In research published in Plant Journal, a team led by Professor Richard
Morris from the John Innes Centre, Norwich, Professor Silke Robatzek of The
Sainsbury Laboratory, Norwich, and collaborators from the University of
Madrid, developed the first ever full 3D model of a guard cell. Guard cells
control the opening of stomata, the tiny pores used by plants for gas
exchange, water regulation, and pathogen defense.
The research reveals the importance of three distinct characteristics of
guard cells that allow them to function effectively. The first is turgor, or
the level of water pressure inside the cell. Second is the elasticity of the
cell wall, and third is the kidney-shaped geometry that converts pressure
into shape changes.
Additional research found an unexpected stiffening in the guard cell end
regions, or poles. The stiffening reflects a mechanical pinning down of the
guard cell ends, which prevents stomata increasing in length as they open.
This leads to an increased speed of pore opening and larger pores, which
gives 'better' stomata. This was observed in Arabidopsis, tomato, and maize,
which suggests that it is widespread across plant species.