Histopathological and ultrastructural comparison of Stemphylium sarcinaeforme and S. botryosum on red clover foliage

1978 ◽  
Vol 56 (17) ◽  
pp. 2097-2108 ◽  
Author(s):  
Verna J. Higgins ◽  
G. L. Lazarovits
Keyword(s):  
Cell Walls ◽  
Light And Electron Microscopy ◽  
Red Clover ◽  
Epidermal Cells ◽  
Blue Staining ◽  
Mesophyll Cells ◽  
Toluidine Blue Staining ◽  
Different Types ◽  
Wall Appositions ◽  
Palisade Cells

As part of a continuing study of non-host resistance, red clover leaves inoculated with the clover pathogen Stemphylium sarcinaeforme, or the closely related alfalfa pathogen S. botryosum, were examined by light and electron microscopy to compare the events occurring in the initial stages of infection. Stemphylium botryosum penetrated leaves primarily via the stomata with resultant death of the guard cells and with varying effects on adjacent epidermal cells. Appressoria were frequently formed, and although they rarely resulted in successful penetrations, the contacted epidermal cells were often markedly affected as judged by toluidine blue staining. Growth of hyphae was intercellular but very limited in its extent. At some infection sites, one to several mesophyll cells underwent extensive plasmolysis and cytoplasmic disruption. Less severely affected mesophyll cells contained large lipid bodies, abundant rough endoplasmic reticulum, and Golgi vesicles and had wall appositions at points of contact with necrotic cells or with hyphae. Stemphylium sarcinaeforme generally penetrated between or directly through the epidermal cells, causing death of the contacted cells. Hyphae grew intercellularly or intracellularly in the palisade tissue and hyphal elongation was considerably more rapid than that of S. botryosum. Palisade cells adjacent to, or containing, the hyphae underwent several different types of cytoplasmic deterioration. Mesophyll cells surrounding these areas showed the same features as comparable cells in tissue infected by S. botryosum. In tissue infected by either fungus, the exterior of host cell walls was coated with a layer of extracellular material.

Light and electron microscopic demonstration by the PATS reaction of peripheral nerve regeneration

1989 ◽  
Vol 47 ◽  
pp. 952-953 ◽  
Author(s):  
B. Giammara ◽  
E. Anderson ◽  
P. Yates ◽  
J. Hanker
Keyword(s):  
Electron Microscopy ◽  
Toluidine Blue ◽  
Periodic Acid ◽  
Light And Electron Microscopy ◽  
Nerve Fibers ◽  
Blue Staining ◽  
Hydroxyl Groups ◽  
Distal Stump ◽  
Thin Sections ◽  
Toluidine Blue Staining

Although periodic acid-Schiff(PAS) type reactions have been applied to nervous tissues for many years, interest has centered upon staining glycolipids, principally myelin constituents such as the class of sphingolipids. The staining of these compounds such as sphingomyelin has generally been attributed to the presence of amino and hydroxyl groups on adjacent carbon atoms of carbohydrate of the sphingosine moiety. But unsaturated lipids also give the reaction and sphingolipids stain even if carbohydrate moieties are absent. This reaction has been used for staining myelin sheaths but lipid solvents must be avoided in processing the specimens. Toluidine blue staining of semi-thin sections of epoxy- embedded nerve specimens has also been widely used to study regenerating fibers after nerve transection or avulsion. A recent study was made in our laboratories of conduits (sleeves) tailored from biodegradable polyester (VicrylR) mesh to guide the reconnection of regenerating fibers from the proximal stump of a rat sciatic nerve, across an 11 mm gap, with fibers in the distal stump of the interrupted nerve. Complete reconnection of the stumps was observed as early as one month after creating the avulsive nerve injury.Comparison of transverse sections of the repaired sciatic with sections of control nerve with the toluidine blue stain, however, showed little evidence of axonal regeneration after one month (Figs. 1,3). A variation of the PAS reaction (depositing silver) for light and electron microscopy developed in our laboratories (PATS reaction, 5) was than applied to the study of the semi-thin sections of the epoxy-embedded control and repaired sciatic nerves of the same rat one month postsurgery. Correlative light and scanning electron microscopy by SEI and BEI modes could then be performed since the PATS reaction produced very satisfactory staining of the semi-thin sections (Figs. 3-5). Myelin was not stained by the PATS reaction in these specimens since the nerves had been processed with lipid solvents for epoxy embedment. Schwann cells, however, were very prominent in control but not in the repaired nerve. The inner layers of endoneurium and all pericapillaries associated with nerve fibers were intensely stained due to their reticulin content in both control and repaired nerve (Figs. 2,4). This was not unexpected because the PATS reaction employs a silver methenamine reagent. Thus, with the PATS reaction axons could be identified in sections of repaired nerve (Fig. 4) that could not be discerned with toluidine blue staining (Fig. 3). In sections of repaired nerve stained with either toluidine blue or the PATS reaction few axons or axis cylinders were observed but more were seen with the PATS stain (Figs. 3,4). In control nerve sections stained with either procedure many were seen (Figs. 1,2).

