The gene controlling marijuana psychoactivity: molecular cloning and heterologous expression of Delta1-tetrahydrocannabinolic acid synthase from Cannabis sativa L

A draft phased assembly of the diploid Cascade hop (Humulus lupulus) genome

Hop (Humulus lupulus L. var Lupulus) is a diploid, dioecious plant with a history of cultivation spanning more than one thousand years. Hop cones are valued for their use in brewing and contain compounds of therapeutic interest including xanthohumol. Efforts to determine how biochemical pathways responsible for desirable traits are regulated have been challenged by the large (2.8 Gb), repetitive, and heterozygous genome of hop. We present a draft haplotype-phased assembly of the Cascade cultivar genome. Our draft assembly and annotation of the Cascade genome is the most extensive representation of the hop genome to date. PacBio long-read sequences from hop were assembled with FALCON and partially phased with FALCON-Unzip. Comparative analysis of haplotype sequences provides insight into selective pressures that have driven evolution in hop. We discovered genes with greater sequence divergence enriched for stress-response, growth, and flowering functions in the draft phased assembly. With improved resolution of long terminal retrotransposons (LTRs) due to long-read sequencing, we found that hop is over 70% repetitive. We identified a homolog of cannabidiolic acid synthase (CBDAS) that is expressed in multiple tissues. The approaches we developed to analyze the draft phased assembly serve to deepen our understanding of the genomic landscape of hop and may have broader applicability to the study of other large, complex genomes.

The Biochemistry of Phytocannabinoids and Metabolic Engineering of Their Production in Heterologous Systems

The medicinal properties of cannabis and the its legal status in several countries and jurisdictions has spurred the massive growth of the cannabis economy around the globe. The value of cannabis stems from its euphoric activity offered by the unique phytocannabinoid tetrahydrocannabinol (THC). However, this is rapidly expanding beyond THC owing to other non-psychoactive phytocannabinoids with new bioactivities that will contribute to their development into clinically useful drugs. The discovery of the biosynthesis of major phytocannabinoids has allowed the exploration of their heterologous production by synthetic biology, which may lead to the industrial production of rare phytocannabinoids or novel synthetic cannabinoid pharmaceuticals that are not easily offered by cannabis plants. This review summarizes the biosynthesis of major phytocannabinoids in detail, the most recent development of their metabolic engineering in various systems, and the engineering approaches and strategies used to increase the yield.

SNP in Potentially Defunct Tetrahydrocannabinolic Acid Synthase Is a Marker for Cannabigerolic Acid Dominance in Cannabis sativa L

The regulation of cannabinoid synthesis in Cannabis sativa is of increasing research interest as restrictions around the globe loosen to allow the plant's legal cultivation. Of the major cannabinoids, the regulation of cannabigerolic acid (CBGA) production is the least understood. The purpose of this study was to elucidate the inheritance of CBGA dominance in C. sativa and describe a marker related to this chemotype. We produced two crossing populations, one between a CBGA dominant cultivar and a tetrahydrocannabinolic acid (THCA) dominant cultivar, and one between a CBGA dominant cultivar and a cannabidiolic acid (CBDA) cultivar. Chemical and genotyping analyses confirmed that CBGA dominance is inherited as a single recessive gene, potentially governed by a non-functioning allelic variant of the THCA synthase. The "null" THCAS synthase contains a single nucleotide polymorphism (SNP) that may render the synthase unable to convert CBGA to THCA leading to the accumulation of CBGA. This SNP can be reliably used as a molecular marker for CBGA dominance in the selection and breeding of C. sativa.

Analysis and review of trichomes in plants

BACKGROUND

Trichomes play a key role in the development of plants and exist in a wide variety of species.

RESULTS

In this paper, it was reviewed that the structure and morphology characteristics of trichomes, alongside the biological functions and classical regulatory mechanisms of trichome development in plants. The environment factors, hormones, transcription factor, non-coding RNA, etc., play important roles in regulating the initialization, branching, growth, and development of trichomes. In addition, it was further investigated the atypical regulation mechanism in a non-model plant, found that regulating the growth and development of tea (Camellia sinensis) trichome is mainly affected by hormones and the novel regulation factors.

CONCLUSIONS

This review further displayed the complex and differential regulatory networks in trichome initiation and development, provided a reference for basic and applied research on trichomes in plants.

A comprehensive molecular approach to the detection of drug-type versus fiber-type hemp varieties

The availability of molecular markers able to distinguish drug-type from fiber-type Cannabis sativa cultivars would allow fast and cheap analysis of any plant specimen, including seeds and leaves. Several approaches to this issue have been described, mainly using polymorphisms in the genes coding for tetrahydrocannabinol acid synthase or cannabidiolic acid synthase. Some studies reported sequencing of these genes from small groups of hemp varieties belonging to both chemotypes, showing the occurrence of specific DNA signatures. However, the effectiveness of the corresponding primers to discriminate among chemotypes has been validated on a limited number of cultivars, or not tested at all. Here we report a thorough in silico analysis of available gene sequences for both synthases, showing the existence of hypervariable regions at 3' and 5' ends. This notwithstanding, some possible signatures were identified, and 12 putatively specific primer pairs were designed and tested on 16 fiber-type and 11 drug-type varieties. In most cases inconsistent results were obtained, further strengthening the high genetic variability of these genes in hemp germplasm, yet some highly informative polymorphisms were identified. Potentiality and perspectives of this approach are discussed.

Constituents of Cannabis sativa

Cannabis sativa L. is a psychoactive plant that contains more than 500 chemical components. Even though the consumption (in the form of marijuana, hashish, or hashish oil) for recreational purposes, is the most popular way of using the plant, the knowledge of its components has also led to classify Cannabis sativa L. is a plant with medicinal or therapeutical use. Several comprehensive reviews have already been published focused on the chemical composition of Cannabis sativa. In this chapter, we will summarize relevant information about those components, which may help to understand its biological actions that will be described in the following chapters.

Metabolic Engineering Strategies of Industrial Hemp (Cannabis sativa L.): A Brief Review of the Advances and Challenges

Industrial hemp (Cannabis sativa L.) is a diploid (2n = 20), dioecious plant that is grown for fiber, seed, and oil. Recently, there has been a renewed interest in this crop because of its panoply of cannabinoids, terpenes, and other phenolic compounds. Specifically, hemp contains terpenophenolic compounds such as cannabidiol (CBD) and cannabigerol (CBG), which act on cannabinoid receptors and positively regulate various human metabolic, immunological, and physiological functions. CBD and CBG have an effect on the cytokine metabolism, which has led to the examination of cannabinoids on the treatment of viral diseases, including COVID-19. Based on genomic, transcriptomic, and metabolomic studies, several synthetic pathways of hemp secondary metabolite production have been elucidated. Nevertheless, there are few reports on hemp metabolic engineering despite obvious impact on scientific and industrial sectors. In this article, recent status and current perspectives on hemp metabolic engineering are reviewed. Three distinct approaches to expedite phytochemical yield are discussed. Special emphasis has been placed on transgenic and transient gene delivery systems, which are critical for successful metabolic engineering of hemp. The advent of new tools in synthetic biology, particularly the CRISPR/Cas systems, enables environment-friendly metabolic engineering to increase the production of desirable hemp phytochemicals while eliminating the psychoactive compounds, such as tetrahydrocannabinol (THC).

