scholarly journals Effect of Nanoparticles Surface Charge on the Arabidopsis thaliana (L.) Roots Development and Their Movement into the Root Cells and Protoplasts

2019 ◽  
Vol 20 (7) ◽  
pp. 1650 ◽  
Author(s):  
Anna Milewska-Hendel ◽  
Maciej Zubko ◽  
Danuta Stróż ◽  
Ewa Kurczyńska
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Surface Charge ◽  
Physical Barrier ◽  
Root Cells ◽  
Plant Body ◽  
Transmission Electron ◽  
A Cell ◽  
Living Organisms ◽  
Positively Charged

Increasing usage of gold nanoparticles (AuNPs) in different industrial areas inevitably leads to their release into the environment. Thus, living organisms, including plants, may be exposed to a direct contact with nanoparticles (NPs). Despite the growing amount of research on this topic, our knowledge about NPs uptake by plants and their influence on different developmental processes is still insufficient. The first physical barrier for NPs penetration to the plant body is a cell wall which protects cytoplasm from external factors and environmental stresses. The absence of a cell wall may facilitate the internalization of various particles including NPs. Our studies have shown that AuNPs, independently of their surface charge, did not cross the cell wall of Arabidopsis thaliana (L.) roots. However, the research carried out with using light and transmission electron microscope revealed that AuNPs with different surface charge caused diverse changes in the root’s histology and ultrastructure. Therefore, we verified whether this is only the wall which protects cells against particles penetration and for this purpose we used protoplasts culture. It has been shown that plasma membrane (PM) is not a barrier for positively charged (+) AuNPs and negatively charged (−) AuNPs, which passage to the cell.

scholarly journals Organismal view of a plant and a plant cell.

2001 ◽  
Vol 48 (2) ◽  
pp. 443-451 ◽  
Author(s):  
P Wojtaszek
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Cell Walls ◽  
Growth Time ◽  
Dead Cell ◽  
Plant Body ◽  
The Status ◽  
A Cell ◽  
Plant Form ◽  
Biological Organisation

Cell walls are at the basis of a structural, four-dimensional framework of plant form and growth time. Recent rapid progress of cell wall research has led to the situation where the old, long-lasting juxtaposition: "living" protoplast--"dead" cell wall, had to be dropped. Various attempts of re-interpretation cast, however, some doubts over the very nature of plant cell and the status of the walls within such a cell. Following a comparison of exocellular matrices of plants and animals, their position in relation to cells and organisms is analysed. A multitude of perspectives of the biological organisation of living beings is presented with particular attention paid to the cellular and organismal theories. Basic tenets and resulting corollaries of both theories are compared, and evolutionary and developmental implications are considered. Based on these data, "The Plant Body"--an organismal concept of plants and plant cells is described.

SRPP, a cell-wall protein is involved in development and protection of seeds and root hairs in Arabidopsis thaliana

2017 ◽  
pp. pcx008 ◽  
Author(s):  
Natsuki Tanaka ◽  
Hiroshi Uno ◽  
Shohei Okuda ◽  
Shizuka Gunji ◽  
Ali Ferjani ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Root Hairs ◽  
Cell Wall Protein ◽  
A Cell

scholarly journals Cytokinesis in fra2 Arabidopsis thaliana p60-katanin Mutant: Defects in Cell Plate/Daughter Wall Formation

2021 ◽  
Author(s):  
Emmanuel Panteris ◽  
Anna Kouskouveli ◽  
Dimitris Pappas ◽  
Ioannis-Dimosthenis S. Adamakis
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Cell Walls ◽  
Higher Plants ◽  
Cell Plate ◽  
Wild Type ◽  
Microtubule Organization ◽  
Root Cells ◽  
Wall Formation ◽  
In The Wild

