scholarly journals Stomatal Development in Aerial Axes of Psilotum nudum (Psilotaceae)

2012 ◽  
Vol 128 (3-4) ◽  
pp. 95-99 ◽  
Author(s):  
James E. Mickle ◽  
Maria Rosaria Barone Lumaga ◽  
Paolo De Luca
Keyword(s):  
Electron Microscopy ◽  
Guard Cells ◽  
Cytoplasmic Protein ◽  
Stomatal Development ◽  
Wax Deposition ◽  
Psilotum Nudum ◽  
Pd Alloy ◽  
Entire Cell ◽  
Mother Cells ◽  
Scanning Electron

Abstract Apical regions of developing aerial shoots of Psilotum nudum (L.) Beauv. were studied using both scanning electron microscopy (SEM) and light microscopy (LM) with the aim of improving our understanding of early stages in stomatal and epidermal ontogenesis. SEM samples were fixed in gluteraldehyde, critical point dried, and coated with an Au-Pd alloy. LM samples were fixed in FAA and embedded in paraffin. LM sections were stained with 0.05% toluidine blue for protein. SEM shows that P. nudum stomata develop from 20 µm-long domed meristemoid cells into guard cell mother cells (GMCs). A furrow dividing guard cells develops at 30 µm long, and wax deposition that will cover the entire cell begins at 70 µm long. LM longitudinal sections of GMCs show a cytoplasmic protein net that organizes into radial fibers, similar to reports of actin fibers in stomata of angiosperms. This study provides additional details of stomatal development in Psilotum and is the first report of an actin-like protein net in Psilotum.

A Scanning Electron Microscope Study of Isolated Guard Cells

1973 ◽  
Vol 31 ◽  
pp. 454-455 ◽  
Author(s):  
P. Dayanandan ◽  
P. B. Kaufman
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Three Dimensional ◽  
Guard Cells ◽  
Scanning Electron Microscope Study ◽  
Psilotum Nudum ◽  
Subsidiary Cells ◽  
Welwitschia Mirabilis ◽  
Cycas Revoluta ◽  
Scanning Electron

A three dimensional appreciation of the guard cell morphology coupled with ultrastjuctural studies should lead to a better understanding of their still obscure dynamics of movement. We have found the SEM of great value not only in studies of the surface details of stomata but also in resolving the structures and relationships that exist between the guard and subsidiary cells. We now report the isolation and SEM studies of guard cells from nine genera of plants.Guard cells were isolated from the following plants: Psilotum nudum, four species of Equisetum, Cycas revoluta, Ceratozamia sp., Pinus sylvestris, Ephedra cochuma, Welwitschia mirabilis, Euphorbia tirucalli and Allium cepa.

Stomatal ontogeny and morphology in Phaseolus vulgaris in relation to infection structure initiation by Uromyces appendiculatus

1991 ◽  
Vol 69 (3) ◽  
pp. 477-484 ◽  
Author(s):  
B. T. Terhune ◽  
E. A. Allen ◽  
H. C. Hoch ◽  
W. P. Wergin ◽  
E. F. Erbe
Keyword(s):  
Electron Microscopy ◽  
Phaseolus Vulgaris ◽  
Guard Cells ◽  
Uromyces Appendiculatus ◽  
Stomatal Development ◽  
Appressorium Formation ◽  
Stomatal Complex ◽  
Thin Sections ◽  
Transmission Electron ◽  
Stomatal Guard Cells

The development and morphology of the stomatal complex in Phaseolus vulgaris was examined by light microscopy, scanning electron microscopy, and transmission electron microscopy (TEM). The outer aperture formed between the stomatal guard cells was bordered by cuticular ledges, 1.2–5.3 μm wide. These were composed of a matrix of electron-dense fibrils supporting an autofluorescent amorphous outer layer, homologous to the cuticle. This layer of cuticle lined the ventral walls of the guard cells and extended into the substomatal chamber. During stomatal development, as the guard cells separated, the outer cuticular layer covering the incipient aperture stretched and split, forming stomatal lips. These lips, 0.2–1.4 μm wide, were oriented horizontally, upright, and folded back from the ledge in TEM thin sections. In cryopreserved stomata, the lips were generally oriented upright regardless of whether the outer aperture was open or closed. Previous studies have implicated that stomatal lips may function to signal appressorium formation in urediniospore germlings of Uromyces appendiculatus. This study indicated that dimensions of the lips were within the parameters required to induce appressorium formation on artificial membranes. Other components of the stomatal architecture may also be involved in the induction of appressorium formation. Key words: Uromyces appendiculatus, Phaseolus vulgaris, stomata, cuticle, appressoria.