Rapid identification of drug-type and fiber-type cannabis by allele specific duplex PCR

Cannabis is classified into two types: drug-type cannabis, which is abused worldwide, and fiber-type cannabis, which is used for industrial purposes. The two types are a result of differences in the sequences of tetrahydrocannabinolic acid synthase (THCAS) and cannabidiolic acid synthase (CBDAS) genes. In the present study, we aimed to establish a PCR-based method to distinguish between drug-type and fiber-type cannabis by detecting the differences in the sequences of THCAS and CBDAS. We constructed a single-plex PCR targeting active THCAS, and observed drug-type cannabis-specific amplification when using 10pg to 1ng of DNA; however, amplification was also observed in fiber-type cannabis when the DNA content reached 10ng. Similarly, single-plex PCR targeting active CBDAS showed fiber-type cannabis-specific amplification in 100pg of DNA, as well as in >1ng of drug-type cannabis DNA. Therefore, when an allele-specific duplex PCR system was constructed, in which both primer sets were mixed at an appropriate ratio, unintended nonspecific amplification was suppressed and amplicons of different sizes were observed between the drug-type and fiber-type cannabis, using DNA samples in the range of 1pg to 10ng. When the constructed duplex PCR was performed on DNA extracted from various cannabis seed samples, it was possible to distinguish between the drug-type and the fiber-type as well as detect a hybrid-type with both active THCAS and active CBDAS and a special type with neither. The identification method developed in the present study can quickly and accurately distinguish between drug-type and fiber-type cannabis, and is expected to be used for various purposes such as the detection of genetic contamination of industrial hemp as well as forensic examination of cannabis-related cases.

The genetics of Cannabis-genomic variations of key synthases and their effect on cannabinoid content

Despite being a controversial crop, Cannabis sativa L. has a long history of cultivation throughout the world. Following recent legalization in Canada, Cannabis is emerging as an important plant for both medicinal and recreational purposes. Recent progress in genome sequencing of both cannabis and hemp varieties allow for systematic analysis of genes coding for enzymes involved in the cannabinoid biosynthesis pathway. Single-nucleotide polymorphisms in the coding regions of cannabinoid synthases play an important role in determining plant chemotype. Deep understanding of how these variants affect enzyme activity and accumulation of cannabinoids will allow breeding of novel cultivars with desirable cannabinoid profiles. Here we present a short overview of the major cannabinoid synthases and present the data on the analysis of their genetic variants and their effect on cannabinoid content using several in-house sequenced Cannabis cultivars.

Bioengineering studies and pathway modeling of the heterologous biosynthesis of tetrahydrocannabinolic acid in yeast

Heterologous biosynthesis of tetrahydrocannabinolic acid (THCA) in yeast is a biotechnological process in Natural Product Biotechnology that was recently introduced. Based on heterologous genes from Cannabis sativa and Streptomyces spp. cloned into Saccharomyces cerevisiae, the heterologous biosynthesis was fully embedded as a proof of concept. Low titer and insufficient biocatalytic rate of most enzymes require systematic optimization of recombinant catalyst by protein engineering and consequent C-flux improvement of the yeast chassis for sufficient precursor (acetyl-CoA), energy (ATP), and NADH delivery. In this review basic principles of in silico analysis of anabolic pathways towards olivetolic acid (OA) and cannabigerolic acid (CBGA) are elucidated and discussed to identify metabolic bottlenecks. Based on own experimental results, yeasts are discussed as potential platform organisms to be introduced as potential cannabinoid biofactories. Especially feeding strategies and limitations in the committed mevalonate and olivetolic acid pathways are in focus of in silico and experimental studies to validate the scientific and commercial potential as a realistic alternative to the plant Cannabis sativa.Key points• First time critical review of the heterologous process for recombinant THCA/CBDA production and critical review of bottlenecks and limitations for a bioengineered technical process• Integrative approach of protein engineering, systems biotechnology, and biochemistry of yeast physiology and biosynthetic cannabinoid enzymes• Comparison of NphB and CsPT aromatic prenyltransferases as rate-limiting catalytic steps towards cannabinoids in yeast as platform organisms Graphical abstract.

An extreme-phenotype genome-wide association study identifies candidate cannabinoid pathway genes in Cannabis

Cannabis produces a class of isoprenylated resorcinyl polyketides known as cannabinoids, a subset of which are medically important and exclusive to this plant. The cannabinoid alkyl group is a critical structural feature that governs therapeutic activity. Genetic enhancement of the alkyl side-chain could lead to the development of novel chemical phenotypes (chemotypes) for pharmaceutical end-use. However, the genetic determinants underlying in planta variation of cannabinoid alkyl side-chain length remain uncharacterised. Using a diversity panel derived from the Ecofibre Cannabis germplasm collection, an extreme-phenotype genome-wide association study (XP-GWAS) was used to enrich for alkyl cannabinoid polymorphic regions. Resequencing of chemotypically extreme pools revealed a known cannabinoid synthesis pathway locus as well as a series of chemotype-associated genomic regions. One of these regions contained a candidate gene encoding a β-keto acyl carrier protein (ACP) reductase (BKR) putatively associated with polyketide fatty acid starter unit synthesis and alkyl side-chain length. Association analysis revealed twenty-two polymorphic variants spanning the length of this gene, including two nonsynonymous substitutions. The success of this first reported application of XP-GWAS for an obligate outcrossing and highly heterozygote plant genus suggests that this approach may have generic application for other plant species.

Synthetic Biology of Cannabinoids and Cannabinoid Glucosides in Nicotiana benthamiana and Saccharomyces cerevisiae

Phytocannabinoids are a group of plant-derived metabolites that display a wide range of psychoactive as well as health-promoting effects. The production of pharmaceutically relevant cannabinoids relies on extraction and purification from cannabis (Cannabis sativa) plants yielding the major constituents, Δ9-tetrahydrocannabinol and cannabidiol. Heterologous biosynthesis of cannabinoids in Nicotiana benthamiana or Saccharomyces cerevisiae may provide cost-efficient and rapid future production platforms to acquire pure and high quantities of both the major and the rare cannabinoids as well as novel derivatives. Here, we used a meta-transcriptomic analysis of cannabis to identify genes for aromatic prenyltransferases of the UbiA superfamily and chalcone isomerase-like (CHIL) proteins. Among the aromatic prenyltransferases, CsaPT4 showed CBGAS activity in both N. benthamiana and S. cerevisiae. Coexpression of selected CsaPT pairs and of CHIL proteins encoding genes with CsaPT4 did not affect CBGAS catalytic efficiency. In a screen of different plant UDP-glycosyltransferases, Stevia rebaudiana SrUGT71E1 and Oryza sativa OsUGT5 were found to glucosylate olivetolic acid, cannabigerolic acid, and Δ9-tetrahydrocannabinolic acid. Metabolic engineering of N. benthamiana for production of cannabinoids revealed intrinsic glucosylation of olivetolic acid and cannabigerolic acid. S. cerevisiae was engineered to produce olivetolic acid glucoside and cannabigerolic acid glucoside.

Validating a predictive model of cannabinoid inheritance with feral, clinical, and industrial Cannabis sativa

PREMISE

How genetic variation within a species affects phytochemical composition is a fundamental question in botany. The ratio of two specialized metabolites in Cannabis sativa, tetrahydrocannabinol (THC) and cannabidiol (CBD), can be grouped into three main classes (THC-type, CBD-type, and intermediate type). We tested a genetic model associating these three groups with functional and nonfunctional alleles of the cannabidiolic acid synthase gene (CBDAS).

METHODS

We characterized cannabinoid content and assayed CBDAS genotypes of >300 feral C. sativa plants in Minnesota, United States. We performed a test cross to assess CBDAS inheritance. Twenty clinical cultivars obtained blindly from the National Institute on Drug Abuse and 12 Canadian-certified grain cultivars were also examined.

RESULTS

Frequencies of CBD-type, intermediate-type, and THC-type feral plants were 0.88, 0.11, and 0.01, respectively. Although total cannabinoid content varied substantially, the three groupings were perfectly correlated with CBDAS genotypes. Genotype frequencies observed in the test cross were consistent with codominant Mendelian inheritance of the THC:CBD ratio. Despite significant mean differences in total cannabinoid content, CBDAS genotypes blindly predicted the THC:CBD ratio among clinical cultivars, and the same was true for industrial grain cultivars when plants exhibited >0.5% total cannabinoid content.

