Recent advances in Cannabis sativa genomics research

Opportunities, Challenges, and Scientific Progress in Hemp Crops

The resurgence of cannabis (Cannabis sativa L.) has been propelled by changes in the legal framework governing its cultivation and use, increased demand for hemp-derived products, and studies recognizing the industrial and health benefits of hemp. This has led to the creation of novel high-cannabidiol, low-Δ9-tetrahydrocannabinol varieties, enabling hemp crop expansion worldwide. This review elucidates the recent implications for hemp cultivation in Europe, with a focus on the legislative impacts on the cultivation practices, prospective breeding efforts, and dynamic scientific landscape surrounding this crop. We also review the current cultivars' cannabinoid composition of the European hemp market and its major differences with that of the United States.

Intra-leaf modeling of Cannabis leaflet shape produces leaf models that predict genetic and developmental identities

The iconic, palmately compound leaves of Cannabis have attracted significant attention in the past. However, investigations into the genetic basis of leaf shape or its connections to phytochemical composition have yielded inconclusive results. This is partly due to prominent changes in leaflet number within a single plant during development, which has so far prevented the proper use of common morphometric techniques. Here, we present a new method that overcomes the challenge of nonhomologous landmarks in palmate, pinnate, and lobed leaves, using Cannabis as an example. We model corresponding pseudo-landmarks for each leaflet as angle-radius coordinates and model them as a function of leaflet to create continuous polynomial models, bypassing the problems associated with variable number of leaflets between leaves. We analyze 341 leaves from 24 individuals from nine Cannabis accessions. Using 3591 pseudo-landmarks in modeled leaves, we accurately predict accession identity, leaflet number, and relative node number. Intra-leaf modeling offers a rapid, cost-effective means of identifying Cannabis accessions, making it a valuable tool for future taxonomic studies, cultivar recognition, and possibly chemical content analysis and sex identification, in addition to permitting the morphometric analysis of leaves in any species with variable numbers of leaflets or lobes.

A simple aptamer-dye fluorescence sensor for detecting Δ9-tetrahydrocannabinol and its metabolite in urban sewage

This work developed an aptamer-dye complex as a label-free ratiometric fluorescence sensor for rapid analysis of THC and its metabolite in sewage samples. Integrated with a portable fluorescence capture device, this sensor exhibited excellent sensitivity with visualization of as low as 0.6 μM THC via naked-eye observation, and THC analysis can be accomplished within 4 min, which would be a complementary tool for quantifying THC in sewage samples to estimate cannabis consumption.

The development of a next-generation sequencing panel targeting cannabinoid synthase genes to distinguish between marijuana and hemp

Hemp and marijuana, both derived from Cannabis sativa L. (C. sativa), are subject to divergent legal regulations due to their different Δ9-tetrahydrocannabinol (Δ9-THC) contents. Cannabinoid synthase genes are considered the key enzymes that determine the chemical composition or chemotype of a particular cultivar. However, existing methods for crop type differentiation based on previous synthase gene theories have limitations in terms of precision and specificity, and a wider range of cannabis varieties must be considered when examining cannabis-based genetic markers. A custom next-generation sequencing (NGS) panel was developed targeting all synthase genes, including Δ9-THC acid synthase, cannabidiolic acid synthase, and cannabichromenic acid synthase, as well as the pseudogenes across diverse C. sativa samples, spanning reference hemp and marijuana, commercial hemp derivatives, and seized marijuana extracts. Interpretation of NGS data revealed a relationship between genotypes and underlying chemotypes, with the principal component analysis indicating a clear distinction between hemp and marijuana clusters. This differentiation was attributed to variations in both synthase genes and pseudogene variants. Finally, this study proposes a genetic cannabis classification method using a differentiation flow chart with novel synthase markers. The flow chart successfully differentiated hemp from marijuana with a 1.3% error rate (n = 147).

Genetic insights into agronomic and morphological traits of drug-type cannabis revealed by genome-wide association studies

Cannabis sativa L., previously concealed by prohibition, is now a versatile and promising plant, thanks to recent legalization, opening doors for medical research and industry growth. However, years of prohibition have left the Cannabis research community lagging behind in understanding Cannabis genetics and trait inheritance compared to other major crops. To address this gap, we conducted a comprehensive genome-wide association study (GWAS) of nine key agronomic and morphological traits, using a panel of 176 drug-type Cannabis accessions from the Canadian legal market. Utilizing high-density genotyping-by-sequencing (HD-GBS), we successfully generated dense genotyping data in Cannabis, resulting in a catalog of 800 K genetic variants, of which 282 K common variants were retained for GWAS analysis. Through GWAS analysis, we identified 18 markers significantly associated with agronomic and morphological traits. Several identified markers exert a substantial phenotypic impact, guided us to putative candidate genes that reside in high linkage-disequilibrium (LD) with the markers. These findings lay a solid foundation for an innovative cannabis research, leveraging genetic markers to inform breeding programs aimed at meeting diverse needs in the industry.