scholarly journals Micromorphology of the floral elements, the structure of the nectary, and the apicultural value of Elaeagnus commutata Bernh. ex Rydb.

2012 ◽  
Vol 64 (1) ◽  
pp. 27-34
Author(s):  
Mirosława Chwil ◽  
Elżbieta Weryszko-Chmielewska
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Honey Bees ◽  
Epidermal Cells ◽  
Sugar Concentration ◽  
Vascular Bundles ◽  
Stomatal Development ◽  
Adaxial Side ◽  
Abaxial Side ◽  
Scanning Electron

The investigations were carried out using light and scanning electron microscopy. The flowers of <i>Elaeagnus commutata</i> grow in clusters of 1-4 in the leaf axils. They are actinomorphic, four-lobed, with a single perianth that is yellow from the adaxial side, while the abaxial side is silvery-white. Peltate hairs of different structure are found on both surfaces of the sepals. The conical epidermal cells of the lobes are covered with a thick striated cuticle. Cylindrical hairs were observed on the edges of the lobes. Peltate hairs also grew on the style. The dish-shaped nectary gland is located at the base of the style. Nectar is secreted through numerous, evenly distributed stomata located above or at the level of other epidermal cells. Different stages of stomatal development are evidence of the asynchronous functioning of the stomata. The nectary consists of small epidermal cells and 5-6 layers of secretory parenchyma. The deeper layers of the gland are composed of larger cells of subglandular parenchyma in which vascular bundles supplying the nectary run. Honey bees were the main pollinators of silverberry. Ten silverberry flowers produced an average of 12 g of nectar with a sugar concentration in the 29.5-34.5% range. The weight of pollen produced by 10 flowers was 3.33 mg.

A comparative light and electron microscopic study of microspore and tapetal development in male fertile and cytoplasmic male sterile oilseed rape (Brassica napus)

1986 ◽  
Vol 64 (5) ◽  
pp. 1055-1068 ◽  
Author(s):  
I. Grant ◽  
W. D. Beversdorf ◽  
R. L. Peterson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Brassica Napus ◽  
Microspore Development ◽  
Male Sterile ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Mother Cells ◽  
Scanning Electron

The cytological development of male cells and the tapetum of male fertile and combined cytoplasmic triazine-resistant cyto-plasmic-genetic male sterile (ctr) lines of B. napus L. was studied using light, scanning electron, and transmission electron microscopy. Development of the cytoplasmic-genetic male sterile anther was similar to the normal anther up to and including meiotic prophase I. After this stage, degeneration of the microspore mother cells occurs within the callose walls, and tetrads of microspores are not formed. These degenerating microspore mother cells appear to develop numerous endoplasmic reticulum derived vesiculated structures, which may be involved in lysis of organelles. Degeneration occurs simultaneously with a proliferation of the tapetum, which eventually fills the anther locule. It is not clear whether the abortion of the microspore mother cells during meiosis stimulates proliferation of the tapetum or whether the proliferating tapetum actually interferes with microspore development thereby causing degeneration. Dilated endoplasmic reticulum cisternae containing crystalline-like deposits, and plastids with osmiophilic bodies, are frequent in cells of the proliferated tapetum of cytoplasmic-genetic male sterile anthers.

scholarly journals TAXONOMIC IMPORTANCE OF ANTICLINAL WALLS AND STOMATA PATTERNING IN SOME MELASTOMA L. SPECIES FROM FRASER HILL

