Edinburgh, Scotland, United Kingdom - TAIR

Growth regulation by GA-GID1-DELLA and
beyond
The DELLA proteins (DELLAs) are a subfamily of the plant-specific GRAS family
of putative transcriptional regulators that regulate plant growth in response to
the phytohormone gibberellin (GA). The DELLAs restrain growth, and GA
promotes growth by opposing DELLA function. Essentially, GA binds to a specific
GA-receptor protein (GID1), thus stimulating a GID1-DELLA protein-protein
interaction. This interaction itself promotes specific targeting of DELLAs for
destruction in the proteasome via the SCF SLY1 E3 ubiquitin ligase. Additional
signalling pathways, such as those associated with phytohormones other than
GA, and environmental variables such as light, temperature and nutrient status,
also influence plant growth via effects on the GA-GID1-DELLA growth-regulatory
mechanism. A genetic approach to identifying novel growth-regulatory factors
via mutagenesis of a DELLA-deficient mutant line will be outlined. The concept
that the DELLAs are integrators of multiple plant growth regulatory signalling
inputs will be explored, and the broader biological significance of DELLA function
will be illustrated, with particular emphasis on the question of how the GA-GID1-
DELLA growth-regulatory mechanism arose during land-plant evolution.
45
L20
Friday 09:30 - 10:00
Signalling in Development
Nicholas P Harberd
Yuki Yasumura
Caifu Jiang
Carly Brown
Eric Belfield
University of Oxford
Department of Plant
Sciences
South Parks Road
Oxford
OX1 3RB
UK