title: A multi-scale model of the interplay between cell signalling and hormone transport in specifying the root meristem of Arabidopsis thaliana.
abstract: 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 differentially 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.
authors.affiliation: Centre for Plant Integrative Biology, University of Nottingham, Loughborough LE12 5RD, UK; The Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK; Mathematical Institute, University of Oxford, Oxford OX2 6GG, UK. Electronic address: Daniele.Muraro@maths.ox.ac.uk.
authors.forename: D
authors.initials: D
authors.lastname: Muraro
authors.affiliation: Centre for Plant Integrative Biology, University of Nottingham, Loughborough LE12 5RD, UK.
authors.forename: A
authors.initials: A
authors.lastname: Larrieu
authors.affiliation: Centre for Plant Integrative Biology, University of Nottingham, Loughborough LE12 5RD, UK; Equipe CERES, UMR DIADE, IRD, 34394 Montpellier, France.
authors.forename: M
authors.initials: M
authors.lastname: Lucas
authors.affiliation: Virtual Plants Project-Team, UMR AGAP, INRIA/CIRAD, Montpellier, France.
authors.forename: J
authors.initials: J
authors.lastname: Chopard
authors.affiliation: Centre for Plant Integrative Biology, University of Nottingham, Loughborough LE12 5RD, UK; Mathematical Institute, University of Oxford, Oxford OX2 6GG, UK; School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: H
authors.initials: H
authors.lastname: Byrne
authors.affiliation: Virtual Plants Project-Team, UMR AGAP, INRIA/CIRAD, Montpellier, France.
authors.forename: C
authors.initials: C
authors.lastname: Godin
authors.affiliation: Centre for Plant Integrative Biology, University of Nottingham, Loughborough LE12 5RD, UK; School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: J
authors.initials: J
authors.lastname: King
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects; D005875:Gibberellins / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D018519:Meristem / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D008954:Models, Biological; D009929:Organ Size / Q000187:drug effects; D010937:Plant Growth Regulators / Q000378:metabolism*; D015203:Reproducibility of Results; D015398:Signal Transduction / Q000187:drug effects; D014230:Triazoles / Q000494:pharmacology; D015026:Zeatin / Q000494:pharmacology
chemical_list: D029681:Arabidopsis Proteins; D005875:Gibberellins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D014230:Triazoles; C053370:paclobutrazol; D015026:Zeatin
keywords: Gene networks; Plant hormones; Tissue differentiation