CONCLUSIONS

Our results extend the generality of the inheritance model for THC:CBD to diverse C. sativa accessions and demonstrate that CBDAS genotyping can predict the ratio in a variety of practical applications. Cannabinoid profiles and associated CBDAS segregation patterns suggest that feral C. sativa populations are potentially valuable experimental systems and sources of germplasm.

It Is Our Turn to Get Cannabis High: Put Cannabinoids in Food and Health Baskets

Cannabis is an annual plant with a long history of use as food, feed, fiber, oil, medicine, and narcotics. Despite realizing its true value, it has not yet found its true place. Cannabis has had a long history with many ups and downs, and now it is our turn to promote it. Cannabis contains approximately 600 identified and many yet unidentified potentially useful compounds. Cannabinoids, phenolic compounds, terpenoids, and alkaloids are some of the secondary metabolites present in cannabis. However, among a plethora of unique chemical compounds found in this plant, the most important ones are phytocannabinoids (PCs). Over hundreds of 21-22-carbon compounds exclusively produce in cannabis glandular hairs through either polyketide and or deoxyxylulose phosphate/methylerythritol phosphate (DOXP/MEP) pathways. Trans-Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) are those that first come to mind while talking about cannabis. Nevertheless, despite the low concentration, cannabinol (CBN), cannabigerol (CBG), cannabichromene (CBC), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabinodiol (CBND), and cannabinidiol (CBDL) may have potentially some medical effects. PCs and endocannabinoids (ECs) mediate their effects mainly through CB1 and CB2 receptors. Despite all concerns regarding cannabis, nobody can ignore the use of cannabinoids as promising tonic, analgesic, antipyretic, antiemetic, anti-inflammatory, anti-epileptic, anticancer agents, which are effective for pain relief, depression, anxiety, sleep disorders, nausea and vomiting, multiple sclerosis, cardiovascular disorders, and appetite stimulation. The scientific community and public society have now increasingly accepted cannabis specifically hemp as much more than a recreational drug. There are growing demands for cannabinoids, mainly CBD, with many diverse therapeutic and nutritional properties in veterinary or human medicine. The main objective of this review article is to historically summarize findings concerning cannabinoids, mainly THC and CBD, towards putting these valuable compounds into food, feed and health baskets and current and future trends in the consumption of products derived from cannabis.

Terpene Synthases and Terpene Variation in Cannabis sativa

Cannabis (Cannabis sativa) resin is the foundation of a multibillion dollar medicinal and recreational plant bioproducts industry. Major components of the cannabis resin are the cannabinoids and terpenes. Variations of cannabis terpene profiles contribute much to the different flavor and fragrance phenotypes that affect consumer preferences. A major problem in the cannabis industry is the lack of proper metabolic characterization of many of the existing cultivars, combined with sometimes incorrect cultivar labeling. We characterized foliar terpene profiles of plants grown from 32 seed sources and found large variation both within and between sets of plants labeled as the same cultivar. We selected five plants representing different cultivars with contrasting terpene profiles for clonal propagation, floral metabolite profiling, and trichome-specific transcriptome sequencing. Sequence analysis of these five cultivars and the reference genome of cv Purple Kush revealed a total of 33 different cannabis terpene synthase (CsTPS) genes, as well as variations of the CsTPS gene family and differential expression of terpenoid and cannabinoid pathway genes between cultivars. Our annotation of the cv Purple Kush reference genome identified 19 complete CsTPS gene models, and tandem arrays of isoprenoid and cannabinoid biosynthetic genes. An updated phylogeny of the CsTPS gene family showed three cannabis-specific clades, including a clade of sesquiterpene synthases within the TPS-b subfamily that typically contains mostly monoterpene synthases. The CsTPSs described and functionally characterized here include 13 that had not been previously characterized and that collectively explain a diverse range of cannabis terpenes.

Comprehending and improving cannabis specialized metabolism in the systems biology era

Cannabis sativa is a source of food, fiber and specialized metabolites such as cannabinoids, with psychoactive and pharmacological effects. Due to its expanding and increasingly-accepted use in medicine, cannabis cultivation is acquiring more importance and less social stigma. Humans initiated different domestication episodes whose later spread gave rise to a plethora of landrace cultivars. At present, breeders cross germplasms from different gene pools depending on their specific use. The fiber (hemp) and drug (marijuana) types of C. sativa differ in their cannabinoid chemical composition phenotype (chemotype) and also in the accumulation of terpenoid compounds that constitute a strain's particular flavor and scent. Cannabinoids are isoprenylated polyketides among which cannabidiolic acid (CBDA) and (-)-trans-Δ⁹-tetrahydrocannabinol acid (THCA) have been well-documented for their many effects on humans. Here, we review the most studied specialized metabolic pathways in C. sativa, showing how terpenes and cannabinoids share both part of the isoprenoid pathway and the same biosynthetic compartmentalization (i.e. glandular trichomes of leaves and flowers). We enlist the several studies that have deciphered these pathways in this species including physical and genetic maps, QTL analyses and localization and enzymatic studies of cannabinoid and terpene synthases. In addition, new comparative modeling of cannabinoid synthases and phylogenetic trees are presented. We describe the genome sequencing initiatives of several accessions with the concomitant generation of next-generation genome maps and transcriptomic data. Very recently, proteomic characterizations and systems biology approaches such as those applying network theory or the integration of multi-omics data have increased the knowledge on gene function, enzyme diversity and metabolite content in C. sativa. In this revision we drift through the history, present and future of cannabis research and on how second- and third-generation sequencing technologies are bringing light to the field of cannabis specialized metabolism. We also discuss different biotechnological approaches for producing cannabinoids in engineered microorganisms.

De novo assembly and annotation of transcriptomes from two cultivars of Cannabis sativa with different cannabinoid profiles

Cannabis has been cultivated for millennia for medicinal, industrial and recreational uses. Our long-term goal is to compare the transcriptomes of cultivars with different cannabinoid profiles for therapeutic purposes. Here we describe the de novo assembly, annotation and initial analysis of two cultivars of Cannabis, a high THC variety and a CBD plus THC variety. Cultivars were grown under different lighting conditions; flower buds were sampled over 71 days. Cannabinoid profiles were determined by ESI-LC/MS. RNA samples were sequenced using the HiSeq4000 platform. Transcriptomes were assembled using the DRAP pipeline and annotated using the BLAST2GO pipeline and other tools. Each transcriptome contained over twenty thousand protein encoding transcripts with ORFs and flanking sequence. Identification of transcripts for cannabinoid pathway and related enzymes showed full-length ORFs that align with the draft genomes of the Purple Kush and Finola cultivars. Two transcripts were found for olivetolic acid cyclase (OAC) that mapped to distinct locations on the Purple Kush genome suggesting multiple genes for OAC are expressed in some cultivars. The ability to make high quality annotated reference transcriptomes in Cannabis or other plants can promote rapid comparative analysis between cultivars and growth conditions in Cannabis and other organisms without annotated genome assemblies.

Cannabinoids-Promising Antimicrobial Drugs orIntoxicants with Benefits?

Novel antimicrobial drugs are urgently needed to counteract the increasing occurrence ofbacterial resistance. Extracts of Cannabis sativa have been used for the treatment of several diseasessince ancient times. However, its phytocannabinoid constituents are predominantly associated withpsychotropic effects and medical applications far beyond the treatment of infections. It has beendemonstrated that several cannabinoids show potent antimicrobial activity against primarily Grampositivebacteria including methicillin-resistant Staphylococcus aureus (MRSA). As first in vivoefficacy has been demonstrated recently, it is time to discuss whether cannabinoids are promisingantimicrobial drug candidates or overhyped intoxicants with benefits.

