Light regulated modulation of Z-box containing promoters by photoreceptors and downstream regulatory components, COP1 and HY5, in Arabidopsis
Article first published online: 5 SEP 2002
The Plant Journal
Volume 31, Issue 6, pages 741–753, September 2002
How to Cite
Yadav, V., Kundu, S., Chattopadhyay, D., Negi, P., Wei, N., Deng, X.-W. and Chattopadhyay, S. (2002), Light regulated modulation of Z-box containing promoters by photoreceptors and downstream regulatory components, COP1 and HY5, in Arabidopsis. The Plant Journal, 31: 741–753. doi: 10.1046/j.1365-313X.2002.01395.x
- Issue published online: 5 SEP 2002
- Article first published online: 5 SEP 2002
- Received 5 April 2002; revised 2 May 2002; accepted 21 May 2002.
The Z-box is one of the light-responsive elements (LREs) found in the promoters of light inducible genes. We have studied the light responsive characteristics of Z-box containing synthetic as well as native promoters. We show that promoters with Z-box as a single LRE or paired with another LRE can respond to a broad spectrum of light. The response is primarily mediated by phyA, phyB and CRY1 photoreceptors at their respective wavelengths of light. We have demonstrated that CAB1 and Z-GATA containing promoters are down-regulated in hy5 mutants in the light. On the other hand, a promoter with Z-box alone is down-regulated in hy5 mutants both in dark and in light conditions, suggesting involvement of a similar regulatory system in the regulation of the promoter in two distinct developmental pathways: skotomorphogenesis and photomorphogenesis. Furthermore, similar to the CAB1 promoter, a Z-GATA containing promoter is derepressed in cop1 mutants in the dark. DNA–protein interaction studies reveal the presence of a DNA-binding activity that is specific to Z-box. These results provide insights into the regulation of the Z-box LRE mediated by various light signaling components.