Peroxidases in Tobacco Abscission Zone Tissue

1973 ◽  
Vol 13 (2) ◽  
pp. 591-601 ◽  
Author(s):  
E. W. HENRY ◽  
T. E. JENSEN
Keyword(s):  
Cell Walls ◽  
Osmium Tetroxide ◽  
Specific Inhibitor ◽  
Potassium Cyanide ◽  
Staining Reaction ◽  
Intercellular Spaces ◽  
Structural Investigations ◽  
Structural Localization ◽  
Nicotiana Tabacum L ◽  
Peripheral Areas

The fine-structural localization of peroxidases during ethylene-induced abscission of flower pedicels of Nicotiana tabacum L. cv. ‘Little Turkish’ has been investigated. Peroxidase activity has been localized in both the cell walls and intercellular spaces of ethylene-treated flower pedicels which were fixed in glutaraldehyde, incubated in diaminobenzidine (DAB) medium with postfixation in 2% osmium tetroxide. Peroxidase staining is present in the cell walls and intercellular spaces of control tissue but is not as intense as in ethylene-treated tissue. Increased peroxidase staining is evident in the intercellular spaces and cell walls after 2 h of exposure to ethylene and increases in intensity between 2 and 5 h. At 5 h, ethylene-induced abscission occurs. Fine-structural investigations revealed prominent staining in the middle-lamellar and peripheral areas of the cell walls in ethylene-treated tissue. The peroxidase staining appears to be due to peroxidase as prior incubation with potassium cyanide gives a marked reduction in the staining reaction. Incubation of the ethylene-exposed tissue in aminotriazole, a specific inhibitor of catalase, does not reduce peroxidase staining, except in the microbodies, which reportedly contain catalase.

scholarly journals A LIGHT AND ELECTRON HISTOCHEMICAL APPROACH TO THE NODE OF RANVIER AND MYELIN OF PERIPHERAL NERVE FIBERS

1967 ◽  
Vol 15 (12) ◽  
pp. 722-731 ◽  
Author(s):  
O. K. LANGLEY ◽  
D. N. LANDON
Keyword(s):  
Osmium Tetroxide ◽  
Node Of Ranvier ◽  
Nerve Fibers ◽  
Blue Pigment ◽  
Staining Reaction ◽  
Myelinated Nerve ◽  
Structural Localization ◽  
Axon Membrane ◽  
Specific Localization ◽  
Exchange Properties

The Hale staining reaction has been used to study the nature and distribution of acid mucopolysaccharides associated with mammalian peripheral myelinated nerve fibers. Histochemical blocking reactions were employed to determine the specificity of the method. Electron micrographs of parallel preparations were examined to discover the fine structural localization of the optically visible Prussian blue pigment. The observations reported suggest that there is a specific localization of a sulfated mucopolysaccharide in the region immediately surrounding the axolemma at the node of Ranvier. Other parts of the fiber, in particular the myelin sheath, show a preponderance of carboxyl groups. Attention is drawn to the variation in the form and distribution of the Hale stain product after differing fixation procedures. The effect of osmium tetroxide on ferrocyanide-treated material is examined and discussed. Attention is directed to possible physiologic implications of the presence of material with the known ion exchange properties of a sulfated mucopolysaccharide in the immediate environment of the ionically active nodal axon membrane.

Morphological peculiarities of seeds of some species of the genus Epipactis Zinn. (Orchidaceae Juss.) of Ukrainian flora

2019 ◽  
Vol 11 (1) ◽  
pp. 93-100
Author(s):  
T Ljubka ◽  
O Tsarenko ◽  
I Tymchenko
Keyword(s):  
Seed Coat ◽  
Cell Walls ◽  
Morphological Study ◽  
Population Level ◽  
Intercellular Spaces ◽  
Different Populations ◽  
Periclinal Walls ◽  
High Degree ◽  
Shape And Size ◽  
Generative Organs

