Chemical and ultrastructural studies on the distribution of sporopolleninlike biopolymers in six genera of lichen phycobionts

1985 ◽  
Vol 63 (12) ◽  
pp. 2221-2230 ◽  
Author(s):  
Ueli Brunner ◽  
Rosmarie Honegger
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Resistant Cell ◽  
Wall Layer ◽  
Conclusive Evidence ◽  
The Other ◽  
Chemical Methods ◽  
Ultrastructural Studies ◽  
Cell Wall Polymer ◽  
Infrared Absorption Spectra

Cell walls of cultured lichen phycobionts of the genera Coccomyxa, Elliptochloris, Myrmecia, Pseudochlorella, Trebouxia, and Trentepohlia were investigated with cytological and chemical methods with regard to the presence or absence of trilaminar sheaths and (or) resistant biopolymers. Trilaminar cell wall layers occurred in Coccomyxa, Elliptochloris, Myrmecia, and (less distinctly) Pseudochlorella species. A biopolymer highly resistant to nonoxidative degradation by phosphoric acid occurred only in the isolated and vigorously extracted cell walls of Coccomyxa and Elliptochloris species. The walls of all the other phycobionts, including Myrmecia and Pseudochlorella, were totally degraded, showing that a trilaminar wall layer is not conclusive evidence for the presence of a resistant cell wall polymer. The infrared absorption spectra of the degradation-resistant cell wall polymer of Coccomyxa and Elliptochloris species were not fully identical with those of natural sporopollenins. When the widely used, but chemically less appropriate acetolysis method was applied to either entire cells or isolated but not fully extracted cell walls of Coccomyxa, Elliptochloris, Myrmecia, Pseudochlorella, Trebouxia, and Trentepohlia species, they all yielded acetolysis-resistant residues whose infrared spectra resembled natural sporopollenin.

Ontogeny and fine structure of effective root nodules of the autumn olive (Elaeagnus umbellata)

1987 ◽  
Vol 65 (1) ◽  
pp. 80-94 ◽  
Author(s):  
William Newcomb ◽  
Dwight Baker ◽  
John G. Torrey
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Root Nodules ◽  
Freeze Fracture ◽  
Wall Layer ◽  
Void Space ◽  
Elaeagnus Umbellata ◽  
Autumn Olive ◽  
Clear Area ◽  
Glycogen Particles

An ultrastructural study of effective root nodules of the autumn olive (Elaeagnus umbellata Thunb.) demonstrated the presence of hyphal and vesicular forms of the actinomycete endophyte. No sporangial forms of the endophyte were observed within these nodules. The hyphae contained septa, prominent nucleoid regions, and many ribosomes. The endophytic vesicles were initially nonseptate and then became multichambered as a result of the inward growth of complete and incomplete septa. Glycogen particles were numerous in nonseptate and early stages of septate endophytic vesicle formation and in adjacent hyphae but were absent in more developed stages of septate endophytic vesicles. The endophytic vesicles also contained prominent nucleoid areas, vesicular mesosomes, and crystalline-like striated bodies. A capsule, probably derived from host Golgi cisternae and profiles of dilated rough endoplasmic reticulum, surrounded both forms of the endophyte. The endophytic vesicle cell walls consisted of an outer layer continuous with the hyphal cell wall, a middle clear area or “void space,” and an electron-dense inner layer. The “void space” of the endophyte cell wall was resolved into many thin laminae by freeze–fracture microscopy. The laminae were presumed to be different from the outermost cell wall layer because they were washed out in the solvents used in preparing specimens for the TEM.

scholarly journals Two Novel Techniques for Determination of Polysaccharide Cross-Links Show that Crh1p and Crh2p Attach Chitin to both β(1-6)- and β(1-3)Glucan in the Saccharomyces cerevisiae Cell Wall

2009 ◽  
Vol 8 (11) ◽  
pp. 1626-1636 ◽  
Author(s):  
Enrico Cabib
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Acetic Acid ◽  
Yeast Cell ◽  
Cell Walls ◽  
Double Mutant ◽  
The Other ◽  
Cross Links

