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

Abstract

The integrity of the cell wall is important for plant cells. Mechanical or chemical distortions, tension, pH changes in the apoplast, disturbance of the ion homeostasis, leakage of cell compounds into the apoplastic space or breakdown of cell wall polysaccharides activate cellular responses which often occur via plasma membrane-localized receptors. Breakdown products of the cell wall polysaccharides function as damage-associated molecular patterns and derive from cellulose (cello-oligomers), hemicelluloses (mainly xyloglucans and mixed-linkage glucans as well as glucuronoarabinoglucans in Poaceae) and pectins (oligogalacturonides). In addition, several types of channels participate in mechanosensing and convert physical into chemical signals. To establish a proper response, the cell has to integrate information about apoplastic alterations and disturbance of its wall with cell-internal programs which require modifications in the wall architecture due to growth, differentiation or cell division. We summarize recent progress in pattern recognition receptors for plant-derived oligosaccharides, with a focus on malectin domain-containing receptor kinases and their crosstalk with other perception systems and intracellular signaling events.

Cellooligomer/CELLOOLIGOMER RECEPTOR KINASE1 Signaling Exhibits Crosstalk with PAMP-Triggered Immune Responses and Sugar Metabolism in Arabidopsis Roots

“…When ISX, which inhibits cellulose biosynthesis and thus impairs proper de novo cell wall biosynthesis [ 50 ], was applied to Arabidopsis roots for 6 or 9 h, we observed no effect on the expression of CORK1 and the related malectin-containing receptor kinase genes At1g56130 and At1g56140 in the roots ( Figure 2 ). Only the uncharacterized At1g56120 gene, which is closely related to the CORK1 , IGP2/ 3 , and IGP4 genes, and also a member of the LRR-malectin domain-receptor kinase gene subfamily [ 6 , 10 ], was significantly upregulated in the shoots (cf. Section 3 ).…”

“…Furthermore, CORK1, At1g56130 (IGP2/3), and At1g56140 (IGP4) were found in mutant screens for the perception of cellooligomers or mixed-linked glucan oligosaccharides [ 5 , 6 ], while At1g56120 was not. The function of At1g56120, which is closely related to CORK1, IGP2/3, and IGP4, and is also a member of the LRR-malectin domain-receptor kinase subfamily [ 6 , 10 ], has to be elucidated.…”

“…Breakdown of callose results in the accumulation of non-branched β-1,3-glucan oligosaccharides perceived by CERK1, LYK4, and LYK5 [ 7 ]. Xyloglucans from hemicellulose function as DAMPs in different plant systems; however, a receptor has not yet been identified [ 10 ]. Cellooligosaccharide perception is considered as an alarm system which informs the cell about the integrity of its wall [ 11 ].…”

The RALF signaling pathway regulates cell wall integrity during pollen tube growth in maize

“…Proper biochemical composition and spatial distribution of cell wall material are critical for maintaining pollen tube growth as mutants defective in the synthesis of cell wall components exhibit pollen tube growth phenotypes such as slow or wavy growth, growth arrest, and burst ( Jiang et al 2005 ; Nishikawa et al 2005 ; Wang et al 2011 ; Chebli et al 2012 ; Oelmüller et al 2023 ). To investigate cell wall material distribution in the maize pollen tube, we first defined the different regions of growing pollen tubes.…”

Arabidopsis WALL-ASSOCIATED KINASES are not required for oligogalacturonide-induced signaling and immunity

“…Cell wall polysaccharides serve as extracellular sources for the generation of damage-associated molecular patterns (DAMPs) that are thought to be released upon mechanical damage or pathogen infection (Pontiggia et al ., 2020). Several such carbohydrate DAMPs have been previously described, including cellulose-derived cellobiose and cellotriose, mixed linked glucans, and pectin-derived oligogalacturonides (OGs) (Bacete et al ., 2018; Oelmüller et al ., 2023). OGs are generated from demethylesterified pectins and represent the best studied pectin-derived cell wall breakdown products.…”