
Host Cell Wall ◽  
Mother Cells ◽  
Mother Cell Wall

Haustoria formed by the monokaryotic stage of Cronartium quercuum f. sp. fusiforme in Pinus taeda differed from those of the dikaryotic phase in Quercus rubra. Monokaryotic (M) haustorial walls were continuous with the walls of relatively undifferentiated haustorial mother cells. The septate M-haustorial neck and expanded M-haustorial body were separated from the invaginated host plasmalemma by a sheath which was continuous with the host cell wall. Collars encasing sheaths were infrequently observed. Dikaryotic (D) haustoria were morphologically similar to M-haustoria; however, they differed in several respects when examined with TEM. The D-haustorial mother cell wall was thickened at the penetration site but a reduction in the number of wall layers occurred between the thickened portion of the mother cell and the D-haustorium. A darkly staining neckband was present in the wall of the nonseptate D-haustorial neck but was lacking in the M-haustorium. An extensive sheath separated the invaginated host plasmalemma from the D-haustorial wall distally from the neckband. However, the sheath was separated from the D-haustorial wall and from the host cell wall by an invaginated host plasmalemma doubled in the haustorial neck region proximally from the neckband.

A participation of weak-bound with plant cell wall peroxidases in ring rot tolerance of wild Mexican species and cultural varieties of potato

2014 ◽  
pp. 103-108
Author(s):  
M.A. Zhivetiev ◽  
◽  
A.V. Papkina ◽  
I.A. Graskova ◽  
V.K. Voinikov ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Ring Rot ◽  
Mexican Species
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