ABSTRACT Previous work, using solubilization of yeast cell walls by carboxymethylation, before or after digestion with β(1-3)- or β(1-6)glucanase, followed by size chromatography, showed that the transglycosylases Crh1p and Crh2p/Utr2p were redundantly required for the attachment of chitin to β(1-6)glucan. With this technique, crh1Δ crh2Δ mutants still appeared to contain a substantial percentage of chitin linked to β(1-3)glucan. Two novel procedures have now been developed for the analysis of polysaccharide cross-links in the cell wall. One is based on the affinity of curdlan, a β(1-3)glucan, for β(1-3)glucan chains in carboxymethylated cell walls. The other consists of in situ deacetylation of cell wall chitin, generating chitosan, which can be extracted with acetic acid, either directly (free chitosan) or after digestion with different glucanases (bound chitosan). Both methodologies indicated that all of the chitin in crh1Δ crh2Δ strains is free. Reexamination of the previously used procedure revealed that the β(1-3)glucanase preparation used (zymolyase) is contaminated with a small amount of endochitinase, which caused erroneous results with the double mutant. After removing the chitinase from the zymolyase, all three procedures gave coincident results. Therefore, Crh1p and Crh2p catalyze the transfer of chitin to both β(1-3)- and β(1-6)glucan, and the biosynthetic mechanism for all chitin cross-links in the cell wall has been established.

scholarly journals Unconventional Constituents and Shared Molecular Architecture of the Melanized Cell Wall of C. neoformans and Spore Wall of S. cerevisiae

2020 ◽  
Vol 6 (4) ◽  
pp. 329
Author(s):  
Christine Chrissian ◽  
Coney Pei-Chen Lin ◽  
Emma Camacho ◽  
Arturo Casadevall ◽  
Aaron M. Neiman ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Building Blocks ◽  
Cell Types ◽  
Resistant Cell ◽  
Spore Wall ◽  
Fungal Species ◽  
Resonance Spectroscopy ◽  
Molecular Architecture ◽  
Fungal Cell

The fungal cell wall serves as the interface between the cell and the environment. Fungal cell walls are composed largely of polysaccharides, primarily glucans and chitin, though in many fungi stress-resistant cell types elaborate additional cell wall structures. Here, we use solid-state nuclear magnetic resonance spectroscopy to compare the architecture of cell wall fractions isolated from Saccharomyces cerevisiae spores and Cryptococcus neoformans melanized cells. The specialized cell walls of these two divergent fungi are highly similar in composition. Both use chitosan, the deacetylated derivative of chitin, as a scaffold on which a polyaromatic polymer, dityrosine and melanin, respectively, is assembled. Additionally, we demonstrate that a previously identified but uncharacterized component of the S. cerevisiae spore wall is composed of triglycerides, which are also present in the C. neoformans melanized cell wall. Moreover, we identify a tyrosine-derived constituent in the C. neoformans wall that, although it is not dityrosine, is a non-pigment constituent of the cell wall. The similar composition of the walls of these two phylogenetically distant species suggests that triglycerides, polyaromatics, and chitosan are basic building blocks used to assemble highly stress-resistant cell walls and the use of these constituents may be broadly conserved in other fungal species.

scholarly journals Cytological Aspects of the Mycobiont–Phycobiont Relationship in Lichens

1984 ◽  
Vol 16 (2) ◽  
pp. 111-127 ◽  
Author(s):  
Rosmarie Honegger
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Wall Layer ◽  
Distinct Pattern ◽  
Homogeneous Material ◽  
Wall Surface ◽  
Surface Layers ◽  
Thin Sectioning ◽  
Cytological Features ◽  
Mother Cell Wall

