Survival of the aligned: ordering of the plant cortical microtubule array

TL;DR

This paper presents a theoretical and simulation-based study demonstrating that microtubule collisions causing depolymerization are sufficient to explain the alignment of cortical microtubules in plant cells, crucial for cell expansion.

Contribution

It introduces a combined coarse-grained model and stochastic simulations to explain microtubule alignment through depolymerization-inducing collisions.

Findings

Collisions induce depolymerization leading to alignment

Theoretical and simulation results agree on alignment mechanism

Depolymerization-driven collisions are sufficient for microtubule ordering

Abstract

The cortical array is a structure consisting of highly aligned microtubules which plays a crucial role in the characteristic uniaxial expansion of all growing plant cells. Recent experiments have shown polymerization-driven collisions between the membrane-bound cortical microtubules, suggesting a possible mechanism for their alignment. We present both a coarse-grained theoretical model and stochastic particle-based simulations of this mechanism, and compare the results from these complementary approaches. Our results indicate that collisions that induce depolymerization are sufficient to generate the alignment of microtubules in the cortical array.