Toward a 3D model of phyllotaxis
Résumé
Auxin-driven patterning operates in two main modes: convergence and canalization. The shoot apical
meristem is a potentially unique system in which these two modes co-occur in a coordinated manner
and in a fully three-dimensional geometry. In the epidermal layer, convergence points form, from
which auxin is canalized towards inner tissue. Each of these two patterning processes has been
extensively investigated separately, but the integration of both in the shoot apical meristem remains
poorly understood. We present a first attempt of a three-dimensional model of auxin-driven
patterning during phyllotaxis. Our simulations are based on a biochemically plausible mechanism of
auxin transport proposed by Cieslak et al. (2015) which generates both convergence and canalization
patterns. We are able to reproduce most of the dynamics of PIN1 polarization in the meristem, and
we explore how the epidermal and inner cell layers act in concert during phyllotaxis. In addition, we
discuss the mechanism by which initiating veins connect to the already existing vascular system.
References:
- Cieslak M, Runions A, Prusinkiewicz P. Auxin-driven patterning with unidirectional fluxes. J Exp Bot.
2015;66(16):5083–5102. https://doi.org/10.1093/jxb/erv262
- Hartmann FP, Barbier de Reuille P, Kuhlemeier C (2019) Toward a 3D model of phyllotaxis based on
a biochemically plausible auxin-transport mechanism. PLoS Comput Biol 15(4): e1006896. https://doi.org/10.1371/journal.pcbi.1006896
Domaines
Biologie végétale
Origine : Fichiers produits par l'(les) auteur(s)
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