A multi-scale model of the interplay between cell signalling and hormone transport in specifying the root meristem of Arabidopsis thaliana

Daniele Muraro (1, 2) , Antoine Larrieu (2) , M. Lucas (2, 3) , J Chopard (4) , H Byrne (2, 5, 6) , Christophe Godin (4) , J King (2, 6)

1 The Weatherall Institute of Molecular Medicine
2 CPIB - Centre for Plant Integrative Biology [Nothingham]
3 UMR DIADE - Diversité, adaptation, développement des plantes
4 VIRTUAL PLANTS - Modeling plant morphogenesis at different scales, from genes to phenotype
5 MI - Mathematical Institute [Oxford]
6 School of Mathematical Sciences [Nottingham]

The growth of the root of Arabidopsis thaliana is sustained by the meristem, a region of cell proliferation and differentiation which is located in the root apex and generates cells which move shootwards, expanding rapidly to cause root growth. The balance between cell division and differentiation is maintained via a signalling network, primarily coordinated by the hormones auxin, cytokinin and gibberellin. Since these hormones interact at different levels of spatial organisation , we develop a multi-scale computational model which enables us to study the interplay between these signalling networks and cell-cell communication during the specification of the root meristem. We investigate the responses of our model to hormonal perturbations, validating the results of our simulations against experimental data. Our simulations suggest that one or more additional components are needed to explain the observed expression patterns of a regulator of cytokinin signalling, ARR1, in roots not producing gibberellin. By searching for novel network components, we identify two mutant lines that affect significantly both root length and meristem size, one of which also differ-* entially expresses a central component of the interaction network (SHY2). More generally, our study demonstrates how a multi-scale investigation can provide valuable insight into the spatio-temporal dynamics of signalling networks in biological tissues.

Mots clés: gene networks; plant hormones; tissue differentiation

Domaines: Modélisation et simulation

Daniele Muraro, Antoine Larrieu, M. Lucas, J Chopard, H Byrne, et al.. A multi-scale model of the interplay between cell signalling and hormone transport in specifying the root meristem of Arabidopsis thaliana. Journal of Theoretical Biology, 2016, 404, pp.182 - 205. ⟨10.1016/j.jtbi.2016.04.036⟩. ⟨hal-01412252⟩