A FLOWERING LOCUS T ortholog is associated with photoperiod-insensitive flowering in hemp (Cannabis sativa L.)

Hemp (Cannabis sativa L.) is an extraordinarily versatile crop, with applications ranging from medicinal compounds to seed oil and fibre products. Cannabis sativa is a short-day plant, and its flowering is highly controlled by photoperiod. However, substantial genetic variation exists for photoperiod sensitivity in C. sativa, and photoperiod-insensitive ("autoflower") cultivars are available. Using a bi-parental mapping population and bulked segregant analysis, we identified Autoflower2, a 0.5 Mbp locus significantly associated with photoperiod-insensitive flowering in hemp. Autoflower2 contains an ortholog of the central flowering time regulator FLOWERING LOCUS T (FT) from Arabidopsis thaliana which we termed CsFT1. We identified extensive sequence divergence between alleles of CsFT1 from photoperiod-sensitive and insensitive cultivars of C. sativa, including a duplication of CsFT1 and sequence differences, especially in introns. Furthermore, we observed higher expression of one of the CsFT1 copies found in the photoperiod-insensitive cultivar. Genotyping of several mapping populations and a diversity panel confirmed a correlation between CsFT1 alleles and photoperiod response, affirming that at least two independent loci involved in the photoperiodic control of flowering, Autoflower1 and Autoflower2, exist in the C. sativa gene pool. This study reveals the multiple independent origins of photoperiod insensitivity in C. sativa, supporting the likelihood of a complex domestication history in this species. By integrating the genetic relaxation of photoperiod sensitivity into novel C. sativa cultivars, expansion to higher latitudes will be permitted, thus allowing the full potential of this versatile crop to be reached.

Transcriptomic and metabolomic analyses reveal the differential accumulation of phenylpropanoids and terpenoids in hemp autotetraploid and its diploid progenitor

BACKGROUND

Cannabis sativa, a dioecious plant that has been cultivated worldwide for thousands of years, is known for its secondary metabolites, especially cannabinoids, which possess several medicinal effects. In this study, we investigated the autopolyploidization effects on the biosynthesis and accumulation of these metabolites, transcriptomic and metabolomic analyses were performed to explore the gene expression and metabolic variations in industrial hemp autotetraploids and their diploid progenitors.

RESULTS

Through these analyses, we obtained 1,663 differentially expressed metabolites and 1,103 differentially expressed genes. Integrative analysis revealed that phenylpropanoid and terpenoid biosynthesis were regulated by polyploidization. No substantial differences were found in the cannabidiol or tetrahydrocannabinol content between tetraploids and diploids. Following polyploidization, some transcription factors, including nine bHLH and eight MYB transcription factors, affected the metabolic biosynthesis as regulators. Additionally, several pivotal catalytic genes, such as flavonol synthase/flavanone 3-hydroxylase, related to the phenylpropanoid metabolic pathway, were identified as being modulated by polyploidization.

CONCLUSIONS

This study enhances the overall understanding of the impact of autopolyploidization in C. sativa and the findings may encourage the application of polyploid breeding for increasing the content of important secondary metabolites in industrial hemp.

A forensic application of genetic markers for distinction between drug-type and fiber-type Cannabis sativa L

Genetic markers can represent a valuable tool for forensic purposes in discriminating between fiber-type and drug-type cannabis. The aim of this research was to evaluate developed genetic markers for tetrahydrocannabinolic acid synthase (THCAS) when applied on certified hemp (14 varieties) and forensic casework samples of four chemotypes (40 seizures). Chemotype-associated PCR-based markers did not enable reliable selective amplification despite the difference in cannabinoid composition. In order to characterize forensic samples of unknown origin, THCAS sequencing was performed. The comparison of THCAS sequences, including additional accessions, indicated high genetic similarity of hemp varieties. Confiscated samples of intermediate, THC, CBD and CBG type were clearly separated from fiber-type accessions and assigned to drug-type cluster. Despite the unknown origin, their position on the tree support the notion that they are more related to drug-type accessions than to the fiber-type. However, no clear distinction between chemotypes was found. Furthermore, 26 amino acid substitutions were revealed in THCAS that clearly separate hemp varieties and neither of them cluster with any other tested sample.

