RESUMEN
The gene expressions of codeinone reductase (COR) and berberine bridge enzyme (BBE) in Papaver somniferum were blocked by RNA hairpin of RNA interference (RNAi). The complete sequences of COR and BBE genes were cloned by reverse transcription-polymerase chain reaction (RT-PCR), the results of homology comparison revealed that the cloned COR and BBE genes had high homology with the other gene family members reported in the GenBank. The target sequences of COR and BBE genes were screened in accordance with the design principle of RNAi, a 643 bp fusion gene was obtained by the method of overlapping PCR, then plant expression vector ihpRNA was constructed based on intermediate vector pHANNIBAL and plant expression vector pCEPSPS. With that 78 transgenic plants were obtained through Agrobacterium-mediated and 17 positive plants were screened by PCR, that could initially indicate that the target fragments of COR and BBE gene had been integrated into tobacco genome.