Final Report Summary - MECHANODEVO (Mechanical signals in plants: from cellular mechanisms to growth coordination and patterning)
Development relies on a complex network of molecular effectors that ultimately modify the mechanical properties of cells and control shape changes. In turn, mechanical forces can also feedback on the molecular network to govern development. Several mechanosensitive proteins have been identified in animals but their role in multicellular development remains poorly documented. Plants are ideal systems to study mechanotransduction in development because their mechanics is mainly mediated by the cell wall. In this ERC project, we revealed the stress pattern in plant tissues (using cell-cell adhesion mutants and image analysis and revisiting Hofmeister’s theory of tissue tension (1859), we unraveled a mechanosensor role of DEK1, we proposed that microtubules can be autonomous mechanosensors, we identified new targets of mechanical signals (phospholipids, homeobox genes), we pioneered nuclear mechanotransduction in plants (the GIP nuclear envelope protein acting as a regulator of this response), we showed that cell divide along the direction of maximal tensile stress direction, revisiting Errera’s rule (1884), we revealed the role of mechanical stress in organ growth arrest and shape robustness, we introduced the concept of mechanical shielding (filtering growth heterogeneity through a mechanical feedback), we identified the role of Paf1C in developmental robustness and its link with thigmormorphogenesis. In the end, combining cell biology, micromechanics and modeling, we revealed how plants perceive their own shape and growth through mechanosensing, in a form of multiscale proprioception.