Expanding the knowledge frontier of mitoviruses in Cannabis sativa

Mitoviruses were initially known for their presence in the mitochondria of fungi and were considered exclusive to these organisms. However, recent studies have shown that they are also present in a large number of plant species. Despite the potential impact that mitoviruses might have on the mitochondria of plant cells, there is a lack of information about these ancient RNA viruses, especially within the Cannabaceae family. Cannabis sativa has been in the spotlight in recent years due to the growing industrial applications of plant derivatives, such as fiber and secondary metabolites. Given the importance of Cannabis in today's agriculture, our study aimed to expand the knowledge frontier of Mitoviruses in C. sativa by increasing the number of reference genomes of CasaMV1 available in public databases and representing a larger number of crops in countries where its industrial-scale growth is legalized. To achieve this goal, we used transcriptomics to sequence the first mitoviral genomes of Colombian crops and analyzed RNA-seq datasets available in the SRA databank. Additionally, the evolutionary analysis performed using the mitovirus genomes revealed two main lineages of CasaMV1, termed CasaMV1_L1 and CasaMV1_L2. These mitoviral lineages showed strong clustering based on the geographic location of the crops and differential expression intensities.

Cannabis sativa: origin and history, glandular trichome development, and cannabinoid biosynthesis

Is Cannabis a boon or bane? Cannabis sativa has long been a versatile crop for fiber extraction (industrial hemp), traditional Chinese medicine (hemp seeds), and recreational drugs (marijuana). Cannabis faced global prohibition in the twentieth century because of the psychoactive properties of ∆9-tetrahydrocannabinol; however, recently, the perspective has changed with the recognition of additional therapeutic values, particularly the pharmacological potential of cannabidiol. A comprehensive understanding of the underlying mechanism of cannabinoid biosynthesis is necessary to cultivate and promote globally the medicinal application of Cannabis resources. Here, we comprehensively review the historical usage of Cannabis, biosynthesis of trichome-specific cannabinoids, regulatory network of trichome development, and synthetic biology of cannabinoids. This review provides valuable insights into the efficient biosynthesis and green production of cannabinoids, and the development and utilization of novel Cannabis varieties.

Comparative genomics of flowering behavior in Cannabis sativa

Cannabis sativa L. is a phenotypically diverse and multi-use plant used in the production of fiber, seed, oils, and a class of specialized metabolites known as phytocannabinoids. The last decade has seen a rapid increase in the licit cultivation and processing of C. sativa for medical end-use. Medical morphotypes produce highly branched compact inflorescences which support a high density of glandular trichomes, specialized epidermal hair-like structures that are the site of phytocannabinoid biosynthesis and accumulation. While there is a focus on the regulation of phytocannabinoid pathways, the genetic determinants that govern flowering time and inflorescence structure in C. sativa are less well-defined but equally important. Understanding the molecular mechanisms that underly flowering behavior is key to maximizing phytocannabinoid production. The genetic basis of flowering regulation in C. sativa has been examined using genome-wide association studies, quantitative trait loci mapping and selection analysis, although the lack of a consistent reference genome has confounded attempts to directly compare candidate loci. Here we review the existing knowledge of flowering time control in C. sativa, and, using a common reference genome, we generate an integrated map. The co-location of known and putative flowering time loci within this resource will be essential to improve the understanding of C. sativa phenology.

Molecular Mechanisms Underlying Potential Pathogen Resistance in Cannabis sativa

Cannabis (Cannabis sativa L.) is one of the earliest cultivated crops, valued for producing a broad spectrum of compounds used in medicinal products and being a source of food and fibre. Despite the availability of its genome sequences, few studies explore the molecular mechanisms involved in pathogen defense, and the underlying biological pathways are poorly defined in places. Here, we provide an overview of Cannabis defence responses against common pathogens, such as Golovinomyces spp., Fusarium spp., Botrytis cinerea and Pythium spp. For each of these pathogens, after a summary of their characteristics and symptoms, we explore studies identifying genes involved in Cannabis resistance mechanisms. Many studies focus on the potential involvement of disease-resistance genes, while others refer to other plants however whose results may be of use for Cannabis research. Omics investigations allowing the identification of candidate defence genes are highlighted, and genome editing approaches to generate resistant Cannabis species based on CRISPR/Cas9 technology are discussed. According to the emerging results, a potential defence model including both immune and defence mechanisms in Cannabis plant-pathogen interactions is finally proposed. To our knowledge, this is the first review of the molecular mechanisms underlying pathogen resistance in Cannabis.

