Systematic mapping of cell wall mechanics in the regulation of cell morphogenesis

Abstract

Walled cells of plants, fungi, and bacteria come with a large range of shapes and sizes, which are ultimately dictated by the mechanics of their cell wall. This stiff and thin polymeric layer encases the plasma membrane and protects the cells mechanically by opposing large turgor pressure derived mechanical stresses. To date, however, we still lack a quantitative understanding for how local and/or global mechanical properties of the wall support cell morphogenesis. Here, we combine subresolution imaging and laser-mediated wall relaxation to quantitate subcellular values of wall thickness (h) and bulk elastic moduli (Y) in large populations of live mutant cells and in conditions affecting cell diameter in the rod-shaped model fission yeast. We find that lateral wall stiffness, defined by the surface modulus, σ = hY, robustly scales with cell diameter. This scaling is valid across tens of mutants spanning various functions—within the population of individual isogenic strains, along single misshaped cells, and even across the fission yeasts clade. Dynamic modulations of cell diameter by chemical and/or mechanical means suggest that the cell wall can rapidly adapt its surface mechanics, rendering stretched wall portions stiffer than unstretched ones. Size-dependent wall stiffening constrains diameter definition and limits size variations; it may also provide an efficient means to keep elastic strains in the wall below failure strains, potentially promoting cell survival. This quantitative set of data impacts our current understanding of the mechanics of cell walls and its contribution to morphogenesis.

Precise regulation of the relative rates of surface area and volume synthesis in bacterial cells growing in dynamic environments

“…Compared to the bacterial species, S. pombe exhibited a smaller change in cell width (~5%), presumably due to its thicker cell wall 29 . Such changes in cell width have been previously observed in S. pombe during nutrient depletion 30 . The SA/V dynamics in S. pombe (Fig.…”

Plant cell adhesion and growth on artificial fibrous scaffolds as an in vitro model for plant development

“…The plant body consists largely of diffusively growing cells that are attached to their neighbors by their cell walls. The rigid cell wall provides structural support as well as mechanical and biochemical cues that guide cell morphogenesis and development ( 6 , 9 , 10 , 18 – 20 ). The physical coupling of cells by the cell wall also enables direct force transmission to coordinate the growth of adjoining cells in developing tissues and organs ( 6 , 20 , 21 ).…”

Multiscale Mechanical Performance of Wood: From Nano- to Macro-Scale across Structure Hierarchy and Size Effects

“…In order to expand the capabilities of the analysis of mechanical properties in their connection with the architecture of wood ring structures, the following methods have been used: two-dimensional mapping of properties on cross-sections of tree trunks by AFM methods [ 89 , 90 , 91 , 92 ] and NI [ 93 ] scanning, 3D X-ray [ 94 , 95 ] and NMR tomography [ 96 ], and synchrotron-based X-ray microscopy [ 97 ]. However, these methods are complicated, labor-intensive and require expensive or unique equipment; therefore, they are used only sporadically.…”

“…To study mechanical properties of wood cells, various SSMT methods are used [ 45 ], and the most widespread ones are AFM [ 89 , 92 ] and NI [ 70 , 71 , 74 , 75 , 93 ]. Let us present some typical examples of NI application with load P max = 0.1–1 mN to this problem.…”