Charlotte Kirchhelle
Panagiotis Moschou
Virtual Seminar via Zoom
14:00 - 15:30
The importance of being edgy: directional growth control in plants
Méchanotransduction et développement - Laboratoire Reproduction et  DÉveloppement des PlantesA fundamental question in biology is how multicellular organisms
robustly produce organ shapes. The underlying process of morphogenesis
involves the integration of biochemical, genetic, and mechanical
factors across multiple spatio-temporal scales. In plants,
morphogenesis is dominated by the rigid cell wall, which fixes cells
in their position. Adjacent cells must therefore coordinate their
growth patterns, which are in turn controlled by the mechanical
properties of the cell wall. Cell walls are assembled by a complex
intracellular trafficking machinery that delivers cell wall components
and their associated biosynthetic machinery to different subcellular
We have recently discovered that a trafficking route directed to cell
edges is essential for cell wall assembly and directional growth at
the cell and organ scale. Edge-based growth regulation is independent
of oriented cellulose deposition, the central paradigm of directional
growth control in plants. Based on our latest data, we now propose
that morphogenesis is controlled by a signalling module at cell edges
which integrates feedback from the cell wall. We propose that a
receptor-like protein recently identified as the first known cargo of
edge-directed trafficking acts as a core component of a cell wall
signalling module at edges. This hypothesis provides a mechanistic
explanation for the role of cell edges as integrators of cell and
tissue-level mechanical factors into coordinated cell wall assembly.