2020 ◽  
Vol 4 (1) ◽  
pp. 24-26
Author(s):  
Siti- Maisarah, Z. ◽  
Nurul-Aini C.A.C. ◽  
Rozilawati, S. ◽  
Noor-Syaheera, M. Y.
Keyword(s):  
Electron Microscopy ◽  
Guard Cell ◽  
Guard Cells ◽  
Species Level ◽  
Abaxial Surface ◽  
Epidermal Peel ◽  
Taxonomic Importance ◽  
Scanning Electron ◽  
Diagnostic Investigations

The epidermal characteristics of five selected Melastoma L. species in Fraser Hill, Pahang that belongs to Melastomataceae family had been investigated. These five species namely M. muticum Ridl., M. decemfidum Roxb., M. perakense Ridl., M. sanguineum x malabathricum and M. malabathricum var. normale. The objective of this study is to determine whether epidermal characteristics in Melastoma could be taxonomic value in systematic and diagnostic investigations. Methods of the investigation involved epidermal peel and scanning electron microscopy. Results obtained revealed that the presence of hypostomatic stomata and guard cells pairs were elliptic in shaped for all species studied. Apart, the pattern of anticlinal walls on adaxial and abaxial surfaces was straight to wavy for all species studied except for wavy to sinuous anticlinal walls on abaxial surface of M. sanguineum x malabathricum. Furthermore, two types of stomata were observed among species studied such as anomocytic and diacytic stomata. Results showed that diacytic type was only present in M. sanguineum x malabathricum therefore could be a criterion to diagnose the species. Lastly, this present study was also reported on the presence of two types of guard cell pairs such as raised or slightly raised and sunken guard cell pairs. In conclusion, the present study revealed that the anticlinal walls and stomata patterning possess as taxonomic importance in identification and classification of Melastoma either at genus or species level.

scholarly journals The position and structure of the nectary in spring heath (Erica carnea L.) flowers

2012 ◽  
Vol 62 (2) ◽  
pp. 13-21 ◽  
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Mirosław Chwil ◽  
Marek Wróbel
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Guard Cells ◽  
Small Degree ◽  
Nectar Secretion ◽  
Ecological Traits ◽  
Anomocytic Stomata ◽  
Pore Opening ◽  
Floral Nectaries ◽  
Scanning Electron

Ecological traits of <i>Erica carnea</i> L. flowers and the morphology of floral nectaries were investigated using stereoscopic, light and scanning electron microscopy. The nectary in the flowers of <i>Erica carnea</i> is located in the basal part of the ovary. It represents the gynoecial nectary type. It has the form of a yellow, ribbed ring with eight outgrowths, pointed towards the base, which alternately adjoin the stamen filaments. The height of the nectary is 400 µm and its thickness 200 - 250 µm. The parenchyma of the nectary is composed of 6 - 8 layers. Nectar secretion occurs through anomocytic stomata with a diameter of 17 µm. Guard cells are only found on the outgrowths of the nectary and they are situated most frequently at the level of other epidermal cells. During nectar secretion, a small degree of pore opening was observed. In the flowers of <i>Erica carnea</i>, secondary nectar presentation was found, with the nectar accumulating at the base of the fused corolla.

Étude comparée de l'ultrastructure des stomates ouverts et fermés chez le Tradescantia virginiana

1984 ◽  
Vol 62 (7) ◽  
pp. 1505-1512 ◽  
Author(s):  
J. Couot-Gastelier ◽  
D. Laffray ◽  
P. Louguet
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Guard Cells ◽  
Cell Physiology ◽  
Effective Surface ◽  
Tradescantia Virginiana ◽  
Peripheral Reticulum ◽  
Rapid Exchange ◽  
Subsidiary Cells ◽  
Scanning Electron

Guard cells and subsidiary cells of Tradescantia virginiana L. were examined with transmission and scanning electron microscopy. No plasmodesmata occur in the walls between the guard cells and the subsidiary cells. The numerous mitochondria suggest that guard cells are very active. Numerous small vacuoles were observed in closed stomata, whereas few and large vacuoles were present in opened stomata. A specialized peripheral reticulum and some invaginations containing cytoplasm were observed in chloroplasts of opened stomata. This increase of effective surface of the membrane presumably allows a rapid exchange of substances to or from the chloroplast. This was not observed in mesophyll plastids. The structures described are discussed in relation to guard cell physiology.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

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