A computational model of the effect of symplastic growth on cell mechanics in a linear leaf blade

2015 ◽  
Vol 13 (01) ◽  
pp. 1540005 ◽  
Author(s):  
Ulyana Zubairova ◽  
Sergey Golushko ◽  
Aleksey Penenko ◽  
Sergey Nikolaev

The epidermis of a linear leaf, as in Poaceae, is established by parallel files of cells originating from the leaf base. Their feature is symplastic growth where neighboring cell walls adhere and do not slide along each other. We developed a simple mechanical cell-based model for symplastic growth of linear leaf blade. The challenge is to determine what restrictions on cell size symplastic growth creates compared to the free growing cells. We assume an unidirectional growing cell ensemble starting from a meristem-like layer of generative cells and then generating parallel cell rows from every cell of the initial layer. Each cell is characterized by its growth function, and growth of the whole leaf blade is accompanied by mutual adjustment between all the cells. Cells divide once they have reached a threshold area. A mathematical model and its implementation are proposed for computational simulation of 1D symplastic growth of tissues. The question analyzed is how a cell grows in a plant tissue if there is a mechanism for regulating the growth of an isolated growing cell and the behavior of the cell wall matter is elastoplastic. The results of the simulation of linear leaf blade growth are compared to those for a free-growing cell population.

2019 ◽  
Vol 35 (6) ◽  
Author(s):  
João Everthon da Silva Ribeiro ◽  
Ester dos Santos Coêlho ◽  
Francisco Romário Andrade Figueiredo ◽  
Sérgio de Faria Lopes ◽  
Manoel Bandeira de Albuquerque

Erythroxylum citrifolium is a neotropical plant species recorded in all regions of Brazil. Determining leaf area is of fundamental importance to studies related to plant propagation and growth. The objective was to obtain an equation to estimate the leaf area of E. citrifolium from linear dimensions of the leaf blade (length and width). A total of 200 leaf blades were collected in Parque Estadual Mata do Pau-Ferro in the municipality of Areia, state of Paraíba, Northeast Brazil. The models evaluated were: linear, linear without intercept, quadratic, cubic, power and exponential. The best model was determined by the criteria of: high coefficient of determination (R²), low root mean square error (RMSE), low Akaike information criterion (AIC), high Willmott concordance index (d) and a BIAS index close to zero. All of the models constructed satisfactorily estimated the leaf area of E. citrifolium, with coefficients of determination above 0.9050, but the power model using the product between length and width (L*W) ŷ = 0.5966 * LW1.0181 was the best, with the highest values of R² and d, low values of RMSE and AIC, and a BIAS index closest to zero.


Nanoscale ◽  
2020 ◽  
Vol 12 (27) ◽  
pp. 14573-14580
Author(s):  
Min Xu ◽  
Xueyan Feng ◽  
Feng Feng ◽  
Hantao Pei ◽  
Ruping Liu ◽  
...  

Interactions of magnetic nanoparticles with cells were investigated from a cell mechanics perspective, and magnetic nanoparticle-based force spectroscopy was developed as a novel method to measure the adhesion force among various cancer cell lines.


2018 ◽  
Vol 30 (19) ◽  
pp. 1704463 ◽  
Author(s):  
Dedy Septiadi ◽  
Federica Crippa ◽  
Thomas Lee Moore ◽  
Barbara Rothen-Rutishauser ◽  
Alke Petri-Fink

2002 ◽  
Vol 57 (3-4) ◽  
pp. 319-322 ◽  
Author(s):  
Kolishka Tsekova ◽  
Dessislava Todorova

The influence of copper (II) ions on the growth, accumulation properties and superoxide dismutase (SOD) activity of a growing culture of Aspergillus niger B-77 were studied. Microbial growth, the level of copper (II) accumulation and SOD activity depended on the initial copper (II) concentration. Aspergillus niger is able to accumulate large amounts of copper (II) from the nutrient medium with 200 mg.l-1 copper (II) ions without loosing its biological activities. Addition of copper (II) ions increased the SOD activity in the growing cell cultures. The changes in enzyme activity induced by heavy metal ions might be used as an indicator of intracellular oxy-intermediate generation in a cell culture growing under stress conditions


Author(s):  
Alexander Erlich ◽  
Gareth W. Jones ◽  
Françoise Tisseur ◽  
Derek E. Moulton ◽  
Alain Goriely

In biological systems, the growth of cells, tissues and organs is influenced by mechanical cues. Locally, cell growth leads to a mechanically heterogeneous environment as cells pull and push their neighbours in a cell network. Despite this local heterogeneity, at the tissue level, the cell network is remarkably robust, as it is not easily perturbed by changes in the mechanical environment or the network connectivity. Through a network model, we relate global tissue structure (i.e. the cell network topology) and local growth mechanisms (growth laws) to the overall tissue response. Within this framework, we investigate the two main mechanical growth laws that have been proposed: stress-driven or strain-driven growth. We show that in order to create a robust and stable tissue environment, networks with predominantly series connections are naturally driven by stress-driven growth, whereas networks with predominantly parallel connections are associated with strain-driven growth.


