The Role of Mechanoperception in Plant Cell Wall Integrity Maintenance

Abstract

The plant cell walls surrounding all plant cells are highly dynamic structures, which change their composition and organization in response to chemical and physical stimuli originating both in the environment and in plants themselves. They are intricately involved in all interactions between plants and their environment while also providing adaptive structural support during plant growth and development. A key mechanism contributing to these adaptive changes is the cell wall integrity (CWI) maintenance mechanism. It monitors and maintains the functional integrity of cell walls by initiating adaptive changes in cellular and cell wall metabolism. Despite its importance, both our understanding of its mode of action and knowledge regarding the molecular components that form it are limited. Intriguingly, the available evidence implicates mechanosensing in the mechanism. Here, we provide an overview of the knowledge available regarding the molecular mechanisms involved in and discuss how mechanoperception and signal transduction may contribute to plant CWI maintenance.

Dampening the DAMPs: How Plants Maintain the Homeostasis of Cell Wall Molecular Patterns and Avoid Hyper-Immunity

“…These changes may cause a direct enzymatic release of fragments possessing growth-regulating/DAMP activity from each of the major wall components. The impairment of CWI itself could function as a mechano-sensory signal of damage that may also regulate cellular events, such as meristem patterning and the cell cycle (Bacete and Hamann, 2020). Notably, microtubule organization, orientation, and deposition of cellulose microfibrils are reorganized, and several CWDEs are activated in response to mechanical stimuli (Vaahtera et al, 2019).…”

“…Arabinoxylan (AX), another hemicellulose present in both the primary and secondary walls, consists of copolymers of two pentoses: arabinose and xylose. Very recently, by analyzing mutants in Arabidopsis Response Regulators (ARRs), which mediate cytokinin signaling and modulate the disease resistance (Bacete and Hamann, 2020), it was demonstrated that the AX-derived pentasaccharide 3 3 -α-L-arabinofuranosylxylotetraose (XA3XX) triggers a strong immune response in Arabidopsis and enhances disease resistance of some crop plants (Mélida et al, 2020).…”

“…The cell wall represents the interface between plants and the environment and acts as a physical barrier to protect plants against biotic and abiotic stresses. Main components of the cell wall are the polysaccharides cellulose, hemicellulose, and pectin, which interact among themselves and with lignin to form a complex structure that influences the shape, rigidity, growth, and differentiation of plant cells (Bacete and Hamann, 2020;Zhang and Zhang, 2020). All three types of polysaccharides are also a repository of extracellular damage-associated molecular patterns (DAMPs), potentially released during microbial infections or upon mechanical damage (De Lorenzo et al, 2018;Hou et al, 2019).…”

A Genomic Perspective on the Evolutionary Diversity of the Plant Cell Wall

“…The diversification of plant cell wall genes has important implications for numerous interactions between plants and the surrounding environment. Owing to their sessile life histories, plants have evolved not only appropriate phenotypical adjustments in response to changing environmental conditions but also unique protective mechanisms to counter the adverse effects of environmental stress [ 97 ]. Cell walls constitute an interface for plant interactions with the environment, and consequently play multiple roles in the related molecular processes [ 98 , 99 , 100 , 101 ].…”

Phosphate Deprivation Can Impair Mechano-Stimulated Cytosolic Free Calcium Elevation in Arabidopsis Roots

“…Candidates include MCA1 (Mid1-Complementing Activity1, [ 1 ]), MCA2 [ 8 ], OSCA1 (reduced hyperosmolality-induced [CA 2+ ] cyt increase1, [ 9 , 10 ]), MSL10 (MscS-like10, [ 11 ]) and DEK1 (Defective Kernel 1, [ 12 , 13 ]). Alternatively, PM Ca 2+ channels governed by PM receptor-like kinases (that may or may not be wall-associated) would be competent to elevate [Ca 2+ ] cyt [ 3 , 14 , 15 ]. Regarding roots, mechanical stimulation can evoke a spatially complex [Ca 2+ ] cyt elevation and sensitivity varies along the root [ 2 , 3 , 16 , 17 ].…”