Thesis subject

Evolution of biosynthesis genes in cannabis and hop

Cannabis sativa is valued for its psychotropic and medicinal effect due to unique prenylated polyketides known as cannabinoids. Its closest relative, hop (Humulus lupulus) is valued as a flavouring agent in the production of beer due to two other kinds of unique prenylated polyketides known as bitter acids and xanthohumols.

Start date

01/01/2022

End date

31/12/2024

Biosynthesis pathways for these compounds in both Cannabis and hop are relatively well understood and there are many intriguing commonalities:

  1. They occur primarily in glands on female inflorescence;
  2. They involve prenyltransferase (PT) and chalcone synthase (CHS) genes.

This suggest some level of shared evolution. However, the relationships among these genes and hence the evolutionary trajectory towards the unique biosynthesis pathways remains unknown.

You will assess the evolution of cannabinoid, bitter acid, and xanthohumol biosynthesis pathway genes in Cannabis, hops, and related species. This involves phylogenetic and synteny analysis across closely related genomes. In addition, you can look at expression in glands of these species using RNA sequencing. Specific research questions are:

  • Do these pathways rely on the same (i.e. orthologous) genes or on different gene copies (i.e. paralogs) within the PT and CHS gene families?
  • What are the mechanisms (gene duplications, DNA sequence evolution) underlying the evolution of these pathways?

Results will help identify functional differences between related genes as well as elucidate the evolution of novel biochemical pathways in plants.