Genome-Scale Metabolic Reconstruction, Non-Targeted LC-QTOF-MS Based Metabolomics Data, and Evaluation of Anticancer Activity of Cannabis sativa Leaf Extracts

Over the past decades, Colombia has suffered complex social problems related to illicit crops, including forced displacement, violence, and environmental damage, among other consequences for vulnerable populations. Considerable effort has been made in the regulation of illicit crops, predominantly Cannabis sativa, leading to advances such as the legalization of medical cannabis and its derivatives, the improvement of crops, and leaving an open window to the development of scientific knowledge to explore alternative uses. It is estimated that C. sativa can produce approximately 750 specialized secondary metabolites. Some of the most relevant due to their anticancer properties, besides cannabinoids, are monoterpenes, sesquiterpenoids, triterpenoids, essential oils, flavonoids, and phenolic compounds. However, despite the increase in scientific research on the subject, it is necessary to study the primary and secondary metabolism of the plant and to identify key pathways that explore its great metabolic potential. For this purpose, a genome-scale metabolic reconstruction of C. sativa is described and contextualized using LC-QTOF-MS metabolic data obtained from the leaf extract from plants grown in the region of Pesca-Boyaca, Colombia under greenhouse conditions at the Clever Leaves facility. A compartmentalized model with 2101 reactions and 1314 metabolites highlights pathways associated with fatty acid biosynthesis, steroids, and amino acids, along with the metabolism of purine, pyrimidine, glucose, starch, and sucrose. Key metabolites were identified through metabolomic data, such as neurine, cannabisativine, cannflavin A, palmitoleic acid, cannabinoids, geranylhydroquinone, and steroids. They were analyzed and integrated into the reconstruction, and their potential applications are discussed. Cytotoxicity assays revealed high anticancer activity against gastric adenocarcinoma (AGS), melanoma cells (A375), and lung carcinoma cells (A549), combined with negligible impact against healthy human skin cells.

Challenges and potentials of new breeding techniques in Cannabis sativa

Cannabis sativa L. is an ancient crop used for fiber and seed production and not least for its content of cannabinoids used for medicine and as an intoxicant drug. Due to the psychedelic effect of one of the compounds, tetrahydrocannabinol (THC), many countries had regulations or bands on Cannabis growing, also as fiber or seed crop. Recently, as many of these regulations are getting less tight, the interest for the many uses of this crop is increasing. Cannabis is dioecious and highly heterogenic, making traditional breeding costly and time consuming. Further, it might be difficult to introduce new traits without changing the cannabinoid profile. Genome editing using new breeding techniques might solve these problems. The successful use of genome editing requires sequence information on suitable target genes, a genome editing tool to be introduced into plant tissue and the ability to regenerate plants from transformed cells. This review summarizes the current status of Cannabis breeding, uncovers potentials and challenges of Cannabis in an era of new breeding techniques and finally suggests future focus areas that may help to improve our overall understanding of Cannabis and realize the potentials of the plant.

Investigation of the Effect of the Auxin Antagonist PEO-IAA on Cannabinoid Gene Expression and Content in Cannabis sativa L. Plants under In Vitro Conditions

The in vitro shoot propagation of Cannabis sativa L. is an emerging research area for large-scale plant material production. However, how in vitro conditions influence the genetic stability of maintained material, as well as whether changes in the concentration and composition of secondary metabolites can be expected are aspects that need to be better understood. These features are essential for the standardised production of medicinal cannabis. This work aimed to find out whether the presence of the auxin antagonist α-(2-oxo-2-phenylethyl)-1H-indole-3-acetic acid (PEO-IAA) in the culture media influenced the relative gene expression (RGE) of the genes of interest (OAC, CBCA, CBDA, THCA) and the concentrations of studied cannabinoids (CBCA, CBDA, CBC, ∆⁹-THCA, and ∆⁹-THC). Two C. sativa cultivars, 'USO-31' and 'Tatanka Pure CBD', were cultivated by in vitro conditions with PEO-IAA presence and then analysed. The RT-qPCR results indicated that even though some changes in the RGE profiles could be observed, no differences were statistically significant compared with the control variant. The results of the phytochemical analyses demonstrate that although there were some differences from the control variant, only the cultivar 'Tatanka Pure CBD' showed a statistically significant increase (at a statistical significance level α = 0.05) in the concentration of the cannabinoid CBDA. In conclusion, it would appear that using PEO-IAA in the culture medium is a suitable approach to improve in vitro cannabis multiplication.

Cannabis Extraction Technologies: Impact of Research and Value Addition in Latin America

The Cannabis genus of plants has been widely used in different cultures for various purposes. It is separated into three main species: sativa, indica, and ruderalis. In ancient practices, the plant was used as a multipurpose crop and valued for its fiber, food, and medicinal uses. Since methodologies for the extraction, processing, and identification of components have become available, medical, and food applications have been increasing, allowing potential development in the pharmaceutical and healthy functional food industries. Although the growing legalization and adoption of cannabis for the treatment of diseases are key factors pushing the growth of its market, the biggest challenge is to obtain higher-quality products in a time- and cost-effective fashion, making the process of extraction and separation an essential step. Latin American countries exhibit great knowledge of extraction technologies; nevertheless, it is still necessary to verify whether production costs are economically profitable. In addition, there has been an increase in commercial cannabis products that may or may not be allowed, with or without quality fact sheets, which can pose health risks. Hence, legalization is mandatory and urgent for the rest of Latin American countries. In this article, the phytochemical compounds (cannabinoids, terpenes, and phenolic compounds), the current status of legalization, extraction techniques, and research advances in cannabis in Latin America are reviewed.

