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.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Dislocations in alumina deformed by prismatic slip

1978 ◽  
Vol 36 (1) ◽  
pp. 606-607
Author(s):  
J. Cadoz ◽  
J. Castaing ◽  
J. Philibert
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basal Slip ◽  
Prismatic Slip ◽  
Compression Tests ◽  
Thin Sections ◽  
Burgers Vector ◽  
Maximum Deformation ◽  
Transmission Electron ◽  
Mechanical Thinning

Plastic deformation of alumina has been much studied; basal slip occurs and dislocation structures have been investigated by transmission electron microscopy (T.E.M.) (1). Non basal slip has been observed (2); the prismatic glide system <1010> {1210} has been obtained by compression tests between 1400°C and 1800°C (3). Dislocations with <0110> burgers vector were identified using a 100 kV microscope(4).We describe the dislocation structures after prismatic slip, using high voltage T.E.M. which gives much information.Compression tests were performed at constant strainrate (∿10-4s-1); the maximum deformation reached was 0.03. Thin sections were cut from specimens deformed at 1450°C, either parallel to the glide plane or perpendicular to the glide direction. After mechanical thinning, foils were produced by ion bombardment. Details on experimental techniques can be obtained through reference (3).

Some early history of replica techniques for electron microscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1076-1077
Author(s):  
Robert M. Fisher
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Optical Microscope ◽  
Early History ◽  
Bulk Materials ◽  
Thin Sections ◽  
Transmission Electron ◽  
Reflected Light ◽  
History Of ◽  
Electron Microscopes

By 1940, a half dozen or so commercial or home-built transmission electron microscopes were in use for studies of the ultrastructure of matter. These operated at 30-60 kV and most pioneering microscopists were preoccupied with their search for electron transparent substrates to support dispersions of particulates or bacteria for TEM examination and did not contemplate studies of bulk materials. Metallurgist H. Mahl and other physical scientists, accustomed to examining etched, deformed or machined specimens by reflected light in the optical microscope, were also highly motivated to capitalize on the superior resolution of the electron microscope. Mahl originated several methods of preparing thin oxide or lacquer impressions of surfaces that were transparent in his 50 kV TEM. The utility of replication was recognized immediately and many variations on the theme, including two-step negative-positive replicas, soon appeared. Intense development of replica techniques slowed after 1955 but important advances still occur. The availability of 100 kV instruments, advent of thin film methods for metals and ceramics and microtoming of thin sections for biological specimens largely eliminated any need to resort to replicas.

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.

Dislocations and stacking faults in stainless steel

1957 ◽  
Vol 240 (1223) ◽  
pp. 524-538 ◽  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stainless Steel ◽  
Grain Boundaries ◽  
Stacking Faults ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Thin Sections ◽  
Partial Dislocations ◽  
Transmission Electron

Further experiments by transmission electron microscopy on thin sections of stainless steel deformed by small amounts have enabled extended dislocations to be observed directly. The arrangement and motion of whole and partial dislocations have been followed in detail. Many of the dislocations are found to have piled up against grain boundaries. Other observations include the formation of wide stacking faults, the interaction of dislocations with twin boundaries, and the formation of dislocations at thin edges of the foils. An estimate is made of the stacking-fault energy from a consideration of the stresses present, and the properties of the dislocations are found to be in agreement with those expected from a metal of low stacking-fault energy.

scholarly journals Submicroscopical Features of Leaves of Xyris Species

2001 ◽  
Vol 44 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Maria das Graças Sajo ◽  
Silvia Rodrigues Machado
Keyword(s):  
Electron Microscope ◽  
Cell Walls ◽  
Guard Cells ◽  
Leaf Ultrastructure ◽  
Mesophyll Cells ◽  
Transmission Electron ◽  
Inner Surface ◽  
Stomatal Guard Cells ◽  
Adaptative Significance ◽  
Scanning Electron

The leaf ultrastructure of five Xyris species were examined using scanning electron microscope (SEM), transmission electron microscope (TEM) and histochemical methods. All studied leaves show some features in epidermis and mesophyll, which were of considerable adaptative significance to drought stress. Such features included the occurrence of a pectic layer on the stomatal guard cells and the presence of a network of pectic compounds in the cuticle. Pectic compunds were also in abundance in lamellated walls of the mesophyll cells and on the inner surface of the sclerified cell walls of the vascular bundle sheaths. There were also specialized chlorenchymatous "peg cells" in the mesophyll and drops of phenolic compounds inside the epidermal cells.

