[MS12] Mathematical and Computational Perspectives of Phyllotaxis and Growth of Plants

[MS12-05] Stochasticity in phyllotaxis: analysis and modeling

*Christophe Godin¹, Teva Vernoux¹ (1. Inria (France))

Keywords:

Phyllotaxis,Stochastic model,Divergence angle,Noise,Molecular regulation

Over the last two centuries, multidisciplinary research on phyllotaxis has led to a common deterministic explanation of the striking symmetries displayed by the arrangement of organs along plant axes. In this view, recently created primodia at the tip of axes locally inhibit the formation of other primordia in their immediate vicinity. Due to growth, these already existing primordia get progressively away from the initiation zone, leaving periodically space for new initiations at the tip. The frequency and position of these initiations emerge from this dynamical process and produce these familiar spiral and whorl patterns. This deterministic vision, based on the production of a field of inhibition by each primordium, largely prevailed at the end of the 20th century as the “classical model” of phyllotaxis. However, it has been noticed in the recent years that phyllotaxis may surprisingly present noise in these deterministic patterns, where strong perturbations in the angle between consecutive organs are observed locally. In this talk, I will show that such perturbations are actually ubiquitous in plants, and that their quantification and analysis leads to replace the classical deterministic view by a more general, stochastic vision of phyllotaxis, in which the biological noise at cellular scale propagates to the organ scale by altering phyllotaxis with patterns with remarkable perturbation signature.