AbstractCytological aspects of the mycobiont-phycobiont contact were investigated in the lichen species Peltigera aphthosa, Cladonia macrophylla, Cladonia caespiticia and Parmelia tiliacea by means of freeze-etch and thin sectioning techniques, and by replication of isolated fragments of myco- and phycobiont cell walls.In the symbiotic state of the mycobionts investigated a thin outermost wall layer with a distinct pattern was observed mainly in the hyphae contacting phycobiont cells and in the upper medullary layer. No comparable structures were noted on the hyphal surface of the cultured mycobionts of the Cladonia and Parmelia species investigated. A distinct rodlet layer was found on the hyphal surface of the mycobiont of Peltigera aphthosa, while mycobionts of Cladonia macrophylla, C. caespiticia and Parmelia tiliacea had a mosaic of small, irregular ridges, each corresponding in its size to a bundle of rodlets on the outermost wall layer. Comparable surface layers have been described in aerial hyphae of a great number of non-lichenized fungi.The rodlet layer of the mycobiont wall surface of Peltigera aphthosa adheres tightly to the outermost layer of the sporopollenin-containing cell wall of the Coccomyxa phycobiont. Mature trebouxioid phycobiont cells of the Cladonia and Parmelia species investigated in the symbiotic state had an outermost wall layer which was structurally indistinguishable from the tessellated surface layer of the mycobiont cells. A rodlet pattern was detected in the outermost wall layer of Trebouxia autospores still surrounded by the cellulosic mother cell wall. In mature Trebouxia cells the bundles of rodlets became increasingly covered by a homogeneous material, and thus attained the same tessellated pattern which was observed on the mycobiont wall surface. No comparable structures were found on the wall surface after culturing the Trebouxia phycobionts axenically in liquid media. Confluence of the tessellated surface layers of fungal and algal origin was noted at the contact sites of growing hyphal tips and young Trebouxia cells.The possible correlations between these cytological features and published immunological data on the cell surface of cultured and symbiotic lichen myco- and phycobionts are discussed.

scholarly journals The Role of Cutinsomes in Plant Cuticle Formation

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1778 ◽  
Author(s):  
Dariusz Stępiński ◽  
Maria Kwiatkowska ◽  
Agnieszka Wojtczak ◽  
Justyna Teresa Polit ◽  
Eva Domínguez ◽  
...  
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Cell Walls ◽  
The Other ◽  
Land Plants ◽  
Plant Cuticle ◽  
Cuticle Formation ◽  
Linear Chains ◽  
Main Components

The cuticle commonly appears as a continuous lipophilic layer located at the outer epidermal cell walls of land plants. Cutin and waxes are its main components. Two methods for cutin synthesis are considered in plants. One that is based on enzymatic biosynthesis, in which cutin synthase (CUS) is involved, is well-known and commonly accepted. The other assumes the participation of specific nanostructures, cutinsomes, which are formed in physicochemical self-assembly processes from cutin precursors without enzyme involvement. Cutinsomes are formed in ground cytoplasm or, in some species, in specific cytoplasmic domains, lipotubuloid metabolons (LMs), and are most probably translocated via microtubules toward the cuticle-covered cell wall. Cutinsomes may additionally serve as platforms transporting cuticular enzymes. Presumably, cutinsomes enrich the cuticle in branched and cross-linked esterified polyhydroxy fatty acid oligomers, while CUS1 can provide both linear chains and branching cutin oligomers. These two systems of cuticle formation seem to co-operate on the surface of aboveground organs, as well as in the embryo and seed coat epidermis. This review focuses on the role that cutinsomes play in cuticle biosynthesis in S. lycopersicum, O. umbellatum and A. thaliana, which have been studied so far; however, these nanoparticles may be commonly involved in this process in different plants.

