We find that salicylic acid and ethephon treatment in hot pepper increases the expression of a putative basic/leucine zipper (bZIP) transcription factor gene. CabZIP1. CabZIP1 mRNA is expressed ubiquitously in various organs. The green fluorescent protein-fused transcription factor, CabZIP1::GFP, can be specifically localized to the nucleus, an action that is consistent with the presence of a nuclear localization signal in its protein sequence. Transient over-expression of the CabZIP1 transcription factor results in ail increase in PR-1 transcripts level in Nicotiana benthamiana leaves. Using chromatin immunoprecipitation, we demonstrate that CabZIPI binds to the G-box elements in native promoter of the hot pepper pathogenesis-related protein 1 (CaPR-1) gene in vivo. Taken together, our results suggest that CabZIPI plays a role as a transcriptional regulator of the CaPR-1 gene. (c) 2006 Elsevier Inc. All rights reserved.