Multi-physics modeling for ion homeostasis in multi-compartment plant cells using an energy function.

Area of Science:

• Plant Cell Biology
• Biophysics
• Computational Biology

Background:

• Plant cell volume is controlled by osmotic potential, involving complex solute exchanges governed by multiple physical forces.
• Existing multi-compartment models struggle to integrate these coupled chemical, electrical, and mechanical effects.
• New modeling strategies are needed to address the multi-physics challenges in plant cell volume regulation.

Purpose of the Study:

• To introduce a novel energy-based approach for modeling coupled physical processes in plant cells.
• To provide a unified and systematic method for deriving equations governing multi-compartment plant cell dynamics.
• To apply this formalism to understand ion and water transport during guard cell stoma opening.

Main Methods:

• Developed an energy-based framework to couple chemical, electrical, and mechanical processes.
• Formulated an energy function to systematically derive governing equations for subcompartment variables.
• Modeled stoma opening as a quasi-static process driven by hydrogen pumps in guard cells.

Main Results:

• The energy-based approach successfully integrates diverse physical effects in a modular manner.
• The model explains directional system variations in response to perturbations during stoma opening.
• Numerical simulations elucidated the specific roles of hydrogen pumps in the guard cell system.

Conclusions:

• The energy-based approach offers a powerful, unified strategy for modeling complex plant cell processes.
• This formalism highlights the hierarchy of forces and dissects the contribution of each physical effect.
• The method provides new insights into ion and water transport regulation in plant cells, particularly guard cells.