Observations on the Scutellum. II. Histochemistry and Autofluorescence of the Cell Wall in Mature Grain and During Germination of Wheat, Barley, Oats and Ryegrass

1979 ◽  
Vol 27 (4) ◽  
pp. 403 ◽  
Author(s):  
MG Smart ◽  
TP O'Brien
Keyword(s):  
Cell Wall ◽  
Phenolic Compounds ◽  
Toluidine Blue ◽  
Cell Walls ◽  
Periodic Acid ◽  
Blue Staining ◽  
Carboxyl Groups ◽  
Purple Colour ◽  
Toluidine Blue Staining ◽  
Green Coloration

Histochemical studies and fluorescence microscopy of the scutella of wheat, barley, oats and ryegrass indicate that the cell walls of these grasses are basically similar in composition. They are all periodic acid-Schiff's positive, presumably owing to large amounts of hemicelluloses such as xylans. All scutellar cell walls stain with protein stains at all stages of germination, with the exception of the epithelial cell walls of oats which do not stain. Scutellar cell walls stain metachromatically red to purple (hydrated sections) or green (dehydrated sections) when stained with toluidine blue 0. The red to purple colour is indicative of free carboxyl groups, usually owing to the presence of pectin. However, this is not confirmed in this case since two pectin stains fail to react. The green coloration with toluidine blue staining is indicative of phenolic compounds (lignin). This conclusion is supported by the autofluorescence shown by the scutella of all genera. The autofluorescence of oats and rye- grass is initially low, especially at the apex, but increases as germination progresses. Wheat and barley lose fluorescence intensity 3 days after germination but later regain it.

An analysis of the effects of gibberellic acid on the leaflet structure of dwarf cultivars of pea (Pisum sativum)

1979 ◽  
Vol 57 (10) ◽  
pp. 1089-1092 ◽  
Author(s):  
G. F. Israelstam ◽  
Erica Davis
Keyword(s):  
Pisum Sativum ◽  
Gibberellic Acid ◽  
Surface Area ◽  
Epidermal Cells ◽  
Mesophyll Cells ◽  
Spongy Mesophyll ◽  
Number Of Layers ◽  
Dwarf Cultivar ◽  
Palisade Cells ◽  
Degree Of Differentiation

The effects of gibberellic acid (GA3) on the penultimate leaflets of dwarf and normal cultivars of pea were investigated. In control plants, the leaflets of the dwarf were heavier, thicker, and had a smaller surface area than the normal. Epidermal and palisade cells of the dwarf were longer than those of the normal cultivar and the dwarf had longer spongy mesophyll cells and more layers of spongy mesophyll than the normal, with fewer intercellular spaces.Application of GA3 to dwarf plants increased leaflet surface area and length of epidermal cells, while leaflet weight and thickness and the number of layers of spongy mesophyll cells decreased. No significant changes in the leaflet of the normal cultivar were induced by GA3.The overall effect of GA3 application to the dwarf cultivar was to induce a degree of differentiation in the penultimate leaflets such that they tended to resemble more closely those of the normal cultivar.

