An expressed sequence tag(EST)obtained from a subtractive-suppression hybridization cDNA library constructed using Catharanthus roseus cell line C_(20)hi and its parental cell line C_(20)D was used to clone a ful-length cytochrome P450 cDNA of cyp71d1.The encoded polypeptide contained 507 amino acids with 39-56% identity to other CYP7ID subfamily members at the.amino acid level.Expression characteristics of cyp71d1 were determined using semi-quantitative RT-PCR.The cyp71d1 transcript was expressed in all three cell lines with the highest level in the cell line C_(20)hi.In the mature C.roseus plant,the cyp71d1 cDNA was highly expressed in petals,roots and stems,but very weakly expressed in young leaves.Its transcription level increased with the development of flowers.2,4-D could down-regulate the transcription of cyp71d1,as did KT,but only to a minor degree.Neither light nor yeast elicitor could induce the transcription of cyp71d1.