The investigation of macro- and micromorphological peculiarities of seeds of four species of genus Epipactis (Orchidaceae) of Ukrainian flora were carried out. The genus Epipactis is difficult in the in in taxonomic terms and for its representatives are characterized by polymorphism of morphological features of vegetative and generative organs of plants and ability of species to hybridize. The aim of the research was to perform a comparative morphological study of seeds of E. helleborine, E. albensis, E. palustris, E. purpurata and to determine carpological features that could more accurately identify species at the stage of fruiting. A high degree of variation in the shape of the seeds in different populations within the species and overlap of most quantitative carpological characteristics of studied species are noted. There were no significant differences in micromorphological features of the structure of the testa at species or population level. The reticulate surface of the testa is characteristic of all species, the cells of testa are mostly elongated, penta-hexagonal, individual cells almost isodiametric-pentagonal. From the micropillary to the chalasal end, a noticeable change in the shape and size of the seed coat cells is not observed. There are no intercellular spaces, the anticlinal walls of adjacent cells are intergrown and the boundaries between them become invisible. The outer periclinal walls have a single, mainly longitudinal thin ribbed thickenings. Anticlinal cell walls are thick, dense, smooth. The longitudinal Anticlinal walls are almost straight, transverse - straight or sometimes curved in some cells. Epicuticular deposits on the periclinal walls are absent. It is concluded that the use of macro and micromorphological characteristics of seeds of these species for clearer diagnosis at the stage of fruiting is low informative.

MICROSTRUCTURE ANALYSIS OF MOSO BAMBOO (Phyllostachys pubescens MAZEL) SURFACE AFTER UV RADIATION

2019 ◽  
Vol 27 (01) ◽  
pp. 1950090
Author(s):  
HAIXIA YU ◽  
XIN PAN ◽  
WEIMING YANG ◽  
WENFU ZHANG ◽  
XIAOWEI ZHUANG
Keyword(s):  
Uv Radiation ◽  
Cell Walls ◽  
Uv Light ◽  
Parenchyma Cell ◽  
Moso Bamboo ◽  
Thick Wall ◽  
Phyllostachys Pubescens ◽  
Thin Wall ◽  
Intercellular Spaces ◽  
Parenchyma Cell Walls

Bamboo material is widely used in outdoor applications. However, they are easily degraded when exposed to sunlight, their smooth surface will gradually turn to rough, and small cracks will appear and finally develop to large cracks. The paper presents a first-time investigation on the microstructure changes in the tangential section of Moso bamboo (Phyllostachys pubescens Mazel) radiated by artificial UV light. The results showed that the cracks mainly appeared at intercellular spaces of fibers where lignin content was high, the parenchyma cell walls and neighbor pits where the cell wall was very thin and more vulnerable than the other parts. In addition, the part of raised area and pit cavity tended to absorb more UV light radiation and showed more and larger cracks than the otherwhere. Cracks at the intercellular spaces of fibers were larger and bigger than those on the parenchyma cell walls. The cracks on the pits of the parenchyma cell walls normally appeared at one pit and then extended to the several surrounding pits. Bordered pits cavity showed more and larger cracks than the pits on the thin wall cells. The simple pits on the thick wall cells and the fiber cells were unaffected by UV radiation.

scholarly journals Ultrastructure of the Developing Aleurone Cells of Wheat Grain

1963 ◽  
Vol 16 (4) ◽  
pp. 768 ◽  
Author(s):  
MS Buttrose
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Cell Walls ◽  
Osmium Tetroxide ◽  
Aleurone Layer ◽  
Wheat Grain ◽  
Aleurone Cells ◽  
Wheat Kernel ◽  
Large Numbers ◽  
Inner Surface

The developing aleurone layer cells of the wheat kernel have been investigated by electron microscopy and the results compared with those of light microscopy. Two weeks after flowering vacuoles appear in the cells and deposits accumulate in these until maturity when the cells are filled 'with the resulting "vacuolar units" 2-3p. in diameter, corresponding to the aleurone grains of light microscopy. The wheat aleurone grain consists of a bounding membrane (of vacuole origin) enclosing a matrix in which are embedded spherical deposits. Some of these deposits are translucent and others opaque to electrons after potassium permanganate and osmium tetroxide fixation. At all stages examined the cytoplasm of aleurone cells contained large numbers of small unidentified bodies with irregular outline and dense contents. At first they are dispersed, but towards maturity are organized as a monolayer over the surface of each aleurone grain and the inner surface of the cell walls. The apparent specificity of these structures to aleurone cells is discussed in relation to future chemical and physiological studies of the tissue.

