In vivo target promoter-binding activities of a xenobiotic stress-activated TGA factor

Citation
C. Johnson et al., In vivo target promoter-binding activities of a xenobiotic stress-activated TGA factor, PLANT J, 28(2), 2001, pp. 237-243
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT JOURNAL
ISSN journal
0960-7412 → ACNP
Volume
28
Issue
2
Year of publication
2001
Pages
237 - 243
Database
ISI
SICI code
0960-7412(200110)28:2<237:IVTPAO>2.0.ZU;2-Z
Abstract
Xenobiotic chemicals induce the expression of nuclear detoxification genes. A full understanding of this protective response will require characteriza tion 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 t ranscription factor whose activity is potentiated by herbicide-induced xeno biotic stress. TGA1a selectively binds as-1-type cis-elements, which regula te transcription of putative detoxification and defense genes. With ChIP, w e show that endogenous TGA1a binds as-1-containing promoter sequences of tw o tobacco glutathione S-transferase genes, GNT1 and GNT35. This binding act ivity 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 insen sitive to this stimulus. The findings here thus discriminate between a numb er of possible functional promoter binding sites for a trans-regulatory fac tor, within the context of a signal response pathway.