Scheme: University Research Fellowship
Organisation: University of Nottingham
Dates: Oct 2012-Sep 2017
Summary: Multicellular organisms comprise many different and highly specialized cell types arranged in specific patterns in space and time. The formation of pattern is encoded in genetic and environmental responses. All multicellular organisms start as a single cell. This cell and its daughter cells divide to produce new cells. These divisions are highly orchestrated and both division and growth occur asymmetrically.
Plant cells are locked into place by substantial cell walls. All these cells have the same genetic information and positional cues are required to assign specific identities to cells in defined positions. Roots provide an ideal system to investigate cellular pattern as cells are arranged in well-defined lineages extending out of an organizing centre.
During embryogenesis, cells in the embryonic root are arranged in a radially symmetric pattern of concentric rings. However, as the seedling grows new cell fates (xylem and phloem) are assigned in the central part of the root to transport water and nutrients throughout the plants. The differentiation of these transporting cells represents a crude symmetry breakage with a shift from radial to bisymmetry (two planes of symmetry at 90o to each other).
I have been investigating the network of interactions necessary to produce this symmetry break. We have developed experimental evidence demonstrating the involvement of two components (auxin and cytokinin) as well as a mathematical model for predicting how these components act in space and time to produce pattern. We have been generating new transgenic plants to investigate how this network can be manipulated to produce alternative patterns.