scholarly journals Extracellular matrix and wall composition are diverse in the organogenic and non-organogenic calli of Actinidia arguta

2020 ◽  
Vol 39 (6) ◽  
pp. 779-798 ◽  
Author(s):  
Marzena Popielarska-Konieczna ◽  
Katarzyna Sala ◽  
Mohib Abdullah ◽  
Monika Tuleja ◽  
Ewa Kurczyńska
Keyword(s):  
Extracellular Matrix ◽  
Callus Tissue ◽  
Experimental System ◽  
Arabinogalactan Protein ◽  
Bright Field ◽  
Actinidia Arguta ◽  
Rhamnogalacturonan I ◽  
Structural Organisation ◽  
Peripheral Cells ◽  
Microscopy Techniques

Abstract Key message Differences in the composition and the structural organisation of the extracellular matrix correlate with the morphogenic competence of the callus tissue that originated from the isolated endosperm of kiwifruit. Abstract The chemical composition and structural organisation of the extracellular matrix, including the cell wall and the layer on its surface, may correspond with the morphogenic competence of a tissue. In the presented study, this relationship was found in the callus tissue that had been differentiated from the isolated endosperm of the kiwiberry, Actinidia arguta. The experimental system was based on callus samples of exactly the same age that had originated from an isolated endosperm but were cultured under controlled conditions promoting either an organogenic or a non-organogenic pathway. The analyses which were performed using bright field, fluorescence and scanning electron microscopy techniques showed significant differences between the two types of calli. The organogenic tissue was compact and the outer walls of the peripheral cells were covered with granular structures. The non-organogenic tissue was composed of loosely attached cells, which were connected via a net-like structure. The extracellular matrices from both the non- and organogenic tissues were abundant in pectic homogalacturonan and extensins (LM19, LM20, JIM11, JIM12 and JIM20 epitopes), but the epitopes that are characteristic for rhamnogalacturonan I (LM5 and LM6), hemicellulose (LM25) and the arabinogalactan protein (LM2) were detected only in the non-organogenic callus. Moreover, we report the epitopes, which presence is characteristic for the Actinidia endosperm (LM21 and LM25, heteromannan and xyloglucan) and for the endosperm-derived cells that undergo dedifferentiation (loss of LM21 and LM25; appearance or increase in the content of LM5, LM6, LM19, JIM11, JIM12, JIM20, JIM8 and JIM16 epitopes).

Bright-Field Microscopy Techniques

2017 ◽  
pp. 307-344
Author(s):  
Onkar D. Dhingra ◽  
James B. Sinclair
Keyword(s):  
Bright Field ◽  
Bright Field Microscopy ◽  
Microscopy Techniques

Immunogold localization of callose and other plant cell wall components in soybean roots infected with the oomycete Phytophthora sojae

1997 ◽  
Vol 75 (9) ◽  
pp. 1509-1517 ◽  
Author(s):  
K. Enkerli ◽  
C. W. Mims ◽  
M. G. Hahn
Keyword(s):  
Plasma Membrane ◽  
Plant Cell Wall ◽  
Arabinogalactan Proteins ◽  
Phytophthora Sojae ◽  
Arabinogalactan Protein ◽  
Electron Microscopic ◽  
Rhamnogalacturonan I ◽  
Host Plasma Membrane ◽  
Wall Appositions ◽  
Extrahaustorial Matrix

Immunolabeling and transmission electron microscopic techniques were used to investigate the chemical nature of wall appositions in roots of susceptible and resistant soybean plants inoculated with Phytophthora sojae race 2. The extrahaustorial matrix associated with the haustorium of Phytophthora sojae also was examined. Antibodies against (1 → 3)-β-glucan, a terminal α-fucosyl-containing epitope present in xyloglucan and rhamnogalacturonan I, and an arabinosylated (1 → 6)-β-galactan epitope present in arabinogalactan proteins were used. (1 → 3)-β-Glucan (callose), xyloglucan, and arabinogalactan proteins were found to be localized in all wall appositions regardless of how long after inoculation the appositions developed or whether plants were susceptible or resistant to Phytophthora sojae. (1 → 3)-β-Glucan also was found in fungal walls and at host cell plasmodesmata. None of the four antibodies labeled the extrahaustorial matrix. The antibody against arabinogalactan protein recognized the host plasma membrane, but not the invaginated host plasma membrane associated with the extrahaustorial matrix. This result indicates that the properties or the composition of the host plasma membrane may change locally once it becomes an extrahaustorial membrane. Key words: Phytophthora sojae, Glycine max, callose, immunolabeling, wall appositions, papillae.

