Localized growth and remodelling drives spongy mesophyll morphogenesis

Area of Science:

• Plant biology
• Biophysics
• Developmental biology

Background:

• Spongy mesophyll is a porous plant leaf tissue crucial for carbon capture and mechanical support.
• Unlike most tissues, it develops from a confluent state to a porous network with intercellular airspaces.
• The mechanism for developing porosity while maintaining mechanical stability is not understood.

Purpose of the Study:

• To investigate the mechanical principles governing the development of spongy mesophyll porosity.
• To model the morphogenesis of spongy mesophyll using computational simulations.

Main Methods:

• Utilized computer simulations of deformable polygons to create a mechanical model.
• Simulated cell wall growth and remodeling restricted to areas near void space.
• Validated the model against spongy mesophyll development in *Arabidopsis thaliana*.

Main Results:

• The computational model successfully recapitulated observed spongy mesophyll development.
• Demonstrated that pore space generation requires a balance of cell growth, adhesion, stiffness, and tissue pressure.
• Showed that these factors ensure porous yet mechanically stable cell networks.

Conclusions:

• Simple physical principles can drive the development of complex plant tissues like the spongy mesophyll.
• A purely mechanical model can explain the morphogenesis of this essential leaf tissue.
• Highlights the interplay between mechanical forces and biological development in plants.