In carrot suspension-cultured cells, the expression of phenylalanine ammonia-lyase 1 (DcPAL1) gene was crucially regulated by the transcription regulatory factor Daucus carota MYB1 (DcMYB1). To elucidate the regulatory mechanism of DcMYB1 expression, we isolated and identified the transcription regulatory factor D. carota ethylene-insensitive3 (EIN3)-like protein (DcEIL) from a cDNA library prepared from suspension-cultured carrot cells treated with the “dilution effect” using a yeast one-hybrid system. DcEIL bound to a region of the DcMYB1 promoter containing a putative cis-element, which suppressed DcMYB1 promoter expression. The amino acid sequence of DcEIL contained the predicted signal sequence for nuclear localization, and transportation to the nucleus was confirmed using a green fluorescent protein-DcEIL fusion protein expressed in suspension-cultured Arabidopsis thaliana cells. The DcEIL gene was constitutively expressed irrespective of the elicitor treatment or the dilution effect. These results suggest that the binding of DcEIL to a cis-element of the DcMYB1 promoter might be regulated at the posttranslational level as a consequence of the regulation of DcPAL1 gene expression via DcMYB1 expression.