Seminar - SCM

The emergence of forms in living systems arises from the interplay of biochemical signalling and physical forces. In this talk, I will present a biophysical perspective on growth and shape regulation across plant and animal systems, combining theory, modelling, and experiments.
 

I will first discuss plant root gravitropism, addressing how roots sense gravity and translate this into directed growth. By integrating high-throughput experiments with theory, we develop a compact model that couples tip-based sensing, signal transduction, and biomechanical response. This sensing-growth feedback framework quantitatively captures both transient and long-term bending dynamics across a wide range of conditions, and reveals the interplay of sensing, signalling, and mechanics across overlapping timescales. We demonstrate our results in the mean-field to capture population dynamics as well as in a stochastic individual root setting.

I will then turn to animal morphogenesis, where tissue deformation is driven by internally generated active stresses. Motivated by morphogen gradients, we analyse the stability of compressible active tissues under scalar-field gradients. We find that gradient-extensile systems are generically stable (further stabilised by diffusion), whereas gradient-contractile systems are typically unstable to long-wavelength perturbations. These results refine theoretical understanding and offer insights into the apparent evolutionary preference to the extensile morphogenetic processes.

Together, these studies underscore common physical principles-feedback, transport, and mechanics that drive the emergence of forms and shapes across biological systems.