Ultrastructural and biochemical effects of endopectate lyase on cell walls from cell suspension cultures of bean and rice

1980 ◽  
Vol 58 (8) ◽  
pp. 867-880 ◽  
Author(s):  
Con J. Baker ◽  
James R. Aist ◽  
Durward F. Bateman
Keyword(s):  
Cell Wall ◽  
Cell Suspension ◽  
Cell Walls ◽  
Plant Cell Wall ◽  
Middle Lamella ◽  
Cell Suspension Cultures ◽  
Suspension Cultures ◽  
Cell Wall Integrity ◽  
Wall Material ◽  
Wall Structure

Cell walls prepared from suspension cell cultures of bean and rice in log-phase growth were used to examine the effects of endopectate lyase (PL) on the solubilization of cell wall carbohydrates and concomitant ultrastructural alterations. Cell wall preparations from both plant sources were heterogeneous and contained a range of wall types from primary walls to xylem elements with spiral, secondary wall thickenings. Marked differences in wall thickness and number of wall laminations typified both preparations.Bean cell walls were more susceptible to degradation by PL than were those of rice. Upon treatment of the former with 2.3 × 10−3 units/mL of PL (1 unit released 1 μmol of unsaturated uronide/min at 30 °C from polygalacturonic acid at pH 8.5), 27% of the noncellulosic wall carbohydrate was solubilized in 1 h. This represented 50% of the PL susceptible carbohydrate in the preparation. Only 3% of the noncellulosic carbohydrate was released from rice cell walls in 1 h when treated with 115 × 10−3 units of PL/mL. This accounted for 60% of the PL susceptible wall fractions. Only uronic acid, rhamnose, galactose, and arabinose were solubilized from both preparations by PL.Cell walls in the bean and rice preparations were affected differentially by the PL. Those walls with secondary thickenings did not appear to be degraded, while the distinct fibrillar appearance of both bean and rice walls tended to fade or disappear. The middle lamella tended to dissolve to varying degrees in the presence of PL. Bean walls were more severely degraded than were the rice walls and many exhibited swelling, separation of wall layers, markedly reduced staining intensity, and (or) a granular ultrastructure.This study has demonstrated that as PL acts on susceptible cell walls there are major changes evoked in cell wall structure which suggest that the rhamnogalacturonan fraction of the higher plant cell wall contributes significantly to cell wall integrity. This study also emphasizes the need for cell wall material of proven uniformity for investigations of both cell wall composition and effects of specific polysaccharide degrading enzymes on cell wall integrity. Preliminary studies indicate that tobacco pith may provide more uniform cell walls than do cell suspension cultures.

Ultrastructure des parois de cerises Bigarreau Burlat de textures différentes au cours de la maturation

1996 ◽  
Vol 74 (12) ◽  
pp. 1974-1981 ◽  
Author(s):  
C. Batisse ◽  
P. J. Coulomb ◽  
C. Coulomb ◽  
M. Buret
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Middle Lamella ◽  
Primary Cell ◽  
Wall Material ◽  
Cell Wall Degradation ◽  
Composition And Structure ◽  
Cell Wall Texture ◽  
Synthesis And Degradation ◽  
Soft Fruits

The changes in texture of fruits during ripening are linked to cell wall degradation involving synthesis and degradation of polymers. An increase in pectin solubility leads to cell sliding and an elastic aspect of tissues. The biochemical cell wall process differs between soft and crisp fruits originating from a same cultivar but cultivated under different agroclimatic conditions. Although the proportions of cell wall material are similar, the composition and structure of the two cell walls are very different at maturity. A solubilization of the middle lamella and a restructuration of the primary cell walls arising from the cells separation is observed in crisp fruits. In contrast, the middle lamella of the soft fruits is better preserved and the primary cell walls are thin and show degradation bags delimited by residual membrane formations. In addition, the macroendocytosis process by endosome individualization is more important in soft fruits. In conclusion, the fruit texture depends on the extent of the links between cell wall polymers. Keywords: cherry, cell wall, texture, ultrastructural study.