Biosynthesis of Phytocannabinoids and Structural Insights: A Review

Cannabis belongs to the family Cannabaceae, and phytocannabinoids are produced by the Cannabis sativa L. plant. A long-standing debate regarding the plant is whether it contains one or more species. Phytocannabinoids are bioactive natural products found in flowers, seeds, and fruits. They can be beneficial for treating human diseases (such as multiple sclerosis, neurodegenerative diseases, epilepsy, and pain), the cellular metabolic process, and regulating biological function systems. In addition, several phytocannabinoids are used in various therapeutic and pharmaceutical applications. This study provides an overview of the different sources of phytocannabinoids; further, the biosynthesis of bioactive compounds involving various pathways is elucidated. The structural classification of phytocannabinoids is based on their decorated resorcinol core and the bioactivities of naturally occurring cannabinoids. Furthermore, phytocannabinoids have been studied in terms of their role in animal models and antimicrobial activity against bacteria and fungi; further, they show potential for therapeutic applications and are used in treating various human diseases. Overall, this review can help deepen the current understanding of the role of biotechnological approaches and the importance of phytocannabinoids in different industrial applications.

Polymeric structure of the Cannabis sativa L. mitochondrial genome identified with an assembly graph model

Cannabis sativa L. belongs to the family Cannabaceae in Rosales. It has been widely used as medicines, building materials, and textiles. Elucidating its genome is critical for molecular breeding and synthetic biology study. Many studies have shown that the mitochondrial genomes (mitogenomes) and even chloroplast genomes (plastomes) had complex polymeric structures. Using the Nanopore sequencing platform, we sequenced, assembled, and analyzed its mitogenome and plastome. The resulting unitig graph suggested that the mitogenome had a complex polymeric structure. However, a gap-free, circular sequence was further assembled from the unitig graph. In contrast, a circular sequence representing the plastome was obtained. The mitogenome major conformation was 415,837 bp long, and the plastome was 153,927 bp long. To test if the repeat sequences promote recombination, which corresponds to the branch points in the structure, we tested the sequences around repeats by long-read mapping. Among 208 pairs of predicted repeats, the mapping results supported the presence of cross-over around 25 pairs of repeats. Subsequent PCR amplification confirmed the presence of cross-over around 15 of the 25 repeats. By comparing the mitogenome and plastome sequences, we identified 19 mitochondria plastid DNAs, including seven complete genes (trnW-CCA, trnP-UGG, psbJ, trnN-GUU, trnD-GUC, trnH-GUG, trnM-CAU) and nine gene fragments. Furthermore, the selective pressure analysis results showed that five genes (atp1, ccmB, ccmC, cox1, nad7) had 19 positively selected sites. Lastly, we predicted 28 RNA editing sites. A total of 8 RNA editing sites located in the coding regions were successfully validated by PCR amplification and Sanger sequencing, of which four were synonymous, and four were nonsynonymous. In particular, the RNA editing events appeared to be tissue-specific in C. sativa mitogenome. In summary, we have confirmed the major confirmation of C. sativa mitogenome and characterized its structural features in detail. These results provide critical information for future variety breeding and resource development for C. sativa.

The Cannabis Plant as a Complex System: Interrelationships between Cannabinoid Compositions, Morphological, Physiological and Phenological Traits

Maintaining specific and reproducible cannabinoid compositions (type and quantity) is essential for the production of cannabis-based remedies that are therapeutically effective. The current study investigates factors that determine the plant's cannabinoid profile and examines interrelationships between plant features (growth rate, phenology and biomass), inflorescence morphology (size, shape and distribution) and cannabinoid content. An examination of differences in cannabinoid profile within genotypes revealed that across the cultivation facility, cannabinoids' qualitative traits (ratios between cannabinoid quantities) remain fairly stable, while quantitative traits (the absolute amount of Δ⁹-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabichromene (CBC), cannabigerol (CBG), Δ⁹-tetrahydrocannabivarin (THCV) and cannabidivarin (CBDV)) can significantly vary. The calculated broad-sense heritability values imply that cannabinoid composition will have a strong response to selection in comparison to the morphological and phenological traits of the plant and its inflorescences. Moreover, it is proposed that selection in favour of a vigorous growth rate, high-stature plants and wide inflorescences is expected to increase overall cannabinoid production. Finally, a range of physiological and phenological features was utilised for generating a successful model for the prediction of cannabinoid production. The holistic approach presented in the current study provides a better understanding of the interaction between the key features of the cannabis plant and facilitates the production of advanced plant-based medicinal substances.

