RT Journal Article
SR Electronic
T1 Microtubule-based nucleation results in a large sensitivity to cell geometry of the plant cortical array
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2024.03.25.586463
DO 10.1101/2024.03.25.586463
A1 Saltini, Marco
A1 Deinum, Eva E.
YR 2024
UL http://biorxiv.org/content/early/2024/07/31/2024.03.25.586463.abstract
AB Many plant cell functions, including cell morphogenesis and anisotropic growth, rely on the self-organisation of cortical microtubules into aligned arrays with the correct orientation. An important ongoing debate is how cell geometry, wall mechanical stresses, and other internal and external cues are integrated to determine the orientation of the cortical array. Through the development of a new, more realistic algorithm for nucleation, we have found that the details of microtubule nucleation have a major impact on the balance between different factors. In particular, we have found that the impact of cell geometry is likely much larger than previously thought. Existing computational algorithms for microtubule nucleation are either insufficiently realistic, which also results in less realistic behaviour of the whole array, or computationally very costly. Current algorithms that do incorporate the fact that most nucleation occurs from existing microtubules behave least realistic due to computational artefacts: they result in arrays with very inhomogeneous microtubule density, including large empty areas. In real cells, such arrays would be detrimental to cell wall integrity. Our new algorithm efficiently simulates microtubule nucleation via approximating the diffusion of nucleation complexes at the membrane. This algorithm supports uniform arrays by maintaining realism in the nucleation process without the computational burden of explicit diffusion simulation. We found that the enhanced biological realism of the nucleation process strongly increased the tendency to adopt a transverse orientation on cylindrical cells. This demonstrates that nucleation must be carefully considered in all studies about how array orientation is controlled. By offering both fast and realistic nucleation, our approach opens up new avenues for quantitative comparisons of different factors influencing array behaviour, including orientation and patterning.Competing Interest StatementThe authors have declared no competing interest.