Struggling for light: della regulation during plant-plant interactions.
We recently described how DELLA proteins are involved in plant growth responses to neighbors in dense stands. These responses that are called shade avoidance include enhanced stem and petiole elongation and are a classic example of adaptive phenotypic plasticity. Although much is known about neighbor detection, much less is known about the signal transduction network downstream of these signals. We will discuss here how a group of growth-supressors, called DELLA proteins, are functionally regulated upon the detection of neighbors. DELLA proteins are degraded upon binding of gibberellin (GA) to its receptor, thus releasing the restraint of GA responses. We discuss here that GA positively regulates shade avoidance by reducing DELLA protein levels. Furthermore, we will show that this is an essential step in shade avoidance, but also that reduced DELLA abundance alone is not sufficient to induce these growth responses. It is concluded that GA-dependent DELLA degradation is one essential step in the signal transduction network from light-mediated neighbor detection towards adaptive shoot elongation responses.
Pierik
Ronald
R
Plant Ecophysiology; Institute of Environmental Biology; Utrecht University; Utrecht, Netherlands.
Djakovic-Petrovic
Tanja
T
de Wit
Mieke
M
Voesenek
Laurentius Acj
LA
Nature. 2005 Sep 29;437(7059):627-8
16193028
Ann Bot. 2005 Aug;96(2):169-75
15894550
Plant J. 2007 Jul;51(1):117-26
17488236
Plant Cell. 2003 Dec;15(12):2816-25
14615596
New Phytol. 2003 Mar;157(3):449-463
33873406
Nature. 2003 Feb 13;421(6924):740-3
12610625
Plant J. 2005 Aug;43(4):597-610
16098112
Plant J. 2004 Apr;38(2):310-9
15078333
Curr Opin Plant Biol. 2005 Oct;8(5):462-8
16040269
Trends Plant Sci. 1999 Mar;4(3):97-102
10322540
Trends Ecol Evol. 1990 Nov;5(11):360-4
21232393