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Functional analysis of regulatory sequences controlling PR‐1 gene expression in Arabidopsis
Author(s) -
Lebel Edouard,
Heifetz Peter,
Thorne Leigh,
Uknes Scott,
Ryals John,
Ward Eric
Publication year - 1998
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1998.00288.x
Subject(s) - biology , microbiology and biotechnology , transcription factor , gene , arabidopsis , linker , leucine zipper , genetics , promoter , transcription (linguistics) , reporter gene , gene expression , mutant , computer science , operating system , linguistics , philosophy
Summary The Arabidopsis PR‐1 gene is one of a suite of genes induced co‐ordinately during the onset of systemic acquired resistance (SAR), a plant defense pathway triggered by pathogen infection or exogenous application of chemicals such as salicylic acid (SA) and 2,6‐dichloroisonicotinic acid (INA). We have characterizedcis‐acting regulatory elements in the PR‐1 promoter involved in INA induction using deletion analysis, linker‐scanning mutagenesis, andin vivofootprinting. Compared to promoter fragments of 815 bp or longer (which show greater than 10‐fold inducibility after INA treatment), induction of a 698 bp long promoter fragment is reduced by half and promoter fragments of 621 bp or shorter have lost all inducibility. Additionally, two 10‐bp linker‐scanning mutations centered at 640 bp and 610 bp upstream from the transcription initiation site are each sufficient to abolish chemical inducibility of a GUS reporter fusion. The –640 linker‐scanning mutation encompasses a region highly homologous to recognition sites for transcription factors of the basic leucine zipper class, while the –610 linker‐scanning mutation contains a sequence similar to a consensus recognition site for the transcription factor NF‐κB. Furthermore, several induciblein vivofootprints located at or nearby these motifs demonstrate significant and highly reproducible changes in DNA accessibility following SAR induction. Thisin vivosignature of protein–DNA interactions after INA induction is tightly correlated with the functionally important regions of the promoter identified by mutation analysis.