Characterization Of Peyote Hybird Lophophora williamsii var Jourdaniana Through Genomic Analysis And Molecular Studies

Abstract

Peyote cactus (Lophophora williamsii var. Jourdaniana) along with many other cacti can synthesize the hallucinogen, mescaline. They have recently garnered public attention after they re-emerged as a potential source as the new generation of mental health medications. Particularly since restrictions for psychoactive-based medication in research was relaxed in Canada. Despite the attention in plant psychedelics as the future of psychotherapy, there is a lack of fundamental knowledge about the biosynthetic pathways in plants that can produce these molecules. Here we provide biochemical information of peyote through a scaffolded genome, an assembled transcriptome, preliminary RNA-seq data, a metabolite profile, and microscopy work. De-novo shotgun genome sequencing of Lophophora williamsii var. Jourdaniana showed that it has two discrete genome territories. This suggests a recent, intragenic coupling where the large genome compartment is attributed to the wildtype L. williamsii and the small genome compartment belongs to an unknown species. As a result, the allopolyploid nature has manifested in the accession through biased fractionation and unequal enzymatic expression of the mescaline biosynthetic pathway. This offers a new development in how hybrid genomes manifest in plants, including genomic composition and metabolic differences from the parental plant. Additional molecular experimentation was conducted through western blots, sucrose density gradients, and proteomics to explore enzymatic localization of the mescaline biochemical pathways. Previous literature suggested that mescaline aggregated to the epidermis of the cactus but our immunolocalization microscopy of mescaline biosynthetic enzymes revealed new hypotheses around sub-cellular localization of TyDC, NMT, and OMT10. There are so few cacti genomic resources, this additional high-quality chromosome-level genome and accompanying data, will allow for more detailed phylogenetic analysis of cacti evolutionary history and how hybridization affects metabolic pathways.