Leaf epidermal characters of Brazilian species of Solanum section Torva as taxonomic evidence

Botany ◽  
2012 ◽  
Vol 90 (9) ◽  
pp. 806-814 ◽  
Author(s):  
Kiriaki Nurit-Silva ◽  
Rafael Costa-Silva ◽  
Ionaldo J.L.D. Basílio ◽  
Maria de Fátima Agra
Keyword(s):  
Cell Walls ◽  
Wave Pattern ◽  
Morphological Characters ◽  
Epidermal Cells ◽  
Leaf Epidermis ◽  
Taxonomic Significance ◽  
Abaxial Surface ◽  
Solanum Torvum ◽  
Different Types ◽  
Additional Support

To evaluate their taxonomic significance, the yet unknown epidermal characters of the leaves of 10 species of Solanum section Torva Nees (Solanaceae) from Brazil were determined using light and scanning electron microscopy. Our results indicated that the leaf epidermis showed epidermal cells of straight to wavy outlines. The curved pattern of anticlinal cell walls was predominant on the adaxial surface, and the wave pattern was predominant on the abaxial surface. Leaves are amphistomatic in six species ( Solanum acutilobum Dunal, Solanum bonariense L., Solanum guaraniticum A. St.-Hil., Solanum metrobotryon Dunal, Solanum scuticum M. Nee, and Solanum torvum Sw.) and hypostomatic in four species ( Solanum adspersum Witasek, Solanum paniculatum L., Solanum subumbellatum Vell., and Solanum variabile Mart.). Four different types of stomata (anisocytic, anomocytic, paracytic, and diacytic) were recognized, with the anisocytic type predominant on adaxial and abaxial surfaces. The combination of some micro-morphological characters such as density, distribution and type of stellate trichomes, the anticlinal walls of epidermal cells, and also the type and distribution of stomata proved to be the most useful and distinctive characters for the separation of species. This set of characters also may help as additional support in quality control of species having medicinal importance.

Penetration of Zea mays by Helminthosporium carbonum

1975 ◽  
Vol 53 (23) ◽  
pp. 2872-2883 ◽  
Author(s):  
Gordon M. Murray ◽  
Douglas P. Maxwell
Keyword(s):  
Electron Microscopy ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Epidermal Cells ◽  
Cell Cytoplasm ◽  
Mesophyll Cells ◽  
Fibrillar Material ◽  
Transmission Electron ◽  
Corn Plants ◽  
Resistant Genotypes

Light microscopy showed that on corn leaves, 81–93% of appressoria of Helminthosporium carbonum races I and II are formed over junctions of epidermal cells. During the early stages of penetration of corn plants resistant and susceptible to race I, 63–83% of appressoria have an epidermal cell nucleus within 10 μm. Transmission electron microscopy of race II on inbred W187R showed that appressoria are attached to the cuticle by fibrillar material. Vesicles are present in the appressorium at the site of cuticle penetration and initial cuticle penetration appears to be enzymic; subsequent rupture may be mechanical as the penetration peg widens. A septum forms between the appressorium and the subcuticular hyphae. Epidermal cell cytoplasm is thicker beneath penetration sites than elsewhere under the epidermal wall. Changes in epidermal cytoplasm were observed 8 h after inoculation; by 18 h epidermal cells beneath subcuticular hyphae have electron-opaque contents. Hyphae are mainly subcuticular up to 48 h after inoculation, and underlying epidermal and mesophyll cells are frequently collapsed. Results indicate that H. carbonum races I and II have similar initial reactions on susceptible and resistant genotypes and that penetration occurs by degradation of the cuticle and host cell walls.

scholarly journals Histological Study of Some Echium vulgare, Pulmonaria officinalis and Symphytum officinale Populations

