A UDP-glycosyltransferase gene (Pq3-O-UGT2) was cloned and identified from P. quinquefolius. The RNAi silencing component was constructed and transferred into P. ginseng and P. quinquefolius. Transgenic plants showed decrease in the content of Rd, PPD-type and total ginsenoside. P. quinquefolius had much sensitivity to the RNAi silencing component when compared with P. ginseng.