Catania, TheresaLi, YiWinzer, ThiloHarvey, DavidMeade, FergusCaridi, AnnaLeech, AndrewLarson, Tony R.Ning, ZeminChang, JiyangVan de Peer, YvesGraham, Ian A.2023-09-282023-09-282022-04Catania, T., Li, Y., Winzer, T. et al. 2022, 'A functionally conserved STORR gene fusion in Papaver species that diverged 16.8 million years ago', Nature Communications, vol. 13, ART. 3150, pp. 1-11. DOI : 10.1038/s41467-022-30856-w.2041-1723 (online)10.1038/s41467-022-30856-whttp://hdl.handle.net/2263/92445The STORR gene fusion event is considered essential for the evolution of the promorphinan/ morphinan subclass of benzylisoquinoline alkaloids (BIAs) in opium poppy as the resulting bimodular protein performs the isomerization of (S)- to (R)-reticuline essential for their biosynthesis. Here, we show that of the 12 Papaver species analysed those containing the STORR gene fusion also contain promorphinans/morphinans with one important exception. P. californicum encodes a functionally conserved STORR but does not produce promorphinans/ morphinans. We also show that the gene fusion event occurred only once, between 16.8-24.1 million years ago before the separation of P. californicum from other Clade 2 Papaver species. The most abundant BIA in P. californicum is (R)-glaucine, a member of the aporphine subclass of BIAs, raising the possibility that STORR, once evolved, contributes to the biosynthesis of more than just the promorphinan/morphinan subclass of BIAs in the Papaveraceae.en© The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International License.STORR geneEvolutionBenzylisoquinoline alkaloids (BIAs)PapaveraceaeArticle