Ultrastructural analysis of basidiosporogenesis in Panellus stypticus

1992 ◽  
Vol 70 (10) ◽  
pp. 2017-2027 ◽  
Author(s):  
Wilma L. Lingle ◽  
Ronald P. Clay ◽  
David Porter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Wheat Germ Agglutinin ◽  
Cell Walls ◽  
Wheat Germ ◽  
Freeze Substitution ◽  
Rapid Freezing ◽  
Transmission Electron ◽  
Meiosis I

The ultrastructure of events in basidiosporogenesis in Panellus stypticus was examined using conventional, aqueous-based fixation procedures and freeze substitution fixation following plunge freezing in liquid propane. Freeze substitution was superior in preserving cytological features and in retaining cell wall and extracellular materials. Synapsis, all stages of meiosis I (including prophase, metaphase, anaphase, and telophase), and prophase of meiosis II were observed. The nuclear envelope breaks down during meiosis I, temporarily reforms during interphase, and is at least partially broken down during meiosis II. Many stages of spore development, including sterigma initiation, sterigma elongation, organelle translocation, and nuclear migration, were observed. Spindle pole bodies with microtubule arrays were associated with nuclear migration into developing spores. Analysis of hymenial cells with gold-tagged lectins and enzymes revealed an α-amylase positive outer cell wall layer specific to basidiospores. Only after basidiospore release were surfaces of sterigmata and basidia similarly labeled. All cell walls observed were positive for wheat germ agglutinin, indicating the presence of chitin. Septa-delimiting basidiospores from sterigmata were heavily labeled with wheat germ agglutinin. This is the first investigation of basidiosporogenesis in a homobasidiomycete preserved for transmission electron microscopy by rapid freezing and freeze substitution. Key words: fungal cell walls, lectins, gold labeling, meiosis, rapid freezing, transmission electron microscopy.

Ultrastructure of hyperparasitism of Coniothyrium minitans on sclerotia of Sclerotinia sclerotiorum

1987 ◽  
Vol 65 (12) ◽  
pp. 2483-2489 ◽  
Author(s):  
H. C. Huang ◽  
E. G. Kokko
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Sclerotinia Sclerotiorum ◽  
Cell Walls ◽  
Chemical Activity ◽  
Coniothyrium Minitans ◽  
Medullary Tissue ◽  
Transmission Electron

Transmission electron microscopy revealed that hyphae of the hyperparasite Coniothyrium minitans invade sclerotia of Sclerotinia sclerotiorum, resulting in the destruction and disintegration of the sclerotium tissues. The dark-pigmented rind tissue is more resistant to invasion by the hyperparasite than the unpigmented cortical and medullary tissues. Evidence from cell wall etching at the penetration site suggests that chemical activity is required for hyphae of C. minitans to penetrate the thick, melanized rind walls. The medullary tissue infected by C. minitans shows signs of plasmolysis, aggregation, and vacuolization of cytoplasm and dissolution of the cell walls. While most of the hyphal cells of C. minitans in the infected sclerotium tissue are normal, some younger hyphal cells in the rind tissue were lysed and devoid of normal contents.

scholarly journals Rapid Freezing/Freeze Substitution Transmission Electron Microscopy Assessment of Cultured Endothelial Cell Glycocalyx Structure

2011 ◽  
Vol 17 (S2) ◽  
pp. 162-163
Author(s):  
E Ebong ◽  
F Macaluso ◽  
D Spray ◽  
J Tarbell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endothelial Cell ◽  
Freeze Substitution ◽  
Rapid Freezing ◽  
Transmission Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

Ultrastructure of the ungerminated conidium of Blumeria graminis f.sp. hordei

1996 ◽  
Vol 74 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Donald R. Roberts Jr. ◽  
Charles W. Mims ◽  
Melvin S. Fuller
Keyword(s):  
Electron Microscopy ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Freeze Substitution ◽  
Golgi Body ◽  
Blumeria Graminis ◽  
Hydroxyl Groups ◽  
Multivesicular Bodies ◽  
Transmission Electron ◽  
Large Spherical

