Strand 1: Growth of the primary root via cell elongation.
Strand 1 focuses on cell elongation during radicle emergence and primary root growth. Root expansion is collectively driven by biomolecular-networks withi n each root cell-type; the sources from which initial datasets will be modelled include NASCarrays , KEGG and other pathway databases, and the literature, by text mining using Ondex.
We also intend to generate new transcriptomic datasets at NASC to probe expression changes important for expansion of each cell in response to plant hormones which are k ey regulators of root growth. The resulting models are likely to flag the importance of hormone distribution and perception by distinct cell types. These will provide crucial input into the cellular-level work, where we shall investigate cell structure using imaging techniques and model this intra-cellular architecture to investigate how the cytoskeleton and other organelles give rise to anisotropic cell growth.
We shall monitor differences in the behaviour of these components in different cell types in response to different classes of hormones in order to unde rstand the roles of each tissue during organ expansion.
Organ-level data will be generated using time-lapse confocal microscopy to enable 3D root-growth reconstruction, and tr
acking will be used to tag, and determine the growth rate of each cell. Confocal microscope images are well suited to such techniques.
The growth of individual cells will be tracked using active contours to track the expansion of the vacuole, while the motion of cells over time will be monitored using particle-filter based trackers. The influence of hormone signals on rates of cell and tissue expansion, and their overall impact on root architecture, will also be investigated.
Multi-scale methods will be needed to embed cell-scale hormone behaviour into macroscopic models for active transport and to determine tissue constitut ive relations from properties that vary strongly on the cell scale; these constitutive models will be tested against experimental data collected on the fo rces between cells and on their gross mechanical behaviour (e.g. intercellular pressure and cell-wall material properties).
Models at both cell and tissue scales will be simulated, allowing cell and multi-cell responses to environmental factors subsequently to be modelled.