In vivo target promoter-binding activities of a xenobiotic stress-activated TGA factor
Article first published online: 23 DEC 2001
The Plant Journal
Volume 28, Issue 2, pages 237–243, October 2001
How to Cite
Johnson, C., Boden, E., Desai, M., Pascuzzi, P. and Arias, J. (2001), In vivo target promoter-binding activities of a xenobiotic stress-activated TGA factor. The Plant Journal, 28: 237–243. doi: 10.1046/j.1365-313X.2001.01147.x
- Issue published online: 23 DEC 2001
- Article first published online: 23 DEC 2001
- Received 18 May 2001; revised 16 July 2001; accepted 23 July 2001.
- chromatin immunoprecipitation;
- glutathione S-transferase;
- xenobiotic stress
Xenobiotic chemicals induce the expression of nuclear detoxification genes. A full understanding of this protective response will require characterization of its transcriptional regulatory machinery. We describe here the use of a recently developed plant chromatin immunoprecipitation (ChIP) assay to define nuclear promoter targets of TGA1a, a tobacco basic/leucine zipper transcription factor whose activity is potentiated by herbicide-induced xenobiotic stress. TGA1a selectively binds as-1-type cis-elements, which regulate transcription of putative detoxification and defense genes. With ChIP, we show that endogenous TGA1a binds as-1-containing promoter sequences of two tobacco glutathione S-transferase genes, GNT1 and GNT35. This binding activity is strongly enhanced by xenobiotic stress, as is expression of these genes. In contrast, TGA1a apparently does not bind in vivo to functional as-1 elements in promoters of PR-1a and PG13, genes whose expression is insensitive to this stimulus. The findings here thus discriminate between a number of possible functional promoter binding sites for a trans-regulatory factor, within the context of a signal response pathway.