Ungerminated conidia of Blumeria graminis f.sp. hordei were prepared for transmission electron microscopy using cryofixation and freeze-substitution. Conidia were uninucleate, with the nucleus located in the central portion of the conidium, typically off to one side. The nucleus was spherical and contained a distinct nucleolus with an associated satellite. Conidia contained numerous large, spherical vacuoles that occupied much of the spore volume. Vacuolar contents were mostly homogeneous with occasional electron-opaque inclusions. Much of the cytoplasm consisted of lightly staining aggregations of glycoprotein that could be labelled with Concanavalin A – gold and that stained darkly using a modified Thiéry's reaction specific for carbohydrates containing vicinal hydroxyl groups. Mitochondria, strands of endoplasmic reticulum, Golgi body equivalents, multivesicular bodies, microbodies, Woronin bodies, and microtubules were present in the conidium. Cuboidal, stacked, electron-translucent structures also were present in the cytoplasm. The conidium was surrounded by a two-layered wall that labelled with gold-conjugated wheat germ agglutinin-ovomucoid, indicating the presence of chitin. The wall between attached conidia contained areas that did not label with gold-conjugated wheat germ agglutinin-ovomucoid. Keywords: Erysiphe, ultrastructure, electron microscopy, freeze substitution.

Weight Loss and Cell Wall Degradation in Rubberwood Caused by Sapstain Fungus Botryodiplodia theobromae

Holzforschung ◽  
2002 ◽  
Vol 56 (3) ◽  
pp. 225-228 ◽  
Author(s):  
E. J. M. Florence ◽  
R. Gnanaharan ◽  
P. Adya Singh ◽  
J. K. Sharma
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Weight Loss ◽  
Cell Wall ◽  
Cell Walls ◽  
Cell Wall Degradation ◽  
Botryodiplodia Theobromae ◽  
Percent Weight Loss ◽  
Transmission Electron

Summary Botryodiplodia theobromae is the predominant fungus causing sapstain in rubberwood in Kerala, India. The fungus causes up to 12.2 percent weight loss in rubberwood over a period of sixteen weeks. Transmission Electron Microscopy (TEM) of sapstained rubberwood provided evidence on hyphal invasion of cells by B. theobromae through the pit region, facilitated by its ability to degrade pit membranes. The study also revealed that B. theobromae caused degradation of lignified cell walls by erosion of the cell wall surfaces of wood elements.

Cell wall differentiation during early somatic embryogenesis in plants. II. Ultrastructural study and pectin immunolocalization on chicory embryos

2000 ◽  
Vol 78 (6) ◽  
pp. 824-831 ◽  
Author(s):  
Audrey Chapman ◽  
Anne-Sophie Blervacq ◽  
Théo Hendriks ◽  
Christian Slomianny ◽  
Jacques Vasseur ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Somatic Embryogenesis ◽  
Cell Walls ◽  
Ultrastructural Changes ◽  
Outer Cell ◽  
Embryogenic Cell ◽  
Transmission Electron ◽  
Outer Cell Wall

In Cichorium hybrid clone 474 (C. intybus L. var. sativum × C. endivia L. var. latifolia), direct somatic embryogenesis was induced from roots. Using transmission electron microscopy, we followed the ultrastructural changes of the outer cell wall in relation to embryo developmental stage. During the transition from an embryogenic cell to a somatic embryo, the differentiation of the outer cell wall involved both deposition and rearrangement processes. During the first divisions, the cell wall of few-celled embryos still enclosed in the root tissue appeared as a large amorphous layer of cellulose, thicker than the cell walls of the root cortex cells. When the proembryo emerged from the root cells, the outer wall surface exhibited a fibrillar material designated as the supraembryonic network. As this network disappeared, the outer cell wall changed organization, and two domains were distinguished. At the torpedo stage, the outer cell wall was more compact without any gaps and the protoderm was differentiated. Immunolocalization of an epitope recognised by JIM5 antibody revealed the unesterified nature of the supraembryonic network. Such pectins were also located at the outer third of the outer cell wall of protodermal cells as well as in the intercellular spaces. Highly methylesterified pectins recognized by JIM7 antibodies were slightly present in the cell walls during the embryogenesis process. The different stages of the outer cell wall differentiation as well as the development of the transient supraembryonic network are described, and its possible roles in somatic embryogenesis are proposed.Key words: cell differentiation, cell wall, Cichorium (chicory), pectin, somatic embryogenesis, transmission electron microscopy.