1992 ◽  
Vol 19 (5) ◽  
pp. 565 ◽  
Author(s):  
JB Passioura ◽  
SC Fry

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.


Phytotaxa ◽  
2017 ◽  
Vol 314 (2) ◽  
pp. 285 ◽  
Author(s):  
SILVIO FICI

A new species of Capparis, C. parvifolia, is described and illustrated from New Caledonia, where it is known from a few localities on Mont Kaala on ultramafic substrata. The new species is characterized by the relatively small, linear leaf-blade and by the small size of the sepals, petals, stamens, gynophore and fruit. Its affinities with related taxa are discussed and its conservation status assessed.


2021 ◽  
Author(s):  
Amir Vahabikashi ◽  
Suganya Sivagurunathan ◽  
Fiona Ann Sadsad Nicdao ◽  
Yu Long Han ◽  
Chan Young Park ◽  
...  

The ability of a cell to regulate its mechanical properties is central to its function. Emerging evidence suggests that interactions between the cell nucleus and cytoskeleton influence cell mechanics through poorly understood mechanisms. Here we show that A- and B-type nuclear lamin isoforms distinctively modulate both nuclear and cellular volume and selectively stabilize the linker of nucleoskeleton and cytoskeleton (LINC) complexes that couple the nucleus to cytoskeletal actin and vimentin. We reveal, further, that loss of each of the four-known lamin isoforms in the mouse embryonic fibroblasts differentially affects cortical and cytoplasmic stiffness as well as cellular contractility, and then propose a LINC complex mediated model that explains these impaired mechanical phenotypes. Finally, we demonstrate that loss of each lamin isoform softens the nucleus in a manner that correlates with loss of heterochromatin. Together, these findings uncover distinctive roles for each lamin isoform in maintaining cellular and nuclear mechanics.


2007 ◽  
Vol 37 (5) ◽  
pp. 1458-1461 ◽  
Author(s):  
Fábio Luiz Partelli ◽  
Henrique Duarte Vieira ◽  
Alexandre Pio Viana

This research was aimed at establishing regression equations to estimate black pepper (Piper nigrum) leaf area based on linear leaf measures. Different black pepper varieties where growth on the field, four different size leaves were collected per plant with a total of 52 leaves to establish the regression equation and 28 to validate the equation for each variety (Bragantina, Laçará, Guajarina e Cingapura). Leaf midrib length (LML), maximum leaf broad width (MLBW) and leaf area (LA) were measured. Pearson's linear correlation coefficients were determined between observed and predicted measures with the observed LA, besides estimating the linear regression equation for each variety. The equations best-fitted to estimate LA based on circumscript rectangle were: 1) LA = 2.2689 + 0.6900 x LML x MLBW; 2) LA = 1.6402 + 0.6816 x LML x MLBW; 3) LA = 1.4942 + 0.6215 x LML x MLBW and 4) LA = 0.7467 + 0.6735 x LML x MLBW, for Bragantina, Laçará, Guajarina and Cingapura varieties respectively. For all equations predicted values had high correlation coefficient with observed values thus showing that these equations must be variety specific and that they are appropriate for black pepper leaf area estimative.


1964 ◽  
Vol 42 (11) ◽  
pp. 1525-1530 ◽  
Author(s):  
C. C. Gordon ◽  
C. Gardner Shaw

In Diporotheca rhizophila Gordon & Shaw upright unicellular perithecial initials are produced on the superficial mycelium covering the host's roots. By septation the initial becomes a three-celled primordium. Two cells, produced laterally from the penultimate cell of the primordium, by division in two planes, form the perithecial wall. During final maturation two to three divisions in the third plane make the wall three to five cells thick. The centrum originates from the apical cell of the primordium. Dikaryotization of an immature perithecium involves the production of one to many hyaline receptive hyphae from the dark, pigmented, peridial cells. These receptive hyphae fuse with superficial vegetative hyphae, and a nucleus from a cell of the vegetative hypha apparently migrates into the centrum. No structure within the centrum of the perithecium could be interpreted as an ascogonium. The same hyaline, pseudoparenchymatous filaments which form the ascal generative cells in the basal and central areas of the centrum give rise to periphyses within the perithecial neck.


Sign in / Sign up

Export Citation Format

Share Document