Abstract

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 DELL As 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 targetting of DELL As for destruction in the proteasome via the SCFSLY1 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-DELLA growth-regulatory mechanism. The concept that the DELL As 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-DELLA growth-regulatory mechanism arose during land-plant evolution.

http://www.jic.ac.uk/staff/nicholas-harberd/