Dual role of the receptor kinase FERONIA in regulating tissue mechanics and growth

During morphogenesis, growing organisms adapt to internal and external mechanical stress. In plants, the receptor kinase FERONIA is involved in a broad range of responses to perturbations of the cell wall, but it is unclear which cues are sensed and how this sensing controls growth. Here, we addressed these questions in Marchantia vegetative propagules. We combined culture in microfluidic chips to quantify growth and mechanical properties of propagules, perturbations with osmotic treatments, characterisation of cell wall polysaccharides, and a mathematical model of cell wall expansion that incorporates sensing. We found that FERONIA independently regulates tissue mechanical properties and growth rates. We propose that the regulation of growth by the FERONIA pathway relies on both a positive feedback from elastic deformation of the wall and a negative feedback from wall expansion. Altogether, we expect our quantitative framework to be broadly relevant to the investigation of how mechanical cues guide development.