scholarly journals The ERECTA Receptor-Like Kinase Regulates Cell Wall–Mediated Resistance to Pathogens in Arabidopsis thaliana

2009 ◽  
Vol 22 (8) ◽  
pp. 953-963 ◽  
Author(s):  
Clara Sánchez-Rodríguez ◽  
José Manuel Estévez ◽  
Francisco Llorente ◽  
Camilo Hernández-Blanco ◽  
Lucía Jordá ◽  
...  
Keyword(s):  
Cell Wall ◽  
Disease Resistance ◽  
Cell Walls ◽  
Control Plant ◽  
Biological Processes ◽  
Uronic Acids ◽  
Wild Type ◽  
Receptor Like Kinase ◽  
Neutral Sugars ◽  
Plectosphaerella Cucumerina

Some receptor-like kinases (RLK) control plant development while others regulate immunity. The Arabidopsis ERECTA (ER) RLK regulates both biological processes. To discover specific components of ER-mediated immunity, a genetic screen was conducted to identify suppressors of erecta (ser) susceptibility to Plectosphaerella cucumerina fungus. The ser1 and ser2 mutations restored disease resistance to this pathogen to wild-type levels in the er-1 background but failed to suppress er-associated developmental phenotypes. The deposition of callose upon P. cucumerina inoculation, which was impaired in the er-1 plants, was also restored to near wild-type levels in the ser er-1 mutants. Analyses of er cell walls revealed that total neutral sugars were reduced and uronic acids increased relative to those of wild-type walls. Interestingly, in the ser er-1 walls, neutral sugars were elevated and uronic acids were reduced relative to both er-1 and wild-type plants. The cell-wall changes found in er-1 and the ser er-1 mutants are unlikely to contribute to their developmental alterations. However, they may influence disease resistance, as a positive correlation was found between uronic acids content and resistance to P. cucumerina. We propose a specific function for ER in regulating cell wall–mediated disease resistance that is distinct from its role in development.

scholarly journals Arabidopsis cell wall composition determines disease resistance specificity and fitness

2021 ◽  
Vol 118 (5) ◽  
pp. e2010243118 ◽  
Author(s):  
Antonio Molina ◽  
Eva Miedes ◽  
Laura Bacete ◽  
Tinguaro Rodríguez ◽  
Hugo Mélida ◽  
...  
Keyword(s):  
Cell Wall ◽  
Disease Resistance ◽  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Walls ◽  
Wild Type ◽  
Glycome Profiling ◽  
Enhanced Resistance ◽  
Trade Offs ◽  
Resistance Specificity

Plant cell walls are complex structures subject to dynamic remodeling in response to developmental and environmental cues and play essential functions in disease resistance responses. We tested the specific contribution of plant cell walls to immunity by determining the susceptibility of a set of Arabidopsis cell wall mutants (cwm) to pathogens with different parasitic styles: a vascular bacterium, a necrotrophic fungus, and a biotrophic oomycete. Remarkably, most cwm mutants tested (29/34; 85.3%) showed alterations in their resistance responses to at least one of these pathogens in comparison to wild-type plants, illustrating the relevance of wall composition in determining disease-resistance phenotypes. We found that the enhanced resistance of cwm plants to the necrotrophic and vascular pathogens negatively impacted cwm fitness traits, such as biomass and seed yield. Enhanced resistance of cwm plants is not only mediated by canonical immune pathways, like those modulated by phytohormones or microbe-associated molecular patterns, which are not deregulated in the cwm tested. Pectin-enriched wall fractions isolated from cwm plants triggered immune responses in wild-type plants, suggesting that wall-mediated defensive pathways might contribute to cwm resistance. Cell walls of cwm plants show a high diversity of composition alterations as revealed by glycome profiling that detect specific wall carbohydrate moieties. Mathematical analysis of glycome profiling data identified correlations between the amounts of specific wall carbohydrate moieties and disease resistance phenotypes of cwm plants. These data support the relevant and specific function of plant wall composition in plant immune response modulation and in balancing disease resistance/development trade-offs.

