Session 3A: Lectures by Fellows/Associates

Chairperson: U C Mohanty, Centre for Climate Smart Agriculture, Bhubaneswar

Self-Organized Morphogenesis in Plant Regeneration: Integrating Mechanochemical and Geometric Cues

Morphogenesis is driven by intricate mechanical forces that orchestrate cellular and tissue-wide deformations. These forces, in concert with cell geometry and biochemical cues, including hormonal signals, propel the morphogenetic process. Utilizing Arabidopsis thaliana as a model system, we investigate morphogenesis through tissue culture-mediated shoot regeneration. Our findings reveal the pivotal role of mechanical forces in guiding the self-organization of shoot progenitors from undifferentiated callus into functional shoot meristems. We propose a "stretch–compress" model, illustrating how mechanical forces induce compression in progenitor cells and expansion in neighbouring cells. This dynamic interplay reshapes cell geometry and mechanical tensions, which are essential for the formation of the characteristic dome-shaped shoot meristem. Remarkably, this mechanistic framework is also recapitulated in organ regeneration following injury. In Arabidopsis root tip regeneration, we identify a similar "push–pull" mechanism, facilitating the convergence of longitudinal cell files at the regenerating tip and the re- establishment of the stem cell niche (SCN). Our study highlights the fundamental role of cell geometry and mechanochemical feedback as key regulators of tissue morphogenesis, offering new insights into the forces shaping developmental processes.