Cell wall of Fusarium sulphureum. II. Chemical composition of the conidial and chlamydospore walls

1977 ◽  
Vol 23 (6) ◽  
pp. 763-769 ◽  
Author(s):  
E. F. Schneider ◽  
L. R. Barran ◽  
P. J. Wood ◽  
I. R. Siddiqui
Keyword(s):  
Cell Wall ◽  
Glucuronic Acid ◽  
Dry Weight ◽  
Outer Wall ◽  
Wall Layer ◽  
Dense Layer ◽  
Glucose Content ◽  
Fusarium Sulphureum ◽  
Spore Walls ◽  
Wall Components

Examination of the conidial and chlamydospore walls of Fusarium sulphureum by electron microscopy showed the presence of two distinct layers of differing electron densities. These include a relatively narrow outer electron-dense layer and a broader more transparent inner layer. Both chlamydospore cell wall layers were thicker than the conidial wall. The outer wall of the chlamydospore wall was 30% thicker while the inner cell wall layer was 250% thicker than the corresponding cell wall layers in the conidia. During conidial differentiation to form chlamydospores there was a considerable augmentation of all cell wall components which varied from 7 to 26-fold per cell. The augmentation of the major cell wall constituents (N-acetylglucoseamine (NAG), glucose, and protein) and the vast increase in the inner cell wall of the chlamydospore wall indicated that these newly synthesized constituents are predominently located in the inner cell wall layer.The major carbohydrate constituents on a dry weight basis in both the conidial and chlamydospore walls were glucose, glucuronic acid, and N-acetylglycosamine (NAG). However, the proportion of these and the other carbohydrate constituents were different for both spore walls. Thus, the conidial wall contained about 50% less NAG and glucuronic acid but twice the glucose content of the chlamydospore wall. Protein was a major component of both spore walls (21.6%, conidial wall; 28.5%, chlamydospore wall). Amino acid analysis indicated differences in the types of protein present in the two spore walls. The lipid content of both conidia and chlamydospore was low (1–2%).

Cell wall structures of Epicoccum nigrum (Hyphomycetes)

1973 ◽  
Vol 51 (5) ◽  
pp. 1071-1073 ◽  
Author(s):  
J. A. Brushaber ◽  
R. H. Haskins
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Outer Layer ◽  
Secondary Wall ◽  
Outer Wall ◽  
Wall Layer ◽  
Wall Material ◽  
Primary Wall ◽  
Electron Dense Material ◽  
Wall Structures

Two structurally distinct types of secondary wall layers are present in older hyphae in addition to the primary wall. A coarsely fibrous outer wall layer often becomes quite massive and frequently fuses with the outer wall layers of adjacent cells in the formation of hyphal strands. The uneven deposition of this outer layer often produces large verrucosities. The inner secondary wall layer is relatively electron transparent and contains a reticulum of electron-dense lines. The interface of the inner secondary wall with the cytoplasm is often very irregular, and sections of the plasma membrane are frequently overlain by wall material. The outer secondary wall of conidia is composed of an electron-dense material different from that of the outer wall of hyphae. Cells in the multicellular conidia tend to be polyhedral in shape with either very thick primary walls or thin primary walls having a thick inner wall deposit.

Ultrastructure of sporodochium and conidium development in the anamorphic fungus Epicoccum nigrum

2005 ◽  
Vol 83 (10) ◽  
pp. 1354-1363 ◽  
Author(s):  
C.W. Mims ◽  
E.A. Richardson
Keyword(s):  
Basal Cell ◽  
Apical Cell ◽  
Outer Wall ◽  
Wall Layer ◽  
Dense Layer ◽  
Epicoccum Nigrum ◽  
Transparent Layer ◽  
Transmission Electron ◽  
Anamorphic Fungus ◽  
Agar Surface

Scanning and transmission electron microscopy were used to examine sporodochium and conidium development in Epicoccum nigrum Link. Each sporodochium, a slightly raised mass of hyphae consisting of a pseudoparenchymous stroma covered with muriform conidia, arose from a group of loosely packed hyphae that formed on the agar surface. Conidiophores developed from the surface of the stroma. Each possessed a two-layered wall consisting of an inner electron transparent layer and an outer electron dense layer. Most conidiophores consisted of only two cells, the apical of which became swollen and gave rise to a solitary conidium initial in a holoblastic fashion. This initial enlarged and became divided into a smaller basal cell and a larger apical cell by a transverse septum. While the basal cell did not divide further, the apical cell became divided into numerous cells as the result of the formation of longitudinal and transverse septa. As a conidium matured the electron transparent inner layer of its wall thickened while the surface of its electron dense outer wall layer became transformed into small wart-like surface ornaments. Conidium secession was schizolytic and involved a transverse splitting of the septum separating the basal cell of a conidium from its conidiophore. The end of the basal cell and the tip of the conidiophore became rounded off during conidium secession.

The fine structure and development of chlamydospores of Fusarium oxysporum

1972 ◽  
Vol 18 (7) ◽  
pp. 997-1002 ◽  
Author(s):  
I. L. Stevenson ◽  
S. A. W. E. Becker
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Fine Structure ◽  
Electron Microscope ◽  
Cell Surface ◽  
Outer Layer ◽  
Outer Wall ◽  
Wall Layer ◽  
Thin Sections ◽  
Hyphal Wall

Methods have been developed for the rapid, reproducible induction of high-density populations of F. oxysporum chlamydospores. On transferring washed pregerminated conidia to a simple two-salts medium, chlamydospore morphogenesis was evident by 12 h and masses of mature spores could be harvested at the end of 4 days. Electron-microscope studies of thin sections of mature chlamydospores reveal a thick triple-layered cell wall. The cytoplasm contains, in addition to large lipid deposits, a nucleus, mitochondria, and endoplasmic reticulum all typical of fungal cells. Chlamydospores of F. oxysporum exhibit two distinct types of cell surface in thin section. The outer wall layer of two of the isolates studied was smooth-surfaced while the outer layer of the two other isolates was distinctly fibrillose. Some evidence is presented suggesting that the fibrillose material arises through the partial breakdown of the original hyphal wall.

