Divergent Proteomic Profiles of Opium Poppy Cultivars

Opium poppy (Papaver somniferum L.), a member of the Papaveraceae family of the Papaverales order, is a medicinal and industrial plant species with many different uses and significant economic value.The primary significance of the opium poppy arises from its the benzylisoquinoline alkaloids (BIA), which are structurally different group of secondary metabolites specific to the plants it produces.Although alkaloids were found in approximately 20% of plants, the opium poppy is the sole producer of morphinan alkaloids.Opium poppy produces many important BIAs, such as morphine, codeine, which exhibit narcotic analgesic effects; thebaine, which is used as a pain reliever; sanguinarine, which has antimicrobial properties; and noscapine, which has anticancer and antiviral properties (Singh et al., 2019).For these reasons, opium poppy is accepted as one of the most important natural product sources in the pharmaceutical industry (Bulut et al., 2020).To date, about 2500 metabolites belonging to the BIA group have been identified, and more than 80 alkaloids have been isolated from the opium poppy plant, most of which are intermediates in the complex multibranched BIA pathway (Zulak et al., 2007).BIA biosynthesis is localized to sieve elements in the laticifer, while the opium alkaloids are mainly accumulated in the capsule (Bird et al., 2003;Onoyovwe et al., 2013).The BIA biosynthesis is a complex pathway, involving several enzymes (Singh et al., 2019).BIA alkaloids are a structurally differentiated group of tyrosine-derived metabolites (Li et al., 2020).BIA biosynthesis begins with the conversion of dopamine and 4-hydroxyphenylacetaldehyde (4-HPAA) derived from the amino acid tyrosine to (S)-norcoclaurine by the enzyme norcoclaurine synthase (NCS).Subsequently, (S)-norcoclaurine is converted to (S)-reticulin which is the central intermediate molecule.The last common intermediate molecule, (S)-reticulin, splits into different branches and terminates with either sanguinarine, noscapine, berberine or morphine alkaloids (Gurkok et al., 2015).Morphine, noscapine, thebaine, codeine, and papaverine are the major alkaloids, and morphine is the most abundant BIA produced in opium poppy (Zulak et al., 2007).While various alkaloids are synthesized by Papaver species, morphine is produced only by P. somniferum and P. setgerum species.On the other hand, Noscapine is among the major alkaloids in latex, exhibiting anticancer and antiviral properties alongside its utilization as a cough suppressant (Chen et al., 2015).Noscapine has also been shown to play a neuroprotective role in neurodegenerative diseases (Tomar et al., 2017).Moreover, interest in this alkaloid has further increased, given its nonaddictive and its recent identification as a drug candidate for treating the Covid-19 epidemic (Ebrahimi 2020;Kumar et al., 2022).