scholarly journals NACL STRESS ALTERS PRIMARY CELL WALL TENSILE STRENGTH IN THE HALOPHYTIC GRASS, DISTICHLIS SPICATA L.

HortScience ◽  
1992 ◽  
Vol 27 (12) ◽  
pp. 1261c-1261
Author(s):  
Francisco Lopez-Gutierrez ◽  
Harrison G. Hughes ◽  
Nicholas C. Carpita
Keyword(s):  
Tensile Strength ◽  
Cell Wall ◽  
Cultured Cells ◽  
Turgor Pressure ◽  
Nacl Stress ◽  
Primary Cell ◽  
Cellulose Microfibrils ◽  
Distichlis Spicata ◽  
Primary Cell Wall ◽  
Stressed Cells

After 6 months of growth in 200,400, and 500 mm NaCl, cultured cells of Distichlis spicata showed a decreased cell volume (size) despite maintenance of turgor pressure sometimes 2-fold higher than that of the control. Tensile strength, as measured by a nitrogen gas decompression technique, showed empirically that the walls of NaCl-stressed cells were weaker than those of nonstressed cells. Breaking pressures of the walls of control cells were ≈68 ± 4 bars, while that of the walls of cells grown in 500 mm NaCl (-25 bars) were 14 ± 2 bars. The relative amount of cellulose per cell remained about constant despite salt stress. However, glucuronoarabinoxylans were more readily extractable, presumably because of a decrease in cross-linkage with phenol substances. Therefore, we suggest that cellulose microfibrils are not the only determinants that confer tensile strength to the primary cell wall, but rather subtle changes in the matrix polysaccharides are likely responsible for this event.

scholarly journals Xyloglucan Is Not Essential for the Formation and Integrity of the Cellulose Network in the Primary Cell Wall Regenerated from Arabidopsis Protoplasts

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 629 ◽  
Author(s):  
Hiroaki Kuki ◽  
Ryusuke Yokoyama ◽  
Takeshi Kuroha ◽  
Kazuhiko Nishitani
Keyword(s):  
Cell Wall ◽  
Cellulose Microfibril ◽  
Mechanical Stability ◽  
Molecular Model ◽  
Primary Cell ◽  
Cellulose Microfibrils ◽  
Primary Cell Wall ◽  
Imaging Analysis ◽  
Cellulose Deposition ◽  
Initial Assembly

The notion that xyloglucans (XG) play a pivotal role in tethering cellulose microfibrils in the primary cell wall of plants can be traced back to the first molecular model of the cell wall proposed in 1973, which was reinforced in the 1990s by the identification of Xyloglucan Endotransglucosylase/Hydrolase (XTH) enzymes that cleave and reconnect xyloglucan crosslinks in the cell wall. However, this tethered network model has been seriously challenged since 2008 by the identification of the Arabidopsis thaliana xyloglucan-deficient mutant (xxt1 xxt2), which exhibits functional cell walls. Thus, the molecular mechanism underlying the physical integration of cellulose microfibrils into the cell wall remains controversial. To resolve this dilemma, we investigated the cell wall regeneration process using mesophyll protoplasts derived from xxt1 xxt2 mutant leaves. Imaging analysis revealed only a slight difference in the structure of cellulose microfibril network between xxt1 xxt2 and wild-type (WT) protoplasts. Additionally, exogenous xyloglucan application did not alter the cellulose deposition patterns or mechanical stability of xxt1 xxt2 mutant protoplasts. These results indicate that xyloglucan is not essential for the initial assembly of the cellulose network, and the cellulose network formed in the absence of xyloglucan provides sufficient tensile strength to the primary cell wall regenerated from protoplasts.

