Targeted transcriptomics of the Mexican prickly poppy (Argemone mexicana L.) reveals diverse proteins related to benzylisoquinoline alkaloid biosynthesis.

Abstract A transcriptomic approach was employed to describe a set of putatively protein-coding sequences involved in biosynthesis of berberine and sanguinarine; the two major benzylisoquinoline alkaloids (BIA) from Argemone mexicana (L.; Papaveraceae). A robust de novo assembled transcriptome was obtained from developing seedlings. Initial screening identified 514 unigenes, from eight different Pfam domains, such as Cyt-P450 dependent proteins, which are recurrently involved in BIA biosynthesis. Additional annotation by KEGG Orthology and Gene Ontology supported putative participation of the selected proteins in alkaloid biosynthesis. Moreover, in silico structure prediction of sanguinarine reductase (SanR), dihydrobenzophenantridine oxidase (DHBO) and tetrahydroprotoberberine oxidase (STOX), involved in the last reactions of sanguinarine and berberine biosynthesis, fitted with that of previously characterized proteins from related species further supporting proper annotation. Hence, the pipeline analysis presented could provide a comprehensive description of the biosynthetic potential of this plant through the functionality associated with its transcripts.