Barriers to the wider adoption of medicinal Cannabis

The use of Cannabis-based preparations for medicinal use has waxed and waned in the multi-millennial history of human co-existence with the plant and its cultivation. Recorded use of preparations from Cannabis is effectively as old as recorded history with examples from China, India and Ancient Egypt. Prohibition and restriction of availability allowed a number of alternatives to take the place of Cannabis preparations. However, there has been a worldwide resurgence in medicinal Cannabis advocacy from the public. Media interest has been piqued by particular evocative cases. Altogether, therefore, there is pressure on healthcare professionals to prescribe and dispense Cannabis-based preparations. This review enunciates some of the barriers which are slowing the wider adoption of medicinal Cannabis.

The Genomics of Cannabis and Its Close Relatives

Cannabis sativa L. is an important yet controversial plant with a long history of recreational, medicinal, industrial, and agricultural use, and together with its sister genus Humulus, it represents a group of plants with a myriad of academic, agricultural, pharmaceutical, industrial, and social interests. We have performed a meta-analysis of pooled published genomics data, andwe present a comprehensive literature review on the evolutionary history of Cannabis and Humulus, including medicinal and industrial applications. We demonstrate that current Cannabis genome assemblies are incomplete, with ∼10% missing, 10-25% unmapped, and 45S and 5S ribosomal DNA clusters as well as centromeres/satellite sequences not represented. These assemblies are also ordered at a low resolution, and their consensus quality clouds the accurate annotation of complete, partial, and pseudogenized gene copies. Considering the importance of genomics in the development of any crop, this analysis underlines the need for a coordinated effort to quantify the genetic and biochemical diversity of this species.

Terpene synthases in disguise: enzymology, structure, and opportunities of non-canonical terpene synthases

Covering: up to July 2019 Terpene synthases (TSs) are responsible for generating much of the structural diversity found in the superfamily of terpenoid natural products. These elegant enzymes mediate complex carbocation-based cyclization and rearrangement cascades with a variety of electron-rich linear and cyclic substrates. For decades, two main classes of TSs, divided by how they generate the reaction-triggering initial carbocation, have dominated the field of terpene enzymology. Recently, several novel and unconventional TSs that perform TS-like reactions but do not resemble canonical TSs in sequence or structure have been discovered. In this review, we identify 12 families of non-canonical TSs and examine their sequences, structures, functions, and proposed mechanisms. Nature provides a wide diversity of enzymes, including prenyltransferases, methyltransferases, P450s, and NAD+-dependent dehydrogenases, as well as completely new enzymes, that utilize distinctive reaction mechanisms for TS chemistry. These unique non-canonical TSs provide immense opportunities to understand how nature evolved different tools for terpene biosynthesis by structural and mechanistic characterization while affording new probes for the discovery of novel terpenoid natural products and gene clusters via genome mining. With every new discovery, the dualistic paradigm of TSs is contradicted and the field of terpene chemistry and enzymology continues to expand.

Spatio-Temporal and Cultivar-Dependent Variations in the Cannabis Microbiome

The incipient legalization and commercialization of Cannabis sativa in Canada have promulgated research into characterizing the plant’s microbiome as it promotes many facets of plant growth and health. The emblematic production of commercially important secondary metabolites, namely tetrahydrocannabinol (THC), cannabidiol (CBD) and terpenes, has warranted investigating the modulating capacity of these molecules on the plant microbiome. C. sativa cultivars can be classified into chemotypes depending on the relative levels of THC and CBD they produce; their biosynthesis also varies spatially and temporally during the life cycle of the plant. To study the differential microbiome structure and diversity between cultivars in a spatio-temporal manner, we extracted microbial DNA from the rhizosphere, endorhizosphere, and phyllosphere during the entire life cycle of three different chemotypes; CBD Yummy (<1% THC/13% CBD), CBD shark (6% THC/10% CBD) and Hash (14% THC/ < 1% CBD). Illumina marker gene sequencing of bacterial (16S) and fungal (ITS) communities were coupled to the QIIME2, PICRUSt, and LEfSe pipelines for analysis. Our study describes spatio-temporal and cultivar-dependent variations in the fungal and bacterial microbiome of C. sativa, and details strong cultivar-dependent variance in the belowground microbiome. Furthermore, the predicted pathway abundance of the bacterial microbiome is concomitantly subject to spatio-temporal variations; pathways related to lipid, amino acid, glucose and pentose metabolism were noteworthy. These results describe, for the first time, spatio-temporal and cultivar-dependent variations in the microbiome of C. sativa produced under strict commercial settings. Describing the microbiome is the first step in discoveries that could help in engineering a plant growth and health promoting microbiome in future works.

Discovery of key regulators of dark gland development and hypericin biosynthesis in St. John's Wort (Hypericum perforatum)

Hypericin is a molecule of high pharmaceutical importance that is synthesized and stored in dark glands (DGs) of St. John's Wort (Hypericum perforatum). Understanding which genes are involved in dark gland development and hypericin biosynthesis is important for the development of new Hypericum extracts that are highly demanded for medical applications. We identified two transcription factors whose expression is strictly synchronized with the differentiation of DGs. We correlated the content of hypericin, pseudohypericin, endocrocin, skyrin glycosides and several flavonoids with gene expression and DG development to obtain a revised model for hypericin biosynthesis. Here, we report for the first time genotypes which are polymorphic for the presence/total absence (G+/G-) of DGs in their placental tissues (PTs). DG development was characterized in PTs using several microscopy techniques. Fourier transform infrared microscopy was established as a novel method to precisely locate polyaromatic compounds, such as hypericin, in plant tissues. In addition, we obtained transcriptome and metabolome profiles of unprecedented resolution in Hypericum. This study addresses for the first time the development of dark glands and identifies genes that constitute strong building blocks for the further elucidation of hypericin synthesis, its manipulation in plants, its engineering in microbial systems and its applications in medical research.

Distribution of Chemical Phenotypes (Chemotypes) in European Agricultural Hemp (Cannabis sativa L.) Cultivars

In Europe, more than 50 approved cultivars of fiber hemp (Cannabis sativa L.) are in agricultural production. Their content of psychoactive tetrahydrocannabinol (THC) is legally restricted to <0.2% (%w/w in the dry, mature inflorescences). Cannabis strains with much higher THC contents are also grown, illegally or under license for drug production. Differentiation between these two groups relies on biochemical quantification of cannabinoid contents in mature floral material. For nonflowering material or tissue devoid of cannabinoids, the genetic prediction of the chemical phenotype (chemotype) provides a suitable method of distinction. Three discrete chemotypes, depending on the ratio of THC and the noneuphoric cannabidiol (CBD), can be distinguished: a "THC-predominant" type, a "CBD-predominant" type, and an intermediate chemotype. We present a systematic genetic prediction of chemotypes of 62 agricultural hemp cultivars grown in Europe. The survey reveals the presence of up to 35% B_T allele-carrying individuals (representing either a THC-predominant or an intermediate chemotype) in some cultivars-which is unexpected considering the legal THC limit of 0.2% THC. The fact that 100% of the seized drug-type seeds in this study revealed at least one B_T allele, reflects that plant breeding efforts have resulted in a fixation of the B_T allele in recreational Cannabis. To guarantee a sincere forensic application based on a genetic chemotype prediction, we recommend not to classify material of unknown origin if the samples size is below nine genetically independent individuals.

Cannabidiol-from Plant to Human Body: A Promising Bioactive Molecule with Multi-Target Effects in Cancer

Cannabis sativa L. is a plant long used for its textile fibers, seed oil, and oleoresin with medicinal and psychoactive properties. It is the main source of phytocannabinoids, with over 100 compounds detected so far. In recent years, a lot of attention has been given to the main phytochemicals present in Cannabis sativa L., namely, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC). Compared to THC, CBD has non-psychoactive effects, an advantage for clinical applications of anti-tumor benefits. The review is designed to provide an update regarding the multi-target effects of CBD in different types of cancer. The main focus is on the latest in vitro and in vivo studies that present data regarding the anti-proliferative, pro-apoptotic, cytotoxic, anti-invasive, anti-antiangiogenic, anti-inflammatory, and immunomodulatory properties of CBD together with their mechanisms of action. The latest clinical evidence of the anticancer effects of CBD is also outlined. Moreover, the main aspects of the pharmacological and toxicological profiles are given.