Ultrastructural studies on the cell walls in Fusarium sulphureum

1979 ◽  
Vol 25 (1) ◽  
pp. 75-85 ◽  
Author(s):  
Edward F. Schneider ◽  
Alan B. Wardrop
Keyword(s):  
Cell Walls ◽  
Outer Wall ◽  
Wall Layer ◽  
Additional Treatment ◽  
Degree Of Crystallinity ◽  
Thick Wall ◽  
Wall Material ◽  
Fungal Cell ◽  
Ultrastructural Studies ◽  
Fusarium Sulphureum

The cell walls of Fusarium sulphureum have a microfibrillar component that is randomly arranged. X-ray-diffraction diagrams of the microfibrils are consistent with a high degree of crystallinity and show that they are chitin. The chitin microfibrils of the peripheral walls envelop the hyphal apex and extend across the septae. During the first 8 h in culture, the conversion of conidial cells to chlamydospores is evidenced by a swelling of the cells and the original microfibrils remain randomly arranged. Within 24 h new wall material is deposited as the cells expand and the wall thickens. The new microfibrils are indistinguishable from those of the original conidial cells.After 3 days in culture, the chlamydospores are fully developed and have the characteristic thick wall which is a continuous layer of randomly arranged microfibrils. Chlamydospores maintained in a conversion medium for 8 days have microfibrils identical with those in 3-day-old cultures; thus a further change in the microfibril orientation did not occur during that period.Alkaline hydrolysis of the walls removes most of the electron-dense staining constituents from the inner wall layer and leaves the outer wall layer intact. This treatment also reveals some of the wall microfibrils. An additional treatment of the walls with HAc/H2O2 completely removes the wall components that react positively to heavy metal stains. The results are discussed in relation to the structure of other fungal cell walls.

scholarly journals THE LABELING OF CULTURED CELLS OF ACER WITH [14C]PROLINE AND ITS SIGNIFICANCE

1974 ◽  
Vol 60 (3) ◽  
pp. 695-701 ◽  
Author(s):  
F. C. Steward ◽  
H. W. Israel ◽  
M. M. Salpeter
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Cell Walls ◽  
Cultured Cells ◽  
The State ◽  
The Other ◽  
Electron Microscope Autoradiography ◽  
Cells In Culture ◽  
Microscope Autoradiography ◽  
The Status

The distribution of the radioactivity from [14C]proline that is bound in cultured cells of Acer has been determined by electron microscope autoradiography. In this way proline may be related to the cell wall as a morphological entity rather than as a fraction in a biochemical separation of a heterogeneous crop of cells. The cells in culture may vary greatly. Some are active growing, turgid cells, with thin protoplasts tightly pressed against their walls; in others the protoplasts may spontaneously withdraw from the wall; in still others the protoplasts disorganize, and walls thicken and become sculptured as the cells differentiate and even senesce. Different culturing practices may affect the status of the cells, and this, in turn, affects the distribution of radioactivity from proline in the cells. Cells which are actively growing, turgid, and nucleated have the highest grain density in their protoplasts and nuclei; as the protoplasts of such cells withdraw from their walls, they retain the bulk of the radioactivity. On the other hand, in cells which have thickened walls and sparse protoplast contents, the radioactivity is accumulated in their walls. A high content of proline and hydroxyproline-rich protein is, therefore, not a necessary or invariable feature of the cell walls of cultured Acer cells but depends on the state of development of these cells.

scholarly journals Cell Wall Layer Induced in Xylem Fibers of Flax Upon Gravistimulation Is Similar to Constitutively Formed Cell Walls of Bast Fibers

2021 ◽  
Vol 12 ◽  
Author(s):  
Anna Petrova ◽  
Liudmila Kozlova ◽  
Oleg Gorshkov ◽  
Alsu Nazipova ◽  
Marina Ageeva ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Secondary Cell Wall ◽  
Wall Layer ◽  
Cell Wall Layer ◽  
Wall Deposition ◽  
Secondary Cell Walls ◽  
Phloem Fibers ◽  
Xylem Fibers ◽  
Cell Wall Deposition

