Plant hormone perception and action: a role for G-protein signal transduction?
Plants perceive and respond to a profusion of environmental and endogenous signals that influence their growth and development. The G-protein signalling pathway is a mechanism for transducing extracellular signals that is highly conserved in a range of eukaryotes and prokaryotes. Evidence for the existence of G-protein signalling pathways in higher plants is reviewed, and their potential involvement in plant hormone signal transduction evaluated. A range of biochemical and molecular studies have identified potential components of G-protein signalling in plants, most notably a homologue of the G-protein coupled receptor superfamily (GCR1) and the G alpha and G beta subunits of heterotrimeric G-proteins. G-protein agonists and antagonists are known to influence a variety of signalling events in plants and have been used to implicate heterotrimeric G-proteins in gibberellin and possibly auxin signalling. Antisense suppression of GCR1 in Arabidopsis leads to a phenotype which supports a role for this receptor in cytokinin signalling. These observations suggest that higher plants have at least some of the components of G-protein signalling pathways and that these might be involved in the action of certain plant hormones.
Hooley
R
R
Institute of Arable Crops Research (IACR), Department of Agricultural Sciences, University of Bristol, UK. richard.hooley@bbsrc.ac.uk
D017360:Arabidopsis / Q000235:genetics / Q000502:physiology; D003583:Cytokinins / Q000502:physiology; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D005875:Gibberellins / Q000378:metabolism; D007210:Indoleacetic Acids / Q000502:physiology; D010834:Phytochrome / Q000502:physiology; D010937:Plant Growth Regulators / Q000502:physiology*; D011487:Protein Conformation; D015398:Signal Transduction / Q000502:physiology*
D003583:Cytokinins; D005875:Gibberellins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010834:Phytochrome; D019204:GTP-Binding Proteins