Cell Wall Pectic Arabinans Influence the Mechanical Properties of Arabidopsis thaliana Inflorescence Stems and Their Response to Mechanical Stress

Abstract Plants are known to exhibit a thigmomorphogenetic response to mechanical stimuli by altering their morphology and mechanical properties. Wind is widely perceived as mechanical stress and in many experiments its influence is simulated by applying mechanical perturbations. However, it is known that wind-induced effects on plants can differ and at times occur even in the opposite direction compared with those induced by mechanical perturbations. In the present study, the long-term response of Arabidopsis thaliana to a constant unidirectional wind was investigated. We found that exposure to wind resulted in a positive anemotropic response and in significant alterations to Arabidopsis morphology, mechanical properties, and anatomical tissue organization that were associated with the plant’s strategy of acclimation to a windy environment. Overall, the observed response of Arabidopsis to wind differs significantly from previously reported responses of Arabidopsis to mechanical perturbations. The presented results suggest that the response of Arabidopsis is sensitive to the type of mechanical stimulus applied, and that it is not always straightforward to simulate one type of perturbation by another.

Download Full-text

Regulation Of The Microtubule Cytoskeleton And Cell Wall Development In Arabidopsis Thaliana

10.30707/etd2020.fornero.c ◽

2019 ◽

Author(s):

Christy J. Fornero

Keyword(s):

Arabidopsis Thaliana ◽

Cell Wall ◽

Microtubule Cytoskeleton ◽

Cell Wall Development

Download Full-text

Inhibition of cell expansion enhances cortical microtubule stability in the root apex of Arabidopsis thaliana

Journal of Biological Research-Thessaloniki ◽

10.1186/s40709-021-00143-8 ◽

2021 ◽

Vol 28 (1) ◽

Author(s):

Veronica Giourieva ◽

Emmanuel Panteris

Keyword(s):

Arabidopsis Thaliana ◽

Cell Wall ◽

Cell Expansion ◽

Cortical Microtubule ◽

Root Apex ◽

Cellulose Synthase ◽

Cellulose Biosynthesis ◽

Cortical Microtubules ◽

Wild Type ◽

Microtubule Stability

Abstract Background Cortical microtubules regulate cell expansion by determining cellulose microfibril orientation in the root apex of Arabidopsis thaliana. While the regulation of cell wall properties by cortical microtubules is well studied, the data on the influence of cell wall to cortical microtubule organization and stability remain scarce. Studies on cellulose biosynthesis mutants revealed that cortical microtubules depend on Cellulose Synthase A (CESA) function and/or cell expansion. Furthermore, it has been reported that cortical microtubules in cellulose-deficient mutants are hypersensitive to oryzalin. In this work, the persistence of cortical microtubules against anti-microtubule treatment was thoroughly studied in the roots of several cesa mutants, namely thanatos, mre1, any1, prc1-1 and rsw1, and the Cellulose Synthase Interacting 1 protein (csi1) mutant pom2-4. In addition, various treatments with drugs affecting cell expansion were performed on wild-type roots. Whole mount tubulin immunolabeling was applied in the above roots and observations were performed by confocal microscopy. Results Cortical microtubules in all mutants showed statistically significant increased persistence against anti-microtubule drugs, compared to those of the wild-type. Furthermore, to examine if the enhanced stability of cortical microtubules was due to reduced cellulose biosynthesis or to suppression of cell expansion, treatments of wild-type roots with 2,6-dichlorobenzonitrile (DCB) and Congo red were performed. After these treatments, cortical microtubules appeared more resistant to oryzalin, than in the control. Conclusions According to these findings, it may be concluded that inhibition of cell expansion, irrespective of the cause, results in increased microtubule stability in A. thaliana root. In addition, cell expansion does not only rely on cortical microtubule orientation but also plays a regulatory role in microtubule dynamics, as well. Various hypotheses may explain the increased cortical microtubule stability under decreased cell expansion such as the role of cell wall sensors and the presence of less dynamic cortical microtubules.

Download Full-text

With an Ear up Against the Wall: An Update on Mechanoperception in Arabidopsis.

Plants ◽

10.3390/plants10081587 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1587

Author(s):

Sara Behnami ◽

Dario Bonetta

Keyword(s):

Cell Wall ◽

Plasma Membrane ◽

Immune Responses ◽

Mechanical Stress ◽

Mechanosensitive Channels ◽

Compensatory Responses ◽

Cell Wall Damage ◽

Mechanical Signals ◽

Hormone Signalling

Cells interpret mechanical signals and adjust their physiology or development appropriately. In plants, the interface with the outside world is the cell wall, a structure that forms a continuum with the plasma membrane and the cytoskeleton. Mechanical stress from cell wall damage or deformation is interpreted to elicit compensatory responses, hormone signalling, or immune responses. Our understanding of how this is achieved is still evolving; however, we can refer to examples from animals and yeast where more of the details have been worked out. Here, we provide an update on this changing story with a focus on candidate mechanosensitive channels and plasma membrane-localized receptors.

Download Full-text

Comparison of mechanical properties of thermally modified wood at growth ring and cell wall level by means of instrumented indentation tests

Holzforschung ◽

10.1515/hf.2009.085 ◽

2009 ◽

Vol 63 (4) ◽

Cited By ~ 21

Author(s):

Stefanie Stanzl-Tschegg ◽

Wilfried Beikircher ◽

Dieter Loidl

Keyword(s):

Mechanical Properties ◽

Cell Wall ◽

Thermal Treatment ◽

Mechanical Performance ◽

Growth Ring ◽

Beech Wood ◽

Thermal Modification ◽

Wood Structure ◽

Instrumented Indentation ◽

Indentation Tests

Abstract Thermal modification is a well established method to improve the dimensional stability and the durability for outdoor use of wood. Unfortunately, these improvements are usually accompanied with a deterioration of mechanical performance (e.g., reduced strength or higher brittleness). In contrast, our investigations of the hardness properties in the longitudinal direction of beech wood revealed a significant improvement with thermal modification. Furthermore, we applied instrumented indentation tests on different hierarchical levels of wood structure (growth ring and cell wall level) to gain closer insights on the mechanisms of thermal treatment of wood on mechanical properties. This approach provides a variety of mechanical data (e.g., elastic parameters, hardness parameters, and viscoelastic properties) from one single experiment. Investigations on the influence of thermal treatment on the mechanical properties of beech revealed similar trends on the growth ring as well as the on the cell wall level of the wood structure.

Download Full-text