Studies on the cell wall of Spirillum serpens. 1. Isolation and partial purification of the outermost cell wall layer

1970 ◽  
Vol 16 (10) ◽  
pp. 1011-1022 ◽  
Author(s):  
Francis L. A. Buckmire ◽  
Robert G. E. Murray
Keyword(s):  
Cell Wall ◽  
Intact Cell ◽  
Guanidine Hydrochloride ◽  
Casein Hydrolysate ◽  
Wall Layer ◽  
Partial Purification ◽  
Repeated Heating ◽  
Physical Study ◽  
Backing Layer ◽  
Wall Components

The presence of the hexagonal array of macromolecules on the outer surface of the cell wall of Spirillum serpens VHA required the addition of calcium to an otherwise effective growth medium (vitamin-free casein hydrolysate); slightly improved growth resulted from addition of a complex salts mixture. A means of isolating this layer for chemical and physical study was sought and controlled by electron microscopy of freeze-etched, negatively stained, and sectioned preparations. The structure was destroyed, extracted, or removed by extremes of pH (<4.5, >9), 1 M guanidine hydrochloride (pH 7), 2 M urea, and dimethyl sulfoxide, with varying damage to the cell. Heat (60° for 1 h) removed much of the outer layer from the intact cell as an array of units disposed on a delicate backing layer, leaving the basic Gram-negative triplet wall components. These fragments remained stable through washing and repeated heating in the presence of 0.001 M calcium chloride. Guanidine hydrochloride (1.5 M) dissolved the units from the tubes and vesicles formed by the backing layer. Dialysis against water removed salts and guanidine, caused the precipitation of residual contaminants, and provided a supernatant which, when lyophilized, provided a product containing 98% protein.

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.

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.

Modes of cell-wall degradation of Sphagnum fuscum by Acremonium cf. curvulum and Oidiodendron maius

2001 ◽  
Vol 79 (1) ◽  
pp. 93-100 ◽  
Author(s):  
A Tsuneda ◽  
M N Thormann ◽  
R S Currah
Keyword(s):  
Cell Walls ◽  
Amorphous Matrix ◽  
Matrix Material ◽  
Outer Wall ◽  
Amorphous Layer ◽  
Wall Layer ◽  
Sphagnum Fuscum ◽  
The Matrix ◽  
Oidiodendron Maius ◽  
Wall Components

Electron microscopy of cryo-fractured hyaline leaf cells of Sphagnum fuscum Klinggr. revealed that their cell walls consist of three layers: a thick central layer flanked on either side by a thinner, amorphous layer. Acremonium cf. curvulum W. Gams and Oidiodendron maius Barron, both isolated from partly decomposed S. fuscum plants, were capable of degrading leaf cell walls of Sphagnum. Where hyphae of A. curvulum accumulated, the amorphous, outer wall layer of S. fuscum was first fragmented and then removed. The exposed central wall layer consisted of bundles of microfibrils embedded in an amorphous matrix material. After the matrix material and the inner surface wall layer were mostly removed, degradation of microfibrils occurred and localized voids were produced. Unlike A. cf. curvulum, O. maius degraded all wall components more or less simultaneously. In both fungi, active and autolysing hyphae frequently occurred in proximity on the Sphagnum leaves.Key words: hyphomycetes, peat, phenolics, cellulose, SEM.

Ultracytochemical Localization of Acid Phosphatase in Humicola lutea Conidia and Mycelia

2007 ◽  
Vol 62 (1-2) ◽  
pp. 65-69
Author(s):  
Dimitrina Spasova ◽  
Penka Aleksieva ◽  
Lilyana Nacheva ◽  
Spasimira Radoevska
Keyword(s):  
Cell Wall ◽  
Acid Phosphatase ◽  
Enzymatic Degradation ◽  
Outer Wall ◽  
Wall Layer ◽  
Outer Side ◽  
Electron Microscopic ◽  
Exterior Surface ◽  
The Relationship ◽  
Humicola Lutea

Electron microscopic cytochemical procedures were used to determine the cellular location of acid phosphatase in the fungus Humicola lutea grown in casein-containing medium lacking in mineral orthophosphates. In our investigations acid phosphatase in nongerminating conidia was localized on the outer side of the cell wall, in the cell wall, and on the exterior surface of the plasma membrane. The reaction product of acid phosphatase in germinating conidia was seen in the outer wall layer while in young mycelium on the cell surface and in the exocellular space. The relationship between phosphatase activities localized in the cell wall and their role in the enzymatic degradation of the phosphoprotein casein providing available phosphates for cell growth is discussed.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

Mitogenic Activity of Cell Wall Components from Lactobacillus acidophilus

1993 ◽  
Vol 64 (5) ◽  
pp. 505-511 ◽  
Author(s):  
Masahiro YAMADA ◽  
Haruki KITAZAWA ◽  
Junko UEMURA ◽  
Tadao SAITOH ◽  
Takatoshi ITOH
Keyword(s):  
Cell Wall ◽  
Lactobacillus Acidophilus ◽  
Mitogenic Activity ◽  
Cell Wall Components ◽  
Wall Components
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