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Previous microarray analyses of Arabidopsis roots identified two closely related WRKY transcription factors (
WRKY25
and
WRKY33
) among the transcripts that increased in abundance following treatment with NaCl. Here, we report further characterization of these genes, which we found to be inducible by a variety of abiotic stresses in an SOS-pathway independent manner, although
WRKY33
induction was dependent on ABA signaling. Transcripts of both genes were detected in roots and leaves, while specific patterns of enrichment were observed in stems and floral buds for
WRKY25
and
WRKY33
, respectively. We also identified upstream intergenic regions from each gene that were sufficient to confer stress-inducible expression on a reporter gene. However, the stress sensitivity of
wrky25
null mutants did not differ from wild-type under any assay condition, while
wrky33
null mutants and
wrky25wrky33
double mutants showed only a moderate increase in NaCl-sensitivity, suggesting functional redundancy with other transcription factors. Nevertheless, overexpression of
WRKY25
or
WRKY33
was sufficient to increase Arabidopsis NaCl tolerance, while increasing sensitivity to ABA. Through microarray analyses of relevant genotypes, we identified 31 and 208 potential downstream targets of WRKY25 and WRKY33, respectively, most of which contained a W-box in their upstream regions.