Cytokinesis is accomplished in higher plants by the phragmoplast, creating and conducting the cell plate, to separate daughter nuclei by a new cell wall. The microtubule-severing enzyme p60-katanin plays an important role in the centrifugal expansion and timely disappearance of phragmoplast microtubules. Consequently, aberrant structure and delayed expansion rate of the phragmoplast occur in p60-katanin mutants. Here, the consequences of p60-katanin malfunction in cell plate/daughter wall formation were investigated by transmission electron microscopy (TEM), while deviations in the chemical composition of cell plate/new cell wall were identified by immunolabeling and confocal microscopy, in root cells of the fra2 Arabidopsis thaliana mutant. It was found that, apart from defective phragmoplast microtubule organization, cell plates/new cell walls appeared also faulty in structure, being unevenly thick and perforated by large gaps. In addition, demethylesterified homogalacturonans were prematurely present in fra2 cell plates, while callose content was significantly lower than in the wild-type. Furthermore, KNOLLE syntaxin disappeared from newly formed cell walls in fra2 earlier than in the wild-type. Taken together, these observations indicate that delayed cytokinesis, due to faulty phragmoplast organization and expansion, results in a loss of synchronization between cell plate growth and its chemical maturation.

Cellular Characteristics of Dinitroaniline Herbicide-Resistant Goosegrass (Eleusine indica)

Weed Science ◽  
1991 ◽  
Vol 39 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Bernal E. Valverde ◽  
Arnold P. Appleby ◽  
Steven R. Radosevich ◽  
Alfred Soeldner
Keyword(s):  
North Carolina ◽  
Cell Wall ◽  
South Carolina ◽  
Cell Walls ◽  
Primary Root ◽  
Wall Material ◽  
Root Cells ◽  
Eleusine Indica ◽  
Herbicide Resistant ◽  
Transmission Electron

Primary root cells from five dinitroaniline-resistant (R) and three susceptible (S) goosegrass biotypes from North Carolina and South Carolina were observed by transmission electron microscopy to determine whether resistance was associated with changes in cell wall formation. Cell wall malformations were found in some cells from two of the R-biotypes and in one of the S-biotypes. Malformations consisted of partially deposited cell walls and the inclusion of cell wall material in the cytoplasm. Some of the affected cells also had abnormal, lobed nuclei and malformed mitochondria. There seems to be little or no correlation between dinitroaniline resistance and cell wall malformations.

scholarly journals Cytokinesis in fra2 Arabidopsis thaliana p60-Katanin Mutant: Defects in Cell Plate/Daughter Wall Formation

2021 ◽  
Vol 22 (3) ◽  
pp. 1405
Author(s):  
Emmanuel Panteris ◽  
Anna Kouskouveli ◽  
Dimitris Pappas ◽  
Ioannis-Dimosthenis S. Adamakis
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Cell Walls ◽  
Higher Plants ◽  
Cell Plate ◽  
Wild Type ◽  
Microtubule Organization ◽  
Root Cells ◽  
Wall Formation ◽  
In The Wild

Cytokinesis is accomplished in higher plants by the phragmoplast, creating and conducting the cell plate to separate daughter nuclei by a new cell wall. The microtubule-severing enzyme p60-katanin plays an important role in the centrifugal expansion and timely disappearance of phragmoplast microtubules. Consequently, aberrant structure and delayed expansion rate of the phragmoplast have been reported to occur in p60-katanin mutants. Here, the consequences of p60-katanin malfunction in cell plate/daughter wall formation were investigated by transmission electron microscopy (TEM), in root cells of the fra2 Arabidopsis thaliana loss-of-function mutant. In addition, deviations in the chemical composition of cell plate/new cell wall were identified by immunolabeling and confocal microscopy. It was found that, apart from defective phragmoplast microtubule organization, cell plates/new cell walls also appeared faulty in structure, being unevenly thick and perforated by large gaps. In addition, demethylesterified homogalacturonans were prematurely present in fra2 cell plates, while callose content was significantly lower than in the wild type. Furthermore, KNOLLE syntaxin disappeared from newly formed cell walls in fra2 earlier than in the wild type. Taken together, these observations indicate that delayed cytokinesis, due to faulty phragmoplast organization and expansion, results in a loss of synchronization between cell plate growth and its chemical maturation.

