Scanning electron microscopy of pear blossom invasion by Pseudomonas syringae pv. syringae

1987 ◽  
Vol 65 (12) ◽  
pp. 2523-2529 ◽  
Author(s):  
E. Lucienne Mansvelt ◽  
Martin J. Hattingh
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pseudomonas Syringae ◽  
Internal Tissue ◽  
Nectariferous Tissue ◽  
Scanning Electron

Colonization of 'Packham's Triumph' pear blossoms by Pseudomonas syringae pv. syringae van Hall was examined by scanning electron microscopy. All flower parts examined were colonized. One day after inoculation, numerous bacteria occurred between papillae and in the underlying tissue of stigmas, and on the surface of nectariferous tissue. Small colonies with distinct cells were seen on filaments. Masses of bacteria were present in receptacle tissue 2 days after inoculation. The pressure exerted by the expanding mass of bacteria within some regions of this tissue separated the cuticle from the epidermis. The pathogen probably entered internal tissue through natural openings present in the nectariferous region of the blossoms.

scholarly journals Structure of nectaries of Malus sylvestris (L.) Mill.

2012 ◽  
Vol 59 (1) ◽  
pp. 41-48
Author(s):  
Agata Konarska
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Middle Part ◽  
Epidermal Cells ◽  
Secretory Cells ◽  
Floral Nectary ◽  
Malus Sylvestris ◽  
Parenchyma Cells ◽  
Nectariferous Tissue ◽  
Scanning Electron

The structure of floral nectary of <i>Malus sylvestris</i> was examined using light and scanning electron microscopy. Nectaries in <i>M. sylvestris</i> flowers were situated on the adaxial surface of the receptacle, between the style and the base of filaments. The middle part of the nectary was covered epidermal cells with striated cuticle. The remaining part of the nectary was covered with smooth cuticle. Open and modified nectarostomata were situated at the same level as epidermal cells. The nectariferous tissue was formed by densely packed small parenchyma cells (secretory cells) with dark protoplasts.

scholarly journals A Scanning Electron Microscopy Technique for Viewing Plant−Microbe Interactions at Tissue and Cell-Type Resolution

2019 ◽  
Vol 109 (7) ◽  
pp. 1302-1311 ◽  
Author(s):  
Denise Caldwell ◽  
Anjali S. Iyer-Pascuzzi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Pseudomonas Syringae ◽  
Plant Cell ◽  
Plant Pathogen ◽  
Specific Cell ◽  
Cell Type ◽  
Pathogen Colonization ◽  
Scanning Electron

Observing pathogen colonization and localization within specific plant tissues is a critical component of plant pathology research. High-resolution imaging, in which the researcher can clearly view the plant pathogen interacting with a specific plant cell, is needed to enhance our understanding of pathogen lifestyle and virulence mechanisms. However, it can be challenging to find the pathogen along the plant surface or in a specific cell type. Because of the time-consuming and expensive nature of high-resolution microscopy, techniques that allow a researcher to find a region of pathogen colonization more quickly at low resolution and subsequently move to a high-resolution microscope for detailed observation are needed. Here we present paraffin scanning electron microscopy (PSEM), a technique in which paraffin-embedded samples are first sectioned to identify a region of interest. Subsequently the same block is recut, deparaffinized, and used in scanning electron microscopy (SEM) to generate high-resolution images of plant-pathogen interactions in specific plant cell types. This method has several additional advantages over traditional SEM techniques, including reduced noise and better image quality. Here we use this technique to show that Fusarium oxysporum f. sp. lycopersici colonization is restricted in resistant Solanum pimpinellifolium and that PSEM works well in additional pathosystems, including maize leaves and Clavibacter michiganensis subsp. nebraskensis and Arabidopsis leaves and Pseudomonas syringae.

scholarly journals Comparison of features of the epidermis and the size of the floral nectary in four species of the genus Cotoneaster Med.

2012 ◽  
Vol 64 (4) ◽  
pp. 47-58 ◽  
Author(s):  
Mirosława Chwil ◽  
Elżbieta Weryszko-Chmielewska
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Stomatal Density ◽  
Epidermal Cells ◽  
Floral Nectary ◽  
Cuticular Ornamentation ◽  
Floral Nectaries ◽  
Nectariferous Tissue ◽  
Nectar Flow ◽  
Scanning Electron

The investigations involved four species of the <i>Cotoneaster</i> genus: <i>C. divaricatus</i>, <i>C. horizontalis</i>, <i>C. lucidus</i>, <i>C. praecox</i>, which are commonly grown for decorative purposes. In Poland, these plants bloom in May and June and are a source of abundant spring nectar flow for insects. The floral nectaries of the above-mentioned species were examined using stereoscopic, light, and scanning electron microscopy in order to assess their size and epidermal microstructure. In the plants studied, the upper part of the hypanthium is lined by nectariferous tissue. The nectaries in the four species vary in terms of their sizes. Nectar is secreted onto the surface of the epidermis through anomocytic, slightly elongated or circular stomata. The largest stomata on the nectary epidermis were found in the flowers of <i>C. horizontalis</i>, and the smallest ones in <i>C. divaricatus</i>.Their size and location in relation to other epidermal cells were taxon-specific. The highest density of stomata in the nectary epidermis was found in <i>C. divaricatus</i> (205 per mm<sup>2</sup>), whereas <i>C. horizontalis</i> flowers exhibited the lowest (98 per mm<sup>2</sup>) stomatal density. The cuticular ornamentation on the nectary epidermis surface was diverse. The stomatal indices calculated for the nectary epidermis were considerably lower than for the leaves in the particular species.

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.

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.

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).

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