Ibrahim Cheddadi: Role of water fluxes in the shoot apical meristem development: a biophysical approach

Plant aerial organs are initiated in the Shoot Apical Meristems (SAM), located at the tip of the stems. Various key molecular actors have been identified and their functions in patterning the SAM have been mapped in space and time. These molecular actors likely induce the physical deformation of tissues by modifying cell wall mechanical properties, for instance allowing more water to enter the cells and inducing leaf or flower primordia outgrowth. Water fluxes have long been considered as non limiting in this picture and most theoretical models of plant development focus on walls mechanical properties, but this view is being challenged by recent theoretical and experimental results. In this talk, I will present an ongoing project where we try to elucidate the role of water fluxes in organ morphogenesis in the SAM, combining mathematical modelling and biophysical and biochemical measurements. In particular, we posit that growing organs create water sinks that modify mechanical properties along the water pathway, affecting in turn growth and cell identity.