Evaluation of salicylic acid treatment on expression of some genes involving in morphine synthesis pathway in Opium Poppy (Papaver Somniferum L)

The present study was performed to investigate the effect of salicylic acid at different times on the expression of three genes involved in the morphine production end pathway (T6ODM, COR and CODM) in Opium Poppy capsules. It should be noted that these genes play an important role in the production of morphine as a medicinal alkaloid.

Seeds of Papaver Somniferum were grown in pots under greenhouse conditions. When the plants reached the flowering stage, two to three days after the petals fell; a superficial scratch was created in the plant capsule and then treated with salicylic acid at a concentration of 50 μM. Capsule sampling was performed at three times zero (a few minutes after spraying salicylic acid solution on the capsule), three and 12 hours after salicylic acid treatment, compared to the control plant. RNA was extracted from the capsule samples, followed by cDNA, and finally the results obtained by qRT-PCR were analyzed using GenEX software.

The results of this study showed that with increasing the time after treatment of the capsules with salicylic acid, the expression level of all three genes decreased compared to the control plant. The expression of T6ODM gene at zero time increased about 1.84 times the expression of gene compared to the control plant, but the expression of this gene at 3 and 12 hours decreased by 46% and 21%, respectively, compared to the gene expression in the control plant. The results also showed that the expression of COR gene increased by about 1.26 times in zero hours compared to the control plant and decreased by 15% in three hours and by almost 30% in 12 hours compared to the control plant. . The expression level of CODM gene at zero hours was almost equal to that of the control plant and at three and 12 hours their expression level was almost zero. Also, the graphs related to T6ODM, CODM and COR genes showed that there is a significant difference in terms of gene expression between different times in each gene.

It is generally inferred that salicylic acid treatment reduces the expression of the three end genes involved in the morphine production pathway by increasing the time from zero hours to 12 hours.