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 The Role of Mechanoperception in Plant Cell Wall Integrity Maintenance

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 574 ◽  
Author(s):  
Laura Bacete ◽  
Thorsten Hamann
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Cell Walls ◽  
Molecular Mechanisms ◽  
Plant Cell Wall ◽  
Cell Wall Integrity ◽  
Adaptive Changes ◽  
Structural Support ◽  
Dynamic Structures ◽  
Molecular Components

The plant cell walls surrounding all plant cells are highly dynamic structures, which change their composition and organization in response to chemical and physical stimuli originating both in the environment and in plants themselves. They are intricately involved in all interactions between plants and their environment while also providing adaptive structural support during plant growth and development. A key mechanism contributing to these adaptive changes is the cell wall integrity (CWI) maintenance mechanism. It monitors and maintains the functional integrity of cell walls by initiating adaptive changes in cellular and cell wall metabolism. Despite its importance, both our understanding of its mode of action and knowledge regarding the molecular components that form it are limited. Intriguingly, the available evidence implicates mechanosensing in the mechanism. Here, we provide an overview of the knowledge available regarding the molecular mechanisms involved in and discuss how mechanoperception and signal transduction may contribute to plant CWI maintenance.

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.

Elicitor-induced formation of free and cell-wall-bound stilbenes in cell-suspension cultures of Scots pine (Pinus sylvestris L.)

Planta ◽  
1994 ◽  
Vol 194 (1) ◽  
pp. 143-148 ◽  
Author(s):  
Bernd Markus Lange ◽  
Monika Trost ◽  
Werner Heller ◽  
Christian Langebartels ◽  
Heinrich Sandermann
Keyword(s):  
Cell Wall ◽  
Pinus Sylvestris ◽  
Cell Suspension ◽  
Scots Pine ◽  
Cell Suspension Cultures ◽  
Suspension Cultures

scholarly journals Proteomics of loosely bound cell wall proteins ofArabidopsis thaliana cell suspension cultures: A critical analysis

2003 ◽  
Vol 24 (1920) ◽  
pp. 3421-3432 ◽  
Author(s):  
Gisèle Borderies ◽  
Elisabeth Jamet ◽  
Claude Lafitte ◽  
Michel Rossignol ◽  
Alain Jauneau ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Suspension ◽  
Critical Analysis ◽  
Cell Suspension Cultures ◽  
Suspension Cultures ◽  
Cell Wall Proteins ◽  
Ofarabidopsis Thaliana

scholarly journals Auxin protects Arabidopsis thaliana cell suspension cultures from programmed cell death induced by the cellulose biosynthesis inhibitors thaxtomin A and isoxaben

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Fatima Awwad ◽  
Guillaume Bertrand ◽  
Michel Grandbois ◽  
Nathalie Beaudoin
Keyword(s):  
Mechanical Properties ◽  
Cell Death ◽  
Cell Wall ◽  
Cell Suspension ◽  
Cell Suspension Cultures ◽  
Suspension Cultures ◽  
Cellulose Synthesis ◽  
Cellulose Biosynthesis ◽  
Thaxtomin A ◽  
Wall Stiffness

Abstract Background Thaxtomin A (TA) is a natural cellulose biosynthesis inhibitor (CBI) synthesized by the potato common scab-causing pathogen Streptomyces scabies. Inhibition of cellulose synthesis by TA compromises cell wall organization and integrity, leading to the induction of an atypical program of cell death (PCD). These processes may facilitate S. scabies entry into plant tissues. To study the mechanisms that regulate the induction of cell death in response to inhibition of cellulose synthesis, we used Arabidopsis thaliana cell suspension cultures treated with two structurally different CBIs, TA and the herbicide isoxaben (IXB). Results The induction of cell death by TA and IXB was abrogated following pretreatment with the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) and the natural auxin indole-3-acetic acid (IAA). The addition of auxin efflux inhibitors also inhibited the CBI-mediated induction of PCD. This effect may be due to intracellular accumulation of auxin. Auxin has a wide range of effects in plant cells, including a role in the control of cell wall composition and rigidity to facilitate cell elongation. Using Atomic Force Microscopy (AFM)-based force spectroscopy, we found that inhibition of cellulose synthesis by TA and IXB in suspension-cultured cells decreased cell wall stiffness to a level slightly different than that caused by auxin. However, the cell wall stiffness in cells pretreated with auxin prior to CBI treatment was equivalent to that of cells treated with auxin only. Conclusions Addition of auxin to Arabidopsis cell suspension cultures prevented the TA- and IXB-mediated induction of cell death. Cell survival was also stimulated by inhibition of polar auxin transport during CBI-treatment. Inhibition of cellulose synthesis perturbed cell wall mechanical properties of Arabidopsis cells. Auxin treatment alone or with CBI also decreased cell wall stiffness, showing that the mechanical properties of the cell wall perturbed by CBIs were not restored by auxin. However, since auxin’s effects on the cell wall stiffness apparently overrode those induced by CBIs, we suggest that auxin may limit the impact of CBIs by restoring its own transport and/or by stabilizing the plasma membrane - cell wall - cytoskeleton continuum.

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