The extracellular matrix of the developing cornea: diversity, deposition and function*

Development ◽  
1988 ◽  
Vol 103 (Supplement) ◽  
pp. 195-205
Author(s):  
J. B. L. Bard ◽  
M. K. Bansal ◽  
A. S. A. Ross
Keyword(s):  
Extracellular Matrix ◽  
Chondroitin Sulphate ◽  
Corneal Stroma ◽  
Experimental System ◽  
Collagen I ◽  
And Function ◽  
20 Nm

This paper examines the role of the extracellular matrix (ECM) in the development of the cornea. After a brief summary of the corneal structure and ECM, we describe evidence suggesting that the differentiation of neural crest (NC) cells into endothelium and fibroblasts is under the control of ocular ECM. We then examine the role of collagen I in stromal morphogenesis by comparing normal corneas with those of homozygous Movl3 mice which do not make collagen I. We report that, in spite of this absence, the cellular morphology of the Movl3 eye is indistinguishable from that of the wild type. In the 16-day mutant stroma, however, the remaining collagens form small amounts of disorganized, thin fibrils rather than orthogonally organized 20 nm-diameter fibrils; a result implying that collagen I plays only a structural role and that its absence is not compensated for. It also suggests that, because these remaining collagens will not form the normal fibrils that they will in vitro, fibrillogenesis in the corneal stroma differs from that elsewhere. The latter part of the paper describes our current work on chick stromal deposition using corneal epithelia isolated with an intact basal lamina that lay down in vitro ∼3μm-thick stromas of organized fibrils similar to that seen in vivo. This experimental system has yielded two unexpected results. First, the amount of collagen and proteoglycans produced by such epithelia is not dependent on whether its substratum is collagenous and we therefore conclude that stromal production by the intact epithelium is more autonomous than hitherto thought. Second, chondroitin sulphate (CS), the predominant proteoglycan, appears to play no role in stromal morphogenesis: epithelia cultured in testicular hyaluronidase, which degrades CS, lay down stromas whose organization and fibrildiameter distribution are indistinguishable from controls. One possible role for CS, however, is as a lubricant which facilitates corneal growth: it could allow fibrils to move over one another without deforming their orthogonal organization. Finally, we have examined the processes of fibrillogenesis in the corneal stroma and conclude that they are different from those elsewhere in the embryo and in vitro, perhaps because there is in the primary stroma an unidentified, highly hydrated ECM macromolecule that embeds the fibrils and that may mediate their morphogenesis.

Extracellular matrix of plant callus tissue visualized by ESEM and SEM

PROTOPLASMA ◽  
2010 ◽  
Vol 247 (1-2) ◽  
pp. 121-125 ◽  
Author(s):  
Marzena Popielarska-Konieczna ◽  
Jerzy Bohdanowicz ◽  
Ewa Starnawska
Keyword(s):  
Extracellular Matrix ◽  
Callus Tissue

scholarly journals Development of an open source program to identify the size of objects using bright-field microscopy - an automated calibration tool

2021 ◽  
Author(s):  
Gerard Glowacki ◽  
Alexis Gkantiragas ◽  
Brooke Brett-Holt ◽  
Peter He ◽  
Daniel Mihalik
Keyword(s):  
Light Microscopy ◽  
Open Source ◽  
Object Identification ◽  
Bright Field ◽  
Open Source Program ◽  
Source Program ◽  
Bright Field Microscopy ◽  
Microscopy Techniques ◽  
Calibration Tool ◽  
Microscopy Images

In light microscopy, eyepiece graticules are commonly used to gauge the size of objects at the micron scale. While this is a relatively simple tool to use, not all microscopes possess this feature. Furthermore, calibrating an eyepiece graticule with a stage micrometer can be time-consuming, particularly for inexperienced microscopists. Similarly, calculating the size of individual objects may also take some time. We present an open-source program to determine the size of objects under a microscope using Python and OpenCV. Taking photos of a stage micrometer under a microscope, we identify gradations on the micrometer and calculate the distance between lines on the micrometer in pixels. From this, we can infer the size of objects from bright-field microscopy images. We believe this will improve access to quantitative microscopy techniques and increase the speed at which samples may be analyzed by light microscopy. Future studies may aim to integrate this with machine learning for object identification

II-VI Semiconductor Heterostructures: Pointers to Appropriate Analysis Techniques

1990 ◽  
Vol 216 ◽  
Author(s):  
Erica G. Bithell
Keyword(s):  
Dark Field ◽  
Semiconductor Heterostructures ◽  
Alternative Methods ◽  
Composition Change ◽  
Bright Field ◽  
Approximate Methods ◽  
Analysis Techniques ◽  
Transmission Electron ◽  
Quantitative Characterisation ◽  
Microscopy Techniques

ABSTRACTApproximate methods are used, for a variety of II–VI semiconductor alloys, to estimate the sensitivity to composition change of quantitative transmission electron microscopy techniques which have proved successful in characterising III–V heterostructures. It is shown that bright field thickness fringe matching at the [001] axis is likely to prove relatively more successful than 200 dark field intensity measurement for many alloy systems. It is also noted that alternative methods would be necessary if quantitative characterisation of (Mn,Zn) compounds were required.