Extraction and analysis of polysaccharides from tissues of Retama monosperma branches

2020 ◽  
Vol 9 (5) ◽  
pp. 214-221
Author(s):  
H. Bokhari-Taieb Brahimi ◽  
D. E. Aizi ◽  
A. Bouhafsoun ◽  
K. Hachem ◽  
R. Mezemaze ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Biochemical Analysis ◽  
Colorimetric Assay ◽  
Structural Characteristics ◽  
Water Extract ◽  
Uronic Acids ◽  
Symbiotic Associations ◽  
Physical Chemical ◽  
Retama Monosperma

Retama monosperma is a fabaceous shrub that colonizes dune sands owing to its particularly important root system at depth and on the surface. It establishes symbiotic associations with rhizobia and thus plays a role in the bio -fertilization of soils. The stem fibers of R. monosperma are an interesting material for industry because of their useful biometric, physical, chemical and structural characteristics. The aim of this study was to complete these data with a biochemical analysis of the cell walls tissues of adult branches of R. monosperma. Cellulose, hemicelluloses and pectins were extracted from cell wall. The weight dosage indicated that cellulose remained the major component of the wall (56% from the crude cell wall and 52% from the delignified cell wall) ahead of hemicelluloses (16% from the crude cell wall and 14% from the delignified cell wall) and pectins (5.6% from the crude cell wall and 5% from the delignified cell wall for water extract pectins and 3% from the crude cell wall and 2.4% from the delignified cell wall for oxalate extract pectins). The colorimetric assay of pectins extracted from lignified cell wall of R. monosperma suggested presence of more uronic acids (14.95µg/mL) than pectins extracted from a delignified cell wall (12.37 µg/mL). Gas chromatographic analysis of hemicellulosic extracts showed the presence of xylose as the major ose (54.7% from the crude cell wall and 46.7% from the delignified cell wall). Pectins were represented by homogalacturonan chains and rhamnogalacturonans 1. Data generated in this study are helpful for valorization of this plant.

scholarly journals The unusual cell wall of the Lyme disease spirochaete Borrelia burgdorferi is shaped by a tick sugar

2021 ◽  
Vol 6 (12) ◽  
pp. 1583-1592
Author(s):  
Tanner G. DeHart ◽  
Mara R. Kushelman ◽  
Sherry B. Hildreth ◽  
Richard F. Helm ◽  
Brandon L. Jutras
Keyword(s):  
Cell Wall ◽  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Cell Walls ◽  
Structural Strength ◽  
Cell Envelope ◽  
Wild Type ◽  
Tick Vector ◽  
Cell Wall Alteration ◽  
Main Component

AbstractPeptidoglycan—a mesh sac of glycans that are linked by peptides—is the main component of bacterial cell walls. Peptidoglycan provides structural strength, protects cells from osmotic pressure and contributes to shape. All bacterial glycans are repeating disaccharides of N-acetylglucosamine (GlcNAc) β-(1–4)-linked to N-acetylmuramic acid (MurNAc). Borrelia burgdorferi, the tick-borne Lyme disease pathogen, produces glycan chains in which MurNAc is occasionally replaced with an unknown sugar. Nuclear magnetic resonance, liquid chromatography–mass spectroscopy and genetic analyses show that B. burgdorferi produces glycans that contain GlcNAc–GlcNAc. This unusual disaccharide is chitobiose, a component of its chitinous tick vector. Mutant bacteria that are auxotrophic for chitobiose have altered morphology, reduced motility and cell envelope defects that probably result from producing peptidoglycan that is stiffer than that in wild-type bacteria. We propose that the peptidoglycan of B. burgdorferi probably evolved by adaptation to obligate parasitization of a tick vector, resulting in a biophysical cell-wall alteration to withstand the atypical torque associated with twisting motility.

scholarly journals Arabidopsis cell wall composition determines disease resistance specificity and fitness

2020 ◽  
Author(s):  
Antonio Molina ◽  
Eva Miedes ◽  
Laura Bacete ◽  
Tinguaro Rodríguez ◽  
Hugo Mélida ◽  
...  
Keyword(s):  
Cell Wall ◽  
Disease Resistance ◽  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Walls ◽  
Response Modulation ◽  
Glycome Profiling ◽  
Enhanced Resistance ◽  
Trade Offs ◽  
Resistance Specificity

