Abstract
Cannabis sativa L. has been long cultivated for its narcotic potential due to the accumulation of tetrahydrocannabinolic acid (THCA) in female inflorescences, but nowadays its production for fiber, seeds, edible oil and bioactive compounds has spread throughout the world. However, some hemp varieties still accumulate traces of residual THCA close to the 0.20% limit set by European Union, despite the functional gene encoding for THCA synthase (THCAS) is lacking. Even if some hypotheses have been produced, studies are often in disagreement especially on the role of the cannabichromenic acid synthase (CBCAS). In this work a set of European Cannabis genotypes, representative of all chemotypes, were investigated from a chemical and molecular point of view. Highly specific primer pairs were developed to allow an accurate distinction of different cannabinoid synthases genes. In addition to their use as markers to detect the presence of CBCAS at genomic level, they allowed the analysis of transcriptional profiles in hemp or marijuana plants. While the high level of transcription of THCAS and cannabidiolic acid synthase (CBDAS) clearly reflects the chemical phenotype of the plants, the low but stable transcriptional level of CBCAS in all genotypes suggests that these genes are active and might contribute to the final amount of cannabinoids.
Highlights
Enzymatic cannabinoid biosynthesis is catalyzed by a number of oxidocyclases, among which the most prominent are the tetrahydrocannabinolic acid, cannabidiolic acid- and cannabichromenic acid-synthase, leading to the accumulation of tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA) and cannabichromenic acid (CBCA) respectively [1]
A single amplification band at 1192 bp was obtained for CINBOL, while for CINRO both bands of expected size were amplified (Appendix A)
While the higher levels of transcription detected for THCA synthase (THCAS) in respect to cannabidiolic acid synthase (CBDAS) can be related to the different end use of THCA-rich varieties compared with fiber varieties, the meaning of the low but almost constant level of transcription of cannabichromenic acid synthase (CBCAS)
Summary
Cannabinoids are produced by condensation of a phenolic moiety (usually olivetolic acid) with a terpenic one (geranylgeraniol-diphosphate). Enzymatic cannabinoid biosynthesis is catalyzed by a number of oxidocyclases, among which the most prominent are the tetrahydrocannabinolic acid-, cannabidiolic acid- and cannabichromenic acid-synthase, leading to the accumulation of tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA) and cannabichromenic acid (CBCA) respectively [1]. These enzymes are thought to be poorly or completely non-functional in CBGAaccumulating plants [2]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