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 Raman imaging of Micrasterias: new insights into shape formation

PROTOPLASMA ◽  
2021 ◽  
Author(s):  
Martin Felhofer ◽  
Konrad Mayr ◽  
Ursula Lütz-Meindl ◽  
Notburga Gierlinger
Keyword(s):  
Cell Wall ◽  
Raman Spectra ◽  
Secondary Cell Wall ◽  
Raman Imaging ◽  
Primary Cell ◽  
Cellulose Microfibrils ◽  
Primary Cell Wall ◽  
Crystalline Cellulose ◽  
Wall Thickening ◽  
Cell Wall Carbohydrates

AbstractThe algae Micrasterias with its star-shaped cell pattern is a perfect unicellular model system to study morphogenesis. How the indentations are formed in the primary cell wall at exactly defined areas puzzled scientists for decades, and they searched for chemical differences in the primary wall of the extending tips compared to the resting indents. We now tackled the question by Raman imaging and scanned in situ Micrasterias cells at different stages of development. Thousands of Raman spectra were acquired from the mother cell and the developing semicell to calculate chemical images based on an algorithm finding the most different Raman spectra. Each of those spectra had characteristic Raman bands, which were assigned to molecular vibrations of BaSO4, proteins, lipids, starch, and plant cell wall carbohydrates. Visualizing the cell wall carbohydrates revealed a cell wall thickening at the indentations of the primary cell wall of the growing semicell and uniplanar orientation of the cellulose microfibrils to the cell surface in the secondary cell wall. Crystalline cellulose dominated in the secondary cell wall spectra, while in the primary cell wall spectra, also xyloglucan and pectin were reflected. Spectral differences between the indent and tip region of the primary cell wall were scarce, but a spectral mixing approach pointed to more cellulose fibrils deposited in the indent region. Therefore, we suggest that cell wall thickening together with a denser network of cellulose microfibrils stiffens the cell wall at the indent and induces different cell wall extensibility to shape the lobes.

scholarly journals Influence of biological origin on the tensile properties of cellulose nanopapers

Cellulose ◽  
2021 ◽  
Author(s):  
Katri S. Kontturi ◽  
Koon-Yang Lee ◽  
Mitchell P. Jones ◽  
William W. Sampson ◽  
Alexander Bismarck ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Cell Wall ◽  
Bacterial Cellulose ◽  
Raw Materials ◽  
Cellulose Nanofibers ◽  
Nanofibrillated Cellulose ◽  
Primary Cell Wall ◽  
Biological Origin ◽  
Basic Principles ◽  
Fiber Mats

Abstract Cellulose nanopapers provide diverse, strong and lightweight templates prepared entirely from sustainable raw materials, cellulose nanofibers (CNFs). Yet the strength of CNFs has not been fully capitalized in the resulting nanopapers and the relative influence of CNF strength, their bonding, and biological origin to nanopaper strength are unknown. Here, we show that basic principles from paper physics can be applied to CNF nanopapers to illuminate those relationships. Importantly, it appeared that ~ 200 MPa was the theoretical maximum for nanopapers with random fibril orientation. Furthermore, we demonstrate the contrast in tensile strength for nanopapers prepared from bacterial cellulose (BC) and wood-based nanofibrillated cellulose (NFC). Endemic amorphous polysaccharides (hemicelluloses) in NFC act as matrix in NFC nanopapers, strengthening the bonding between CNFs just like it improves the bonding between CNFs in the primary cell wall of plants. The conclusions apply to all composites containing non-woven fiber mats as reinforcement. Graphic abstract

scholarly journals A Specialized Outer Layer of the Primary Cell Wall Joins Elongating Cotton Fibers into Tissue-Like Bundles

2009 ◽  
Vol 150 (2) ◽  
pp. 684-699 ◽  
Author(s):  
Bir Singh ◽  
Utku Avci ◽  
Sarah E. Eichler Inwood ◽  
Mark J. Grimson ◽  
Jeff Landgraf ◽  
...  
Keyword(s):  
Cell Wall ◽  
Outer Layer ◽  
Primary Cell ◽  
Primary Cell Wall ◽  
Cotton Fibers
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