Endocytosis in elongating root cells of Lobelia erinus

1990 ◽  
Vol 97 (1) ◽  
pp. 157-165
Author(s):  
A. L. SAMUELS ◽  
T. BISALPUTRA
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Multivesicular Bodies ◽  
Secretory Vesicles ◽  
Membrane Material ◽  
Root Cells ◽  
Transmission Electron ◽  
Dense Deposits ◽  
The Relationship ◽  
Conventional Transmission Electron Microscope

Endocytosis was demonstrated in elongating cortical and epidermal root cells of Lobelia erinus using the apoplast marker lanthanum nitrate. Lanthanum treatment produced electron-dense deposits throughout the cell wall, as well as in coated and smooth vesicles, partially coated reticula, and multivesicular bodies. This labelling pattern was observed in root cells that had been ultrarapidly frozen on a copper mirror and freeze-substituted (cryofixation) or fixed by conventional transmission electron microscope (TEM) techniques. The amount of endocytosis occurring was measured by counting the number of vesicles μm−2 in root cells at various stages of development. Endocytosis occurred most in actively elongating cells, and least in mature cells, which were no longer elongating. The relationship between endocytosis and active cell wall secretion suggests that endocytosis may be acting to remove excess plasma membrane material added during exocytosis of secretory vesicles.

scholarly journals Analysis of Lactobacillus sakei Mutants Selected after Adaptation to the Gastrointestinal Tracts of Axenic Mice

2010 ◽  
Vol 76 (9) ◽  
pp. 2932-2939 ◽  
Author(s):  
Fabrizio Chiaramonte ◽  
Patricia Anglade ◽  
Fabienne Baraige ◽  
Jean-Jacques Gratadoux ◽  
Philippe Langella ◽  
...  
Keyword(s):  
Cell Wall ◽  
Stress Proteins ◽  
Carbon Sources ◽  
Helical Structure ◽  
Selective Advantage ◽  
Lactobacillus Sakei ◽  
Cell Wall Modification ◽  
Tem Analysis ◽  
Transmission Electron ◽  
A Cell

ABSTRACT We recently showed that Lactobacillus sakei, a natural meat-borne lactic acid bacterium, can colonize the gastrointestinal tracts (GIT) of axenic mice but that this colonization in the intestinal environment selects L. sakei mutants showing modified colony morphology (small and rough) and cell shape, most probably resulting from the accumulation of various mutations that confer a selective advantage for persistence in the GIT. In the present study, we analyzed such clones, issued from three different L. sakei strains, in order to determine which functions were modified in the mutants. In the elongated filamentous cells of the rough clones, transmission electron microscopy (TEM) analysis showed a septation defect and dotted and slanted black bands, suggesting the presence of a helical structure around the cells. Comparison of the cytoplasmic and cell wall/membrane proteomes of the meat isolate L. sakei 23K and of one of its rough derivatives revealed a modified expression for 38 spots. The expression of six oxidoreductases, several stress proteins, and four ABC transporters was strongly reduced in the GIT-adapted strain, while the actin-like MreB protein responsible for cell shaping was upregulated. In addition, the expression of several enzymes involved in carbohydrate metabolism was modified, which may correlate with the observation of modified growth of mutants on various carbon sources. These results suggest that the modifications leading to a better adaptation to the GIT are pleiotropic and are characterized in a rough mutant by a different stress status, a cell wall modification, and modified use of energy sources, leading to an improved fitness for the colonization of the GIT.

TOUCH ME – ‘Touch’ genes in the micropylar endosperm

2013 ◽  
Vol 23 (4) ◽  
pp. 217-221 ◽  
Author(s):  
Hiroyuki Nonogaki
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Hormonal Regulation ◽  
Critical Event ◽  
Specific Gene ◽  
Transcriptome Data ◽  
Physical Barrier ◽  
Radicle Emergence ◽  
Micropylar Endosperm

AbstractThe micropylar region of endosperm (ME) is a physical barrier to radicle emergence in seeds of many different species, including tomato (Solanum lycopersicum) and Arabidopsis thaliana. ME is thought to be weakened through cell wall-modifying proteins, and this is supported by transcriptome data showing enrichment of cell wall-associated genes in ME. Gibberellin and ethylene have been suggested to be involved in induction of these genes in ME. However, mechanisms underlying this critical event for germination still remain elusive. In addition to hormonal regulation of ME weakening, recent data from high-throughput analyses suggested that it might be important for the radicle tip to ‘touch’ ME (or mechanosensing), in terms of ME-specific gene induction. This emerging hypothesis can be integrated with previous hypotheses about hormonal regulation of ME-specific gene expression in seeds.

