scholarly journals The comparison of nectaries structure of some varieties of ornamental apple

2012 ◽  
Vol 60 (1) ◽  
pp. 35-43
Author(s):  
Agata Konarska
Keyword(s):  
Cell Wall ◽  
Light Microscope ◽  
Outer Wall ◽  
Epidermal Cells ◽  
Outer Cell ◽  
Glandular Tissue ◽  
Floral Nectary ◽  
Apple Cultivars ◽  
Outer Cell Wall ◽  
Scanning Electron

The study of floral nectary structures of thirteen ornamental apple cultivars examined using light microscope (MS) and scanning electron microscope (SEM) was performed. It was found that nectary glands in the selected cultivars were located in the upper part of the flower receptacle, between the ovary of the pistil and the base of stamen filaments, and they generally belonged to the epimorphic or transitoric type. The nectary surface area, its thickness, the number of glandular tissue layers, the height of epidermal cells of the nectary and the thickness of the outer wall of the epidermis, together with the cuticle, were determined by light microscope. By using SEM, the structure of the surface of nectaries in four ornamental apple cultivars was observed. The epidermis of the upper part of the nectaries was composed of elongated cells of which outer cell wall was covered with a striated cuticle. The remaining part of the nectary was characterised by cells of similar arrangement and shape, but their surface was marked by a thinner and smoother layer of cuticle. Closed or opened stomata were generally situated at the level of the epidermal cells. Their pores were often filled with granular or plate-shaped structures.

scholarly journals Micromorphology of Sorbus intermedia Pers. nectary surface in different phases of blooming

2012 ◽  
Vol 59 (1) ◽  
pp. 49-59
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Agata Konarska
Keyword(s):  
Flower Development ◽  
Cell Walls ◽  
Guard Cells ◽  
Outer Cell ◽  
Final Phase ◽  
Floral Nectary ◽  
Pollen Release ◽  
Epidermis Cell ◽  
Outer Cell Wall ◽  
Scanning Electron

The structure of floral nectary surface of <i>Sorbus intermedia</i> in different phases of flower development was examined using scanning electron microscopy. Nectaries in <i>S. intermedia</i> flowers represent a receptacle type. The sculpture of cuticule on nectary epidermis and overlaying cells was described. The differences in the size of striaes on the outer cell wall of epidermis during the flower development were stated. Nectarostomata were situated in small hollows. In the buds, they were closed and not fully developed. During pollen release phase, the outer ledges of the guard cells were better developed than at the beginning of blooming. Depressions on nectary epidermis cell walls were observed in the final phase of blooming.

Spheroplasts of Methanospirillum hungatii formed upon treatment with dithiothreitol

1979 ◽  
Vol 25 (6) ◽  
pp. 730-738 ◽  
Author(s):  
G. D. Sprott ◽  
J. R. Colvin ◽  
R. C. McKellar
Keyword(s):  
Cell Wall ◽  
Attachment Site ◽  
Outer Wall ◽  
Methanogenic Bacteria ◽  
Methanosarcina Barkeri ◽  
Outer Cell ◽  
Alkaline Ph ◽  
Adhesive Material ◽  
Thin Sections ◽  
Outer Cell Wall

Strains of Methanospirillum hungatii, when treated with dithiothreitol at alkaline pH, formed spheroplasts which lysed in the absence of an osmotic stabilizer. Other methanogenic bacteria showed no response to this treatment, including Methanobacterium thermoautotrophicum. Methanobacterium strain M.o.H., Methanobacterium strain G2R, and Methanosarcina barkeri. The reaction with M. hungatii proceeded slowly at pH 8.0, but increased dramatically up to a pH of 10. Spheroplasts did not form in the presence of MgCl2 or if large amounts of FeS precipitate had been deposited on the cells during growth. Ultra-thin sections of M. hungatii GPI confirmed that individual cells, surrounded by a membrane and an inner wall, were contained within an outer wall or sheath. Adhesive material, which stained in the region of the cell spacer, was observed to bind together the inner and outer wall layers. After treatment with dithiothreitol, the spheroplasts, which retained the flexible inner wall and membrane, were released from the rigid outer wall. Examination of the isolated outer cell wall revealed that dithiothreitol (and dodecyl sodium sulfate) dissolved the adhesive material and damaged the cell spacer at the attachment site to the outer wall. It is proposed that dithiothreitol at alkaline pH loosens both the cell spacer and inner wall attachments to the outer wall, thereby allowing the osmotic pressure of the cytoplasm to eject the spheroplast. Resistance of the cells to lysis by Triton X-100 is lost upon spheroplast formation, indicating that protection to the cell is conferred by the outer cell wall.