Localisation structurale et ultrastructurale d'activités peroxydasiques dans les parois du mésophylle et des fibres en cours de lignification chez l'alfa (Stipa tenacissima)

1984 ◽  
Vol 62 (12) ◽  
pp. 2644-2649 ◽  
Author(s):  
M. Harche
Keyword(s):  
Peroxidase Activity ◽  
Oxidase Activity ◽  
Cell Walls ◽  
Secondary Wall ◽  
Outer Part ◽  
Potassium Cyanide ◽  
Primary Wall ◽  
Stipa Tenacissima ◽  
Parenchyma Cells

Using diaminobenzidine as substrate, peroxidase activity was localized in the walls of parenchyma cells and differentiating fibres. In mature fibres and parenchyma a slight activity could be recognized in primary walls only. In parenchyma cells, peroxidase activity was fairly inhibited with heat, potassium cyanide, and aminotriazole, which could indicate the presence of catalase within the cell walls. However, in plasmodesmatal regions peroxidases were- resistant to the above inhibitors. Syringaldazine oxidase activity was present only in the primary wall and the outer part of the secondary wall of differentiating fibres. The parallelism between lignification and peroxidase activity in the secondary walls supports the hypothesis of the involvement of these enzymes in the lignification process.

Bayoud disease of date palm: ultrastructure of root infection through pneumatodes

1986 ◽  
Vol 64 (8) ◽  
pp. 1703-1711 ◽  
Author(s):  
Rosa Belarbi-Halli ◽  
François Mangenot
Keyword(s):  
Cell Walls ◽  
Date Palm ◽  
Root Colonization ◽  
Phoenix Dactylifera ◽  
Root Infection ◽  
Intercellular Spaces ◽  
Main Root ◽  
The Matrix ◽  
Bayoud Disease ◽  
Root Apices

Young axenically grown plants of date palm, Phoenix dactylifera cv. Deglet-nour, were inoculated with Fusarium oxysporum Schl. f. sp. albedinis (Killian et Maire) Gordon, using conidia applied either on the pneumatode-free main root or on the pneumatodes of rootlets. After incubation for 15 days, infection was successful only in the latter case. The fungus grew inside the aerenchyma and clung tightly to the cell walls, the wartlike outgrowths, and the matrix present in the intercellular spaces. These structures were more or less altered in the presence of the hyphae. The fungus proceeded both intercellularly and intracellularly through the cortex. A dense hyphal sheet was observed facing the suberized endodermis, but the fungus somehow made its way into the stele. Penetrations of thick-walled cells commonly occurred through pits. Root colonization was slower toward the root apices than toward the base. After 15 days, the fungus was present at least 8 cm above the inoculation point at the base of the root.

Morphological stabilization of the glycocalyces of 23 strains of five Bacteroides species using specific antisera

1984 ◽  
Vol 30 (6) ◽  
pp. 809-819 ◽  
Author(s):  
Dwight W. Lambe Jr. ◽  
K. J. Mayberry-Carson ◽  
Kaethe P. Ferguson ◽  
J. William Costerton
Keyword(s):  
Cell Walls ◽  
Indirect Fluorescent Antibody Test ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Ruthenium Red ◽  
Intercellular Spaces ◽  
Outer Membranes ◽  
Bacteroides Species ◽  
Heterologous Antiserum ◽  
Specific Antisera

Cells of five Bacteroides species were examined following treatment with homologous antisera and staining with ruthenium red. They were enveloped by glycocalyces and these extensive fibrous exopolysaccharide matrices were fully retained as an integral "capsule" by some cells, while other cells showed "capsule" as well as detached glycocalyx components forming an intercellular "slime." These extensive glycocalyces collapsed during dehydration for electron microscopy and formed electron-dense accretions on cell surfaces and electron-dense reticula in intercellular spaces when the cells were treated with heterologous antiserum or when antibody stabilization was omitted. The glycocalyces of all strains, both stabilized and unstabilized, were observed outside the outer membranes of cell walls that showed the "classic" gram-negative structural organization. Appropriate modifications of the indirect fluorescent antibody test demonstrated an integral "capsule" on all strains examined; detached glycocalyx and varying amounts of slime were demonstrated after stabilization with homologous, but not heterologous, antiserum.

