Beyond the Bilayer: Organization and Interactions in the Arabidopsis thaliana Cell Wall–Plasma Membrane System in Atomistic Simulations

Atomistic studies of plant cell surfaces have typically focused either on plasma membranes or on individual cell wall polymers, such as cellulose and hemicellulose, rather than on combined plasma membrane–cell wall models. Here, we present an atomistic model of the Arabidopsis thaliana cell membrane that explicitly includes both the plasma membrane and the primary cell wall. Simulations reveal that cell wall interactions thin the plasma membrane, especially in the upper leaflet facing the wall, increase lipid area per molecule, and increase the acyl chain disorder. Lipid–cellulose interactions were quantified, showing that phosphate headgroups dominate binding and that lipid species differ in interaction strength. These results provide a molecular-level description of how the cell wall modifies plasma membrane structure and dynamics, establishing a framework for modeling more complex plant cell surfaces.