Jodie Armand

Swinging Stomata: 4D capture of plant cell morphodynamics to inform on wall mechanics

About me

Born and raised in the south of England, in 2016 I moved up north to start a 4 year integrated Masters course in Plant Science at the University of Sheffield. Whilst covering a broad range of topics from ecology to molecular biotechnology, I became particularly fascinated in cell shape, how it develops, how it is coordinated at the tissue level and how it can affect the efficiency of physiological processes. For my 4th year research project I investigated the variation in leaf cell size, shape and number between rice ecotypes and found that differences in their photosynthetic capacity could be explained by the cellular architecture of their leaves.

Afterwards, I stayed on at Sheffield University to become a research technician on the ongoing project ‘Shape shifting stomata: the role of geometry in plant cell function’ which is focused on understanding whether the rapidity of grass stomatal movements can be attributed to the specialised shape and structure of their guard cells and surrounding cell walls. Inspired by our early findings and with a few more technical skills under my belt, I then branched off and began leading my own research into the form and function of the kidney-shaped stomata found within non-grass species, which is now the focus of my PhD project.

My research

Stomata are microscopic pores on the leaf surface which open to enable photosynthetic gas exchange and close to limit evaporative water loss, thereby playing a crucial role in plant survival on land. Surrounding each stomatal pore are a pair of guard cells (GCs) that adjust pore aperture by reversibly changing shape as they swell and contract, driven by the osmotic movement of water between GCs and neighbouring cells (NCs). Our current understanding on the mechanics of stomatal movement is far from complete. For it to progress any further, a more accurate knowledge of the changes that occur to stomatal cell shape during turgor flux will be required.

My project aims to provide this by using advanced 3D confocal imaging to capture the precise morphodynamics of GCs and NCs during stomatal opening/closure in the model plant Arabidopsis thaliana. After characterising the functional geometry of wildtype stomata, I will then make comparisons with the geometric behaviour of mutant and/or immature stomata that differ in terms of their cell wall structure, providing a route to observe the effects of altered guard cell wall architecture on the biomechanics of guard cell shape change and stomatal function. This information will be used directly in the development of an accurate, 4D computational model of stomatal mechanics in collaboration with the John Innes Centre which will be used to test hypotheses concerning the specific contribution of aspects of cell wall structure and composition to efficient stomatal dynamics.