Interactions between circadian and hormonal signalling in plants.
Growth and development of plants is controlled by external and internal signals. Key internal signals are those generated by hormones and the circadian clock. We highlight interactions between the circadian clock and hormonal signalling networks in regulating the physiology and growth of plants. Microarray analysis has shown that a significant proportion of transcripts involved in hormonal metabolism, catabolism, perception and signalling are also regulated by the circadian clock. In particular, there are interactions between the clock and abscisic acid, auxin, cytokinin and ethylene signalling. We discuss the role of circadian modulation ('gating') of hormonal signals in preventing temporally inappropriate responses. A consideration of the daily changes in physiology provides evidence that circadian gating of hormonal signalling couples the rhythmic regulation of carbon and water utilisation to rhythmic patterns of growth.
Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
Fiona C
FC
Robertson
Alastair W
AW
Skeffington
Michael J
MJ
Gardner
Alex A R
AA
Webb
D000040:Abscisic Acid / Q000502:physiology / Q000528:radiation effects; D002940:Circadian Rhythm; D003624:Darkness; D005030:Ethylenes / Q000378:metabolism / Q000528:radiation effects; D018546:Hypocotyl / Q000502:physiology / Q000528:radiation effects; D008027:Light; D010937:Plant Growth Regulators / Q000502:physiology* / Q000528:radiation effects; D018521:Plant Physiological Phenomena / Q000528:radiation effects*; D015398:Signal Transduction / Q000502:physiology / Q000528:radiation effects
D005030:Ethylenes; D010937:Plant Growth Regulators; D000040:Abscisic Acid; C036216:ethylene