Moss flavonoids and their ultrastructural localization under enhanced UV-B radiation

Polar Record ◽  
2002 ◽  
Vol 38 (206) ◽  
pp. 211-218 ◽  
Author(s):  
Tiia Taipale ◽  
Satu Huttunen
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Intracellular Localization ◽  
Outer Part ◽  
Ultrastructural Localization ◽  
Wall Structure ◽  
Hylocomium Splendens ◽  
Wall Structures ◽  
Dense Deposits ◽  
Cell Layers

AbstractA study was made of methanol-extractable UV-B-absorbing pigments under enhanced UV-B treatment. UV-B-absorbing pigments in two common ectohydric mosses showed seasonal variation during the summer months. Pigment contents were highest in June, decreased in July, and thereafter remained unchanged until September. In Hylocomium splendens, a significant increase of pigments was observed at the end of the experiment. The intracellular localization of caffeine-stabilized flavonoids was manifested as dark electron-dense deposits in the cell walls and intracellular dark deposits in the cell plasma. The dark deposits in the cell walls of Pleurozium schreberi were located either in the outer part of the cell wall or in the middle lamellae of the wall structures. Hylocomium splendens had a stratified cell-wall structure, in which three dark electron-dense cell layers could be identified. Intracellular deposits were located in different parts of the cell, but electron-dense deposits were observed at the cell margins and in the proximity of the nucleus. Although certain cell ultrastructural disturbances (for example, lipid accumulation, chloroplast disintegration) in moss leaf cells were observed, the short-term UV-B treatment did not increase the intensity of the dark deposits.

scholarly journals Novel tool to quantify cell wall porosity relates wall structure to cell growth and drug uptake

2019 ◽  
Vol 218 (4) ◽  
pp. 1408-1421 ◽  
Author(s):  
Xiaohui Liu ◽  
Jiazhou Li ◽  
Heyu Zhao ◽  
Boyang Liu ◽  
Thomas Günther-Pomorski ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Dynamic Structure ◽  
Cell Types ◽  
Antifungal Drugs ◽  
Drug Uptake ◽  
Wall Structure ◽  
Quenching Efficiency ◽  
Model Plant Arabidopsis Thaliana ◽  
Cell Wall Porosity

Even though cell walls have essential functions for bacteria, fungi, and plants, tools to investigate their dynamic structure in living cells have been missing. Here, it is shown that changes in the intensity of the plasma membrane dye FM4-64 in response to extracellular quenchers depend on the nano-scale porosity of cell walls. The correlation of quenching efficiency and cell wall porosity is supported by tests on various cell types, application of differently sized quenchers, and comparison of results with confocal, electron, and atomic force microscopy images. The quenching assay was used to investigate how changes in cell wall porosity affect the capability for extension growth in the model plant Arabidopsis thaliana. Results suggest that increased porosity is not a precondition but a result of cell extension, thereby providing new insight on the mechanism plant organ growth. Furthermore, it was shown that higher cell wall porosity can facilitate the action of antifungal drugs in Saccharomyces cerevisiae, presumably by facilitating uptake.

scholarly journals Investigation of the Mechanical Properties of Flax Cell Walls during Plant Development: The Relation between Performance and Cell Wall Structure

Fibers ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 6 ◽  
Author(s):  
Camille Goudenhooft ◽  
David Siniscalco ◽  
Olivier Arnould ◽  
Alain Bourmaud ◽  
Olivier Sire ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Plant Development ◽  
Cell Walls ◽  
Cell Wall Structure ◽  
Wall Structure

Ultrastructural localization of succinate dehydrogenase in a self-parasitic isolate of Saprolegnia megasperma

1977 ◽  
Vol 23 (5) ◽  
pp. 491-496
Author(s):  
Sharon Faye Murrin ◽  
Richard A. Nolan
Keyword(s):  
Electron Microscopy ◽  
Succinate Dehydrogenase ◽  
Cell Walls ◽  
Ultrastructural Localization ◽  
Ultrastructural Level ◽  
Mitochondrial Membranes ◽  
Hyphal Cell ◽  
Dense Deposits

The enzyme succinate dehydrogenase (SDH, succinate: (acceptor) oxidoreductase, EC 1.3.99.1) was localized by the combined techniques of cytochemistry and electron microscopy in the hyphae of a self-parasitizing isolate of Saprolegnia megasperma Coker. The enzyme was localized in the mitochondrial membranes; its activity was inhibited by malonate. Electron-dense deposits, whose formation was not prevented by the addition of malonate, appeared outside of the hyphal cell walls. No evidence was found at the ultrastructural level within the vegetative hyphae for any abnormalities which could be linked to the phenomenon of self-parasitism.

