scholarly journals Catalysts of plant cell wall loosening

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 119 ◽  
Author(s):  
Daniel J. Cosgrove
Keyword(s):  
Cell Wall ◽  
Plant Cell Wall ◽  
Turgor Pressure ◽  
Wall Stress ◽  
Primary Cell Wall ◽  
Wall Structure ◽  
Xyloglucan Endotransglycosylase ◽  
Growing Cell ◽  
Tensile Forces ◽  
Wall Loosening

The growing cell wall in plants has conflicting requirements to be strong enough to withstand the high tensile forces generated by cell turgor pressure while selectively yielding to those forces to induce wall stress relaxation, leading to water uptake and polymer movements underlying cell wall expansion. In this article, I review emerging concepts of plant primary cell wall structure, the nature of wall extensibility and the action of expansins, family-9 and -12 endoglucanases, family-16 xyloglucan endotransglycosylase/hydrolase (XTH), and pectin methylesterases, and offer a critical assessment of their wall-loosening activity

Incorporation of β-(1,6)-linked glucooligosaccharides (pustulooligosaccharides) into plant cell wall structures

2012 ◽  
Vol 66 (9) ◽  
Author(s):  
Zuzana Zemková ◽  
Soňa Garajová ◽  
Dana Flodrová ◽  
Pavel Řehulka ◽  
Ivan Zelko ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell Wall ◽  
Structural Similarity ◽  
Size Exclusion ◽  
Primary Cell Wall ◽  
Specific Cell ◽  
Specific Substrate ◽  
Xyloglucan Endotransglycosylase ◽  
Dot Blot ◽  
Wall Structures

AbstractProtein extract of germinating nasturtium (Tropaeolum majus) seeds containing xyloglucan endotransglycosylase (xyloglucan xyloglucosyl transferase, EC 2.4.1.207, abbreviated XET) exhibited the heterotransglycosylating activity with donor/acceptor substrate pair xyloglucan/sulphorhodamine labelled pustulooligosaccharides (XG/PUOS-SR) in a dot blot assay. The heterotransglycosylating activity was confirmed by the substrate-product changes during transglycosylation by HPLC size-exclusion chromatography. Another donor substrate capable of being coupled with PUOS-SR was cellulose, probably owing to its structural similarity to xyloglucan. Surprisingly, microscopic comparison of the incorporation of the labelled xyloglucan nonasaccharide XGO9-SR (specific substrate for XET) and PUOS-SR into the cell wall structures clearly showed differences in their binding to specific cell structures: the primary cell wall and the plasma membrane. These findings indicate the existence in nasturtium of XETs with different localisation, substrate specificity and, probably, function.

A fibre-reinforced fluid model of anisotropic plant cell growth

2010 ◽  
Vol 655 ◽  
pp. 472-503 ◽  
Author(s):  
R. J. DYSON ◽  
O. E. JENSEN
Keyword(s):  
Cell Wall ◽  
Cell Growth ◽  
Fluid Model ◽  
Turgor Pressure ◽  
Cellulose Microfibrils ◽  
Wall Material ◽  
Primary Cell Wall ◽  
Growing Cell ◽  
Asymptotic Reduction ◽  
Simple Sets

Many growing plant cells undergo rapid axial elongation with negligible radial expansion. Growth is driven by high internal turgor pressure causing viscous stretching of the cell wall, with embedded cellulose microfibrils providing the wall with strongly anisotropic properties. We present a theoretical model of a growing cell, representing the primary cell wall as a thin axisymmetric fibre-reinforced viscous sheet supported between rigid end plates. Asymptotic reduction of the governing equations, under simple sets of assumptions about the fibre and wall properties, yields variants of the traditional Lockhart equation, which relates the axial cell growth rate to the internal pressure. The model provides insights into the geometric and biomechanical parameters underlying bulk quantities such as wall extensibility, and shows how either dynamical changes in wall material properties or passive fibre reorientation may suppress cell elongation.

