Live 3D imaging sheds new light on the cellular mechanics of stomatal movement in Arabidopsis thaliana

Jodie Armand, Andrew J. Fleming, Julie E.Gray
School of Biosciences, The University of Sheffield, Alfred Denny Building, Sheffield, S10 2TN, UK

Stomatal movements are enacted by reversible, turgor-driven shape changes in the guard cell (GC) pair that surrounds each pore. Understanding how the structure of the GC wall gives rise to the mechanical properties required for GC shape change is an area of continued interest, and computational modelling is proving to be a useful tool for testing hypotheses in silico. However, most of our computational models have only been built from 2D observations of stomatal movement. To address this, we have combined 3D confocal time-lapse imaging and advanced image segmentation to capture and quantify the 3D changes in GC shape that take place during stomatal movement in Arabidopsis thaliana. This has revealed previously unseen changes to the cross-sectional shape of the GCs during stomatal dynamics which we believe may be facilitated by the differential thickness of the GC wall. To help test this we are now developing a more accurate computational model of stomatal mechanics – one that’s guided directly by our 3D data on GC morphodynamics and that incorporates a more accurate GC wall thickness profile - which we plan to use to elucidate more precise structure-function relationships within the GC wall and advance our understanding of stomatal function.