Die gemeinsame Wurzel der Lyse von Escherichia coli durch Penicillin oder durch Phagen

1957 ◽  
Vol 12 (7) ◽  
pp. 421-427 ◽  
Author(s):  
W. Weidel ◽  
J. Primosigh
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Building Blocks ◽  
Diaminopimelic Acid ◽  
Wall Structure ◽  
Gram Positive ◽  
E Coli ◽  
Growing Cell ◽  
Cell Wall Disruption ◽  
Entire Cell

One of the two layers of the E. coli B cell wall is shown to possess the chemical composition typical of a gram-positive microorganism. It is this layer which lends support and strength to the entire cell wall structure, its rigidity depending up on the incorporation of building blocks made up from alanine, glutamic acid, diaminopimelic acid, muramic acid and glucosamine.Phage enzyme is an agent capable of removing these stabilizing units from the „gram-positive “ layer, thereby causing it to collapse. Penicillin appears to prevent the biosynthetic incorporation of the same stabilizing units into growing cell walls, thus producing eventually the effect of cell wall disruption in a basically similar way.The rather manifold aspects of these findings are discussed at some length.

scholarly journals Chilling Injury in Peaches: A Cytochemical and Ultrastructural Cell Wall Study

1992 ◽  
Vol 117 (1) ◽  
pp. 114-118 ◽  
Author(s):  
J.G. Luza ◽  
R. van Gorsel ◽  
V.S. Polito ◽  
A.A. Kader
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Prunus Persica ◽  
Periodic Acid ◽  
Chilling Injury ◽  
Middle Lamella ◽  
Wall Structure ◽  
Positive Staining ◽  
Intercellular Matrix ◽  
Parenchyma Cells

Fruits of mid- (`O'Henry'), late (`Airtime'), and extra-late-season (`Autumn Gem') peach [Prunus persica (L.) Batsch] cultivars were examined for changes in cell wall structure and cytochemistry that accompany the onset of mealiness and leatheriness of the mesocarp due to chilling injury. The peaches were stored at 10C for up to 18 days or at SC for up to 29 days. Plastic-embedded sections were stained by the Schiff's-periodic acid reaction, Calcofluor white MR2, and Coriphosphine to demonstrate total insoluble carbohydrates, ß-1,4 glucans, and pectins, respectively. Mealiness was characterized by separation of mesocarp parenchyma cells leading to increased intercellular spaces and accumulation of pectic substances in the intercellular matrix. Little structural change was apparent in the cellulosic component of the cell walls of these fruits. In leathery peaches, the mesocarp parenchyma cells collapsed, intercellular space continued to increase, and pectin-positive staining in the intercellular matrix increased greatly. In addition, the component of the cell walls that stained positively for ß-1,4 glucans became thickened relative to freshly harvested or mealy fruit. At the ultrastructural level, dissolution of the middle lamella, cell separation, irregular thickening of the primary wall, and plasmolysis of the mesocarp parenchyma cells were seen as internal breakdown progressed.

scholarly journals Aplikasi Kalsium dan NAA untuk Mengendalikan Getah Kuning Buah Manggis (Garcinia mangostana L.)

2018 ◽  
Vol 9 (1) ◽  
pp. 10-18
Author(s):  
Yulinda Tanari ◽  
Darda Efendi ◽  
Roedhy Poerwanto ◽  
Didy Sopandie ◽  
Ketty Suketi
Keyword(s):  
Cell Wall ◽  
Cell Division ◽  
Cell Walls ◽  
Block Design ◽  
Wall Structure ◽  
Sink Strength ◽  
Naphthaleneacetic Acid ◽  
Garcinia Mangostana ◽  
Random Block ◽  
Random Block Design