Impact of Nitrogen Nutrition on Cannabis sativa: An Update on the Current Knowledge and Future Prospects

Nitrogen (N) availability represents one of the most critical factors affecting cultivated crops. N is indeed a crucial macronutrient influencing major aspects, from plant development to productivity and final yield of lignocellulosic biomass, as well as content of bioactive molecules. N metabolism is fundamental as it is at the crossroad between primary and secondary metabolic pathways: Besides affecting the synthesis of fundamental macromolecules, such as nucleic acids and proteins, N is needed for other types of molecules intervening in the response to exogenous stresses, e.g. alkaloids and glucosinolates. By partaking in the synthesis of phenylalanine, N also directly impacts a central plant metabolic 'hub'-the phenylpropanoid pathway-from which important classes of molecules are formed, notably monolignols, flavonoids and other types of polyphenols. In this review, an updated analysis is provided on the impact that N has on the multipurpose crop hemp (Cannabis sativa L.) due to its renewed interest as a multipurpose crop able to satisfy the needs of a bioeconomy. The hemp stalk provides both woody and cellulosic fibers used in construction and for biocomposites; different organs (leaves/flowers/roots) are sources of added-value secondary metabolites, namely cannabinoids, terpenes, flavonoids, and lignanamides. We survey the available literature data on the impact of N in hemp and highlight the importance of studying those genes responding to both N nutrition and abiotic stresses. Available hemp transcriptomic datasets obtained on plants subjected to salt and drought are here analyzed using Gene Ontology (GO) categories related to N metabolism. The ultimate goal is to shed light on interesting candidate genes that can be further studied in hemp varieties growing under different N feeding conditions and showing high biomass yield and secondary metabolite production, even under salinity and drought.

Highly Predictive Genetic Markers Distinguish Drug-Type from Fiber-Type Cannabis sativa L

Genetic markers can be used in seeds and in plants to distinguish drug-type from fiber-type Cannabis Sativa L. varieties even at early stages, including pre-germination when cannabinoids are not accumulated yet. With this aim, this paper reports sequencing results for tetrahydrocannabinolic acid synthase (THCAS) and cannabidiolic acid synthase (CBDAS) genes from 21 C. sativa L. varieties. Taking into account that THCAS- and CBDAS-derived enzymes compete for the same substrate, the novelty of this work relies in the identification of markers based on both THCAS and CBDAS rather than THCAS alone. Notably, in our panel, we achieved an adequate degree of discrimination (AUC 100%) between drug-type and fiber-type cannabis samples. Our sequencing approach allowed identifying multiple genetic markers (single-nucleotide polymorphisms-SNPs-and a deletion/insertion) that effectively discriminate between the two subgroups of cannabis, namely fiber type vs. drug type. We identified four functional SNPs that are likely to induce decreased THCAS activity in the fiber-type cannabis plants. We also report the finding on a deletion in the CBDAS gene sequence that produces a truncated protein, possibly resulting in loss of function of the enzyme in the drug-type varieties. Chemical analyses for the actual concentration of cannabinoids confirmed the identification of drug-type rather than fiber-type genotypes. Genetic markers permit an early identification process for forensic applications while simplifying the procedures related to detection of therapeutic or industrial hemp.

Medically Useful Plant Terpenoids: Biosynthesis, Occurrence, and Mechanism of Action

Specialized plant terpenoids have found fortuitous uses in medicine due to their evolutionary and biochemical selection for biological activity in animals. However, these highly functionalized natural products are produced through complex biosynthetic pathways for which we have a complete understanding in only a few cases. Here we review some of the most effective and promising plant terpenoids that are currently used in medicine and medical research and provide updates on their biosynthesis, natural occurrence, and mechanism of action in the body. This includes pharmacologically useful plastidic terpenoids such as p-menthane monoterpenoids, cannabinoids, paclitaxel (taxol®), and ingenol mebutate which are derived from the 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway, as well as cytosolic terpenoids such as thapsigargin and artemisinin produced through the mevalonate (MVA) pathway. We further provide a review of the MEP and MVA precursor pathways which supply the carbon skeletons for the downstream transformations yielding these medically significant natural products.

Identification of Cannabis sativa L. (hemp) Retailers by Means of Multivariate Analysis of Cannabinoids

In this work, the concentration of nine cannabinoids, six neutral cannabinoids (THC, CBD, CBC, CBG, CBN and CBDV) and three acidic cannabinoids (THCA CBGA and CBDA), was used to identify the Italian retailers of Cannabis sativa L. (hemp), reinforcing the idea that the practice of categorizing hemp samples only using THC and CBD is inadequate. A high-performance liquid chromatography/high-resolution mass spectrometry (HPLC-MS/MS) method was developed for screening and simultaneously analyzing the nine cannabinoids in 161 hemp samples sold by four retailers located in different Italian cities. The hemp samples dataset was analyzed by univariate and multivariate analysis with the aim to identify the hemp retailers without any other information on the hemp samples like Cannabis strains, seeds, soil and cultivation characteristics, geographical origin, product storage, etc. The univariate analysis highlighted that the hemp samples could not be differentiated by using any of the nine cannabinoids analyzed. To evaluate the real efficiency of the discrimination among the four hemp retailers a partial least squares discriminant analysis (PLS-DA) was applied. The PLS-DA results showed a very good discrimination between the four hemp retailers with an explained variance of 100% and low classification errors in both calibration (5%) and cross validation (6%). A total of 92% of the hemp samples were correctly classified by the cannabinoid variables in both fitting and cross validation. This work contributed to show that an analytical method coupled with multivariate analysis can be used as a powerful tool for forensic purposes.

Terpenes in Cannabis sativa - From plant genome to humans

Cannabis sativa (cannabis) produces a resin that is valued for its psychoactive and medicinal properties. Despite being the foundation of a multi-billion dollar global industry, scientific knowledge and research on cannabis is lagging behind compared to other high-value crops. This is largely due to legal restrictions that have prevented many researchers from studying cannabis, its products, and their effects in humans. Cannabis resin contains hundreds of different terpene and cannabinoid metabolites. Many of these metabolites have not been conclusively identified. Our understanding of the genomic and biosynthetic systems of these metabolites in cannabis, and the factors that affect their variability, is rudimentary. As a consequence, there is concern about lack of consistency with regard to the terpene and cannabinoid composition of different cannabis 'strains'. Likewise, claims of some of the medicinal properties attributed to cannabis metabolites would benefit from thorough scientific validation.

Cannabinoid synthases and osmoprotective metabolites accumulate in the exudates of Cannabis sativa L. glandular trichomes

Cannabinoids are terpenophenolic compounds produced by Cannabis sativa L., which accumulate in storage cavities of glandular trichomes as a part of the exudates. We investigated if tetrahydrocannabinolic acid synthase and cannabidiolic acid synthase, which are involved in the last step of cannabinoid biosynthesis, are also secreted into Cannabis trichome exudates. The exudates were collected by microsuction from storage cavities of Cannabis glandular trichomes and were subjected for proteomic and metabolomic analyses. The catalytic activity of the exudates was documented by cannabigerolic acid biotransformation studies under hydrophobic conditions. Electrophoretic separations revealed protein bands at ˜65 kDa, which were further identified as tetrahydrocannabinolic acid synthase and cannabidiolic acid synthase. The accumulation of the enzymes in trichome exudates increased substantially during the flowering period in the drug-type Cannabis plants. The content of cannabinoids increased significantly after incubating hexane-diluted trichome exudates with cannabigerolic acid. In this study, we showed that Cannabis glandular trichomes secrete and accumulate cannabinoid synthases in storage cavities, and the enzymes able to convert cannabigerolic acid under hydrophobic trichome-mimicking conditions. Metabolite profiling of the exudates revealed compounds with hydrophilic, osmoprotective and amphiphilic properties, which may play a role in providing a necessary aqueous microenvironment, which enables enzyme solubility and biocatalysis under hydrophobic conditions of glandular trichomes.

