Cannabinoids are predominantly produced in the glandular trichomes on cannabis female flowers. There is little known about how cannabinoid biosynthesis is regulated during female flower development. In this study, the researchers aim to understand the rate‐limiting step(s) in the cannabinoid biosynthetic pathway. "We investigated the transcript levels of cannabinoid biosynthetic genes together with cannabinoid contents during seven weeks of female flower development."
The study demonstrates that the enzymatic steps for producing cannabigerol (CBG), which involve genes GPPS, PT, TKS, and OAC, could rate limit cannabinoid biosynthesis. The findings further suggest that upregulation of cannabinoid synthases, CBDAS and THCAS in a commercial hemp and medical cannabis variety, respectively, is not critical for cannabinoid biosynthesis. The cannabinoid biosynthetic genes are generally upregulated during flower maturation; increased expression occurs coincident with glandular trichome development and cannabinoid production in the maturing flower.
The results also suggest that different cannabis varieties may experience discrete transcriptional regulation of cannabinoid biosynthetic genes. In addition, the researchers showed that methyl jasmonate (MeJA) can potentially increase cannabinoid production. "We propose that biweekly applications of 100 μM MeJA starting from flower initiation would be efficacious for promoting cannabinoid biosynthesis. Our findings provide important genetic information for cannabis breeding to generate new varieties with favorable traits."
Apicella, Peter & Sands, Lauren & Ma, Yi & Berkowitz, Gerald. (2022). Delineating genetic regulation of cannabinoid biosynthesis during female flower development in Cannabis sativa. Plant Direct. 6. 10.1002/pld3.412.
To read the complete study, go to www.researchgate.net
"Important information to generate new varieties"