ABSTRACTThe yellow sap is produced naturally in mangosteen organ except in the root. The yellow sap contaminated the aryl and rind if the epithelial cell walls rupture due to deficiency of calcium (Ca). Calcium is one of structural component of cell walls, whereas naphthaleneacetic acid (NAA) has its role in improving cell division and cell elongation. Interaction of Ca and NAA can improve sink strength and capacity because the newly formed cells need Ca to construct wall structure. This experiment aimed at finding out the effect of Ca and NAA applications in reducing the contamination of yellow sap in mangosteen. The experiment was conducted by using factorial random block design consisting of 2 factors and 3 replications. The first factor was Ca dosage (0 and 4.8 kg/tree), and the second factor was NAA concentration (0, 200, 400 and 600 ppm). The results showed that application of 4.8 Ca/tree and 200 ppm NAA as much as 5 ml / fruit effectively improve the content of Ca pectate in pericarp, reduced the percentage of yellow sap contamination on the fruit segment, aryl and rind to 0% and 12.3% respectively compared to control (17.8% on fruit segment, 36.8% on aryl and 56.1% on rind).Key words: aryl, Ca pectate, cell wall, middle lamela.ABSTRAKGetah kuning adalah getah yang dihasilkan secara alami pada setiap organ manggis, kecuali pada akar. Getah kuning akan keluar dan mencemari aril serta kulit jika dinding sel epitel pecah karena kekurangan kalsium (Ca). Kalsium adalah komponen dinding sel, berperan dalam struktur dan permeabilitas membran sedangkan asam naftalenasetat (NAA) berperan penting dalam meningkatkan pembelahan dan pembesaran sel. Interaksi keduanya dapat meningkatkan kapasitas sink buah karena sel yang baru terbentuk membutuhkan Ca dalam menyusun struktur dinding sel. Percobaan bertujuan untuk mengetahui pengaruh aplikasi Ca dan NAA dalam menurunkan cemaran getah kuning manggis. Percobaan menggunakan rancangan acak kelompok faktorial 2 faktor dengan 3 ulangan. Faktor ke-1 yaitu dosis Ca (0 dan 4.8 kg Ca/pohon) dan faktor ke-2 yaitu konsentrasi NAA (0, 200, 400 dan 600 ppm) dengan volume semprot 5 ml perbuah. Hasil percobaan menunjukkan bahwa aplikasi 4.8 kg Ca/pohon dengan NAA 200 ppm sebanyak 5 ml/buah efektif meningkatkan kandungan Ca pektat perikarp dan menurunkan persentase buah tercemar getah kuning menjadi 0% pada juring dan aril serta 12.3% pada kulit dibandingkan dengan perlakuan kontrol (17.8% pada juring, 36.8% pada aril dan 56.1% pada kulit buah).Kata kunci: aril, Ca pektat, dinding sel, lamela tengah

scholarly journals Staphylococcus aureus cell wall structure and dynamics during host-pathogen interaction

2021 ◽  
Vol 17 (3) ◽  
pp. e1009468
Author(s):  
Joshua A. F. Sutton ◽  
Oliver T. Carnell ◽  
Lucia Lafage ◽  
Joe Gray ◽  
Jacob Biboy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Walls ◽  
Ex Vivo ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Human Macrophages ◽  
Structure And Dynamics

Peptidoglycan is the major structural component of the Staphylococcus aureus cell wall, in which it maintains cellular integrity, is the interface with the host, and its synthesis is targeted by some of the most crucial antibiotics developed. Despite this importance, and the wealth of data from in vitro studies, we do not understand the structure and dynamics of peptidoglycan during infection. In this study we have developed methods to harvest bacteria from an active infection in order to purify cell walls for biochemical analysis ex vivo. Isolated ex vivo bacterial cells are smaller than those actively growing in vitro, with thickened cell walls and reduced peptidoglycan crosslinking, similar to that of stationary phase cells. These features suggested a role for specific peptidoglycan homeostatic mechanisms in disease. As S. aureus penicillin binding protein 4 (PBP4) has reduced peptidoglycan crosslinking in vitro its role during infection was established. Loss of PBP4 resulted in an increased recovery of S. aureus from the livers of infected mice, which correlated with enhanced fitness within murine and human macrophages. Thicker cell walls correlate with reduced activity of peptidoglycan hydrolases. S. aureus has a family of 4 putative glucosaminidases, that are collectively crucial for growth. Loss of the major enzyme SagB, led to attenuation during murine infection and reduced survival in human macrophages. However, loss of the other three enzymes Atl, SagA and ScaH resulted in clustering dependent attenuation, in a zebrafish embryo, but not a murine, model of infection. A combination of pbp4 and sagB deficiencies resulted in a restoration of parental virulence. Our results, demonstrate the importance of appropriate cell wall structure and dynamics during pathogenesis, providing new insight to the mechanisms of disease.

scholarly journals Bundling of cellulose microfibrils in native and polyethylene glycol-containing wood cell walls revealed by small-angle neutron scattering

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Paavo A. Penttilä ◽  
Michael Altgen ◽  
Muhammad Awais ◽  
Monika Österberg ◽  
Lauri Rautkari ◽  
...  
Keyword(s):  
Cell Wall ◽  
Neutron Scattering ◽  
Plant Cell ◽  
Small Angle ◽  
Cell Walls ◽  
Small Angle Neutron Scattering ◽  
Plant Cell Wall ◽  
Raw Materials ◽  
Cellulose Microfibrils ◽  
Wall Structure