Current status and future prospects in cannabinoid production through in vitro culture and synthetic biology

For centuries, cannabis has been a rich source of fibrous, pharmaceutical, and recreational ingredients. Phytocannabinoids are the most important and well-known class of cannabis-derived secondary metabolites and display a broad range of health-promoting and psychoactive effects. The unique characteristics of phytocannabinoids (e.g., metabolite likeness, multi-target spectrum, and safety profile) have resulted in the development and approval of several cannabis-derived drugs. While most work has focused on the two main cannabinoids produced in the plant, over 150 unique cannabinoids have been identified. To meet the rapidly growing phytocannabinoid demand, particularly many of the minor cannabinoids found in low amounts in planta, biotechnology offers promising alternatives for biosynthesis through in vitro culture and heterologous systems. In recent years, the engineered production of phytocannabinoids has been obtained through synthetic biology both in vitro (cell suspension culture and hairy root culture) and heterologous systems. However, there are still several bottlenecks (e.g., the complexity of the cannabinoid biosynthetic pathway and optimizing the bioprocess), hampering biosynthesis and scaling up the biotechnological process. The current study reviews recent advances related to in vitro culture-mediated cannabinoid production. Additionally, an integrated overview of promising conventional approaches to cannabinoid production is presented. Progress toward cannabinoid production in heterologous systems and possible avenues for avoiding autotoxicity are also reviewed and highlighted. Machine learning is then introduced as a powerful tool to model, and optimize bioprocesses related to cannabinoid production. Finally, regulation and manipulation of the cannabinoid biosynthetic pathway using CRISPR- mediated metabolic engineering is discussed.

Single-Molecule Real-Time Sequencing of Full-Length Transcriptome and Identification of Genes Related to Male Development in Cannabis sativa

Female Cannabis sativa plants have important therapeutic properties. The sex ratio of the dioecious cannabis is approximately 1:1. Cultivating homozygous female plants by inducing female plants to produce male flowers is of great practical significance. However, the mechanism underlying cannabis male development remains unclear. In this study, single-molecule real-time (SMRT) sequencing was performed using a mixed sample of female and induced male flowers from the ZYZM1 cannabis variety. A total of 15,241 consensus reads were identified, and 13,657 transcripts were annotated across seven public databases. A total of 48 lncRNAs with an average length of 986.54 bp were identified. In total, 8202 transcripts were annotated as transcription factors, the most common of which were bHLH transcription factors. Moreover, tissue-specific expression pattern analysis showed that 13 MADS transcription factors were highly expressed in male flowers. Furthermore, 232 reads of novel genes were predicted and enriched in lipid metabolism, and qRT-PCR results showed that CER1 may be involved in the development of cannabis male flowers. In addition, 1170 AS events were detected, and two AS events were further validated. Taken together, these results may improve our understanding of the complexity of full-length cannabis transcripts and provide a basis for understanding the molecular mechanism of cannabis male development.

Secondary Terpenes in Cannabis sativa L.: Synthesis and Synergy

Cannabis is a complex biosynthetic plant, with a long history of medicinal use. While cannabinoids have received the majority of the attention for their psychoactive and pharmacological activities, cannabis produces a diverse array of phytochemicals, such as terpenes. These compounds are known to play a role in the aroma and flavor of cannabis but are potent biologically active molecules that exert effects on infectious as well as chronic diseases. Furthermore, terpenes have the potential to play important roles, such as synergistic and/or entourage compounds that modulate the activity of the cannabinoids. This review highlights the diversity and bioactivities of terpenes in cannabis, especially minor or secondary terpenes that are less concentrated in cannabis on a by-mass basis. We also explore the question of the entourage effect in cannabis, which studies to date have supported or refuted the concept of synergy in cannabis, and where synergy experimentation is headed, to better understand the interplay between phytochemicals within Cannabis sativa L.

Profiling Cannabinoid Contents and Expression Levels of Corresponding Biosynthetic Genes in Commercial Cannabis (Cannabis sativa L.) Cultivars

