Cellular heterogeneity in pressure and growth emerges from tissue topology and geometry

By Yuchen Long, I. Cheddadi, Vincent Mirabet, G. Mosca, M. Dumond, J. Traas, C. Godin, Arezki Boudaoud. bioRxiv, 2018

91 citations recorded by the source corpus.

Cell-to-cell heterogeneity prevails in many biological systems, although its origin and function are often unclear. Cell hydrostatic pressure, alias turgor pressure, is essential in physiology and morphogenesis, and its spatial variations are often overlooked. Here, based on a mathematical model describing cell mechanics and water movement in a plant tissue, we predict that cell pressure anticorrelates with cell neighbour number. Using atomic force microscopy, we confirm this prediction in the Arabidopsis shoot apical meristem, a population of stem cells that generate all plant aerial organs. Pressure is predicted to correlate either positively or negatively with cellular growth rate depending on osmotic drive, cell wall extensibility, and hydraulic conductivity. The meristem exhibits one of these two regimes depending on conditions, suggesting that, in this tissue, water conductivity is non-negligible in growth control. Our results illustrate links between local topology, cell mechanical state and cell growth, with potential roles in tissue homeostasis. Highlights A mechano-hydraulic model of tissue growth predicts heterogeneity in cell pressure and in cell growth according to local tissue topology. Indentation-based measurement of cell pressure in the shoot apical meristem of Arabidopsis thaliana, together with a realistic mechanical model of tissue indentation, reveals pressure variations according to cell size and cell neighbour number. Cell growth in the Arabidopsis shoot apical meristem either correlates or anti-correlates with cell neighbour number, which can be retrieved by the model using experimentally-based parameters.

Subfields: Cell Biology, Molecular Biology, Plant Science

View Paper: https://www.semanticscholar.org/paper/e3cd5a52c58ce0753db43216ffecb89d5d720c11