AbstractPlant cell walls are complex structures subject to dynamic remodeling in response to developmental and environmental cues, and play essential functions in disease resistance responses. We tested the specific contribution of plant cell walls to immunity by determining the susceptibility of a set of Arabidopsis cell wall mutants (cwm) to pathogens with different parasitic styles: a vascular bacterium, a necrotrophic fungus and a biotrophic oomycete. Remarkably, most cwm mutants tested (31/38; 81.6%) showed alterations in their resistance responses to at least one of these pathogens, in comparison to wild-type plants, illustrating the relevance of wall composition in determining disease resistance phenotypes. We found that the enhanced resistance of cwm plants to the necrotrophic and vascular pathogens negatively impacted on cwm fitness traits, like biomass and seed yield. Enhanced resistance of cwm plants is not only mediated by canonical immune pathways, like those modulated by phytohormones or Microbe-Associated Molecular Patterns, which are not de-regulated in all cwm tested. Pectin-enriched wall fractions isolated from cwm plants triggered immune responses in other plants, suggesting that wall-mediated defensive pathways might contribute to cwm resistance. Cell walls of cwm plants show a high diversity of composition alterations as revealed by glycome profiling that detect specific wall carbohydrate moieties. Mathematical analysis of glycome profiling data identified correlations between the amounts of specific wall carbohydrate moieties and disease resistance phenotypes of cwm plants. These data support the relevant and specific function of plant wall composition in plant immune response modulation and in balancing disease resistance/development trade-offs.

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.

Wound repair and disease resistance in stems of Pachysandra terminalis

1986 ◽  
Vol 64 (11) ◽  
pp. 2406-2410 ◽  
Author(s):  
George W. Hudler ◽  
Mark T. Banik
Keyword(s):  
Cell Wall ◽  
Disease Resistance ◽  
Microscopic Examination ◽  
Cell Walls ◽  
Wound Repair ◽  
Intercellular Spaces ◽  
Cortical Cells ◽  
Reduced Frequency

Changes in cortical cells around wounds in pachysandra (Pachysandra terminalis Sieb. & Zucc.) stems were monitored by microscopic examination of some wounds and by inoculation of others with conidia of Volutella pachysandricola B. O. Dodge. Stems with young wounds ( < 3 days old) were readily colonized by the pathogen. In progressively older wounds, reduced frequency of infection was correlated with deposition of lignin in cell walls and intercellular spaces, and of suberin on inner lignified cell wall surfaces in one or two layers of parenchyma around the wound. Histological events associated with wound repair in pachysandra appear to be similar to those described for other species of angiosperms and gymnosperms.

Ultrastructure of a palmelloid-forming strain of Chlamydomonas eugametos

1978 ◽  
Vol 56 (19) ◽  
pp. 2348-2356 ◽  
Author(s):  
Kazuo Nakamura ◽  
Douglas F. Bray ◽  
Emile B. Wagenaar
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Transitional Region ◽  
Chloroplatinic Acid ◽  
Cell Wall Formation ◽  
Body Structure ◽  
Wild Type ◽  
Adhesive Properties ◽  
Chlamydomonas Eugametos ◽  
Unicellular Green Alga

A palmelloid-forming mutant of the unicellular green alga Chlamydomonas eugametos has been studied ultrastructurally. The repetition, within the palmelloid envelope, of four-celled groups surrounded by wall layers suggests that normal asexual cytokinesis occurs but successive cell generations are unable to separate. Individual palmelloid cells are smaller than wild-type cells and possess flagella which are short (1–2 μm) and occasionally bulbous at the tip but appear normal with regard to internal microtubular, transitional region, and basal body structure. The association of granules with the outer surface of the palmelloid envelope and the tendency of palmelloids to form large aggregates in culture indicate a change in the adhesive properties of the cell walls of this mutant. A comparison of the ultrastructure of mutant palmelloids with previously described chloroplatinic-acid-induced palmelloids shows that the two types differ in both flagellar development and in the extent of cell wall formation.

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.

Carbon source dependent differences in the composition of the cell walls of the basidiomycete Picnoporus cinnabarinus

1977 ◽  
Vol 23 (9) ◽  
pp. 1313-1317 ◽  
Author(s):  
J. A. Cury ◽  
Déa Amaral
Keyword(s):  
Cell Wall ◽  
Carbon Source ◽  
Cell Walls ◽  
Amino Sugars ◽  
Enzymatic Analysis ◽  
Wild Type ◽  
Monokaryotic Strain ◽  
Morphological Differences ◽  
Isolated Cell

A wild-type monokaryotic strain of Picnoporus cinnabarinus grown on glucose produced shorter and thicker hyphae than cultures grown on acetate. Colonies from glucose media were smaller and more compact than acetate-grown colonies. Chemical and enzymatic analysis of the isolated cell wall of both morphological types showed that the amount of amino sugars and the ratio glucosamine:galactosamine were higher in the acetate-grown cells. This may be the cause of morphological differences observed.

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