Cannabis (Cannabis sativa L.) is widely cultivated and studied for its psychoactive and medicinal properties. As the major cannabinoids are present in acidic forms in Cannabis plants, non-enzymatic processes, such as decarboxylation, are crucial for their conversion to neutral active cannabinoid forms. Herein, we detected the levels of cannabidivarin (CBDV), cannabidiol (CBD), cannabichromene (CBC), and Δ9-tetrahydrocannabinol (Δ9-THC) in the leaves and vegetative shoots of five commercial Cannabis cultivars using a combination of relatively simple extraction, decarboxylation, and high-performance liquid chromatography analyses. The CBDV, CBC, and Δ9-THC levels were 6.3-114.9, 34.4-187.2, and 57.6-407.4 μg/g, respectively, and the CBD levels were the highest, ranging between 1.2-8.9 μg/g in leaf and vegetative shoot tissues of Cannabis cultivars. Additionally, correlations were observed between cannabinoid accumulation and transcription levels of genes encoding key enzymes for cannabinoid biosynthesis, including CsCBGAS, CsCBDAS, CsCBCAS, and CsTHCAS. These data suggest that the high accumulation of cannabinoids, such as CBC, Δ9-THC, and CBD, might be derived from the transcriptional regulation of CsCBGAS and CsCBDAS in Cannabis plants.

Novel Insights into the Nature of Intraspecific Genome Size Diversity in Cannabis sativa L

Cannabis sativa has been used for millennia in traditional medicine for ritual purposes and for the production of food and fibres, thus, providing important and versatile services to humans. The species, which currently has a worldwide distribution, strikes out for displaying a huge morphological and chemical diversity. Differences in Cannabis genome size have also been found, suggesting it could be a useful character to differentiate between accessions. We used flow cytometry to investigate the extent of genome size diversity across 483 individuals belonging to 84 accessions, with a wide range of wild/feral, landrace, and cultivated accessions. We also carried out sex determination using the MADC2 marker and investigated the potential of flow cytometry as a method for early sex determination. All individuals were diploid, with genome sizes ranging from 1.810 up to 2.152 pg/2C (1.189-fold variation), apart from a triploid, with 2.884 pg/2C. Our results suggest that the geographical expansion of Cannabis and its domestication had little impact on its overall genome size. We found significant differences between the genome size of male and female individuals. Unfortunately, differences were, however, too small to be discriminated using flow cytometry through the direct processing of combined male and female individuals.

New Insight into Ornamental Applications of Cannabis: Perspectives and Challenges

The characteristic growth habit, abundant green foliage, and aromatic inflorescences of cannabis provide the plant with an ideal profile as an ornamental plant. However, due to legal barriers, the horticulture industry has yet to consider the ornamental relevance of cannabis. To evaluate its suitability for introduction as a new ornamental species, multifaceted commercial criteria were analyzed. Results indicate that ornamental cannabis would be of high value as a potted-plant or in landscaping. However, the readiness timescale for ornamental cannabis completely depends on its legal status. Then, the potential of cannabis chemotype Ⅴ, which is nearly devoid of phytocannabinoids and psychoactive properties, as the foundation for breeding ornamental traits through mutagenesis, somaclonal variation, and genome editing approaches has been highlighted. Ultimately, legalization and breeding for ornamental utility offers boundless opportunities related to economics and executive business branding.

Portable biosensors for rapid on-site determination of cannabinoids in cannabis, a review

Recent studies highlight the therapeutic virtues of cannabidiol (CBD). Furthermore, due to their molecular enriched profiles, cannabis inflorescences are biologically superior to a single cannabinoid for the treatment of various health conditions. Thus, there is flourishing demand for Cannabis sativa varieties containing high levels of CBD. Additionally, legal regulations around the world restrict the cultivation and consumption of tetrahydrocannabinol (THC)-rich cannabis plants for their psychotropic effects. Therefore, the use of cannabis varieties that are high in CBD is permitted as long as their THC content does not exceed a low threshold of 0.3%-0.5%, depending on the jurisdiction. These chemovars are legally termed 'hemp'. This controlled cannabinoid requirement highlights the need to detect low levels of THC, already in the field. In this review, cannabis profiling and the existing methods used for the detection of cannabinoids are firstly evaluated. Then, selected valuable biosensor technologies are discussed, which suggest portable, rapid, sensitive, reproducible, and reliable methods for on-site identification of cannabinoids levels, mainly THC. Recent cutting-edge techniques of promising potential usage for both cannabis and hemp analysis are identified, as part of the future cultivation and agricultural improvement of this crop.

Multi-Omics Approaches to Study Molecular Mechanisms in Cannabis sativa

Cannabis (Cannabis sativa L.), also known as hemp, is one of the oldest cultivated crops, grown for both its use in textile and cordage production, and its unique chemical properties. However, due to the legislation regulating cannabis cultivation, it is not a well characterized crop, especially regarding molecular and genetic pathways. Only recently have regulations begun to ease enough to allow more widespread cannabis research, which, coupled with the availability of cannabis genome sequences, is fuelling the interest of the scientific community. In this review, we provide a summary of cannabis molecular resources focusing on the most recent and relevant genomics, transcriptomics and metabolomics approaches and investigations. Multi-omics methods are discussed, with this combined approach being a powerful tool to identify correlations between biological processes and metabolic pathways across diverse omics layers, and to better elucidate the relationships between cannabis sub-species. The correlations between genotypes and phenotypes, as well as novel metabolites with therapeutic potential are also explored in the context of cannabis breeding programs. However, further studies are needed to fully elucidate the complex metabolomic matrix of this crop. For this reason, some key points for future research activities are discussed, relying on multi-omics approaches.

