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.

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.

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 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.

scholarly journals Phylogenetic and comparative functional analysis of the cell-separation α-glucanase Agn1p in Schizosaccharomyces

Microbiology ◽  
2014 ◽  
Vol 160 (6) ◽  
pp. 1063-1074 ◽  
Author(s):  
Matthias Sipiczki ◽  
Anita Balazs ◽  
Aniko Monus ◽  
Laszlo Papp ◽  
Anna Horvath ◽  
...  
Keyword(s):  
Cell Wall ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Mother Cell ◽  
Cell Separation ◽  
Yeast Cells ◽  
Glycoside Hydrolase Family ◽  
Binding Domains ◽  
Yeast Phase ◽  
Mother Cell Wall

The post-cytokinetic separation of cells in cell-walled organisms involves enzymic processes that degrade a specific layer of the division septum and the region of the mother cell wall that edges the septum. In the fission yeast Schizosaccharomyces pombe, the 1,3-α-glucanase Agn1p, originally identified as a mutanase-like glycoside hydrolase family 71 (GH71) enzyme, dissolves the mother cell wall around the septum edge. Our search in the genomes of completely sequenced fungi identified GH71 hydrolases in Basidiomycota, Taphrinomycotina and Pezizomycotina, but not in Saccharomycotina. The most likely Agn1p orthologues in Pezizomycotina species are not mutanases having mutanase-binding domains, but experimentally non-characterized hypothetical proteins that have no carbohydrate-binding domains. The analysis of the GH71 domains corroborated the phylogenetic relationships of the Schizosaccharomyces species determined by previous studies, but suggested a closer relationship to the Basidiomycota proteins than to the Ascomycota proteins. In the Schizosaccharomyces genus, the Agn1p proteins are structurally conserved: their GH71 domains are flanked by N-terminal secretion signals and C-terminal sequences containing the conserved block YNFNAY/HTG. The inactivation of the agn1Sj gene in Schizosaccharomyces japonicus, the only true dimorphic member of the genus, caused a severe cell-separation defect in its yeast phase, but had no effect on the hyphal growth and yeast-to-mycelium transition. It did not affect the mycelium-to-yeast transition either, only delaying the separation of the yeast cells arising from the fragmenting hyphae. The heterologous expression of agn1Sj partially rescued the separation defect of the agn1Δ cells of Schizosaccharomyces pombe. The results presented indicate that the fission yeast Agn1p 1,3-α-glucanases of Schizosaccharomyces japonicus and Schizosaccharomyces pombe share conserved functions in the yeast phase.

scholarly journals Macromolecules released into the culture medium during the vegetative cell cycle of the unicellular green alga Chlamydomonas reinhardii

1985 ◽  
Vol 226 (1) ◽  
pp. 259-268 ◽  
Author(s):  
J Voigt
Keyword(s):  
Cell Cycle ◽  
Cell Wall ◽  
Cell Growth ◽  
Mother Cell ◽  
Culture Medium ◽  
Cell Enlargement ◽  
Chlamydomonas Reinhardii ◽  
Time Period ◽  
Protein Components ◽  
Mother Cell Wall

