Present address: Department of Horticulture and Crop Sciences, Agricultural University of Norway, PO Box 5022, N-1432 Ås, Norway.
Phytochrome control of flowering is temperature sensitive and correlates with expression of the floral integrator FT
Article first published online: 28 FEB 2003
The Plant Journal
Volume 33, Issue 5, pages 875–885, March 2003
How to Cite
Halliday, K. J., Salter, M. G., Thingnaes, E. and Whitelam, G. C. (2003), Phytochrome control of flowering is temperature sensitive and correlates with expression of the floral integrator FT. The Plant Journal, 33: 875–885. doi: 10.1046/j.1365-313X.2003.01674.x
- Issue published online: 28 FEB 2003
- Article first published online: 28 FEB 2003
- Received 18 October 2002; revised 27 November 2002; accepted 9 December 2002.
In Arabidopsis flowering is accelerated by reduced red:far-red (R:FR) ratio which signals the presence of neighbouring vegetation. Hastened flowering is one component of the shade-avoidance syndrome of responses, which alter many aspects of development in response to the threat of potential competition. Of the red/far-red-absorbing photoreceptors it is phyB that plays the most prominent role in shade-avoidance, although other related phytochromes act redundantly with phyB. It is well established that the phyB mutant has a constitutively early flowering phenotype. However, we have shown that the early flowering phenotype of phyB is temperature-dependent. We have established that this temperature-sensitive flowering response defines a pathway that appears to be independent of the autonomous-FLC pathway. Furthermore, we have demonstrated that the phytochromes control the expression of the floral promoter FT. We have also shown that other phyB-controlled responses, including petiole elongation, are not sensitive to the same temperature change. This suggests that discrete pathways control flowering and petiole elongation, components of the shade-avoidance response. This work provides an insight into the phytochrome and temperature interactions that maintain flowering control.