Plant Molecular Biology 42: 657–665, 2000.
© 2000 Kluwer Academic Publishers. Printed in the Netherlands.
Organization and expression of two Arabidopsis DREB2 genes encoding
DRE-binding proteins involved in dehydration- and
high-salinity-responsive gene expression
, Zabta K. Shinwari
, Yoh Sakuma
, Motoaki Seki
and Kazuko Yamaguchi-Shinozaki
Biological Resources Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-2
Ohwashi, Tsukuba, Ibaraki 305-8686, Japan;
Laboratory of Plant Molecular Biology, Institute of Physical and
Chemical Research (RIKEN), 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan (
authors for correspondence)
Received 12 January 1999; accepted in revised form 29 December 1999
Key words: DREB, DRE, Arabidopsis, dehydration, high salt stress, promoter
In plants, a cis-acting element, DRE/CRT, is involved in ABA-independent gene expression in response to dehydra-
tion and low-temperature stress. To understand signal transduction pathways from perception of the dehydration
stress signal to gene expression, we characterized a gene family for DRE/CRT-binding proteins DREB2A and
DREB2B in Arabidopsis thaliana. Northern analysis showed that both genes are induced by dehydration and
high-salt stress. Organ-speciﬁc northern analysis with gene-speciﬁc probes showed that these genes are strongly
induced in roots by high-salt stress and in stems and roots by dehydration stress. The DREB2A gene is located on
chromosome 5, and DREB2B on chromosome 3. We screened an Arabidopsis genomic DNA library with cDNA
fragments of DREB2A and DREB2B as probes, and isolated DNA fragments that contained 5
of these genes. Sequence analysis showed that both genes are interrupted by a single intron at identical positions
in their leader sequence. Several conserved sequences were found in the promoter regions of both genes. The
β-glucuronidase (GUS) reporter gene driven by the DREB2 promoters was induced by dehydration and high-salt
stress in transgenic Arabidopsis plants.
Plants respond to drought and high-salt stress, and
the transduced signals cause expression of numerous
genes associated with stress tolerance. A number of
genes have been described that respond to drought and
salinity stress in plants (Ingram and Bartels, 1996;
Bray, 1997; Shinozaki and Yamaguchi-Shinozaki,
1997). We have isolated more than 40 indepen-
dent cDNAs genes for dehydration-inducible genes
in Arabidopsis thaliana and analyzed their structure
and expression patterns (Shinozaki and Yamaguchi-
Shinozaki, 1996, 1997). Sequence analysis of these
The nucleotide sequences reported will appear in the EMBL, Gen-
Bank and DDBJ Nucleotide Sequence Databases under the acces-
sion numbers AB016570 (DREB2A) and AB016571 (DREB2B).
genes indicates that their gene products may function
in response to dehydration tolerance in Arabidopsis.
Some dehydration-responsive genes are induced by
the plant hormone abscisic acid (ABA), but others
are not (Shinozaki and Yamaguchi-Shinozaki, 1997).
Northern analysis of dehydration-inducible genes re-
vealed that there seem to be at least four indepen-
dent signal transduction pathways between the initial
dehydration signal and gene expression (Shinozaki
and Yamaguchi-Shinozaki, 1997); two are ABA-
dependent and two are ABA-independent. One of the
ABA-dependent pathways requires protein biosynthe-
sis; one of the ABA-independent pathways overlaps
with that of cold response.
Cis-andtrans-acting elements involvedin dehydra-
tion-induced gene expression have been analyzed ex-