Detection of rodlets in the outer wall region of conidiospores of Phanerochaete chrysosporium

1994 ◽  
Vol 40 (5) ◽  
pp. 412-416 ◽  
Author(s):  
P. A. Gerin ◽  
M. Asther ◽  
U. B. Sleytr ◽  
P. G. Rouxhet
Keyword(s):  
Surface Morphology ◽  
Phanerochaete Chrysosporium ◽  
Germ Tube ◽  
Fungal Spore ◽  
Outer Wall ◽  
Multilayered Structure ◽  
Spore Wall ◽  
Wall Region ◽  
Parallel Fibres ◽  
Freeze Etching

The surface morphology of the conidiospores of Phanerochaete chrysosporium was investigated using freeze-etching. A multilayered structure composed of rodlets was detected. The rodlets had a diameter of 10.2 ± 0.5 nm and were organised as long parallel fibres. Granules, smooth materials, and bark-like structures were found to cover part of this rodlet layer. During germination, the outer pellicle of the spore wall became fragmented and residual aggregates with rodlets were disseminated on the new conidiospore surface. The latter, as well as the germ tube, was composed of fibrillar material.Key words: conidiospores, rodlet, surface, Phanerochaete chrysosporium, freeze-etching, fungal spore, germination.

Fine structure of sporangiole development in Choanephora cucurbitarum (Mucorales)

1982 ◽  
Vol 60 (11) ◽  
pp. 2313-2324 ◽  
Author(s):  
Michael T. Higham ◽  
Kathleen M. Cole
Keyword(s):  
Electron Microscopy ◽  
Germ Tube ◽  
Tube Wall ◽  
Outer Wall ◽  
Spore Wall ◽  
Wall Layer ◽  
Choanephora Cucurbitarum ◽  
Dark Staining ◽  
Granular Vesicles ◽  
Scanning Electron

Spore development was studied in Choanephora cucurbitarum by using transmission and scanning electron microscopy. Sporangioles are produced by expansion of the ampulla wall. A two-layered spore wall is then constructed within the spine-covered sporangiole wall. The outer spore wall layer is longitudinally grooved and is devoid of spines or appendages. The inner wall layer is thinner and electron transparent. During wall production, dark-staining granular vesicles were observed in the spore cytoplasm. Their contents stained similarly to the material of the outer wall layer. Mature spores possessed a third, innermost wall layer. This was identified as a new wall layer, which was continuous with the germ-tube wall of germinated spores. Released spores were observed to be contained within the sporangiole during dispersal and germination.

Spore wall development in Sphagnum lescurii

1982 ◽  
Vol 60 (11) ◽  
pp. 2394-2409 ◽  
Author(s):  
Roy Curtiss Brown ◽  
Betty E. Lemmon ◽  
Zane B. Carothers
Keyword(s):  
Plasma Membrane ◽  
Outer Layer ◽  
Mature Spore ◽  
Outer Wall ◽  
Spore Wall ◽  
Spore Surface ◽  
Proximal Surface ◽  
Complex Development ◽  
Surface Ornamentation ◽  
Cortical System

The spore wall of Sphagnum is unique in the Bryophyta. The Sphagnum spore exine consists of two layers: an inner, lamellate layer (A layer) and a thick, homogenous, outer layer (B layer). The exine of other mosses consists of only the outermost homogenous layer and, at most, a thin ill-defined opaque layer. During development of the A-layer exine and the intine, a cortical system of evenly spaced microtubules underlies the plasma membrane. The ontogeny of the wall layers is not strictly centripetal. The A-layer exine develops evenly around the young spore immediately after cytokinesis. As the intine is deposited centripetally inside it, the homogenous B-layer exine is deposited outside the first-formed A layer. The B layer is responsible for the primary sculpturing of the spore surface. The mature spore is covered by an outermost perine, which is responsible for secondary surface ornamentation. A trilaesurate aperture develops on the proximal surface of each spore after deposition of the A layer. Ridges of the laesurae develop as a result of deposition of thick areas of intine. The ridges are eventually covered by the outer wall layers, whereas the fissure is covered only by the A layer and a very thin B-layer exine. The complex development of the trilaesurate aperture is evidence that the structure is not merely a mechanically induced "trilete mark" or "scar" resulting from compression of tetrahedrally arranged spores within a sporocyte wall.

scholarly journals Computational analysis of solid particle-erosion produced by bottom ash slurry in 90° elbow

