Mechanisms of plant cell wall surveillance in response to pathogens, cell wall-derived ligands and the effect of expansins to infection resistance or susceptibility

Abstract

Cell wall integrity is tightly regulated and maintained given that non-physiological modification of cell walls could render plants vulnerable to biotic and/or abiotic stresses. Expansins are plant cell wall-modifying proteins active during many developmental and physiological processes, but they can also be produced by bacteria and fungi during interaction with plant hosts. Cell wall alteration brought about by ectopic expression, overexpression, or exogenous addition of expansins from either eukaryote or prokaryote origin can in some instances provide resistance to pathogens, while in other cases plants become more susceptible to infection. In these circumstances altered cell wall mechanical properties might be directly responsible for pathogen resistance or susceptibility outcomes. Simultaneously, through membrane receptors for enzymatically released cell wall fragments or by sensing modified cell wall barrier properties, plants trigger intracellular signaling cascades inducing defense responses and reinforcement of the cell wall, contributing to various infection phenotypes, in which expansins might also be involved. Here, we review the plant immune response activated by cell wall surveillance mechanisms, cell wall fragments identified as responsible for immune responses, and expansin’s roles in resistance and susceptibility of plants to pathogen attack.

Differential Expression Analysis of Cannabis sativa response to thermotherapy of Hops Latent Viroid (HLVd) infection and clearance of the viroid in Tissue Culture Micropropagation

“…In our experiment, we observed cell wall and structure-related proteins being up-regulated, cell wall structural protein being significantly downregulated. This could suggest that the lack of the glycine-rich protein or overexpression of the expansin and hydrolase proteins could be responsible for the brittle-nature of HLVd infected plants (22). Similarly, it has been reported that plants infected with HLVd have also been known to be less vigorous and carry an altered internode length compared to uninfected clones of the same cultivar (9), (23).…”

A novel soybean hairy root system for gene functional validation

“…Conversely, very few reports showed the involvement of α-Expansins in both compatible and incompatible plant-microbe interactions [ 35 , 72 – 76 ]. Recently, some studies also demonstrated the putative role of the Expansin superfamily in mediating resistance responses to simultaneous abiotic and biotic stresses (cross-stress) as well as in defense priming processes and stress memory [ 35 , 77 – 81 ]. Our findings support those studies by showing that AdEXPA24 overexpression improves resistance against Meloidogyne sp.…”

Signals and Their Perception for Remodelling, Adjustment and Repair of the Plant Cell Wall

“…below). The microbial enzymes are involved in establishing beneficial symbiotic interactions, virulence, or generation of short-chain sugar molecules for microbial digestion [ 80 , 81 , 82 , 83 , 84 ]. They have their own evolutionary history and adaptation mechanism to their hosts.…”