Abstract text:

Plant growth relies on two fundamental processes: cell expansion and cell division. Cell expansion depends on a balance between cell wall properties and mechanical forces, particularly turgor pressure and forces exerted by neighbouring cells. Cell division alters cell size and geometry, reshaping tissue structure and modifying the distribution of mechanical stresses. Although both processes are essential for growth, their interaction remains poorly understood.

To clarify how cell division and expansion influence each other and respond to environmental changes, we quantitatively analyse both processes using an interdisciplinary approach. Our methods combine the automated confocal micro-extensometer, atomic force microscopy, time-lapse imaging, quantitative solid-state NMR, and single-cell transcriptomics.

We show that altering the balance between cell division and expansion modifies how tissues respond to environmentally induced growth changes. Furthermore, cell division affects cell wall biochemistry, tissue mechanical properties, and stress patterns. By comparing tissues with different cell geometries, we distinguish the respective contributions of cell wall composition and cell shape to growth dynamics.

Overall, cell expansion, division, and mechanical stress responses form an interconnected system. Understanding these relationships provides a framework to predict and ultimately manipulate plant development under varying environmental conditions.