Complete biosynthesis of cannabinoids and their unnatural analogues in yeast

Cannabis sativa L. has been cultivated and used around the globe for its medicinal properties for millennia¹. Some cannabinoids, the hallmark constituents of Cannabis, and their analogues have been investigated extensively for their potential medical applications². Certain cannabinoid formulations have been approved as prescription drugs in several countries for the treatment of a range of human ailments³. However, the study and medicinal use of cannabinoids has been hampered by the legal scheduling of Cannabis, the low in planta abundances of nearly all of the dozens of known cannabinoids⁴, and their structural complexity, which limits bulk chemical synthesis. Here we report the complete biosynthesis of the major cannabinoids cannabigerolic acid, Δ⁹-tetrahydrocannabinolic acid, cannabidiolic acid, Δ⁹-tetrahydrocannabivarinic acid and cannabidivarinic acid in Saccharomyces cerevisiae, from the simple sugar galactose. To accomplish this, we engineered the native mevalonate pathway to provide a high flux of geranyl pyrophosphate and introduced a heterologous, multi-organism-derived hexanoyl-CoA biosynthetic pathway⁵. We also introduced the Cannabis genes that encode the enzymes involved in the biosynthesis of olivetolic acid⁶, as well as the gene for a previously undiscovered enzyme with geranylpyrophosphate:olivetolate geranyltransferase activity and the genes for corresponding cannabinoid synthases^7,8. Furthermore, we established a biosynthetic approach that harnessed the promiscuity of several pathway genes to produce cannabinoid analogues. Feeding different fatty acids to our engineered strains yielded cannabinoid analogues with modifications in the part of the molecule that is known to alter receptor binding affinity and potency⁹. We also demonstrated that our biological system could be complemented by simple synthetic chemistry to further expand the accessible chemical space. Our work presents a platform for the production of natural and unnatural cannabinoids that will allow for more rigorous study of these compounds and could be used in the development of treatments for a variety of human health problems.

Non-volatile natural products in plant glandular trichomes: chemistry, biological activities and biosynthesis

The investigation methods, chemistry, bioactivities, and biosynthesis of non-volatile natural products involving 489 compounds in plant glandular trichomes are reviewed.

A physical and genetic map of Cannabis sativa identifies extensive rearrangements at the THC/CBD acid synthase loci

Cannabis sativa is widely cultivated for medicinal, food, industrial, and recreational use, but much remains unknown regarding its genetics, including the molecular determinants of cannabinoid content. Here, we describe a combined physical and genetic map derived from a cross between the drug-type strain Purple Kush and the hemp variety "Finola." The map reveals that cannabinoid biosynthesis genes are generally unlinked but that aromatic prenyltransferase (AP), which produces the substrate for THCA and CBDA synthases (THCAS and CBDAS), is tightly linked to a known marker for total cannabinoid content. We further identify the gene encoding CBCA synthase (CBCAS) and characterize its catalytic activity, providing insight into how cannabinoid diversity arises in cannabis. THCAS and CBDAS (which determine the drug vs. hemp chemotype) are contained within large (>250 kb) retrotransposon-rich regions that are highly nonhomologous between drug- and hemp-type alleles and are furthermore embedded within ∼40 Mb of minimally recombining repetitive DNA. The chromosome structures are similar to those in grains such as wheat, with recombination focused in gene-rich, repeat-depleted regions near chromosome ends. The physical and genetic map should facilitate further dissection of genetic and molecular mechanisms in this commercially and medically important plant.

A physical and genetic map of Cannabis sativa identifies extensive rearrangements at the THC/CBD acid synthase loci

Cannabis sativa is widely cultivated for medicinal, food, industrial, and recreational use, but much remains unknown regarding its genetics, including the molecular determinants of cannabinoid content. Here, we describe a combined physical and genetic map derived from a cross between the drug-type strain Purple Kush and the hemp variety “Finola.” The map reveals that cannabinoid biosynthesis genes are generally unlinked but that aromatic prenyltransferase (AP), which produces the substrate for THCA and CBDA synthases (THCAS and CBDAS), is tightly linked to a known marker for total cannabinoid content. We further identify the gene encoding CBCA synthase (CBCAS) and characterize its catalytic activity, providing insight into how cannabinoid diversity arises in cannabis. THCAS and CBDAS (which determine the drug vs. hemp chemotype) are contained within large (>250 kb) retrotransposon-rich regions that are highly nonhomologous between drug- and hemp-type alleles and are furthermore embedded within ∼40 Mb of minimally recombining repetitive DNA. The chromosome structures are similar to those in grains such as wheat, with recombination focused in gene-rich, repeat-depleted regions near chromosome ends. The physical and genetic map should facilitate further dissection of genetic and molecular mechanisms in this commercially and medically important plant.

Elucidation of structure-function relationship of THCA and CBDA synthase from Cannabis sativaL

Cannabinoids are secondary natural products from the plant Cannabis sativaL. Therapeutic indications of cannabinoids currently comprise a significant area of medicinal research. We have expressed the Δ⁹-tetrahydrocannabinolic acid synthase (THCAS) and cannabidiolic acid synthase (CBDAS) recombinantly in Komagataella phaffii and could detect eight different products with a cannabinoid scaffold after conversion of the precursor cannabigerolic acid (CBGA). Besides five products remaining to be identified, both enzymes were forming three major cannabinoids of C. sativa - Δ⁹-tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA) and cannabichromenic acid (CBCA). In pursuit of improved enzyme properties for a biotechnological cannabinoid production, we performed site-directed mutagenesis to investigate the glycosylation pattern, the C-terminal berberine-bridge-enzyme (BBE) domain, the active site and the product specificity of both enzymes. The THCAS variant T_N89Q+N499Q (lacking two glycosylation sites) exerted about two-fold increased activity compared to wild-type enzyme. Variant T_H494C+R532C (additional disulfide bridge) exerted about 1.7-fold increased activity compared to wild-type enzyme and a shifted temperature optimum from 52 °C to 57 °C. We generated two CBDAS variants, C_S116A and C_A414V, with 2.8 and 3.3-fold increased catalytic activities for CBDA production. C_A414V additionally showed a broadened pH spectrum and a 19-fold increased catalytic activity for THCA production. These studies lay the groundwork for further research as well as biotechnological cannabinoid production.

Accumulation of bioactive metabolites in cultivated medical Cannabis

There has been an increased use of medical Cannabis in the United States of America as more states legalize its use. Complete chemical analyses of this material can vary considerably between producers and is often not fully provided to consumers. As phytochemists in a state with legal medical Cannabis we sought to characterize the accumulation of phytochemicals in material grown by licensed commercial producers. We report the development of a simple extraction and analysis method, amenable to use by commercial laboratories for the detection and quantification of both cannabinoids and terpenoids. Through analysis of developing flowers on plants, we can identify sources of variability of floral metabolites due to flower maturity and position on the plant. The terpenoid composition varied by accession and was used to cluster cannabis strains into specific types. Inclusion of terpenoids with cannabinoids in the analysis of medical cannabis should be encouraged, as both of these classes of compounds could play a role in the beneficial medical effects of different cannabis strains.

