Three cytochrome P450 enzymes catalyse the formation of furanoclerodane precursors in Salvia spp
Ruoxi Lin, Haixiu Li, Yiren Xiao, Zhuo Wang, Licheng Liu, Gerhard Saalbach, Carlo Martins, Cathie Martin, Evangelos C. Tatsis
bioRxiv October 17, 2024 preprint DOI: 10.1101/2024.10.13.618057 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Theoretical or biochemical paper |
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| Key points | The authors report identifying three cytochrome P450 enzymes that sequentially convert kolavenol into annonene, hardwickiic acid, and hautriwaic acid in Salvia splendens, and that orthologous genes from Salvia divinorum encode enzymes with kolavenol synthase, annonene synthase, and hardwickiic acid synthase activity. They argue these findings support annonene and hardwickiic acid as intermediate steps in salvinorin A biosynthesis and propose S. splendens as a model species for studying furanoclerodane biosynthesis. |
Abstract
Salvia species native to the Americas are rich in valuable bioactive furanoclerodanes, like the psychoactive salvinorin A found in Salvia divinorum , which is used in treatment of opioid addiction. However, there is relatively little known about their biosynthesis. To address this, we investigated the biosynthesis of salviarin, the simplest furanoclerodane structure in the ornamental sage Salvia splendens . Using a self-organizing map and mutual rank analysis of RNA-seq co-expression data, we identified three cytochrome P450 enzymes responsible for converting kolavenol into salviarin precursors, consecutively: annonene, hardwickiic acid and hautriwaic acid. As annonene and hardwickiic acid have also been proposed as intermediates in the biosynthesis of salvinorin A, and to examine our hypothesis for common evolutionary origin of the furanoclerodane pathway between the two Salvia species, we searched for homologous genes in available data for S. divinorum . The enzymes encoded by orthologous genes from S. divinorum displayed kolavenol synthase (SdKLS), annonene synthase (SdANS), and hardwickiic acid synthase (SdHDAS) activity respectively, supporting the view that these are intermediate steps in the biosynthesis of salvinorin A. We investigated the origin of annonene synthase and the role of gene duplication in the evolution of this specific activity. Our work shows how S. splendens can serve as a model species for studying furanoclerodanes biosynthesis in Salvia species, contributes to understanding the evolution of specialized metabolism in plants, and provides new tools to produce salvinorin A in biotechnological chassis.