Cell and Tissue Journal

Abstract Aim: In this study, the effect of silence on the expression of the key gene expression of DBOX (which encodes the final enzyme for the synthesis of two alkaloids, Sanguinarin and papaverin) was used by VIGS technique in a species of poppy (Papaver somniferum L.).
Material and methods: A fragment of 350 pairs of alkali from the DBOX gene sequence (within the range of 1112-1462bp) was selected based on the highest number of siRNA production with 21 nucleotides length. After cloning this segment into the pTZ57R/T vector and transferring the vector to pTRV2 viral vector, Agrobacterium inoculation liquid containing silencer was injected into the poppy plants leaves. Primary transgenic plants were selected by PCR reaction using a protein-binding protein coding gene primer (CP) and secondary screening was performed by semi-quantitative PCR technique. In the next step, the samples with the maximum silence (lowest expression) of the gene were examined by real-time RT-PCR technique.
Results: Cloning accuracy in pTZ57R/T and pTRV2 plasmids were confirmed using PCR and enzymatic digestion. Based on the results of semi-quantitative PCR, 5 transgenic plants were selected with the lowest expression for DBOX gene. Based on semi-quantitative PCR results, 5 transgenic plants with the lowest expression were selected for DBOX gene. The results of real-time RT-PCR showed averagely decrease of 81% in the expression of DBOX gene transcriptions in transgenic plants compared to control plants (inoculated with the pTRV2 empty plasmid).
Conclusion: The results generally showed that the VIGS technique could successfully reduce the DBOX gene expression in poppy plants. In addition, the results obtained for this gene can be used to understand the biosynthetic pathway of poppy alkaloids and transgenic plants for metabolic engineering purposes.
 

Abstract Aim: Papaver somniferum remains the sole commercial source for several pharmaceutical benzophenanthridine alkaloids from benzylisoquinoline branch alkaloids, which includes the narcotic analgesics codeine and the semi-synthetic drugs such as; oxycodone, buprenorphine and naltrexone. Although, most of the biosynthetic pathways genes of this alkaloid have been identified, the post-transcriptional regulation of these alkaloids pathway has not been completely determined. Virus induced gene silencing (VIGS) is a method for fast functional genomics, and in this study, this technique was used to investigate the silencing one of the most important genes in this alkaloid pathway.
Materials and Methods: In the current research VIGS technique was used for systematic reduction in the level of genes expression involves in benzylisoquinoline alkaloids pathway. For silencing of codeinone reductase gene, pTRV vector was used for cloning. The specific silencing of COR gene was evaluated in 2-3 weeks old leaves of Papaver somniferum using agro-infiltration method.
Results: Result of cloning was confirmed by using of different molecular methods such as enzyme digestion and also PCR. PCR technique was used for confirmation of transgenic plants in some transformed plants. Using of semi-quantitative PCR and real-time PCR showed that the level of reduction in transcription of COR gene was about 89 percent.
Conclusion: The obtained results confirmed that by application of RNA interference method, the level of COR gene expression was significantly reduced compared with control.