scholarly journals The Cell Wall Structure of Xylem Parenchyma

1952 ◽  
Vol 5 (2) ◽  
pp. 223 ◽  
Author(s):  
AB Wardrop ◽  
HE Dadswell
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Secondary Cell Wall ◽  
Primary Cell Wall ◽  
Wall Structure ◽  
Xylem Parenchyma ◽  
Cell Axis ◽  
X Ray ◽  
Ray Methods ◽  
Longitudinal Cell

The fine structure of the cell wall of both ray and vertical parenchyma has been investigated. In all species examined secondary thickening had occurred. In the primary cell wall the micellar orientation was approximately trans"erse to the longitudiJ)aI cell axis. Using optical and X-ray methods the secondary cell wall was shown to possess a helical micellar organization, the micelles being inclined between 30� and 60� to the longitudinal cell axis.

scholarly journals Structure and Biomechanics during Xylem Vessel Transdifferentiation in Arabidopsis thaliana

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1715
Author(s):  
Eleftheria Roumeli ◽  
Leah Ginsberg ◽  
Robin McDonald ◽  
Giada Spigolon ◽  
Rodinde Hendrickx ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Cell Walls ◽  
Turgor Pressure ◽  
Plant Cells ◽  
Building Blocks ◽  
Xylem Vessel ◽  
Primary Cell Wall ◽  
Individual Plant ◽  
Vessel Elements

Individual plant cells are the building blocks for all plantae and artificially constructed plant biomaterials, like biocomposites. Secondary cell walls (SCWs) are a key component for mediating mechanical strength and stiffness in both living vascular plants and biocomposite materials. In this paper, we study the structure and biomechanics of cultured plant cells during the cellular developmental stages associated with SCW formation. We use a model culture system that induces transdifferentiation of Arabidopsis thaliana cells to xylem vessel elements, upon treatment with dexamethasone (DEX). We group the transdifferentiation process into three distinct stages, based on morphological observations of the cell walls. The first stage includes cells with only a primary cell wall (PCW), the second covers cells that have formed a SCW, and the third stage includes cells with a ruptured tonoplast and partially or fully degraded PCW. We adopt a multi-scale approach to study the mechanical properties of cells in these three stages. We perform large-scale indentations with a micro-compression system in three different osmotic conditions. Atomic force microscopy (AFM) nanoscale indentations in water allow us to isolate the cell wall response. We propose a spring-based model to deconvolve the competing stiffness contributions from turgor pressure, PCW, SCW and cytoplasm in the stiffness of differentiating cells. Prior to triggering differentiation, cells in hypotonic pressure conditions are significantly stiffer than cells in isotonic or hypertonic conditions, highlighting the dominant role of turgor pressure. Plasmolyzed cells with a SCW reach similar levels of stiffness as cells with maximum turgor pressure. The stiffness of the PCW in all of these conditions is lower than the stiffness of the fully-formed SCW. Our results provide the first experimental characterization of the mechanics of SCW formation at single cell level.

scholarly journals Three-Dimensional Imaging of Plant Cell Wall Deconstruction Using Fluorescence Confocal Microscopy

2020 ◽  
Vol 1 (2) ◽  
pp. 75-85
Author(s):  
Aya Zoghlami ◽  
Yassin Refahi ◽  
Christine Terryn ◽  
Gabriel Paës
Keyword(s):  
Cell Wall ◽  
Enzymatic Hydrolysis ◽  
Plant Cell Wall ◽  
Enzymatic Reaction ◽  
Time Lapse ◽  
Quantitative Information ◽  
Image Resolution ◽  
Wall Structure ◽  
Hydrolysis Time ◽  
Fluorescence Confocal Microscopy