2011 ◽  
Vol 6 (10) ◽  
pp. 1934578X1100601 ◽  
Author(s):  
Nóra Papp ◽  
Tímea Bencsik ◽  
Kitti Németh ◽  
Kinga Gyergyák ◽  
Alexandra Sulc ◽  
...  
Keyword(s):  
Histological Study ◽  
Cell Number ◽  
Epidermal Cells ◽  
Mesophyll Cells ◽  
Leaf Mesophyll ◽  
Symphytum Officinale ◽  
Radial Cell ◽  
Palisade Cells ◽  
Reported Data ◽  
Ecological Habitats

Plants living in different ecological habitats can show significant variability in their histological and phytochemical characters. The main histological features of various populations of three medicinal plants from the Boraginaceae family were studied. Stems, petioles and leaves were investigated by light microscopy in vertical and transverse sections. The outline of the epidermal cells, as well as the shape and cell number of trichomes was studied in leaf surface casts. Differences were measured among the populations of Echium vulgare in the width and height of epidermis cells in the stem, petiole and leaf, as well as in the size of palisade cells in the leaves. Among the populations of Pulmonaria officinalis significant differences were found in the length of trichomes and in the slightly or strongly wavy outline of epidermal radial cell walls. Populations of Symphytum officinale showed variance in the height of epidermal cells in leaves and stems, length of palisade cells and number of intercellular spaces in leaves, and the size of the central cavity in the stem. Boraginaceae bristles were found to be longer in plants in windy/shady habitats as opposed to sunny habitats, both in the leaves and stems of P. officinalis and S. officinale, which might be connected to varying levels of exposure to wind. Longer epidermal cells were detected in the leaves and stems of both E. vulgare and S. officinale plants living in shady habitats, compared with shorter cells in sunny habitats. Leaf mesophyll cells were shorter in shady habitats as opposed to longer cells in sunny habitats, both in E. vulgare and S. officinale. This combination of histological characters may contribute to the plant's adaptation to various amounts of sunshine. The reported data prove the polymorphism of the studied taxa, as well as their ability to adapt to various ecological circumstances.

Ultrastructural study of the development of the auditory tympana in the cricket Teleogryllus commodus (Walker)

Development ◽  
1978 ◽  
Vol 46 (1) ◽  
pp. 75-87
Author(s):  
E. E. Ball ◽  
A. N. Cowan
Keyword(s):  
Epidermal Cells ◽  
Dense Material ◽  
Blue Staining ◽  
Mature Adult ◽  
Toluidine Blue Staining ◽  
Electron Dense Material ◽  
Acoustic Window ◽  
Teleogryllus Commodus ◽  
Acid And Base ◽  
Pharate Adult

The cuticle in the tympanal area of immature crickets, Teleogryllus commodus (Walker), is ultrastructurally indistinguishable from that elsewhere on the prothoracic leg. It is only in the pharate adult that changes associated with development of the tympana first appear. In pharate adults and adults the external layer of the tympana consists of a layer of electrondense material overlying a layer where the electron-dense material is interspersed with cuticle in which the bundles of microfibrils are coarser and more loosely arranged than elsewhere in the leg. The innermost portion of the tympana consists of this same type of cuticle without the electron-dense material. Associated with the appearance of the electron-dense material in the tympana of the pharate adult is a change in the toluidine blue staining properties from blue to deep purple. The reaction of the tympana in acid and base is consistent with their being composed of chitin. There are no major deposits of resilin in the tympana. In the first few days following the imaginal ecdysis the posterior tympanum and underlying trachea come into tight apposition due to the withdrawal of the epidermal cells. The epidermal cells do not withdraw from beneath the anterior tympanum. The surrounding non-tympanal cuticle continues to thicken for several weeks with the result that in the mature adult the posterior tympanum serves as an acoustic window in the thick cuticle of the leg. The functional significance of the anterior tympanum has not been established.

scholarly journals Leaf structural adaptations of two Limonium miller (Plumbaginales, Plumbaginaceae) taxa

