Towards an active matter theory of plant morphogenesis

TL;DR

This work reframes plant morphogenesis as an open-system, active-matter process driven by osmotic water fluxes, turgor pressure, and cell-wall mechanics, arguing for a unified hydro-chemo-mechanical theory that integrates hydraulics, mechanics, and chemical regulation with gene control. It synthesizes morphometrics, morphogenetics, morphoelasticity, morphodynamics, and multiphysics into a cohesive framework, moving beyond prescribed-turgor and specified-growth paradigms toward dynamic, physically grounded descriptions. Central insights include the multiplicative decomposition $\mathbf{F}=\mathbf{A}\mathbf{G}$ in morphoelasticity, a hydromechanical picture of cell expansion via Lockhart–Ortega relations, and a continuum poro-morpho-elastic approach with a characteristic hydraulic length $\sqrt{KG/\chi}$ that enables analytic descriptions of water competition and tissue tension. Together, these ideas offer a principled, testable pathway to predict plant form from physics and gene regulation, guiding experiments on water transport, wall mechanics, and chemical patterning to achieve cross-scale predictive power in plant morphogenesis.

Abstract

Plant morphogenesis relies on dynamic growth deformations at the cell and tissue scales driven by osmotic fluxes. A mechanistic understanding of this phenomenon demands a physical framework that integrates cell imbibition, tissue mechanics, and water fluxes, as well as their biophysical and molecular regulations, within a theory of plant active matter capturing the open-system and out-of-equilibrium properties of tissues. Building on historical insights into growth geometry, physics, and mechanics, combined with recent experimental results, we outline the key challenges in modelling plant growth and propose steps towards a unified physical theory of plant morphogenesis, in which biological regulation, mechanical forces, and water fluxes interact to shape biological form through the fundamental principles of living matter.

Figures (2)

• Figure 1: Deformation of the initial configuration $\mathcal{B}_0$ by the smooth map $\chi$ to the current configuration $\mathcal{B}$. The tensor $\mathbf{F}$ is the gradient of deformation tensor.
• Figure 2: The multiplicative decomposition of morphoelasticity. Starting from a stress-free initial configuration, a local growth deformation $\mathbf{G}$ is applied on volume elements, resulting in an incompatible intermediate configuration. A second deformation $\mathbf{A}$ ensures compatibility, and results in a stressed configuration that includes residual growth stresses and external loads.