A promoter analysis of the DcMYB1 gene that encodes the transcriptional activator of the stress-inducible DcPAL1 gene

Abstract

DcMYB1, a carrot MYB protein, acts as a transcriptional activator of the stress-inducible carrot PAL gene DcPAL1, and is induced by several environmental cues such as UV-B irradiation and elicitor treatment. Here, the DcMYB1 promoter region was isolated, and its putative cis-elements were characterized using several deletion mutants of the DcMYB1 gene promoter. This was undertaken with transient expression experiments using carrot protoplasts. The results indicated that GCC-box and one MYC binding sequence might participate in the up-regulation of DcMYB1 promoter activity induced by UV-B irradiation, and that the AG-motif-like and/or Box-P might undertake this by elicitor treatment. MYB and/or another MYC binding site neighboring the TATA-box might take part in the negative regulation of promoter activity, and the W-box near the TATA-box might be necessary for the up-regulation of promoter activity by both UV-B irradiation and elicitor treatment.