The culture medium of growing Chlamydomonas reinhardii cells contains hydroxyproline-rich glycoproteins, which are mainly liberated during release of the zoospores from the mother-cell wall. Pulse-labelling studies with [3H]proline and [35S]methionine have been performed in order to detect the protein components released by synchronously growing cells at different stages of the cell cycle. When either [3H]proline or [35S]methionine were applied during the phase of cell growth, radioactive label appeared in the released macromolecules after a lag period of 40 min, whereas incorporation into the insoluble part of the cell wall was delayed only by 20 min. When applied at the end of the growth phase, e.g. 13 h after beginning of the illumination period, the radioactive amino acids were incorporated into the cell wall, but radioactive labelling of macromolecules released into the culture medium could not be detected before the zoospores were liberated from the mother-cell wall. Maximal incorporation of [3H]proline and [35S]methionine into the insoluble part of the cell wall was observed during cell division, but essentially no radioactively-labelled macromolecules were released into the culture medium during this time period. Analysis of the macromolecules, which were liberated during cell enlargement, by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis revealed distinct radioactive bands, which were differentially labelled with [3H]proline and [35S]methionine. Among the macromolecules released into the culture medium during cell growth, a component of an apparent Mr 35 000 was preferentially labelled with [3H]proline. This component was also detected after labelling with [35S]methionine, but components of an apparently higher Mr were more prominent after labelling with [35S]methionine. Macromolecules released during the cell-enlargement period of synchronously growing cultures in the presence of [3H]proline contained radioactively-labelled hydroxyproline in addition to proline. These results show that, during cell-wall growth, specific protein components are released into the culture medium and that at least one of these components contains large amounts of proline and hydroxyproline. At least some of these macromolecules seem to be constituents of the cell wall, because during pulse-chase experiments radioactively-labelled macromolecules appeared in the culture medium mainly during the time period when the specific radioactivity of the insoluble inner-cell-wall layer decreased.

Differentiation and cell wall degrading enzymes in the obligately biotrophic rust fungus Uromyces viciae-fabae

1995 ◽  
Vol 73 (S1) ◽  
pp. 624-631 ◽  
Author(s):  
Holger Deising ◽  
Martina Rauscher ◽  
Marc Haug ◽  
Stefan Heiler
Keyword(s):  
Cell Wall ◽  
Rust Fungus ◽  
Cell Wall Degrading Enzymes ◽  
Chitin Deacetylase ◽  
Infection Structure ◽  
Degrading Enzymes ◽  
Successful Infection ◽  
Serine Esterases ◽  
Polygalacturonate Lyase ◽  
Mother Cells

Rust fungi differentiate a series of complex infection structures to infect their host plants. Artificial membranes providing a signal for the induction of infection structure differentiation have been used to study events taking place during early stages of host–pathogen interaction. During the prepenetration phase, serine esterases, one of which shows cutinase activity, appear to be important for adhesion of uredospores of Uromyces viciae-fabae to the plant cuticle. When the fungus grows through the stomatal opening, chitin deacetylase activity increases drastically. The role of this enzyme in masking and preventing degradation of fungal structures by plant chitinases is discussed. Different isoforms of protease, cellulase, and pectin methylesterases (PME) are formed when the fungus enters the intercellular space, and synthesis of polygalacturonate lyase (PL) coincides with formation of haustorial mother cells. Based on the physicochemical and catalytic properties of these cell wall degrading enzymes a model is presented that explains highly localized breaching of plant cell walls by obligate biotrophs. cDNAs corresponding to genes activated during late stages of infection structure differentiation of Uromyces viciae-fabae have been isolated by differential hybridization. The transcripts of the genes designated rif16 and rif21 occur when haustorial mother cells are formed, and the corresponding gene products may thus be important for successful infection. Key words: adhesion, cell wall degrading enzymes, chitin deacetylase, infection structure differentiation, penetration process, rif genes.

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.

scholarly journals On a Malay Form of Chlorococcum humicola (Näg.), Rabenh

1919 ◽  
Vol 44 (299) ◽  
pp. 473-482 ◽  
Author(s):  
B. Muriel Bristol
Keyword(s):  
Cell Wall ◽  
Mother Cell ◽  
Cell Walls ◽  
Starch Granules ◽  
Red Pigment ◽  
Vegetative Cells ◽  
Daughter Cells ◽  
Set Up ◽  
Mother Cell Wall ◽  
Adult Cells

