Root hairs enable plants to absorb water and minerals from the soil. How do these structures know how far to grow? By observing their development in real time, scientists, in an article published in The Plant Cell, have identified an internal mechanism based on a gradual reorganization of the subcellular architecture, capable of precisely controlling when their growth stops.

Growth Directed Toward a Single End

On the surface of plant roots are thousands of microscopic hairs that play an essential role in absorbing water and nutrients from the soil. These root hairs have a remarkable characteristic: they grow only at their tips. Instead of growing uniformly along their entire length, they continuously add material to their tips, much like a tunnel being built from the inside out.

This strategy is also used by other specialized plant cells, such as pollen tubes involved in flower fertilization. Despite the obstacles they encounter in their environment, these hairs generally continue to grow without being significantly disrupted. This resilience suggests that an internal mechanism determines their final size in advance.

To understand how this growth comes to an end, scientists, in an article published in the journal The Plant Cell, studied the roots of Arabidopsis thaliana, a model plant widely used in biology. The roots were grown in a microfluidic chip, a miniaturized device that allows researchers to track their development directly under a microscope without disturbing them.

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Reference

Dupouy G, Spelman T, Singh G, Herzog E, Baudrey S, Bovio S, Mutterer J, Hamant O, Berr A, Jönsson H, Chabouté ME. « Function behind choreography: cytoskeletal, nuclear, and mechanical dynamics drive growth transition in root hair development ». Plant Cell. 2026 Jul 2;38(7):koag165. DOI: 10.1093/plcell/koag165