Lignocellulosic biomass (LB) is recalcitrant to enzymatic hydrolysis due to its compact and complex cell wall structure. To identify the parameters behind LB recalcitrance, experimental data over hydrolysis time must be collected. Here, we describe a novel method to collect time-lapse images during cell wall deconstruction by enzymatic hydrolysis. The protocol includes instructions for sample preparation, layout of a custom designed incubation chamber and instructions for confocal time lapse acquisition. The protocol sets out a detailed plan where cross-sections of untreated and pretreated poplar samples are mounted in a sealed frame containing a buffer and an enzymatic cocktail. The sealed frame is then placed into an incubator to maintain the sample at a constant temperature of 50 °C, which is optimal for enzymatic reaction while avoiding enzymatic cocktail evaporation. Using lignin natural autofluorescence, confocal z-stacks of untreated and pretreated samples were acquired at regular time intervals during enzymatic hydrolysis for 24 h. Acquisition parameters were optimized to compromise between image resolution and reduced photo-bleaching. The acquired image might then be processed by further development of algorithms to extract precise quantitative information on cell wall deconstruction. This protocol is an important first step towards elucidating the underlying parameters of LB recalcitrance by allowing the acquisition of high-quality images of LB hydrolysis for extracting quantitative data on LB deconstruction.

scholarly journals Primary cell wall inspired micro containers as a step towards a synthetic plant cell

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Paulraj ◽  
S. Wennmalm ◽  
D.C.F. Wieland ◽  
A. V. Riazanova ◽  
A. Dėdinaitė ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Structural Integrity ◽  
Plant Cells ◽  
Lipid Vesicles ◽  
Primary Cell Wall ◽  
Living Plant ◽  
A Cell ◽  
Lipid Tubules

AbstractThe structural integrity of living plant cells heavily relies on the plant cell wall containing a nanofibrous cellulose skeleton. Hence, if synthetic plant cells consist of such a cell wall, they would allow for manipulation into more complex synthetic plant structures. Herein, we have overcome the fundamental difficulties associated with assembling lipid vesicles with cellulosic nanofibers (CNFs). We prepare plantosomes with an outer shell of CNF and pectin, and beneath this, a thin layer of lipids (oleic acid and phospholipids) that surrounds a water core. By exploiting the phase behavior of the lipids, regulated by pH and Mg2+ ions, we form vesicle-crowded interiors that change the outer dimension of the plantosomes, mimicking the expansion in real plant cells during, e.g., growth. The internal pressure enables growth of lipid tubules through the plantosome cell wall, which paves the way to the development of hierarchical plant structures and advanced synthetic plant cell mimics.

scholarly journals Insights into plant cell wall structure, architecture, and integrity using glycome profiling of native and AFEXTM-pre-treated biomass

2015 ◽  
Vol 66 (14) ◽  
pp. 4279-4294 ◽  
Author(s):  
Sivakumar Pattathil ◽  
Michael G. Hahn ◽  
Bruce E. Dale ◽  
Shishir P. S. Chundawat
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Glycome Profiling

Turgor and Cell Expansion: Beyond the Lockhart Equation

1992 ◽  
Vol 19 (5) ◽  
pp. 565 ◽  
Author(s):  
JB Passioura ◽  
SC Fry
Keyword(s):  
Cell Wall ◽  
Cell Expansion ◽  
Molecular Model ◽  
Turgor Pressure ◽  
Expansion Rate ◽  
Transient Responses ◽  
Constant Growth Rate ◽  
Growing Cell ◽  
A Cell ◽  
Constant Growth

The rheology of the expanding cell wall is often analysed in terms of the Lockhart equation, which equates the expansion rate of a cell to m(P - Y), where rn is the extensibility of the cell wall, P is the turgor pressure, and Y is a minimum value of P below which the cell will not grow. Many studies have shown that Y (and sometimes m) are variables which change in response to changes in P at a time scale of about 10 min. The result is that, apart from the transient responses, the expansion rate is often maintained at an approximately steady value despite changes in P. This paper describes a molecular model of the growing cell wall that accounts for how m and Y may vary to maintain a constant growth rate despite changes in turgor.

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