In the fibers of many plant species after the formation of secondary cell walls, cellulose-enriched cell wall layers (often named G-layers or tertiary cell walls) are deposited which are important in many physiological situations. Flax (Linum usitatissimum L.) phloem fibers constitutively develop tertiary cell walls during normal plant growth. During the gravitropic response after plant inclination, the deposition of a cellulose-enriched cell wall layer is induced in xylem fibers on one side of the stem, providing a system similar to that of tension wood in angiosperm trees. Atomic force microscopy (AFM), immunochemistry, and transcriptomic analyses demonstrated that the G-layer induced in flax xylem fibers was similar to the constitutively formed tertiary cell wall of bast (phloem) fibers but different from the secondary cell wall. The tertiary cell walls, independent of tissue of origin and inducibility, were twice as stiff as the secondary cell walls. In the gravitropic response, the tertiary cell wall deposition rate in xylem was higher than that of the secondary cell wall. Rhamnogalacturonan I (RG-I) with galactan side chains was a prominent component in cellulose-rich layers of both phloem and xylem flax fibers. Transcriptomic events underlying G-layer deposition in phloem and xylem fibers had much in common. At the induction of tertiary cell wall deposition, several genes for rhamnosyltransferases of the GT106 family were activated in xylem samples. The same genes were expressed in the isolated phloem fibers depositing the tertiary cell wall. The comparison of transcriptomes in fibers with both inducible and constitutive tertiary cell wall deposition and xylem tissues that formed the secondary cell walls is an effective system that revealed important molecular players involved in the formation of cellulose-enriched cell walls.

The fine structure of some strains of Humicola Traaen

1974 ◽  
Vol 20 (2) ◽  
pp. 237-239 ◽  
Author(s):  
M. de Bertoldi ◽  
F. Mariotti ◽  
C. Filippi
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Cell Surface ◽  
Outer Wall ◽  
Wall Layer ◽  
The Other ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Different Types ◽  
Microscopic Studies

The fine structure of three unclassified strains of Humicola and of H. grisea has been investigated. The hyphae of all the strains show septa with Woronin bodies of the ascomycetous type. The cytoplasm contains many nuclei per cell, mitochondria, ribosomes, and endoplasmic vesicles, all typical of fungal cells. Electron-microscopic studies of thin sections of mature aleuriospores reveal a thick multilayered cell wall and an accumulation, inside the spore, of β-hydroxybutyrate granules. Aleuriospores exhibit different types of cell surface; the outer wall layer of two strains is smooth, while the outer layer of the other strains is rough because of the presence of melanizing bodies on the cell wall matrix. The fine structure of phialospores and microconidia is also described. Differences in the fine structure among the strains studied are reported.

scholarly journals The control of synthesis of bacterial cell walls. Interaction in the synthesis of nucleotide precursors

1973 ◽  
Vol 136 (4) ◽  
pp. 871-876 ◽  
Author(s):  
Raymond G. Anderson ◽  
L. Julia Douglas ◽  
Helen Hussey ◽  
James Baddiley
Keyword(s):  
Cell Wall ◽  
Bacillus Licheniformis ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Energy Charge ◽  
The Other ◽  
Cell Wall Synthesis ◽  
Sugar Nucleotides ◽  
Sugar Phosphates

Phosphoenolpyruvate–UDP-N-acetylglucosamine enolpyruvyltransferase, UDP-N-acetylglucosamine pyrophosphorylase and CDP-glycerol pyrophosphorylase activities were demonstrated in soluble extracts from Bacillus licheniformis A.T.C.C. 9945. The effect of various nucleotides, sugar nucleotides and sugar phosphates on the nucleotide pyrophosphorylases was investigated. UDP-N-acetylglucosamine pyrophosphorylase was inhibited by UDP-MurAc-pentapeptide (UDP-N-acetylmuramyl-l-alanyl-d-glutamyl- meso-diaminopimelyl-d-alanyl -d-alanine) and CDP-glycerol. CDP-glycerol pyrophosphorylase was inhibited by UDP-MurAc-pentapeptide and stimulated by UDP-N-acetylglucosamine. Interaction between a precursor of one cell-wall polymer and an enzyme involved in the synthesis of a precursor of a second polymer has therefore been demonstrated. The possible role of such interaction in the control of bacterial cell-wall synthesis is discussed. Of the other compounds investigated mono- and di-nucleotides were shown to be inhibitory, indicating that nucleotide pyrophosphorylase activities may be influenced by the energy charge of the cell.

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