Diploneis fenestrata sp. nov. (Bacillariophyta), a new aerophilic diatom species from Zambia, Africa

Phytotaxa ◽  
2014 ◽  
Vol 167 (1) ◽  
pp. 79 ◽  
Author(s):  
JONATHAN C. TAYLOR ◽  
BALASUBRAMANIAN KARTHICK ◽  
CHRISTINE COCQUYT ◽  
PAULINE LANG
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Novel Species ◽  
Outer Cell ◽  
Diatom Species ◽  
Outer Cell Wall ◽  
Scanning Electron

Diploneis fenestrata, a new aerophilic diatom is described from Lumangwe falls, Zambia. This novel species occurs as an epiphyte on the roots and stems of trees located within the spray zone of the falls. Its morphology was examined with both light and scanning electron microscopy. Diploneis fenestrata is distinguished from other taxa in the genus Diploneis by its prominent square openings ranging in number from 4-14 occurring within the area of the longitudinal canal only at the outer cell wall. The occurrence of these characteristic square openings found in the genus Diploneis is further discussed.

scholarly journals THE STRUCTURE OF THE PRIMARY EPIDERMAL CELL WALL OF AVENA COLEOPTILES

1957 ◽  
Vol 3 (2) ◽  
pp. 171-182 ◽  
Author(s):  
S. T. Bayley ◽  
J. R. Colvin ◽  
F. P. Cooper ◽  
Cecily A. Martin-Smith
Keyword(s):  
Cell Wall ◽  
Outer Wall ◽  
Epidermal Cells ◽  
Cellulose Microfibrils ◽  
X Rays ◽  
Primary Wall ◽  
Normal Type ◽  
Number Of Layers ◽  
Angle Scattering ◽  
Epidermal Cell Wall

The primary walls of epidermal cells in Avena coleoptiles ranging in length from 2 to 40 mm. have been studied in the electron and polarizing microscopes and by the low-angle scattering of x-rays. The outer walls of these cells are composed of multiple layers of cellulose microfibrils oriented longitudinally; initially the number of layers is between 10 and 15 but this increases to about 25 in older tissue. Where epidermal cells touch, these multiple layers fuse gradually into a primary wall of the normal type between cells. In these radial walls, the microfibrils are oriented transversely. Possible mechanisms for the growth of the multilayered outer wall during cell elongation are discussed.

A freeze-etch study of plant cell walls for ectodesmata

1974 ◽  
Vol 52 (9) ◽  
pp. 2033-2036 ◽  
Author(s):  
N. C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Leaf Tissue ◽  
Physicochemical Characteristics ◽  
Outer Cell ◽  
Plantago Major ◽  
Plant Cell Walls ◽  
Phaseolus Vulgaris L ◽  
Epidermal Cell Wall ◽  
Outer Cell Wall

Leaf tissue of Phaseolus vulgaris L. and Plantago major L. was prepared by the freeze-etch technique and examined in the electron microscope for the presence of ectodesmata. No structures analagous to ectodesmata observed with light microscopy could be found in freeze-etched preparations of chemically unfixed material or in material fixed only in glutaraldehyde. Objects appearing as broad, shallow, granular areas in the epidermal cell wall beneath the cuticle were observed in leaf replicas after fixation in complete sublimate fixative, the acid components of the sublimate fixative, or mercuric chloride alone. Because of their distribution and location, these objects can be considered analagous to ectodesmata observed by light microscopists. Because these areas occur only in chemically fixed walls and are localized within the walls in discrete areas, their presence supports the contention that ectodesmata are sites in the outer cell wall with defined physicochemical characteristics.

