Courtesy of Lift Magazine
A recent study published in PLOS ONE has shed light on the identity of genes responsible for the synthesis of flavor producing compounds known as terpenes.
These compounds are mainly found in the resin produced in glandular trichomes of female cannabis plants. Terpenes can be further classified based on their structure into monoterpenes and sesquiterpenes.
These are the compounds responsible for scent and they provide the unique flavor qualities of various cannabis strains.
While terpenes’ main duty is scent and flavour, they may also play a role in providing various strain-dependent pharmaceutical properties through interactions with cannabinoids (THC and CBD). This is sometimes referred to as the “entourage effect.”
This study is the result of collaborative efforts between graduate student Judith Booth, adjunct professor in the botany department and CEO and founder of Anandia Labs, Jonathan Page, and professor in the faculty of forestry and consultant and adviser to CannaRoyalty Corp., Jörg Bohlmann.
While most research has focused on characterizing phytochemical composition and their respective medicinal properties, few studies have taken a molecular biology approach focused on the formation and synthesis of phytochemicals in cannabis.
Here, transcriptome analysis is performed on the trichomes of one variety of cannabis called ‘finola’. In the finola trichome transcriptome, they were able to identify 9 sets of genes responsible for the expression of terpene biosynthesis enzymes known as terpene synthases. These enzymes are responsible for producing major compounds such as myrcene, limonene, pinene, β-caryophyllene, and humulene.
The researchers noted that there was substantial variation in terpene profiles from plant-to-plant and that there are additional terpene synthase enzymes that were not described in this study. This study also mentions work-in-progress on the purple kush genome where they have identified a total of 33 complete terpene synthase genes along with additional partial sequences.
Pairing the finola transcriptome data and the purple kush data, they were able to compare the two sets of sequences and found the presence of common ancestral genes known as orthologous genes. These genes are derived from the same starting material but have evolved over time in different species resulting in different functions.
For example, pinene is present in both purple kush and finola; however, no obvious orthologous genes were found. In other words, genes with different ancestral background have evolved to produce the same compounds. This is further explained in the presence of myrcene in both purple kush and finola, and the identification of two non-orthologous myrcene synthase enzymes in these two strains.
This research highlights the complexity and diversity of terpenes and terpene synthase genes. This type of research focusing on the biosynthesis of various cannabinoids and terpenes is much needed in order to standardize cannabis varieties, and will be critical in the selection and breeding of plants with specific phytochemical profiles and pharmaceutical properties.
Featured image via payayita.