3-Dimensional biomechanical model for stomata opening

01 November 2017 - By: Sheila McCormick

3-Dimensional biomechanical model for stomata opening

A computational approach for inferring the cell wall properties that govern guard cell dynamics

Woolfenden HC, Bourdais G, Kopischke M, Miedes E, Molina A, Robatzek S, Morris RJ (2017). The Plant Journal 92, 5–18. http://onlinelibrary.wiley.com /doi/10.1111/tpj.13640/full

In the face of climate change, it is crucial to understand how guard cells open and close stomata. How do changes in guard cell turgor pressure translate into stomata opening? How important is guard cell shape? Does cell wall thickness matter? Is isotropic material sufficient? Are microfibrils important? The interdisciplinary study by Woolfenden et al. addresses these and other questions. They present a 3D biomechanical model of dicot guard cells and demonstrate how the key ingredients of pressure, geometry and material properties work together to enable guard cells to open and close stomata. They show that radial strengthening of the guard cells is required and that strain-stiffening of the cell wall contributes to the observed non-linear relationship between pressure and aperture size. The authors show how the kidney-shaped geometry of guard cells effectively limits the overall length change and thus promotes opening. Furthermore, by including their model within an optimization pipeline, they show how this approach can be used to interpret mutants with altered stomatal dynamics. This is an exciting first step in understanding the mechanics of guard cells. Future directions will include linking their biomechanical model to existing computational models for turgor pressure changes that were based on ion fluxes, and adapting the model to grass stomata, which have a different shape and likely a different underlying mechanism.

By Sheila McCormick, Research Highlights Editor

Category: Journals