Pectin Modification in Seed Coat Mucilage by In Vivo Expression of Rhamnogalacturonan-I- and Homogalacturonan-Degrading Enzymes

2021 ◽  
Author(s):  
Robert McGee ◽  
Gillian H Dean ◽  
Di Wu ◽  
Yuelin Zhang ◽  
Shawn D Mansfield ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Wall ◽  
Seed Coat ◽  
Epidermal Cells ◽  
Wall Structure ◽  
Rhamnogalacturonan I ◽  
Degrading Enzymes ◽  
Developing Seed ◽  
Extracellular Matrix Components

Abstract The cell wall is essential for plant survival. Determining the relationship between cell wall structure and function using mutant analysis or overexpressing cell wall-modifying enzymes has been challenging due to the complexity of the cell wall and the appearance of secondary, compensatory effects when individual polymers are modified. In addition, viability of the plants can be severely impacted by wall modification. A useful model system for studying structure-function relationships among extracellular matrix components are the seed coat epidermal cells of Arabidopsis thaliana. These cells synthesize relatively simple, easily-accessible, pectin-rich mucilage that is not essential for plant viability. In this study, we expressed enzymes predicted to modify polysaccharide components of mucilage in the apoplast of seed coat epidermal cells and explored their impacts on mucilage. The seed coat epidermal-specific promoter TESTA ABUNDANT2 (TBA2) was used to drive expression of these enzymes to avoid adverse effects in other parts of the plant. Mature transgenic seeds expressing Rhamnogalacturonate lyase A (RglA) or Rhamnogalacturonate lyase B (RglB) that degrade the pectin rhamnogalacturonan-I (RG-I), a major component of mucilage, had greatly reduced mucilage capsules surrounding the seeds and concomitant decreases in the monosaccharides that comprise the RG-I backbone. Degradation of the minor mucilage component homogalacturonan (HG) using the HG-degrading enzymes Pectin Lyase A (PLA) or ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE2 (ADPG2) resulted in developing seed coat epidermal cells with disrupted cell-cell adhesion and signs of early cell death. These results demonstrate the feasibility of manipulating the seed coat epidermal cell extracellular matrix using a targeted genetic engineering approach.

scholarly journals Isolation and Characterization of Pectic Polysaccharide Fraction from In Vitro Suspension Culture of Fumaria officinalis L.

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Manol Ognyanov ◽  
Yordan Georgiev ◽  
Nadezhda Petkova ◽  
Ivan Ivanov ◽  
Ivelina Vasileva ◽  
...  
Keyword(s):  
Suspension Culture ◽  
Ammonium Oxalate ◽  
Arabinogalactan Protein ◽  
Pectic Polysaccharide ◽  
Polysaccharide Fraction ◽  
Acidic Polysaccharide ◽  
Rhamnogalacturonan I ◽  
Isolation And Characterization ◽  
Fumaria Officinalis

In the current study, an acidic polysaccharide from the in vitro suspension culture of Fumaria officinalis L. was obtained by extraction with 0.8% (w/v) aqueous ammonium oxalate. The polysaccharide fraction mainly consisted of galacturonic acid (41.0%), followed by galactose (7.3%) and arabinose (5.6%). This suggests the presence of arabinogalactan side chains in the rhamnogalacturonan-I segment of the studied pectin, which was mainly built up by homogalacturonan segments. The pectin was evaluated as low-methyl-esterified (45.0%) with degree of acetylation 3.4%. The polymer fraction was consisted of different molecular weight populations in the range of 6–600 kDa. The high amount of 4-L-hydroxyproline (11.7% of total protein) and the specific positive reaction to Yariv’s phenylglycoside reagent indicated the presence of an arabinogalactan protein in the cell walls. The functional properties of the polysaccharide fraction were evaluated, as it possessed better water-holding capacity than oil-holding capacity. The studied pectin demonstrated significant foaming ability and promising emulsifying properties in a concentration 1%. Therefore, the isolated polysaccharide fraction could be successfully used as emulsifier and foaming agent in food products and pharmaceutical supplements.

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