Edinburgh, Scotland, United Kingdom - TAIR

Architecture from stem cell centred feedback
networks
Like in many animal systems, plant stem cells reside in niches and are
maintained by short-range signals emanating from organizing centres. The
Arabidopsis PLETHORA genes encode transcription factors required for root
stem cell specification. PLT expression is induced by the indolic hormone auxin,
depends on auxin response factors and follows auxin accumulation patterns.
The PLT gene clade extensively regulates expression of the PIN facilitators of
polar auxin transport in the root and this contributes to a specific auxin transport
route that maintains stem cells at the appropriate position. We are addressing the
properties of the PLT-PIN feedback loop by gene and protein network analysis
and computational modelling. The emerging picture is one in which flexible
feedback circuits translate auxin accumulation into region- and cell type
specification patterns. The PLT network interacts with the SHORTROOT-
SCARECROW transcription pathway that plays a role in patterning the root stem
cells and in providing mitotic potential to the stem cell daughters that form the
proximal meristem. This interaction involves the conserved RETINO BLAST-
OMA-RELATED pocket protein, and we are investigating links between the RBR
pathway and upstream patterning genes.
30
L05
Wednesday 11:30 - 12:00
Development
Ben Scheres
Utrecht University
The Netherlands