Join Professor Anne-Lise Routier-Kierzkowska of the University of Montreal for a research seminar entitled "The apical hook paradox: how to make an organ grow while keeping its shape" as part of the Force Talk series.

Abstract:

Unlike animals, plants lack muscles or contractile tissues; instead, they generate motion through spatially patterned growth within mechanically coupled tissues. During germination, emerging seedlings bend the tip of their stem to form an apical hook, enabling the young plant to penetrate the soil while protecting its fragile stem cell niche. Remarkably, the hook elongates rapidly while maintaining its curved shape — a striking example of self-similar morphogenesis driven by differential cell expansion. How such behaviour is achieved at the cellular level remains unknown.

Here, we combine quantitative live 3D imaging, molecular approaches, and mathematical modelling to uncover the cellular basis of apical hook dynamics. We demonstrate, for the first time, that self-similar organ growth is maintained by stationary fields of cell expansion that remain spatially stable despite cell movement. We further show that auxin — long considered the primary morphogen controlling hook curvature — is not sufficient to explain these stationary growth patterns. Instead, our modelling and experimental analyses reveal that feedback between organ curvature and cellular dynamics is required for the fine-tuned coordination of growth. We propose mechanical forces as potential signals within a robust closed-loop system that maintains self-similar expansion.

Together, our study provides a multiscale framework for understanding how plant organs achieve robust shape control while developing in mechanically challenging environments, and offers conceptual insights relevant to animal morphogenesis and bio-inspired soft robotic systems.

Speaker:

Anne-Lise Routier-Kierzkowska is an Associate Professor at the Institut de Recherche en Biologie Végétale (IRBV) at the Université de Montréal. She obtained her PhD in Biology from the University of Silesia through the Marie Curie SYSTEMS network before undertaking postdoctoral positions with Professor Cris Kuhlemeier at the University of Bern and Dr Richard Smith at the Max Planck Institute for Plant Breeding Research. She joined the IRBV in 2017, where her group now works at the intersection of plant biophysics, development and climate‑resilient agriculture.

 

Mechanics of Life Leverhulme DSP Force Talks Series

Force Talks is a seminar series hosted by the Mechanics of Life Leverhulme Doctoral Scholarship Programme at King's College London. We are honoured to welcome world leaders in mechanobiology.

The series aims to showcase the rapidly expanding interdisciplinary field of mechanobiology and mechanical forces. We welcome those from academia and industry to attend and take part in the discussions.

The programme is funded by the Leverhulme Trust doctoral scholarship grant "Understanding the mechanics of life".

Learn more about the Mechanics of Life Leverhulme Doctoral Scholarship Programme

How to join:

This event will take place online via Microsoft Teams. To receive the link to join register for the webinar via the "Go to this event" button. 

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