Morphogen Gradients Stable During Growth? an example in plant development

  • Date: 08/07/2007

Veronica Albers Grieneisen (Utrecht University)


University of British Columbia


In plant development, the phytohormone auxin plays a key-role,
controlling cell identity, cell division and cell expansion.
Interestingly, in both distal regions of plant roots and shoots,
characteristic auxin maxima have been found which correlate with these
developmental outputs. It is also known that auxin export facilitators
(PINs) are associated with auxin maxima. Combining such empirical
knowledge, we present a multilevel model for the Arabidopsis root that
spans molecular and cellular levels describing diffusion and
PIN-mediated transport in and across cells within a structured tissue
layout. The modelling study allows us to pinpoint the necessary
elements for the formation and maintenance of an auxin-maximum. It also
permits us to draw connections between PIN-topology and macroscopic
properties such as auxin-capacitance, auxin gradient properties and
timescales. We explain how pattern formation and morphogenesis at
timescales varying from seconds to days/weeks can be understood, and
thus, how such morphogen gradients should be treated as
out-of-equilibrium processes.

Other Information: 

MITACS Math Biology Seminar 2007