An update on receptor-like kinase involvement in the maintenance of plant cell wall integrity

Abstract

This review examines the involvement of cell wall integrity maintenance in different biological processes, defines what constitutes plant cell wall damage that impairs functional integrity, clarifies which stimulus perception and signal transduction mechanisms are required for integrity maintenance and assesses the available evidence regarding the functions of receptor-like kinases during cell wall integrity maintenance. The review concludes by discussing how the plant cell wall integrity maintenance mechanism could form an essential component of biotic stress responses and of plant development, functions that have not been fully recognized to date.

Coordinated Functional Divergence of Genes after Genome Duplication in Arabidopsis thaliana

“…In agreement with our observation that these duplicated genes might function in cell wall maintenance are observations that the plant cell wall is intimately involved in both growth/morphogenesis and (a)biotic stress (Wolf et al, 2012;Engelsdorf and Hamann, 2014), explaining the functional bias of homoeologs to either growth or defense. The opposite expression patterns we observed for the 92 homoeologous gene pairs for growth-related genes versus defense-related genes could be explained by the antagonistic requirements for growth and stress on the plant cell wall.…”

“…Both tip growth and defense are processes where the maintenance of the cell wall is particularly challenged (Engelsdorf and Hamann, 2014). It is becoming clear that similar cellular components that are used for polarized growth and morphogenesis are also used for defense responses, including the acto-myosin cytoskeleton, targeted exocytosis (of cell wall material), and signaling molecules that redirect the cytoskeleton to the site of cell wall damage (Dettmer and Friml, 2011;Pleskot et al, 2013).…”

“…As marker genes for CWI maintenance, we considered 14 genes encoding receptor-like kinases (RLKs) that have been implicated in cell wall damage signaling and that likely function upstream of pathways involved in the maintenance of CWI (Engelsdorf and Hamann, 2014). These RLK genes include those that were identified as primarily functioning in tip growth (e.g., ANX1 and ANX2) as well as genes that primarily function in defense (e.g., WAK1 and WAK2), although functions of RLKs are often pleiotropic (Nissen et al, 2016).…”

“…We used GSEA to test whether module genes showed a statistically significant coexpression association to 14 cell wall integrity marker genes obtained from Engelsdorf and Hamann (2014). In this GSEA approach, we used the Gene Scores obtained by the SA to rank all genes in the gene expression compendium in decreasing order of gene expression similarity to each of the 14 cell wall integrity marker genes (see Figure 5B for examples).…”

Receptor-like cytoplasmic kinase MARIS functions downstream of Cr RLK1L-dependent signaling during tip growth

“…Growing cells must find a balance between loosening their CWs sufficiently to allow expansion but not so much that they lose CW integrity. Because any environmental perturbation affecting the properties of the CW can upset this fragile balance, plant cells have developed complex sensing mechanisms to coordinate the state of the CW with the internal growth machinery (1,2). These CW sensing mechanisms must be particularly robust in fastgrowing cells, such as the tip-growing root hairs and pollen tubes (PTs), the male gametophytes of flowering plants.…”