Abstract text: The leaf epidermis is a dynamic biomechanical shell that integrates growth across spatial scales to influence organ morphology. The dicot epidermis is comprised of pavement cells that morph irreversibly into interdigitated cells that enable planar leaf expansion. The process is intimately linked to continuous cell wall remodeling. Our group is analyzing the biomechanical importance of the cell-cell interface using combinations of genetics, live cell imaging, and finite element (FE) computational modeling. This approach allows us to discover complex interactions among cell/tissue geometry, cell wall material properties, growth patterns, and cell wall force-sensing feedback control mechanisms that drive predictable morphogenetic outputs. We have previously shown that the magnitudes and directions of tensile stresses in cell walls are sensed by the cortical microtubule system to pattern both organ-scale planar morphogenesis and subcellular interdigitated growth. The next generation of FE models contain more realistic cell-cell interactions that are enabling analyses of the forces that destabilize cell-cell contacts and the physical integrity of epidermis. The talk will describe how experiments and models are revealing new types of important forces during development and some of the molecular machineries that sense destabilizing forces and preserve tissue integrity.