Formation and Cleavage of C-C Bonds by Enzymatic Oxidation-Reduction Reactions

Many oxidation-reduction (redox) enzymes, particularly oxygenases, have roles in reactions that make and break C-C bonds. The list includes cytochrome P450 and other heme-based monooxygenases, heme-based dioxygenases, nonheme iron mono- and dioxygenases, flavoproteins, radical S-adenosylmethionine enzymes, copper enzymes, and peroxidases. Reactions involve steroids, intermediary metabolism, secondary natural products, drugs, and industrial and agricultural chemicals. Many C-C bonds are formed via either (i) coupling of diradicals or (ii) generation of unstable products that rearrange. C-C cleavage reactions involve several themes: (i) rearrangement of unstable oxidized products produced by the enzymes, (ii) oxidation and collapse of radicals or cations via rearrangement, (iii) oxygenation to yield products that are readily hydrolyzed by other enzymes, and (iv) activation of O₂ in systems in which the binding of a substrate facilitates O₂ activation. Many of the enzymes involve metals, but of these, iron is clearly predominant.

Designing microorganisms for heterologous biosynthesis of cannabinoids

During the last decade, the use of medical Cannabis has expanded globally and legislation is getting more liberal in many countries, facilitating the research on cannabinoids. The unique interaction of cannabinoids with the human endocannabinoid system makes these compounds an interesting target to be studied as therapeutic agents for the treatment of several medical conditions. However, currently there are important limitations in the study, production and use of cannabinoids as pharmaceutical drugs. Besides the main constituent tetrahydrocannabinolic acid, the structurally related compound cannabidiol is of high interest as drug candidate. From the more than 100 known cannabinoids reported, most can only be extracted in very low amounts and their pharmacological profile has not been determined. Today, cannabinoids are isolated from the strictly regulated Cannabis plant, and the supply of compounds with sufficient quality is a major problem. Biotechnological production could be an attractive alternative mode of production. Herein, we explore the potential use of synthetic biology as an alternative strategy for synthesis of cannabinoids in heterologous hosts. We summarize the current knowledge surrounding cannabinoids biosynthesis and present a comprehensive description of the key steps of the genuine and artificial pathway, systems biotechnology needs and platform optimization.

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

Cannabis 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 Cannabis populations sourced from the Ecofibre Global Germplasm Collection (ecofibre.com.au and anandahemp.com) was used to examine alkyl cannabinoid variation across vegetative, flowering and maturation stages. A wide range of di-/tri-cyclic as well as C₃-/C₅-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 Cannabis genepool could facilitate the metabolic engineering of alkyl cannabinoid chemotypes.

Identification of Putative Precursor Genes for the Biosynthesis of Cannabinoid-Like Compound in Radula marginata

The liverwort Radula marginata belongs to the bryophyte division of land plants and is a prospective alternate source of cannabinoid-like compounds. However, mechanistic insights into the molecular pathways directing the synthesis of these cannabinoid-like compounds have been hindered due to the lack of genetic information. This prompted us to do deep sequencing, de novo assembly and annotation of R. marginata transcriptome, which resulted in the identification and validation of the genes for cannabinoid biosynthetic pathway. In total, we have identified 11,421 putative genes encoding 1,554 enzymes from 145 biosynthetic pathways. Interestingly, we have identified all the upstream genes of the central precursor of cannabinoid biosynthesis, cannabigerolic acid (CBGA), including its two first intermediates, stilbene acid (SA) and geranyl diphosphate (GPP). Expression of all these genes was validated using quantitative real-time PCR. We have characterized the protein structure of stilbene synthase (STS), which is considered as a homolog of olivetolic acid in R. marginata. Moreover, the metabolomics approach enabled us to identify CBGA-analogous compounds using electrospray ionization mass spectrometry (ESI-MS/MS) and gas chromatography mass spectrometry (GC-MS). Transcriptomic analysis revealed 1085 transcription factors (TF) from 39 families. Comparative analysis showed that six TF families have been uniquely predicted in R. marginata. In addition, the bioinformatics analysis predicted a large number of simple sequence repeats (SSRs) and non-coding RNAs (ncRNAs). Our results collectively provide mechanistic insights into the putative precursor genes for the biosynthesis of cannabinoid-like compounds and a novel transcriptomic resource for R. marginata. The large-scale transcriptomic resource generated in this study would further serve as a reference transcriptome to explore the Radulaceae family.

The Case for the Entourage Effect and Conventional Breeding of Clinical Cannabis: No "Strain," No Gain

The topic of Cannabis curries controversy in every sphere of influence, whether politics, pharmacology, applied therapeutics or even botanical taxonomy. Debate as to the speciation of Cannabis, or a lack thereof, has swirled for more than 250 years. Because all Cannabis types are eminently capable of cross-breeding to produce fertile progeny, it is unlikely that any clear winner will emerge between the "lumpers" vs. "splitters" in this taxonomical debate. This is compounded by the profusion of Cannabis varieties available through the black market and even the developing legal market. While labeled "strains" in common parlance, this term is acceptable with respect to bacteria and viruses, but not among Plantae. Given that such factors as plant height and leaflet width do not distinguish one Cannabis plant from another and similar difficulties in defining terms in Cannabis, the only reasonable solution is to characterize them by their biochemical/pharmacological characteristics. Thus, it is best to refer to Cannabis types as chemical varieties, or "chemovars." The current wave of excitement in Cannabis commerce has translated into a flurry of research on alternative sources, particularly yeasts, and complex systems for laboratory production have emerged, but these presuppose that single compounds are a desirable goal. Rather, the case for Cannabis synergy via the "entourage effect" is currently sufficiently strong as to suggest that one molecule is unlikely to match the therapeutic and even industrial potential of Cannabis itself as a phytochemical factory. The astounding plasticity of the Cannabis genome additionally obviates the need for genetic modification techniques.

The application of plant in vitro cultures in cannabinoid production

Cannabinoids have considerable interest in the pharmaceutical industry. However, the production of medicines from hemp (Cannabis sativa L.) in most countries is restricted by law. Large-scale, field cultivation of hemp is difficult to control. Cannabinoid content in plants is variable and depends on multiple factors. Therefore, alternative methods of production have been investigated. The development of micropropagation techniques is a necessary step for genetic modification. Promising results have been obtained for certain narcotic genotypes. However, micropropagation of fibre types requires further research. Hemp can be genetically modified which may contribute to the breeding of new varieties in the future. Cell suspension cultures and hairy root cultures of hemp have been used to produce cannabinoids but obtaining cannabinoids from callus and cell suspension cultures has proved impossible. Adventitious roots can, however, deliver small amounts of these metabolites but production ceases over time and is too low for industrial applications.

Berberine Induces Apoptotic Cell Death via Activation of Caspase-3 and -8 in HL-60 Human Leukemia Cells: Nuclear Localization and Structure–Activity Relationships

Berberine (BBR), an isoquinoline alkaloid, is a well-known bioactive compound contained in medicinal plants used in traditional and folk medicines. In this study, we investigated the subcellular localization and the apoptotic mechanisms of BBR were elucidated. First, we confirmed the incorporation of BBR into the cell visually. BBR showed antiproliferative activity and promptly localized to the nucleus from 5[Formula: see text]min to 15[Formula: see text]min after BBR treatment in HL-60 human promyelocytic leukemia cells. Next, we examined the antiproliferative activity of BBR (1) and its biosynthetically related compounds (2-7) in HL-60 cells. BBR exerted strongest antiproliferative activity among 1-7 and the results of structures and activity relation suggested that a methylenedioxyl group in ring A, an [Formula: see text]-alkyl group at C-9 position, and the frame of isoquinoline may be necessary for antiproliferative activity. Moreover, BBR showed the most potent antiproliferative activity in HL-60 cells among human cancer and normal cell lines tested. Next, we examined the effect of BBR on molecular events known as apoptosis induction. In HL-60 cells, BBR induced chromatin condensation and DNA fragmentation, and triggered the activation of PARP, caspase-3 and caspase-8 without the activation of caspase-9. BBR-induced DNA fragmentation was abolished by pretreatment with inhibitors against caspase-3 and caspase-8, but not against caspase-9. ERK and p38 were promptly phosphorylated after 15 min of BBR treatment, and this was correlated with time of localization to the nucleus of BBR. These results demonstrated that BBR translocated into nucleus immediately after treatments and induced apoptotic cell death by activation of caspase-3 and caspase-8.