Penetration and invasion of sunflowers by Sclerotium bataticola

1973 ◽  
Vol 51 (5) ◽  
pp. 999-1002
Author(s):  
Y. H. Chan ◽  
W. E. Sackston
Keyword(s):  
Cell Walls ◽  
Mass Action ◽  
Adult Plant ◽  
Intercellular Spaces ◽  
Virulent Isolate ◽  
Direct Penetration ◽  
Sclerotial Formation ◽  
Avirulent Isolate

Sclerotium bataticola forms appressoria on the epidermis of inoculated sunflower seedlings. The appressoria may aid both mechanical and chemical penetration. Penetration is direct. Penetration of adult plant stems is by mass action of hyphae.Invading hyphae are both intra- and inter-cellular. Longitudinal spread in the cortex is in the intercellular spaces. Hyphae are closely associated with cell walls and the walls of xylem vessels. Vessels are penetrated through the pits.A virulent isolate formed sclerotia on inoculated seedlings within 24 h. An avirulent isolate formed chlamydospore-like resting structures first, and sclerotia later. Sclerotial formation appeared to reflect level of nutrition rather than relationships of isolates.

THE EFFECT OF PENICILLIN ON THE STRUCTURE OF STAPHYLOCOCCAL CELL WALLS

1959 ◽  
Vol 5 (6) ◽  
pp. 641-648 ◽  
Author(s):  
R. G. E. Murray ◽  
W. H. Francombe ◽  
B. H. Mayall
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Untreated Control ◽  
Osmium Tetroxide ◽  
Wall Material ◽  
Cell Wall Material ◽  
Cell Wall Synthesis ◽  
Cell Wall Component ◽  
A Cell ◽  
Resistant Strains

Cultures of sensitive stains of Staphylococcus aureus were fixed with osmium tetroxide after 1–5 hours' exposure to various does of pencillin and were embedded in methacrylate for sectioning and electron microscopy. They were compared with untreated, control cultures. The contrast of the cell wall material was untreated, control cultures. The contrast of the cell wall material was increased, by cutting the section of lanthanum nitrate.The cells increased in size and the surrounding cell wall was thinner than normal. The main lesions appeared in the developing cell wall septa, which showed a loss in density and gross irregularity of shape. Some questionable inclusions were seen in the cytoplasm. Lysis was prevented in a medium containing 0.3 M sucrose and the stable spheroplasts retained a recognizable cell wall after 24 hours' exposure to penicillin. However, the septa could not be demonstrated in the cells treated in sucrose medium.Two resistant strains were exposed to penicillin. In one, the cells showed no morphological effects; in the other, there was temporary damage to the cell septa with complete recovery.The observations support the hypothesis that penicillin interferes with the synthesis of a cell wall component and indicate that the main point of cell wall synthesis is at the site of septum formation.

Osmium Staining Fails to Detect Early Cell Wall Damage in Brown Rot Wood Decay

IAWA Journal ◽  
1994 ◽  
Vol 15 (2) ◽  
pp. 133-136
Author(s):  
W. Wayne Wilcox
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Cell Walls ◽  
Osmium Tetroxide ◽  
Wood Decay ◽  
Brown Rot ◽  
X Ray ◽  
Polarised Light ◽  
Early Manifestation ◽  
Scanning Electron

Loss of cell wall birefringence under polarised light in the light microscope is an important diagnostic characteristic for early stages of brown rot wood decay not available with the scanning electron microscope (SEM). Osmium tetroxide staining was explored as a means of visualising this early manifestation of decay in the SEM, but proved unsuccessful as X-ray spectroscopy indicated that osmium was evenly distributed across both distorted and non-distorted cell walls.

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