scholarly journals Spreading of a mycobacterial cell-surface lipid into host epithelial membranes promotes infectivity

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
CJ Cambier ◽  
Steven M Banik ◽  
Joseph A Buonomo ◽  
Carolyn R Bertozzi
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Immune Activation ◽  
Cholesterol Synthesis ◽  
Membrane Lipids ◽  
Preventive Therapy ◽  
Outer Cell ◽  
Surface Lipid ◽  
Epithelial Membranes ◽  
Outer Cell Wall

Several virulence lipids populate the outer cell wall of pathogenic mycobacteria. Phthiocerol dimycocerosate (PDIM), one of the most abundant outer membrane lipids, plays important roles in both defending against host antimicrobial programs and in evading these programs altogether. Immediately following infection, mycobacteria rely on PDIM to evade Myd88-dependent recruitment of microbicidal monocytes which can clear infection. To circumvent the limitations in using genetics to understand virulence lipids, we developed a chemical approach to track PDIM during Mycobacterium marinum infection of zebrafish. We found that PDIM's methyl-branched lipid tails enabled it to spread into host epithelial membranes to prevent immune activation. Additionally, PDIM’s affinity for cholesterol promoted this phenotype; treatment of zebrafish with statins, cholesterol synthesis inhibitors, decreased spreading and provided protection from infection. This work establishes that interactions between host and pathogen lipids influence mycobacterial infectivity and suggests the use of statins as tuberculosis preventive therapy by inhibiting PDIM spread.

scholarly journals Changes in structure of red pepper (Capsicum annuum L.) seedlings shoots under aluminum stress conditions

2012 ◽  
Vol 60 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Agata Konarska
Keyword(s):  
Cell Wall ◽  
Capsicum Annuum ◽  
Red Pepper ◽  
Outer Cell ◽  
Aluminum Stress ◽  
Water Culture ◽  
Anatomical Features ◽  
Parenchyma Cells ◽  
Al Treatment ◽  
Outer Cell Wall

The seedlings of the red pepper (<i>Capsicum annuum</i> L.) cv. Trapez grown in water culture for a period of 14 days with Al (0, 10, 20 and 40 mg·dm<sup>-3</sup> AlCl<sub>3</sub>·6 H<sub>2</sub>O). Some morphological and anatomical features of red pepper shoots were analyzed. Reduction in height and diameter of stems as well as decrease in fresh mass of shoots were observed after Al-treatment. In the hypocotyl the thickness of cortex parenchyma layer and the size of their cells were reduced. The aluminum treatment resulted in the increased in thickness of the epidermis outer cell wall. Under Al stress in the cotrex and the central cylinder parenchyma cells were present numerous enlarge plastids which contained large grains of starch and dark little bodies which were possible aluminum deposits. They weren`t observed in control seedlings.

Silver nanoparticles (AgNPs) internalization and passage through the Lactuca sativa (Asteraceae) outer cell wall

2021 ◽  
Author(s):  
Sergimar Kennedy de Paiva Pinheiro ◽  
Thaiz Batista Azevedo Rangel Miguel ◽  
Marlos de Medeiros Chaves ◽  
Francisco Claudio de Freitas Barros ◽  
Camila Pessoa Farias ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Cell Wall ◽  
Lactuca Sativa ◽  
Outer Cell ◽  
Outer Cell Wall

Production of Monoclonal Antibodies Against the Outer Cell Wall ofClostridium tyrobutyricum

Hybridoma ◽  
1994 ◽  
Vol 13 (1) ◽  
pp. 45-51 ◽  
Author(s):  
FRANCOISE TALBOT ◽  
GEORGES ROBREAU ◽  
FRANCOISE GUEGUEN ◽  
ROGER MALCOSTE
Keyword(s):  
Cell Wall ◽  
Monoclonal Antibodies ◽  
Outer Cell ◽  
Outer Cell Wall
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