AbstractWood and other plant-based resources provide abundant, renewable raw materials for a variety of applications. Nevertheless, their utilization would greatly benefit from more efficient and accurate methods to characterize the detailed nanoscale architecture of plant cell walls. Non-invasive techniques such as neutron and X-ray scattering hold a promise for elucidating the hierarchical cell wall structure and any changes in its morphology, but their use is hindered by challenges in interpreting the experimental data. We used small-angle neutron scattering in combination with contrast variation by poly(ethylene glycol) (PEG) to identify the scattering contribution from cellulose microfibril bundles in native wood cell walls. Using this method, mean diameters for the microfibril bundles from 12 to 19 nm were determined, without the necessity of cutting, drying or freezing the cell wall. The packing distance of the individual microfibrils inside the bundles can be obtained from the same data. This finding opens up possibilities for further utilization of small-angle scattering in characterizing the plant cell wall nanostructure and its response to chemical, physical and biological modifications or even in situ treatments. Moreover, our results give new insights into the interaction between PEG and the wood nanostructure, which may be helpful for preservation of archaeological woods.

scholarly journals Anatomical structure overrides temperature controls on magnesium uptake – calcification in the Arctic/subarctic coralline algae <i>Leptophytum laeve</i> and <i>Kvaleya epilaeve</i> (Rhodophyta; Corallinales)

2018 ◽  
Vol 15 (3) ◽  
pp. 781-795 ◽  
Author(s):  
Merinda C. Nash ◽  
Walter Adey
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Magnesium Content ◽  
Coralline Algae ◽  
The Arctic ◽  
Wall Structure ◽  
Adjacent Cell ◽  
Coralline Red Algae ◽  
Primary Basis ◽  
Mg Content

Abstract. Calcified coralline red algae are ecologically key organisms in photic benthic environments. In recent decades they have become important climate proxies, especially in the Arctic and subarctic. It has been widely accepted that magnesium content in coralline tissues is directly a function of ambient temperature, and this is a primary basis for their value as a climate archive. In this paper we show for two genera of Arctic/subarctic corallines, Leptophytum laeve and Kvaleya epilaeve, that previously unrecognised complex tissue and cell wall anatomy bears a variety of basal signatures for Mg content, with the accepted temperature relationship being secondary. The interfilament carbonate has lower Mg than adjacent cell walls and the hypothallial cell walls have the highest Mg content. The internal structure of the hypothallial cell walls can differ substantially from the perithallial radial cell wall structure. Using high-magnification scanning electron microscopy and etching we expose the nanometre-scale structures within the cell walls and interfilament. Fibrils concentrate at the internal and external edges of the cell walls. Fibrils ∼ 10 nm thick appear to thread through the radial Mg-calcite grains and form concentric bands within the cell wall. This banding may control Mg distribution within the cell. Similar fibril banding is present in the hypothallial cell walls but not the interfilament. Climate archiving with corallines can achieve greater precision with recognition of these parameters.

scholarly journals Identifying transcription factors that reduce wood recalcitrance and improve enzymatic degradation of xylem cell wall in Populus

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chiaki Hori ◽  
Naoki Takata ◽  
Pui Ying Lam ◽  
Yuki Tobimatsu ◽  
Soichiro Nagano ◽  
...  
Keyword(s):  
Cell Wall ◽  
Populus Tremuloides ◽  
Cell Walls ◽  
Enzymatic Degradation ◽  
Plant Biomass ◽  
Lignin Content ◽  
Enzymatic Saccharification ◽  
Wall Structure ◽  
Xylem Cell

AbstractDeveloping an efficient deconstruction step of woody biomass for biorefinery has been drawing considerable attention since its xylem cell walls display highly recalcitrance nature. Here, we explored transcriptional factors (TFs) that reduce wood recalcitrance and improve saccharification efficiency in Populus species. First, 33 TF genes up-regulated during poplar wood formation were selected as potential regulators of xylem cell wall structure. The transgenic hybrid aspens (Populus tremula × Populus tremuloides) overexpressing each selected TF gene were screened for in vitro enzymatic saccharification. Of these, four transgenic seedlings overexpressing previously uncharacterized TF genes increased total glucan hydrolysis on average compared to control. The best performing lines overexpressing Pt × tERF123 and Pt × tZHD14 were further grown to form mature xylem in the greenhouse. Notably, the xylem cell walls exhibited significantly increased total xylan hydrolysis as well as initial hydrolysis rates of glucan. The increased saccharification of Pt × tERF123-overexpressing lines could reflect the improved balance of cell wall components, i.e., high cellulose and low xylan and lignin content, which could be caused by upregulation of cellulose synthase genes upon the expression of Pt × tERF123. Overall, we successfully identified Pt × tERF123 and Pt × tZHD14 as effective targets for reducing cell wall recalcitrance and improving the enzymatic degradation of woody plant biomass.

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