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Building a multiscale model of lateral root emergence

Benjamin Péret
University of Nottingham, Centre for Plant Integrative Biology
on 2010/06/04 at 11:00

Summary

Lateral root (LR) formation is a major determinant of root systems architecture. LRs originate deep within the parental root from a small number of founder cells at the periphery of vascular tissues (Péret et al., 2009a) and must emerge through intervening layers of tissues. This process has been defined as "Lateral Root Emergence" (Péret et al., 2009b). The plant hormone auxin accumulates at high concentration at the apex of developing primordia and diffuses into overlying tissues where it reprograms the cells through the action of the auxin influx transporter LAX3. The repertoire of genes activated by auxin ensures that root tissues are not affected during this challenging developmental process by promoting localised cell separation.

Our current research aims at precising the temporal sequence of events leading to activation of LAX3 in the outer tissue. We are using Ordinary Differential Equation (ODE) based models to understand the sequential degradation of Aux/IAA proteins and activation of auxin response factors (ARF) and predict the existence of novel components of the network. Also, we are developing a multiscale 3D model to understand the spatial regulation of auxin transport, from the production site in the xylem pole pericycle towards the outer tissue. Our model predictions are tested using genetic tools, reporter genes and auxin transport inhibitors. I will describe how positive and negative feedback loops are used to achieve a defined pattern of expression of LAX3.

More information and links to full reference and PDF: http://www.cpib.ac.uk/2008/benjamin-peret/