Structural and Chemical Biology of Terpenoid Cyclases

The year 2017 marks the twentieth anniversary of terpenoid cyclase structural biology: a trio of terpenoid cyclase structures reported together in 1997 were the first to set the foundation for understanding the enzymes largely responsible for the exquisite chemodiversity of more than 80000 terpenoid natural products. Terpenoid cyclases catalyze the most complex chemical reactions in biology, in that more than half of the substrate carbon atoms undergo changes in bonding and hybridization during a single enzyme-catalyzed cyclization reaction. The past two decades have witnessed structural, functional, and computational studies illuminating the modes of substrate activation that initiate the cyclization cascade, the management and manipulation of high-energy carbocation intermediates that propagate the cyclization cascade, and the chemical strategies that terminate the cyclization cascade. The role of the terpenoid cyclase as a template for catalysis is paramount to its function, and protein engineering can be used to reprogram the cyclization cascade to generate alternative and commercially important products. Here, I review key advances in terpenoid cyclase structural and chemical biology, focusing mainly on terpenoid cyclases and related prenyltransferases for which X-ray crystal structures have informed and advanced our understanding of enzyme structure and function.

Differentiation of Cannabis subspecies by THCA synthase gene analysis using RFLP

Cannabis sativa subspecies, known as industrial hemp (C. sativa sativa) and marijuana (C. sativa indica) show no evident morphological distinctions, but they contain different levels of psychoactive Δ-9-tetrahidrocanabinol (THC), with considerably higher concentration in marijuana than in hemp. C. sativa subspecies differ in sequence of tetrahydrocannabinolic acid (THCA) synthase gene, responsible for THC production, and only one active copy of the gene, distinctive for marijuana, is capable of producing THC in concentration more then 0,3% in dried plants, usually punishable by the law. Twenty different samples of marijuana that contain THC in concentration more then 0,3% and three varieties of industrial hemp were analyzed for presence of an active copy of THCA synthase gene using in-house developed restriction fragment length polymorphism (RFLP) method All twenty samples of marijuana were positive for the active copy of THCA synthase gene, 16 of them heterozygous. All three varieties of industrial hemp were homozygous for inactive copy. An algorithm for the fast and accurate forensic analysis of samples suspected to be marijuana was constructed, answering the question if an analyzed sample is capable of producing THC in concentrations higher than 0.3%.

In silico discovery of terpenoid metabolism in Cannabis sativa

Due to their efficacy, cannabis based therapies are currently being prescribed for the treatment of many different medical conditions. Interestingly, treatments based on the use of cannabis flowers or their derivatives have been shown to be very effective, while therapies based on drugs containing THC alone lack therapeutic value and lead to increased side effects, likely resulting from the absence of other pivotal entourage compounds found in the Phyto-complex. Among these compounds are terpenoids, which are not produced exclusively by cannabis plants, so other plant species must share many of the enzymes involved in their metabolism. In the present work, 23,630 transcripts from the canSat3 reference transcriptome were scanned for evolutionarily conserved protein domains and annotated in accordance with their predicted molecular functions. A total of 215 evolutionarily conserved genes encoding enzymes presumably involved in terpenoid metabolism are described, together with their expression profiles in different cannabis plant tissues at different developmental stages. The resource presented here will aid future investigations on terpenoid metabolism in Cannabis sativa.

The family of berberine bridge enzyme-like enzymes: A treasure-trove of oxidative reactions

Biological oxidations form the basis of life on earth by utilizing organic compounds as electron donors to drive the generation of metabolic energy carriers, such as ATP. Oxidative reactions are also important for the biosynthesis of complex compounds, i.e. natural products such as alkaloids that provide vital benefits for organisms in all kingdoms of life. The vitamin B₂-derived cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) enable an astonishingly diverse array of oxidative reactions that is based on the versatility of the redox-active isoalloxazine ring. The family of FAD-linked oxidases can be divided into subgroups depending on specific sequence features in an otherwise very similar structural context. The sub-family of berberine bridge enzyme (BBE)-like enzymes has recently attracted a lot of attention due to the challenging chemistry catalyzed by its members and the unique and unusual bi-covalent attachment of the FAD cofactor. This family is the focus of the present review highlighting recent advancements into the structural and functional aspects of members from bacteria, fungi and plants. In view of the unprecedented reaction catalyzed by the family's namesake, BBE from the California poppy, recent studies have provided further insights into nature's treasure chest of oxidative reactions.

Cannabis Pharmacology: The Usual Suspects and a Few Promising Leads

The golden age of cannabis pharmacology began in the 1960s as Raphael Mechoulam and his colleagues in Israel isolated and synthesized cannabidiol, tetrahydrocannabinol, and other phytocannabinoids. Initially, THC garnered most research interest with sporadic attention to cannabidiol, which has only rekindled in the last 15 years through a demonstration of its remarkably versatile pharmacology and synergy with THC. Gradually a cognizance of the potential of other phytocannabinoids has developed. Contemporaneous assessment of cannabis pharmacology must be even far more inclusive. Medical and recreational consumers alike have long believed in unique attributes of certain cannabis chemovars despite their similarity in cannabinoid profiles. This has focused additional research on the pharmacological contributions of mono- and sesquiterpenoids to the effects of cannabis flower preparations. Investigation reveals these aromatic compounds to contribute modulatory and therapeutic roles in the cannabis entourage far beyond expectations considering their modest concentrations in the plant. Synergistic relationships of the terpenoids to cannabinoids will be highlighted and include many complementary roles to boost therapeutic efficacy in treatment of pain, psychiatric disorders, cancer, and numerous other areas. Additional parts of the cannabis plant provide a wide and distinct variety of other compounds of pharmacological interest, including the triterpenoid friedelin from the roots, canniprene from the fan leaves, cannabisin from seed coats, and cannflavin A from seed sprouts. This chapter will explore the unique attributes of these agents and demonstrate how cannabis may yet fulfil its potential as Mechoulam's professed "pharmacological treasure trove."

Endo-cannabinoids system and the toxicity of cannabinoids with a biotechnological approach

Cannabinoids have shown diverse and critical effects on the body systems, which alter the physiological functions. Synthetic cannabinoids are comparatively innovative misuse drugs with respect to their nature of synthesis. Synthetic cannabinoids therapy in healthy, chain smokers, and alcoholic individuals cause damage to the immune and nervous system, eventually leading to intoxication throughout the body. Relevant studies were retrieved using major electronic databases such as PubMed, EMBASE, Medline, Scopus, and Google Scholar. The extensive use of Cannabis Sativa L. (C. Sativa) and its derivatives/analogues such as the nonpsychoactive dimethyl heptyl homolog (CBG-DMH), and tetrahydrocannabivarin (THCV) amongst juveniles and adults have been enhanced in recent years. Cannabinoids play a crucial role in the induction of respiratory, reproductive, immune and carcinogenic effects; however, potential data about mutagenic and developmental effects are still insufficient. The possible toxicity associated with the prolong use of cannabinoids acts as a tumor promoter in animal models and humans. Particular synthetic cannabinoids and analogues have low affinity for CB1 or CB2 receptors, while some synthetic members like Δ9-THC have high affinity towards these receptors. Cannabinoids and their derivatives have a direct or indirect association with acute and long-term toxicity. To reduce/attenuate cannabinoids toxicity, pharmaceutical biotechnology and cloning methods have opened a new window to develop cannabinoids encoding the gene tetrahydrocannabinolic acid (THCA) synthase. Plant revolution and regeneration hindered genetic engineering in C. Sativa. The genetic culture suspension of C. Sativa can be transmuted by the use of Agrobacterium tumefaciens to overcome its toxicity. The main aim of the present review was to collect evidence of the endo-cannabinoid system (ECS), cannabinoids toxicity, and the potential biotechnological approach of cannabinoids synthesis.