Genetic research: Production of THC and CBD really unique for cannabis plant

Scientists are increasingly learning more about the genetic composition of the cannabis plant. All genes have now been mapped so that researchers can study them in-depth.

Dutch plant expert Robin van Velzen has discovered that the genes responsible for making THC, CBD and CBC originated in the cannabis plant. They do not occur, as has been suggested, in the genetically related hop plant. “The question of whether plants that are closely related to the cannabis plant can also make cannabinoids, such as THC and CBD, is virtually ruled out,” said the researcher from Wageningen University, who also works as a scientist for Bedrocan.

Cannabinoid oxidocyclase gene family

Van Velzen, together with fellow researcher Eric Schranz, has analysed available gene sequences from cannabis plants from the Genbank, a worldwide gene database. This genetic research focused on the very last step of biosynthesis. That is the moment when enzymes are controlled to produce cannabinoids, the active substances in the cannabis plant.

Cannabis initially produces CBG (cannabigerol) and then converts it into either THC, CBD or CBC. Van Velzen: “We know which enzymes are responsible for this conversion and which genes are involved. But we didn’t know when these genes originated.” In the research, this gene family is called the cannabinoid oxidocyclase gene family.

Classification

In addition, Van Velzen makes a recommendation for the classification of this gene group: “Many genes within this family are still relatively unknown and did not yet have unambiguous names. I compared all gene sequences that are known so far, and then made an unambiguous classification. That improves communication between scientists.”

The results of the research have now been made public in a so-called preprint with the title Origin and evolution of the cannabinoid oxidocyclase gene family. Fellow researchers can now comment on the findings before the result is published in a scientific journal.

Comprehensive phylogenetic classification of all currently known sequences, including three main clades and seven subclades (top right corner) that is intended to aid unequivocal referencing and identification of cannabinoid oxidocyclase genes.