Current Research

• Functional structural plant models.
• Genetic regulation of plant architectural traits.
• See group web page for more information

Research History

• Modelling of plant cellular morphogenesis
  During the development of multicellular organisms, cells are capable of interacting with each other through a range of biological and physical mechanisms. A description of these networks of cell–cell interactions is essential for an understanding of how cellular activity is co-ordinated in regionalised functional entities such as tissues or organs. The difficulty of experimenting on living tissues has been a major limitation to describing such systems. During my postdoctoral studies in Jim Haseloff's laboratory in the University of Cambridge (Plant Science Department), I have been developing computer approaches to characterise and analyse the behaviour of plant multicellular systems. Using image analysis methods for tracking cell expansion and division, it was possible to extract  information from live microscopy and build quantitative genetic and physical models of plant cellular development. Computer simulation using the CellModeller software (jointly developed with Jonathan Mackenzie) were used to demonstrate how cells interact and coordinate their activity.

Figure 1: In order to understand the complex processes involved in plant cellular morphogenesis; (A) Live imaging data is segmented and the dynamics of plant cellular structures is reconstructed; (B) Kinematics analyses are achieved to extract the fundamental parameters of cell proliferation, such as cell division rules and wall physical properties (data from arabidopsis by Nathalie Wuyts); (C) Simulations of the trichome patterning system revealed that a simple combination of activating / inhibiting molecules can produce a range of plausible phenotypes of trichome placement on the leaf.

• Modelling of plant soil mechanical interactions
  Understanding the mechanism of tree anchorage in a forest is a priority because of the increase in wind storms in recent years and their projected recurrence as a consequence of global warming. However, the current investigation techniques to answer such questions are limited, experimental methods to investigate underground mechanisms being limited. During my PhD studies (2001-2004), I have been working on developing new numerical approach to study the biomechanics of tree uprooting at the Laboratory of Wood Rheology of Bordeaux (now US2B). I have been developing a  developing the software, Archiroot, for digitising root architectures, and the plant architectural collected on the field were used to develop models of root architectures and finite element models of root soil interaction. Using these models, it was possible to analyse the influence of both root architectural traits and soil mechanical properties on the behaviour of the tree anchorage submitted to wind forces.

Figure 2: The modelling of tree anchorage involves three important steps; A) Acquisition of root architectural data; B) The development of architectural models parameterised by simpler geometrical and topological factors; C) The modelling of mechanical interactions using the finite element method. Using this approach, it was possible to explain the dissymmetry of root/soil damage during uprooting on frictional soils and to emphasise the role of architectural traits on the anchorage behaviour of trees.

Recent Publications

• Dupuy, L., Vignes, M., McKenzie, B., White P. J. 2009. The Dynamics of Root Meristem Distribution in the Soil, Plant Cell and Environment (in press). 
• Dupuy, L., Mackenzie, J., Haseloff, J. 2009. Coordination of plant cell division and expansion in a simple morphogenetic system, Proceedings of the National Academy of Sciences USA (in press).
  
• Braga, R.A., Dupuy, L., Pasqual, M., Cardoso, R.R. 2009. Live biospeckle laser imaging of root tissues. European Biophysics Journal 38, 679-686.
• Dupuy, L., Mackenzie, J., Haseloff, J. 2007 A multicellular computational model for plant morphogenesis, Annals of Botany 101, 1255-1265.
• Tobin, B., Cermák, J., Chiatante, D., Danjon, F., Di Iorio, A., Dupuy, L., Eshel, A., Jourdan  C., Kalliokoski, T., Laiho, R., Nadezhdina, N.,Nicoll, B., Pagès, L., Silva, J.,  Spanos, I. 2007 Towards developmental modelling of tree root systems. Plant Biosystems 141, 481-501.
• Dupuy, L., Fourcaud, T, Stokes, A. 2007 A Generic 3D finite element model of tree anchorage integrating soil mechanics and real root system architecture. American Journal of Botany 94, 1506-1514.
• Dupuy, L., Fourcaud, T, Stokes, A. 2005 A numerical investigation into the influence of soil type and root architecture on tree anchorage. Plant and Soil 278,119–134.
• Dupuy, L., Fourcaud, T, Stokes, A. 2005 A numerical investigation into factors affecting the anchorage of roots in tension. European Journal of Soil Science 56, 319–327.
• Dupuy, L., Fourcaud, T., Stokes, A., Danjon, F.  2005 A density based approach for the modelling of root architecture: application to maritime pine. Journal of Theoretical Biology 226, 323–334.

Posters

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Attachment	Size
Root models to improve crop performance From cell to field	323.16 KB
Plant Systems Modelling	2.82 MB
Development of Methods for Visualising Root-Particle Interactions	4.45 MB