Molecular insights into the complex mechanics of plant epidermal cell walls (Science)

Primary plant cell walls are made up of three types of polysaccharides: cellulose, hemicellulose, and pectin, the orientations and interactions of which provide the cell wall with its properties. Here, Zhang et al. examined the outer wall of onion epidermal cells through atomic-force microscopy, stress-strain functional assays, and mesoscale coarse-grained molecular dynamics (CGMD). The models they developed closely match the structures, dynamics and functions of the real cell walls. For example, the models highlight the importance of the cellulose microfibrils, which carry most of the stress. The model allowed the authors to explore the effects of altering proportions of and interactions between different polymers. These studies provide new and unexpected understandings of cell wall properties.  Furthermore, as described by the authors, “The ingenious microstructural and architectural design of plant epidermal cell walls suggests ways to engineer strong and extensible fibrous materials with multifunctional applications.” (Summary by Mary Williams @PlantTeaching) Science 10.1126/science.abf2824