2013 ◽  
pp. 43-54 ◽  
Author(s):  
Lana Zoric ◽  
Goran Anackov ◽  
Dunja Karanovic ◽  
Jadranka Lukovic
Keyword(s):  
Epidermal Cells ◽  
High Dimensions ◽  
Salt Glands ◽  
Abaxial Epidermis ◽  
Mesophyll Cells ◽  
Saline Habitats ◽  
Flat Cell ◽  
Palisade Cells ◽  
Limonium Gmelinii ◽  
Structural Adaptations

Limonium gmelinii (Willd.) O. Kuntze 1891 subsp. hungaricum (Klokov) So? is Pannonian endemic subspecies that inhabits continental halobiomes, while Limonium anfractum (Salmon) Salmon 1924 is one of the indicators of halophyte vegetation of marine rocks and its distribution is restricted to the southern parts of Mediterranean Sea coast. In this work, micromorphological and anatomical characters of leaves of these two Limonium taxa were analyzed, in order to examine their adaptations to specific environmental conditions on saline habitats. The results showed that both taxa exhibited strong xeromorphic adaptations that reflected in flat cell walls of epidermal cells, thick cuticle, high palisade/spongy tissue ratio, high index of palisade cells, the presence of sclereid idioblasts in leaf mesophyll and mechanical tissue by phloem and xylem. Both taxa are crynohalophytes and have salt glands on adaxial and abaxial epidermis for excretion of surplus salt. Relatively high dimensions of mesophyll cells, absence of non-glandular hairs and unprotected stomata slightly increased above the level of epidermal cells, are also adaptations to increased salinity.

scholarly journals Constitutive Modeling of the Densification Behavior in Open-Porous Cellular Solids

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2731
Author(s):  
Ameya Rege
Keyword(s):  
Constitutive Model ◽  
Cell Walls ◽  
Compressive Strain ◽  
Pore Collapse ◽  
Compressive Response ◽  
Linear Elastic ◽  
Nonlinear Springs ◽  
Different Types ◽  
Point Of Intersection ◽  
Good Agreement

The macroscopic mechanical behavior of open-porous cellular materials is dictated by the geometric and material properties of their microscopic cell walls. The overall compressive response of such materials is divided into three regimes, namely, the linear elastic, plateau and densification. In this paper, a constitutive model is presented, which captures not only the linear elastic regime and the subsequent pore-collapse, but is also shown to be capable of capturing the hardening upon the densification of the network. Here, the network is considered to be made up of idealized square-shaped cells, whose cell walls undergo bending and buckling under compression. Depending on the choice of damage criterion, viz. elastic buckling or irreversible bending, the cell walls collapse. These collapsed cells are then assumed to behave as nonlinear springs, acting as a foundation to the elastic network of active open cells. To this end, the network is decomposed into an active network and a collapsed one. The compressive strain at the onset of densification is then shown to be quantified by the point of intersection of the two network stress-strain curves. A parameter sensitivity analysis is presented to demonstrate the range of different material characteristics that the model is capable of capturing. The proposed constitutive model is further validated against two different types of nanoporous materials and shows good agreement.

scholarly journals FlsnRNA-seq: protoplasting-free full-length single-nucleus RNA profiling in plants

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yanping Long ◽  
Zhijian Liu ◽  
Jinbu Jia ◽  
Weipeng Mo ◽  
Liang Fang ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Walls ◽  
Large Scale ◽  
Full Length ◽  
Cell Level ◽  
Root Cells ◽  
Rna Profiling ◽  
Different Types ◽  
Long Read ◽  
Single Nucleus

AbstractThe broad application of single-cell RNA profiling in plants has been hindered by the prerequisite of protoplasting that requires digesting the cell walls from different types of plant tissues. Here, we present a protoplasting-free approach, flsnRNA-seq, for large-scale full-length RNA profiling at a single-nucleus level in plants using isolated nuclei. Combined with 10x Genomics and Nanopore long-read sequencing, we validate the robustness of this approach in Arabidopsis root cells and the developing endosperm. Sequencing results demonstrate that it allows for uncovering alternative splicing and polyadenylation-related RNA isoform information at the single-cell level, which facilitates characterizing cell identities.

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