AUTHOR=Welling Matthew T. , Liu Lei , Raymond Carolyn A. , Ansari Omid , King Graham J. 

TITLE=Developmental Plasticity of the Major Alkyl Cannabinoid Chemotypes in a Diverse Cannabis Genetic Resource Collection

JOURNAL=Frontiers in Plant Science

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.01510

DOI=10.3389/fpls.2018.01510

ISSN=1664-462X

ABSTRACT=<p><italic>Cannabis</italic> is a chemically diverse domesticated plant genus which produces a unique class of biologically active secondary metabolites referred to as cannabinoids. The affinity and selectivity of cannabinoids to targets of the human endocannabinoid system depend on alkyl side chain length, and these structural-activity relationships can be utilized for the development of novel therapeutics. Accurate early screening of germplasm has the potential to accelerate selection of chemical phenotypes (chemotypes) for pharmacological exploitation. However, limited attempts have been made to characterize the plasticity of alkyl cannabinoid composition in different plant tissues and throughout development. A chemotypic diversity panel comprised of 99 individuals from 20 <italic>Cannabis</italic> populations sourced from the Ecofibre Global Germplasm Collection (<ext-link ext-link-type="uri" xlink:href="http://www.ecofibre.com.au" xmlns:xlink="http://www.w3.org/1999/xlink">ecofibre.com.au</ext-link> and <ext-link ext-link-type="uri" xlink:href="http://www.anandahemp.com" xmlns:xlink="http://www.w3.org/1999/xlink">anandahemp.com</ext-link>) was used to examine alkyl cannabinoid variation across vegetative, flowering and maturation stages. A wide range of di-/tri-cyclic as well as C<sub>3</sub>-/C<sub>5</sub>-alkyl cannabinoid composition was observed between plants. Chemotype at the vegetative and flowering stages was found to be predictive of chemotype at maturation, indicating a low level of plasticity in cannabinoid composition. Chemometric cluster analysis based on composition data from all three developmental stages categorized alkyl cannabinoid chemotypes into three classes. Our results suggest that more extensive chemical and genetic characterization of the <italic>Cannabis</italic> genepool could facilitate the metabolic engineering of alkyl cannabinoid chemotypes.</p>