scholarly journals Role of Protein O-Mannosyltransferase Pmt4 in the Morphogenesis and Virulence of Cryptococcus neoformans

2006 ◽  
Vol 6 (2) ◽  
pp. 222-234 ◽  
Author(s):  
Gillian M. Olson ◽  
Deborah S. Fox ◽  
Ping Wang ◽  
J. Andrew Alspaugh ◽  
Kent L. Buchanan
Keyword(s):  
Cell Wall ◽  
Cryptococcus Neoformans ◽  
Cell Separation ◽  
Sodium Dodecyl ◽  
Protein Composition ◽  
Cell Wall Integrity ◽  
Abnormal Growth ◽  
Transmission Electron ◽  
A Cell ◽  
And Function

ABSTRACT Protein O mannosylation is initiated in the endoplasmic reticulum by protein O-mannosyltransferases (Pmt proteins) and plays an important role in the secretion, localization, and function of many proteins, as well as in cell wall integrity and morphogenesis in fungi. Three Pmt proteins, each belonging to one of the three respective Pmt subfamilies, are encoded in the genome of the human fungal pathogen Cryptococcus neoformans. Disruption of the C. neoformans PMT4 gene resulted in abnormal growth morphology and defective cell separation. Transmission electron microscopy revealed defective cell wall septum degradation during mother-daughter cell separation in the pmt4 mutant compared to wild-type cells. The pmt4 mutant also demonstrated sensitivity to elevated temperature, sodium dodecyl sulfate, and amphotericin B, suggesting cell wall defects. Further analysis of cell wall protein composition revealed a cell wall proteome defect in the pmt4 mutant, as well as a global decrease in protein mannosylation. Heterologous expression of C. neoformans PMT4 in a Saccharomyces cerevisiae pmt1pmt4 mutant strain functionally complemented the deficient Pmt activity. Furthermore, Pmt4 activity in C. neoformans was required for full virulence in two murine models of disseminated cryptococcal infection. Taken together, these results indicate a central role for Pmt4-mediated protein O mannosylation in growth, cell wall integrity, and virulence of C. neoformans.

Ultrastructure of the host–pathogen interface in Arabidopsis thaliana leaves infected by the downy mildew Hyaloperonospora parasitica

2004 ◽  
Vol 82 (7) ◽  
pp. 1001-1008 ◽  
Author(s):  
C W Mims ◽  
E A Richardson ◽  
B F Holt III ◽  
J L Dangl
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Arabidopsis Thaliana ◽  
High Pressure ◽  
Cell Wall ◽  
Host Cell ◽  
Hyaloperonospora Parasitica ◽  
Transmission Electron ◽  
Host Pathogen ◽  
Host Cell Wall

Transmission electron microscopy was used to examine the host–pathogen interface in Arabidopsis thaliana (L.) Heynh. leaves infected by the biotrophic downy mildew pathogen Hyaloperonospora parasitica (Pers.:Fr.) Constant. Both conventionally fixed as well as high-pressure frozen samples were examined. Excellent preservation of the host–pathogen interface was obtained in many of our high-pressure frozen samples and provided information not available in conventionally fixed samples. Mature haustoria of H. parasitica were distinctly pyriform in shape. A small collar of host cell wall material surrounded the neck of each haustorium near the host cell wall penetration site. The presence of callose in collars was demonstrated using immunogold labeling with a monoclonal antibody specific for (1→3)-β-glucans. The body of each haustorium was ensheathed by an invaginated portion of the invaded host-cell plasma membrane known as the extrahaustorial membrane. Lying between this membrane and the haustorial wall was a layer of electron-dense material known as the extrahaustorial matrix (EHM). The EHM typically was thicker at the distal end of a haustorium than at the proximal end. The surface of the EHM covered by the extrahaustorial membrane was highly irregular in outline. Considerable vesicular activity was observed in association with the extrahaustorial membrane.Key words: transmission electron microscopy, high-pressure freezing, haustoria, Peronospora parasitica.

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