2019 ◽  
Vol 252 ◽  
pp. 04008
Author(s):  
Jashanpreet Singh ◽  
Jatinder Pal Singh ◽  
Mandeep Singh ◽  
Miroslaw Szala
Keyword(s):  
Bottom Ash ◽  
Outer Wall ◽  
Wall Region ◽  
Erosion Wear ◽  
Slurry Erosion ◽  
Low Velocity ◽  
Drag Forces ◽  
Shape Pattern ◽  
Discrete Phase ◽  
Computational Fluid Dynamics Cfd

Present work is devoted to investigation of the slurry erosion wear in a 90° elbow by using commercial Computational fluid dynamics (CFD) code FLUENT. Discrete phase erosion wear model was used to predict erosion in 90° elbow by solving the governing equations through Euler-Lagrange scheme. Particle tracking was considered by using standard k-ε turbulence scheme for the flow of bottom ash slurry. Erosion wear in elbow was investigated along with velocity distribution and turbulence intensity. The radius-to-diameter (r/D) ratio was taken as 1.5. Results show that erosion rate increases with increase in velocity. Present numerical simulation model holds close agreement with previous studies. Distorted patterns appeared at low velocities. The V-shape pattern appeared on the outer wall of elbow at high velocities. The low velocity region occurs around circumference of elbow wall at outer wall of elbow due to stimulation of the drag forces near the wall region.

The fine structure and selected histochemistry of ungerminated basidiospores of Agrocybe acericola

1996 ◽  
Vol 74 (5) ◽  
pp. 780-787 ◽  
Author(s):  
Donald G. Ruch ◽  
Kiki Nurtjahja
Keyword(s):  
Fine Structure ◽  
Acid Phosphatase ◽  
Glyoxylate Cycle ◽  
Outer Wall ◽  
Spore Wall ◽  
Malate Synthase ◽  
Marker Enzyme ◽  
Wall Ultrastructure ◽  
Membrane Bound ◽  
The Glyoxylate Cycle

The basidiospore wall of Agrocybe acericola is composed of two distinct layers that are continuous around the spores. At the germ pore, the outer wall is very thin and the inner wall becomes thicker. The plasma membrane is appressed to the inner wall and lacks distinct invaginations. The protoplasm is densely packed with ribosomes. Spores contain very little lipid distributed at each end. Mitochondria are well defined and distributed throughout the cytoplasm. Spores are binucleate, with the two nuclei lying on a line nearly perpendicular to the long axis of the cell. Various sizes of single membrane-bound vacuoles are widely distributed in the cytoplasm. These vacuoles were shown to contain acid phosphatase, indicating lysosomal activity. Microbody-like organelles are observed, which are probably glyoxysomes, since assays of malate synthase, a marker enzyme of the glyoxylate cycle, are positive. Keywords: Agrocybe, spore wall ultrastructure, basidiospore ultrastructure, glyoxylate cycle, malate synthase, acid phosphatase.

Ascospore germination, growth in culture, and imperfect spore formation in Cookeina sulcipes and Phillipsia crispata

1975 ◽  
Vol 53 (1) ◽  
pp. 56-61 ◽  
Author(s):  
J. W. Paden
Keyword(s):  
Germ Tube ◽  
Outer Wall ◽  
Wall Layer ◽  
Spore Formation ◽  
Spore Surface ◽  
No Formation ◽  
Ascospore Germination ◽  
Germ Tubes

Ascospores of Cookeina sulcipes germinate by one of two modes: (1) by the production of blastoconidia on sympodially proliferating conidiogenous cells which may arise from any point on the spore surface, and (2) by a thick polar germ tube. No ascospores were seen to germinate both ways. The conidiogenous cells are occasionally modified into narrow hyphae. The blastoconidia germinate readily but are evidently very short-lived. Ascospores of Phillipsia crispata germinate by two polar germ tubes; there is no formation of blastoconidia. In both species the inner ascospore wall separated from an outer wall layer during germination. In culture both C. sulcipes and P. crispata form arthroconidia. The arthroconidia are uninucleate; they germinate readily and reproduce the species when transferred to fresh plates.

