Plant cell walls, consisting of cellulose microfibrils and wall matrix, composed of proteins, water and polysaccharides (hemicelluloses and pectins), have complex dynamical mechanical behavior. This is necessitated by the fact that they must be strong to support a high internal (turgor) pressure, but at the right moment be able to yield to allow for cell growth. It was observed that changes in cell wall elasticity are strongly correlated with changes in the pectin matrix chemistry.
In this talk I will present a microscopic model for plant cell wall biomechanics that takes into account both the microstructure coming from the cellulose microfibrils and the chemical reactions between the cell wall’s constituents. Particular attention is paid to the role of pectin and the impact of calcium-pectin cross-linking chemistry on the mechanical properties of the cell wall. Elastic and viscoelastic Kelvin–Voigt type deformations of the cell wall matrix are considered. To analyse the macroscopic behaviour of plant cell walls, as well as for effective numerical simulations, the macroscopic model for cell wall biomechanics is rigorously derived by applying homogenisation techniques.