scholarly journals A Mechanical Model to Interpret Cell-Scale Indentation Experiments on Plant Tissues in Terms of Cell Wall Elasticity and Turgor Pressure

2016 ◽  
Vol 7 ◽  
Author(s):  
Richard Malgat ◽  
François Faure ◽  
Arezki Boudaoud
1978 ◽  
Vol 56 (17) ◽  
pp. 2153-2161 ◽  
Author(s):  
M. T. Tyree ◽  
M. E. MacGregor ◽  
A. Petrov ◽  
M. I. Upenieks

The pressure bomb is being used to a much greater extent to measure some tissue – water relations parameters such as osmotic pressure, turgor pressure, and cell wall elasticity. Recently, Richards has developed a faster pressure-bomb method of obtaining these and other parameters than the method used by Hammel and modified by us. In this paper, we compare the two methods and conclude that Richards’ method should not be used when accuracy is deemed important. The Richards method usually overestimates osmotic pressure by 0.2 MPa (= 2 bars) and sometimes by 0.8 MPa (= 8 bars).


2019 ◽  
Vol 4 (2) ◽  
pp. 641-646 ◽  
Author(s):  
Jan T. Burri ◽  
Hannes Vogler ◽  
Gautam Munglani ◽  
Nino F. Laubli ◽  
Ueli Grossniklaus ◽  
...  

2021 ◽  
Author(s):  
Hannes Vogler ◽  
Gautam Munglani ◽  
Tohnyui Ndinyanka Fabrice ◽  
Christian Draeger ◽  
Jan Thomas Burri ◽  
...  

Pollen tubes live a life on a razor′s edge. They must maintain cell wall integrity whilst growing towards the ovule at extraordinary speed but explosively burst at just the right moment to release the sperm cells—with fatal consequences for reproduction if things go wrong. The precisely controlled growth of the pollen tube depends on the fine-tuned balance between the expansive force of turgor pressure and the restraining effect of the cell wall. Currently, it is not well understood how the composition of the cell wall affects its mechanical properties. Using Arabidopsis mutants, we have investigated these interactions by combining experimental and simulation techniques to determine instantaneous and time-dependent mechanical parameters. This allowed, for the first time, the quantification of the effects of cell wall biochemistry on turgor pressure and cell wall elasticity and to predict their effects on growth rate. Our systems biology approach is widely applicable to study the implications of mechanical stress on growth.


2013 ◽  
Vol 13 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Frans M. Klis ◽  
Chris G. de Koster ◽  
Stanley Brul

ABSTRACTBionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeastSaccharomyces cerevisiaeand the polymorphic, pathogenic fungusCandida albicans. We discuss the linear relationship between cell size and cell ploidy, the correlation between cell size and specific growth rate, the effect of turgor pressure on cell size, and the reason why using fixed cells for measuring cellular dimensions can result in serious underestimation ofin vivovalues. We further consider the evidence that individual buds and hyphae grow linearly and that exponential growth of the population results from regular formation of new daughter cells and regular hyphal branching. Our calculations show that hyphal growth allowsC. albicansto cover much larger distances per unit of time than the yeast mode of growth and that this is accompanied by strongly increased surface expansion rates. We therefore predict that the transcript levels of genes involved in wall formation increase during hyphal growth. Interestingly, wall proteins and polysaccharides seem barely, if at all, subject to turnover and replacement. A general lesson is how strongly most bionumbers and bioestimates depend on environmental conditions and genetic background, thus reemphasizing the importance of well-defined and carefully chosen culture conditions and experimental approaches. Finally, we propose that the numbers and estimates described here offer a solid starting point for similar studies of other cell compartments and other yeast species.


2009 ◽  
Vol 36 (5) ◽  
pp. 383 ◽  
Author(s):  
John S. Boyer

Recently discovered reactions allow the green alga Chara corallina (Klien ex. Willd., em. R.D.W.) to grow well without the benefit of xyloglucan or rhamnogalactan II in its cell wall. Growth rates are controlled by polygalacturonic acid (pectate) bound with calcium in the primary wall, and the reactions remove calcium from these bonds when new pectate is supplied. The removal appears to occur preferentially in bonds distorted by wall tension produced by the turgor pressure (P). The loss of calcium accelerates irreversible wall extension if P is above a critical level. The new pectate (now calcium pectate) then binds to the wall and decelerates wall extension, depositing new wall material on and within the old wall. Together, these reactions create a non-enzymatic but stoichiometric link between wall growth and wall deposition. In green plants, pectate is one of the most conserved components of the primary wall, and it is therefore proposed that the acceleration-deceleration-wall deposition reactions are of wide occurrence likely to underlie growth in virtually all green plants. C. corallina is one of the closest relatives of the progenitors of terrestrial plants, and this review focuses on the pectate reactions and how they may fit existing theories of plant growth.


2018 ◽  
pp. 335-347 ◽  
Author(s):  
Thomas Torode ◽  
Marina Linardic ◽  
J. Louis Kaplan ◽  
Siobhan A. Braybrook

2010 ◽  
Vol 135 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Qi Chai ◽  
Fang Jin ◽  
Emily Merewitz ◽  
Bingru Huang

The objective of this study was to determine physiological traits for drought survival and post-drought recovery upon re-watering in two C3 perennial grass species, kentucky bluegrass [KBG (Poa pratensis)] and perennial ryegrass [PRG (Lolium perenne)]. Plants were maintained well watered or exposed to drought stress by withholding irrigation and were then re-watered in a growth chamber. KBG had significantly higher grass quality and leaf photochemical efficiency, and lower electrolyte leakage than PRG during 20 days of drought. After 7 days of re-watering, drought-damaged leaves were rehydrated to the control level in KBG, but could not fully recover in PRG. KBG produced a greater number of new roots, while PRG had more rapid elongation of new roots after 16 days of re-watering. Superior drought tolerance in KBG was associated with osmotic adjustment, higher cell wall elasticity, and lower relative water content at zero turgor. Osmotic adjustment, cell wall elasticity, and cell membrane stability could play important roles in leaf desiccation tolerance and drought survival in perennial grass species. In addition, post-drought recovery of leaf hydration level and physiological activity could be associated with the accumulation of carbohydrates in leaves and rhizomes during drought stress and new root production after re-watering.


2021 ◽  
Author(s):  
Maja Brus-Szkalej ◽  
Christian B. Andersen ◽  
Ramesh R. Vetukuri ◽  
Laura J. Grenville-Briggs Didymus

Transglutaminases (TGases) are enzymes highly conserved among prokaryotic and eukaryotic organisms, where their role is to catalyse protein cross-linking. One of the putative TGases of Phytophthora infestans has previously been shown to be localised to the cell wall. Based on sequence similarity we were able to identify six more genes annotated as putative TGases and show that these seven genes group together in phylogenetic analysis. All of the seven proteins are predicted to contain transmembrane helices and both a TGase domain and a MANSC domain, the latter of which was previously shown to play a role in protein stability. Chemical inhibition of transglutaminase activity and silencing of the entire family of the putative cell wall TGases are both lethal to P. infestans indicating the importance of these proteins in cell wall formation and stability. The intermediate phenotype obtained with lower drug concentrations and less efficient silencing displays a number of deformations to germ tubes and appressoria. Both chemically treated and silenced lines show lower pathogenicity than the wild type in leaf infection assays. Finally, we show that appressoria of P. infestans possess the ability to build up turgor pressure and that this ability is decreased by chemical inhibition of TGases.


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