Tetrad pollen formation in quartet mutants of Arabidopsis thaliana is associated with persistence of pectic polysaccharides of the pollen mother cell wall

The cell wall at the tetrad stage in <em>Convallaria majalis</em> L. has been studied by light microscope histochemical techniques. The standard PAS reaction has shown the persistence of the primary pecto-cellulosic pollen mother cell wall localized around the callosic special wall (determined both by Bauer's reaction and the fluorescence technique with aniline blue) of individual tetrcds. A PAS-positive spore precursor wall (primexime) is formed while the tetrad of microspores is still enclosed by intact callose and pollen mother cell walls. The pecto-cellulosic wall and callose layer dissolve simultaneously to release the microspores into another loculi.

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Microspore Separation in the quartet 3 Mutants of Arabidopsis Is Impaired by a Defect in a Developmentally Regulated Polygalacturonase Required for Pollen Mother Cell Wall Degradation

PLANT PHYSIOLOGY ◽

10.1104/pp.103.028266 ◽

2003 ◽

Vol 133 (3) ◽

pp. 1170-1180 ◽

Cited By ~ 113

Author(s):

Seung Y. Rhee ◽

Erin Osborne ◽

Patricia D. Poindexter ◽

Chris R. Somerville

Keyword(s):

Cell Wall ◽

Pollen Mother Cell ◽

Mother Cell ◽

Cell Wall Degradation ◽

Developmentally Regulated ◽

Mother Cell Wall

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Changes in cell ultrastructure and morphology of Arabidopsis thaliana roots after coumarins treatment

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2001.024 ◽

2014 ◽

Vol 70 (3) ◽

pp. 187-198

Author(s):

Ewa Kupidłowska

Keyword(s):

Arabidopsis Thaliana ◽

Cell Wall ◽

Cell Walls ◽

Root Elongation ◽

Inhibitory Effect ◽

Cell Ultrastructure ◽

Radial Expansion ◽

Elongation Zone ◽

Cortical Cells ◽

Mother Cell Wall

The ultrastructure and morphology of roots treated with coumarin and umbelliferone as well as the reversibility of the coumarins effects caused by exogenous GA, were studied in <em>Arabidopsis thaliana</em>. Both coumarins suppressed root elongation and appreciably stimulated radial expansion of epidermal and cortical cells in the upper part of the meristem and in the elongation zone. The gibberellic acid applied simultaneously with coumarins decreased their inhibitory effect on root elongation and reduced cells swelling.Microscopic observation showed intensive vacuolization of cells and abnormalities in the structure of the Golgi stacks and the nuclear envelope. The detection of active acid phosphatase in the cytosol of swollen cells indicated increased membrane permeability. Significant abnormalities of newly formed cell walls, e.g. the discontinuity of cellulose layer, uncorrect position of walls and the lack of their bonds with the mother cell wall suggest that coumarins affected the cytoskeleton.

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

Microbiology ◽

10.1099/mic.0.077511-0 ◽

2014 ◽

Vol 160 (6) ◽

pp. 1063-1074 ◽

Cited By ~ 2

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.

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

Biochemical Journal ◽

10.1042/bj2260259 ◽

1985 ◽

Vol 226 (1) ◽

pp. 259-268 ◽

Cited By ~ 15

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.

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

Botanical Journal of the Linnean Society ◽

10.1111/j.1095-8339.1919.tb00709.x ◽

1919 ◽

Vol 44 (299) ◽

pp. 473-482 ◽

Cited By ~ 4

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.

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Cell Volume and the Control of the Chlamydomonas Cell Cycle

Journal of Cell Science ◽

10.1242/jcs.54.1.173 ◽

1982 ◽

Vol 54 (1) ◽

pp. 173-191 ◽

Cited By ~ 1

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.

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Haustorial mother cell development by Uromyces vignae on collodion membranes

Canadian Journal of Botany ◽

10.1139/b88-108 ◽

1988 ◽

Vol 66 (4) ◽

pp. 736-741 ◽

Cited By ~ 9

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.

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