Phytocannabinoids biosynthesis during early stages of development of young Cannabis sativa L. seedlings: Integrating biochemical and transcription data

Cannabis sativa (L.) is characterized by great genetic and phenotypic diversity, also expressed in the array of bioactive compounds synthesized. Despite its great potential economic interest, knowledge of the biology and genetics of this crop is incomplete, and still many efforts are needed for a complete understanding of the molecular mechanisms regulating its key traits. To better understand the synthesis of these compounds, we analysed the transcription levels of cannabinoid pathway genes during early phases of plant development, then comparing the transcriptional results with a chemical characterization of the same samples. The work was conducted on both industrial and medicinal C. sativa plants, using samples belonging to three different chemotypes. Genes coding for the cannabinoid synthases, involved in the last step of the cannabinoid biosynthetic pathway, were found to be already expressed in the seed, providing a measure of the importance of this metabolism for the plant. Cannabichromenic acid is known as the first cannabinoid accumulating in the seedlings, shortly after emergence, and it was found that there is a good correspondence between transcript accumulation of the cannabichromenic acid synthase gene and accumulation of the corresponding metabolite.