Fine structure of basidiospores of the cedar-apple rust fungus Gymnosporangium juniperi-virginianae

1977 ◽  
Vol 55 (9) ◽  
pp. 1057-1063 ◽  
Author(s):  
Charles W. Mims
Keyword(s):  
Fine Structure ◽  
Thin Layer ◽  
Lipid Droplets ◽  
Germ Tube ◽  
Rust Fungus ◽  
Spore Wall ◽  
Lipid Bodies ◽  
Pore Region ◽  
Hilar Region ◽  
Endoplasmic Reticula

Each basidiospore of Gymnosporangium juniperi-virginianae contains many ribosomes as well as lipid droplets, mitochondria, small vesicles, endoplasmic reticula, and structures thought to be microbodies. Mature spores are either uninucleate or binucleate although larger, tetranucleate spores were occasionally observed. The spore wall appears as a thin layer except around the hilar region where two layers are evident. Germination is almost always lateral although no germ pore region was noted in the wall. Vacuolation takes place during germination and lipid bodies disappear. The wall of the germ tube arising from the spore is continuous with that of the spore. A large number of vesicles is present in the germ tube. Basidiospores may also germinate by repetition.

Teliospore wall structure in Entorrhiza (Tilletiaceae) and its relationship to taxonomy of the genus

1992 ◽  
Vol 70 (10) ◽  
pp. 1964-1983 ◽  
Author(s):  
Brian A. Fineran ◽  
Judith M. Fineran
Keyword(s):  
Electron Microscopy ◽  
Outer Zone ◽  
Spore Wall ◽  
Wall Structure ◽  
Dense Matrix ◽  
Thin Sections ◽  
Transmission Electron ◽  
Layer 2 ◽  
Layer 4 ◽  
Freeze Etching

Spore wall organization in the five species of Entorrhiza (Ustilaginales) has been investigated using thin sections for transmission electron microscopy, supported by light and scanning electron microscopy and some freeze-etching. Material was examined from herbaria, specimens preserved in fixative, and fresh host tissue. The wall has four main layers, numbered 1–4 from the outside to inside of the wall; some layers are further differentiated into zones. Layer 1 in E. aschersoniana, E. caspaiyana, and E. caricicola has two zones: a broad outer zone 2 of dense matrix and a narrow inner zone 1 of less compacted material. Zone 1 is absent in E. cypericola. In E. scirpicola, layer 1 is represented by discontinuous longitudinal ridges. In all spores, layer 2 is composed of a homogeneous electron-dense matrix. Layer 1 in E. aschersoniana, E. casparyana, and E. caricicola is uniformly thick, but in E. cypericola it is broad with an irregular outer margin. In E. scirpicola, layer 2 is differentiated into a distinctive pattern of longitudinal ribs. In all spores of Entorrhiza, layer 3 is resolvable into fine lamellae, corresponding to the mosaic of striations seen after freeze-etching. Layer 3 in Entorrhiza is equivalent to the partition layer described in other Tilletiaceae. Layer 4 has the same organization in all the species, consisting of a very narrow zone 2 abutting layer 3 and a broad zone 1 that forms the rest of the layer. Based on wall structure, E. aschersoniana and E. casparyana represent the most closely related species, followed by E. caricicola, with E. cypericola more distant again. Entorrhiza scirpicola is considered the least related of the species; only its layers 3 and 4 resemble the other species. Key words: Entorrhiza, Tilletiaceae, spore wall ultrastructure, species relationships.

Surface morphology of aeciospores, urediniospores, and teliospores of Uromyces trifolii-repentis

1988 ◽  
Vol 66 (6) ◽  
pp. 1129-1134 ◽  
Author(s):  
S. F. Hwang ◽  
M. E. Neuwirth ◽  
K. F. Chang
Keyword(s):  
Surface Morphology ◽  
White Clover ◽  
Trifolium Repens ◽  
Cell Layer ◽  
Spore Wall ◽  
Germ Pore ◽  
Transmission Electron ◽  
Hilar Region ◽  
Trifolium Repens L ◽  
Electron Microscopes

The surface markings of the spores from the aecial, uredinial, and telial stages of Uromyces trifolii-repentis Liro on leaves and petioles of small white clover (Trifolium repens L.) were examined using scanning and transmission electron microscopes. The short, cylindrical aecium was borne within a peridium which was one cell layer thick. The peridial cells were rhomboidal with irregular club-shaped ornaments. The yellowish aeciospores were densely ornamented with smooth, knoblike verrucae. Thin areas of the spore wall were differentiated into germ pores. Two or three germ pores were equatorially arranged on the golden-brown urediniospores, which except for a circular hilar region were evenly covered with minute conical spines. The spines were situated singly in very shallow depressions surrounded by circular ridges. The dark-brown teliospores had smooth walls with a few linearly arranged fine warts, and the walls were thicker at the apex than on the side. A pale papilla covered the germ pore at the apex of the teliospore, which was borne singly on the fragile pedicel.

Sign in / Sign up

Export Citation Format

Share Document