Use of immunogold cytochemistry to detect Mn(II)-dependent and lignin peroxidases in wood degraded by the white rot fungi Phanerochaete chrysosporium and Lentinula edodes

1990 ◽  
Vol 68 (4) ◽  
pp. 920-933 ◽  
Author(s):  
G. Daniel ◽  
B. Pettersson ◽  
T. Nllsson ◽  
J. Volc
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Phanerochaete Chrysosporium ◽  
Cell Walls ◽  
Lentinula Edodes ◽  
White Rot ◽  
Transmission Electron ◽  
Lignin Peroxidases ◽  
Immunogold Cytochemistry

Using antibodies raised against Mn(II)-dependent peroxidase and transmission electron microscopy immunogold cytochemistry, the spatial distribution of Mn(II)-dependent peroxidase during degradation of wood and wood fragments by Phanerochaete chrysosporium and Lentinula edodes was studied. In P. chrysosporium, the enzyme was localized in peripheral regions of the fungal hyphae on the cell membrane, on membranes of vesicule-like structures, and on the cell wall. The cytoplasmic distribution of Mn(II)-dependent peroxidase appeared similar to that of lignin peroxidase, as determined by double immunogold labeling procedures and antibodies raised against lignin peroxidase. In wood blocks of Betula verrucosa degraded by P. chrysosporium and L. edodes, Mn(II)-dependent peroxidase was detected on all wood cell wall layers showing signs of decay, whether at early or advanced stages of attack. In particular, the enzyme was localized in zones of degradation produced within the S2 wood cell walls. These regions displayed a looser, more open fibrillar structure than unattacked wood cell walls and were readily penetrated by purified preparations of Mn(II)-dependent and lignin peroxidases. With L. edodes, Mn(II)-dependent peroxidase was found to accumulate in middle lamellar regions selectively degraded by the fungus. Mn(II)-dependent peroxidase diffusion into undecayed wood cell walls was not observed. Key words: Mn(II)-dependent peroxidase, Phanerochaete chrysosporium, Lentinula edodes, immunogold cytochemistry, white rot decay, transmission electron microscopy.

The influence of acetylsalicylic acid on oxylipin migration in Cryptococcus neoformans var.neoformansUOFS Y-1378

2008 ◽  
Vol 54 (2) ◽  
pp. 91-96 ◽  
Author(s):  
Olihile M. Sebolai ◽  
Carolina H. Pohl ◽  
Piet J. Botes ◽  
Pieter W.J. van Wyk ◽  
Johan L.F. Kock
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Acetylsalicylic Acid ◽  
Cryptococcus Neoformans ◽  
Cell Walls ◽  
Bone Lesion ◽  
Acid Synthesis ◽  
Immunogold Labeling ◽  
Transmission Electron

In this paper we report the influence of acetylsalicylic acid on oxylipin migration in Cryptococcus neoformans var. neoformans UOFS Y-1378, previously isolated from human bone lesion. Transmission electron microscopy suggests that osmiophilic material originates in mitochondria and is deposited inside the yeast cell wall, from which it is excreted into the environment, along capsule protuberances, or through capsule detachments. Previous studies using immunogold labeling indicate that these osmiophilic layers contain 3-hydroxy oxylipins. In this study, the addition of acetylsalicylic acid (an inhibitor of mitochondrial function) in increasing amounts to the cells abrogated the migration of osmiophilic material, as well as capsule detachment from cell walls, and hence, oxylipin excretion. Consequently, we hypothesize that 3-hydroxy oxylipins are produced in mitochondria, probably via incomplete β-oxidation or fatty acid synthesis, from which they are deposited inside the cell wall and excreted through tubular protuberances attached to the surrounding capsules and (or) through detachment of these oxylipin-containing capsules.

scholarly journals Chemical composition, anatomy, lignin distribution, and cell wall structure of Malaysian plant waste fibers

BioResources ◽  
2006 ◽  
Vol 1 (2) ◽  
pp. 220-232 ◽  
Author(s):  
H. P. S. Abdul Khalil ◽  
M. Siti Alwani ◽  
A. K. Mohd Omar
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Chemical Composition ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Anatomical Characteristics ◽  
Lignin Distribution ◽  
Transmission Electron ◽  
Palm Frond

The chemical composition, anatomical characteristics, lignin distribution, and cell wall structure of oil palm frond (OPF), coconut (COIR), pine-apple leaf (PALF), and banana stem (BS) fibers were analyzed. The chemical composition of fiber was analyzed according to TAPPI Methods. Light microscopy (LM) and transmission electron microscopy (TEM) were used to observe and determine the cell wall structure and lignin distribution of various agro-waste fibers. The results revealed differences in anatomical characteristics, lignin distributions, and cell wall structure of the different types of fibers investigated. Nevertheless, transmission electron microscopy (TEM) micrographs have confirmed that the well wall structure, in each case, could be described in terms of a classical cell wall structure, consisting of primary (P) and secondary (S 1 , S 2 , and S 3 ) layers.

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