Ultrastructure of the Tertiary Envelope of the Cyst of the Tadpole Shrimp Triops longicaudatus (Branchiopoda; Notostraca)

2000 ◽  
Vol 6 (S2) ◽  
pp. 872-873
Author(s):  
James R. Rosowski ◽  
Terry L. Bartels ◽  
James F. Colburn ◽  
Jannell L. Colton ◽  
Denton Belk ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fairy Shrimp ◽  
Distilled Water ◽  
Thin Sections ◽  
Rainfall Events ◽  
Transmission Electron ◽  
Tadpole Shrimp ◽  
Species Specific ◽  
Scanning Electron

Tadpole shrimp inhabit temporary freshwater pools and ponds where their occurrence is largely regulated by rainfall events and water temperature. When dry basins are flooded, cysts of Triops imbibe water and hatch to produce rapidly growing, carapaced larvae. While previous studies show anostracan (fairy shrimp) cyst-surface morphology often species specific, few studies illustrate shell ultrastructure of Triops and none has considered T. longicaudatus. Here we examine the shell of T. longicaudatus (Notostraca) and compare its fine structure to other species of Triops and to that of Artemiafranciscana(Anostraca), which we previously studied.Cysts, produced in culture from Utah broodstock, were purchased from Triops, Inc., 1924 Creighton Rd., Pensacola, FL 32504. Thin sections of cysts were prepared for transmission electron microscopy (TEM) as previously described (Fig. 1). Cysts were also examined with scanning electron microscopy (SEM), dry, whole or fractured (Figs. 2,3), or after imbibition and/or hatching in oxygen saturated, double-distilled water, at 25 ° C.

Neoformation of halloysite on volcanic glass in a marine environment

Clay Minerals ◽  
1987 ◽  
Vol 22 (2) ◽  
pp. 179-185 ◽  
Author(s):  
T. Imbert ◽  
A. Desprairies
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Marine Environment ◽  
Experimental Studies ◽  
Volcanic Glass ◽  
Marine Environments ◽  
Thin Sections ◽  
Transmission Electron ◽  
Glass Shards

AbstractTransmission electron microscopy of ultramicrotomed thin-sections of Pleistocene and Eocene glass shards revealed the neoformation of (i) illite and (ii) halloysite at the glass periphery. According to previous experimental studies, halloysite neoformation in marine environments can occur on glass shards deposited in Si-rich sediments; an excess of Ca tends to inhibit the reaction.

Demountable polished extra-thin sections and their use in transmission electron microscopy

1981 ◽  
Vol 44 (335) ◽  
pp. 357-359 ◽  
Author(s):  
D. J. Barber
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Epoxy Resin ◽  
Essential Feature ◽  
Heterogeneous Materials ◽  
Glass Slide ◽  
Thin Sections ◽  
Fine Grained ◽  
Transmission Electron ◽  
Polished Side

The advantages of polished ultra-thin sections (PUTS) in the study of very fine-grained materials, such as occur in some meteorites, have been illustrated by Fredriksson et al. (1978) whose technique is based on the earlier work of Beauchamp and WiUiford (1974). An essential feature of such methods for friable and heterogeneous materials is the use of a medium, usually an epoxy resin, to consolidate and partially impregnate them. Normally one polished side of the specimen is bonded to a glass slide during preparation, and the finished PUTS are integral with the slide on completion. PUTS are typically 2-5 microns in thickness.

Simplified procedures for releasing and concentrating microorganisms from soil for transmission electron microscopy viewing as thin-sectioned and frozen-etched preparations

1975 ◽  
Vol 21 (3) ◽  
pp. 252-262 ◽  
Author(s):  
D. L. Balkwill ◽  
D. P. Labeda ◽  
L. E. Casida Jr.
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Types ◽  
Soil Slurry ◽  
Thin Sections ◽  
Choice Of Procedure ◽  
Transmission Electron ◽  
Cell Release ◽  
Simplified Procedures ◽  
Simplified Procedure

A simplified procedure is presented for releasing and concentrating indigenous microbial cells from soil for viewing by transmission electron microscopy as thin sections or replicas of frozen-etched preparations. This procedure is compared with two others reported earlier, and their relative merits are discussed as concerns the choice of procedure for the cellular information desired from the soil. Freeze-etching showed that the cell types and size distributions for cells which have been released and concentrated from soil are in general agreement with those for cells in a crude soil slurry in which no attempt to release and concentrate cells was made. Microcolonies were present both in the crude slurry and in the discard soil debris centrifugation pellets from the cell release and concentration procedures. In contrast to the historic assumptions, these microcolonies, as well as some individual cells embedded in soil debris could not be broken up and (or) dislodged so that they would be washed from the soil. The relative numbers of these cells remaining with the soil debris, however, could not be quantitated in the present study.

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