Multiple roles for cytokinin receptors and cross-talk of signaling pathways.
Cytokinin receptors (CRs) are hybrid-type histidine kinases, membrane proteins with a cytokinin-binding extracellular domain. CRs initiate and propagate cytokinin signaling by means of phosphorylation and phosphotransfer to downstream proteins. In legumes, some members of the CR multigenic family are essential for nodulation. In two recent works, we investigated the involvement of two new CRs, MsHK1 from Medicago sativa, and LaHK1 from Lupinus albus, in nodule morphogenesis, senescence and stress response. LaHK1 expression increased during the first stages of lupin nodule development, while MsHK1 expression was localized in the meristem and the invasion zone of alfalfa nodules pointing to a role for CRs in nodule cell proliferation and differentiation. Both CRs were also induced during nodule senescence. MsHK1 expression increased under osmotic stress and both genes were induced following dark stress, indicating that CRs are also likely to play a significant role in the response to stress. We propose multiple roles for CRs which, when analyzed jointly with recent results from other authors, suggest coordinated cross-talk of different signaling systems.
Coba de la Peña
Teodoro
T
Department of Plant Physiology and Ecology; Instituto de Recursos Naturales; Centro de Ciencias Medioambientales; CSIC; Madrid Spain.
Cárcamo
Claudia B
CB
Lucas
M Mercedes
MM
Pueyo
José J
JJ
Plant J. 2002 Nov;32(3):353-60
12410813
Science. 2007 Oct 5;318(5847):68-9
17916725
Annu Rev Plant Physiol Plant Mol Biol. 2001 Jun;52:89-118
11337393
Science. 2007 Jan 5;315(5808):101-4
17110535
Trends Plant Sci. 2008 Feb;13(2):85-92
18262459
Science. 2007 Jan 5;315(5808):52-3
17204633
Plant Physiol. 2006 Jun;141(2):711-20
16648219
Gene. 2006 Nov 1;382:57-65
16919402
Annu Rev Plant Biol. 2003;54:605-27
14503005
Plant Physiol. 2006 Oct;142(2):380-97
16891544
Nature. 2001 Feb 22;409(6823):1060-3
11234017
Curr Opin Plant Biol. 2005 Oct;8(5):518-25
16054432
Proc Natl Acad Sci U S A. 2004 Jun 8;101(23):8821-6
15166290
Planta. 2008 Mar;227(4):769-79
17985155
Plant Cell. 2006 Jan;18(1):40-54
16361392
Plant J. 2007 Jul;51(1):1-17
17488237
Plant Physiol Biochem. 2008 Feb;46(2):219-25
18060799
Plant Cell. 2004 Jun;16(6):1365-77
15155880
J Exp Bot. 2002 Sep;53(376):1989-90
12177139
Proc Natl Acad Sci U S A. 2006 Jan 17;103(3):814-9
16407152
Plant Physiol. 2004 Apr;134(4):1654-61
15064375
Plant J. 2004 Apr;38(2):203-14
15078325
Science. 1995 Dec 22;270(5244):1986-8
8592746
Proc Natl Acad Sci U S A. 2007 Dec 18;104(51):20623-8
18077346
Plant J. 2004 Jun;38(5):779-89
15144379
Science. 2007 Jan 5;315(5808):104-7
17110537
Plant Cell. 2006 Oct;18(10):2680-93
17028204
New Phytol. 2005 Mar;165(3):683-701
15720680