Elicitor-inducible and constitutive in vivo DNA footprints indicate novel cis-acting elements in the promoter of a parsley gene encoding pathogenesis-related protein 1.

The presence of three genes encoding pathogenesis-related protein 1 (PR1) in cultured parsley cells and the activation of all three genes by fungal elicitor are demonstrated. In vivo dimethyl sulfate footprinting was used to identify two putative sites of protein-DNA interaction in the promoter of one PR1 gene, located around positions -240 and -130 relative to the transcription start site. The TATA-distal footprint was elicitor dependent and appeared within 30 minutes of elicitor treatment, concomitant with the onset of PR1 transcription. The second footprint was observed irrespective of whether elicitor was present or absent. The two footprinted regions contain, in opposite orientation, nearly identical 11-base pair motifs that are unrelated to any known cis-acting element in elicitor-activated or pathogen-activated plant genes. The results demonstrate the usefulness of in vivo footprinting for the identification of cis-acting elements within promoters not accessible to other types of analysis.