Fertilization Following Pollination Predominantly Decreases Phytocannabinoids Accumulation and Alters the Accumulation of Terpenoids in Cannabis Inflorescences

Abstract

In the last decades, growing evidence showed the therapeutic capabilities of Cannabis plants. These capabilities were attributed to the specialized secondary metabolites stored in the glandular trichomes of female inflorescences, mainly phytocannabinoids and terpenoids. The accumulation of the metabolites in the flower is versatile and influenced by a largely unknown regulation system, attributed to genetic, developmental and environmental factors. As Cannabis is a dioecious plant, one main factor is fertilization after successful pollination. Fertilized flowers are considerably less potent, likely due to changes in the contents of phytocannabinoids and terpenoids; therefore, this study examined the effect of fertilization on metabolite composition by crossbreeding (-)-Δ9-trans-tetrahydrocannabinol (THC)- or cannabidiol (CBD)-rich female plants with different male plants: THC-rich, CBD-rich, or the original female plant induced to develop male pollen sacs. We used advanced analytical methods to assess the phytocannabinoids and terpenoids content, including a newly developed semi-quantitative analysis for terpenoids without analytical standards. We found that fertilization significantly decreased phytocannabinoids content. For terpenoids, the subgroup of monoterpenoids had similar trends to the phytocannabinoids, proposing both are commonly regulated in the plant. The sesquiterpenoids remained unchanged in the THC-rich female and had a trend of decrease in the CBD-rich female. Additionally, specific phytocannabinoids and terpenoids showed an uncommon increase in concentration followed by fertilization with particular male plants. Our results demonstrate that although the profile of phytocannabinoids and their relative ratios were kept, fertilization substantially decreased the concentration of nearly all phytocannabinoids in the plant regardless of the type of fertilizing male. Our findings may point to the functional roles of secondary metabolites in Cannabis.

Morphometric approaches to Cannabis evolution and differentiation from archaeological sites: interpreting the archaeobotanical evidence from bronze age Haimenkou, Yunnan

“…As explored in Edwards and Whittington ( 1992 ) the intended use of cannabis will also impact preferences for the density of male plants maintained in fields. For drug purposes, female plants are preferred, seeds are less needed and so male plants may be fewer (thus less pollen production) given that for some production pollination is generally undesirable as it reduces the phytocannabinoids (Lipson Feder et al 2021 ); this is even more so with plants reproduced by cloning. In contrast, for oilseed crops more male plants are needed to ensure all potential seeds are produced through pollination.…”

Cannabis for Medical Use: Versatile Plant Rather Than a Single Drug

“…Monoterpenoids are built by two isoprene units (10 carbons) and sesquiterpenoids are built up by three isoprene units (15 carbons) ( Shapira et al, 2019 ). Monoterpenoids and phytocannabinoids share the common biosynthetic precursor GPP and are both biosynthesized in the plastid, while sesquiterpenoids are synthesized in the cytosol from farnesyl pyrophosphate ( Booth et al, 2020 ; Lipson Feder et al, 2021 ). Terpenoids are responsible for the fragrance and taste of plants as they are characterized by a strong and pleasant aroma ( Gershenzon and Dudareva, 2007 ).…”

“…Terpenoids can be detected using static headspace gas chromatography-tandem MS (SHS-GC/MS/MS) ( Shapira et al, 2019 ). Similar to phytocannabinoids, terpenoids with no commercially available analytical standards can still be semi-quantified relying on the calibration curves of molecules with standards and relying on both similar MS spectral characteristics and similar retention times ( Lipson Feder et al, 2021 ).…”

“…The tissue type is also an important factor as within the plant there is a location- and organ-specific distribution of the active secondary metabolites ( Happyana et al, 2013 ; Bernstein et al, 2019a ; Bernstein et al, 2019b ). Phytocannabinoids are synthesized in glandular trichomes that are located in the highest density on the inflorescences of unfertilized female plants ( Lipson Feder et al, 2021 ), and their accumulation varies in the different aerial parts (flowers, fan leaves, inflorescence leaves, stalk and stem). Accumulation patterns also depend on the age of that part ( Flores-Sanchez and Verpoorte, 2008b ; Hazekamp and Fischedick, 2012 ).…”

Tobacco Rattle Virus as a Tool for Rapid Reverse-Genetics Screens and Analysis of Gene Function in Cannabis sativa L.

“…Although sex determination appears to be controlled by a system of sex chromosomes, non-optimal growing conditions and changes in environmental factors, such as photoperiod and temperatures, are known to cause the development of male or hermaphroditic flowers [ 7 , 8 , 9 , 10 ]. The medical cannabis distributed commercially uses only vegetatively propagated female cannabis plants [ 5 , 6 ] because most of the specialized metabolites responsible for the medicinal properties of the cannabis plant are present in high levels, within the trichromes concentrated on mature non-fertilized female inflorescences [ 10 , 11 , 12 ]. These compounds include numerous phytomolecules such as cannabinoids, terpenoids, and flavonoids that are known for their unique medicinal properties [ 6 ].…”