Summary The material described has been obtained from cultures of a sample of dried soil, which was sent from the Malay States about two years before the cultures were set up. The vegetative cells are spherical or subspherical, solitary or collected together into mucilaginous strata, very variable in size, being from 20–80 μ in diameter, each with a thin cellulose cell-wall and a single parietal chloroplast containing from one to several pyrenoids and numerous starch granules. In adult cells a quantity of yellow oil is stored, in which a bright red pigment is often dissolved. The cytoplasm is reticulate. The young cells contain a single minute nucleus and one pyrenoid, both of which multiply by repeated division so that the adult cells are cœnocytic with many pyrenoids. Propagation takes place, by successive bipartition of the contents of the mother-cell, into 8–16 or numerous biciliate zoogonidia which may develop asexually or may act as facultative gametes. In both cases direct development into vegetative cells takes place. Aplanospore-formation may also take place, preceded by the multiplication by constriction of the nuclei of the mother-cell. The aplanospores remain imbedded in a mucous stratum, and enter into a palmelloid state in which further bipartitions may take place. Eventually, the palmelloid cells either acquire cilia and behave as normal zoogonidia or they develop directly into vegetative cells. True vegetative division does not take place, but the cell-contents may divide into two daughter-cells which immediately acquire new cell-walls and are set free as vegetative cells by the dissolution of the mother-cell-wall. Chloroaoccum humicola, differing in no essential particulars from that in the Malay soil, has been found to occur almost universally in English soils. The limit of its resistance against desiccation and of its retention of vitality has been shown, by investigations on long-dried English soils, to lie somewhere between seventy and eighty years. In conclusion, I wish to express my thanks to Professor G. S. West for his valuable help throughout this work.

Cell Volume and the Control of the Chlamydomonas Cell Cycle

1982 ◽  
Vol 54 (1) ◽  
pp. 173-191 ◽  
Author(s):  
R. A. CRAIGIE ◽  
T. CAVALIER-SMITH
Keyword(s):  
Cell Cycle ◽  
Cell Wall ◽  
Cell Division ◽  
Simple Model ◽  
Cell Volume ◽  
Mother Cell ◽  
Dark Period ◽  
Size Fractions ◽  
Daughter Cells ◽  
Mother Cell Wall

Chlamydomonas reinhardii divides by multiple fission to produce 2n daughter cells per division burst, where n is an integer. By separating predivision cells from synchronous cultures into fractions of differing mean cell volumes, and electronically measuring the numbers and volume distributions of the daughter cells produced by the subsequent division burst, we have shown that n is determined by the volume of the parent cell. Control of n can occur simply, if after every cell division the daughter cells monitor their volume and divide again if, and only if, their volume is greater than a fixed minimum value. In cultures synchronized by 12-h light/12-h dark cycles, the larger parent cells divide earlier in the dark period than do smaller cells. This has been shown by two independent methods: (1) by separating cells into different size fractions by Percoll density-gradient centrifugation and using the light microscope to see when they divide; and (2) by studying changes in the cell volume distribution of unfractioned cultures. Since daughter cells remain within the mother-cell wall for some hours after cell division, and cell division causes an overall swelling of the mother-cell wall, the timing of division can be determined electronically by measuring this increase in cell volume that occurs in the dark period in the absence of growth; we find that cells at the large end of the size distribution range undergo this swelling first, and are then followed by successively smaller size fractions. A simple model embodying a sizer followed by a timer gives a good quantitative fit to these data for 12-h light/12-h dark cycles if cell division occurs 12-h after attaining a critical volume of approximately 140 μm3. However, this simple model is called into question by our finding that alterations in the length of the light period alter the rate of progress towards division even of cells that have attained their critical volume. We discuss the relative roles of light and cell volume in the control of division timing in the Chlamydomonas cell cycle.

RELATIONSHIP BETWEEN PRESENCE OF A MOTHER CELL WALL AND SPECIATION IN THE UNICELLULAR MICROALGANANNOCHLORIS(CHLOROPHYTA)1

2003 ◽  
Vol 39 (1) ◽  
pp. 172-184 ◽  
Author(s):  
Maki Yamamoto ◽  
Hisayoshi Nozaki ◽  
Yutaka Miyazawa ◽  
Tomojiro Koide ◽  
Shigeyuki Kawano
Keyword(s):  
Cell Wall ◽  
Mother Cell ◽  
Mother Cell Wall
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