FERONIA and microtubules independently contribute to mechanical integrity in the Arabidopsis shoot

Abstract

To survive, cells must constantly resist mechanical stress. In plants, this involves the reinforcement of cell walls, notably through microtubule-dependent cellulose deposition. How wall sensing might contribute to this response is unknown. Here, we tested whether the microtubule response to stress acts downstream of known wall sensors. Using a multistep screen with 11 mutant lines, we identify FERONIA (FER) as the primary candidate for the cell’s response to stress in the shoot. However, this does not imply that FER acts upstream of the microtubule response to stress. In fact, when performing mechanical perturbations, we instead show that the expected microtubule response to stress does not require FER. We reveal that the feronia phenotype can be partially rescued by reducing tensile stress levels. Conversely, in the absence of both microtubules and FER, cells appear to swell and burst. Altogether, this shows that the microtubule response to stress acts as an independent pathway to resist stress, in parallel to FER. We propose that both pathways are required to maintain the mechanical integrity of plant cells.

THESEUS1 modulates cell wall stiffness and abscisic acid production in Arabidopsis thaliana

“…This suggests that some form of redundancy compensates for loss of THE1 and that THE1 has more specialized and different (opposing) functions than FER, even if both FER and THE1 contribute to stress-induced, cell wall–dependent processes. Redundancy could be mediated by other molecular components involved in mechanoperception or coordination between the cell wall and cellular components ( 3 , 4 , 24 , 48 ).…”

Paf1C denoises transcription and growth patterns to achieve organ shape reproducibility

“…To further confirm this conclusion, and extend it to other vip3-1 tissues, we tested the ability of cells and cell walls to resist hypo-osmotic stress (Malivert et al, 2021; Verger et al, 2018). To test this hypothesis, we subjected the mutant to such conditions, using MS medium containing low concentration of plant agar (0.4% agar instead of 0.8% in normal MS).…”

“…To further confirm this conclusion, and extend it to other vip3-1 tissues, we tested the ability of cells and cell walls to resist hypo-osmotic stress (Malivert et al, 2021;Verger et al, 2018).…”

“…KATANIN is involved in cortical microtubule organization and consequently cellulose biosynthesis (Burk et al, 2001), while XXTs are involved in xyloglucan biosynthesis (Cavalier et al, 2008). FERONIA is a receptor kinase involved in maintaining cell wall integrity (Feng et al, 2018;Malivert et al, 2021). There is ample evidence demonstrating that both katanin (bot1-7) and xxt1 xxt2 mutants have significantly weaker cell walls than the WT in differentiating tissues (Bichet et al, 2001;Burk et al, 2001;Burk & Ye, 2002;Cavalier et al, 2008;Park & Cosgrove, 2012;Ryden et al, 2003).…”

Cell shape: A ROP regulatory tug-of-war in pavement cell morphogenesis

“…The authors propose that the pectin-FER-GEF14-ROP6 complex might transduce mechanical forces to control microtubule orientation 5 . However, this idea is contested in another study which put forward a model in which FER action in response to mechanical stress is independent of microtubule reorganization 16 . Thus, the link between pectin perception and mechanical transduction remains to be fully elucidated.…”