The Use of Cannabis sativa L. for Pest Control: From the Ethnobotanical Knowledge to a Systematic Review of Experimental Studies

Background: Despite the benefits that synthetic pesticides have provided in terms of pest and disease control, they cause serious long-term consequences for both the environment and living organisms. Interest in eco-friendly products has subsequently increased in recent years. Methods: This article briefly analyzes the available ethnobotanical evidence regarding the use of Cannabis sativa as a pesticide and offers a systematic review of experimental studies. Results: Our findings indicate that both ethnobotanical and experimental procedures support the use of C. sativa as a pesticide, as remarkable toxicity has been observed against pest organisms. The results included in the systematic review of experimental studies (n=30) show a high degree of heterogeneity, but certain conclusions can be extracted to guide further research. For instance, promising pesticide properties were reported for most of the groups of species tested, especially Arachnida and Insecta; the efficacy of C. sativa as a pesticide can be derived from a wide variety of compounds that it contains and possible synergistic effects; it is crucial to standardize the phytochemical profile of C. sativa plants used as well as to obtain easily reproducible results; appropriate extraction methods should be explored; and upper inflorescences of the plant may be preferred for the production of the essential oil, but further studies should explore better other parts of the plant. Conclusion: In the coming years, as new findings are produced, the promising potential of C. sativa as a pesticide will be elucidated, and reviews such as the present one constitute useful basic tools to make these processes easier.

Chemical and genetic variation in feral Cannabis sativa populations across the Nebraska climate gradient

Cannabis sativa is a versatile crop that can be cultivated for fiber, seed, or phytochemicals. To take advantage of this versatility and the potential of Cannabis as a feedstock for the bioeconomy, genomics-enabled breeding programs must be strengthened and expanded. This work contributes to the foundation for such by investigating the phytochemistry and genomics of feral Cannabis populations collected from seventeen counties across the climate gradient of Nebraska. Flower tissue from male and female plants (28 total) was studied using (i) gas chromatography-mass spectrometry to assess cannabinoid profiles and (ii) RNA sequencing to determine transcript abundances. Both male and female flower tissues produced cannabinoids, and, though the compounds were more abundant in female flower tissue, the primary cannabinoid in both was usually cannabidiol. The expression of genes that mediate early steps on the cannabinoid biosynthetic pathway were upregulated in female relative to male flowers, suggesting that female versus male flower tissue cannabinoid abundance may be controlled at least in part at the transcriptional level. DNA sequencing was used to place feral Cannabis plants from Nebraska into a previously described genomic context, revealing that all the plants studied here are much more similar to previously characterized hemp-type Cannabis plants than to drug-type Cannabis plants, at least at the genetic level. This work provides foundational phytochemical knowledge and a large set of high-quality single nucleotide polymorphism markers for future studies of feral Nebraska Cannabis.

Industrial hemp seed: from the field to value-added food ingredients

Industrial hemp, with low levels of the intoxicating cannabinoid tetrahydrocannabinol (THC), is grown for fibre and seeds. The industrial hemp industry is poised for expansion. The legalisation of industrial hemp as an agricultural commodity and the inclusion of hemp seed in foods is helping to drive the expansion of the hemp food ingredients industry. This paper discusses the opportunity to build an industrial hemp industry, with a focus on the prospects of hemp seed and its components in food applications. The market opportunities for industrial hemp products are examined. Various aspects of the science that underpins the development of an industrial hemp industry through the food supply chain are presented. This includes a discussion on the agronomy, on-farm and post-harvest considerations and the various types of food ingredients that can be made from hemp seed. The characteristics of hemp seed meal, hemp seed protein and hemp seed oil are reviewed. Different processes for production of value-added ingredients from hemp seed, hemp seed oil and hemp seed protein, are examined. The applicability of hemp seed ingredients in food applications is reviewed. The design of hemp seed ingredients that are fit-for-purpose for target food applications, through the selection of varieties and processing methods for production of various hemp seed ingredients, needs to consider market-led opportunities. This will require an integrated through chain approach, combined with the development of on-farm and post-farm strategies, to ensure that the hemp seed ingredients and foods containing hemp seed are acceptable to the consumer.

Whole-genome resequencing of wild and cultivated cannabis reveals the genetic structure and adaptive selection of important traits

BACKGROUND

Cannabis is an important industrial crop species whose fibre, seeds, flowers and leaves are widely used by humans. The study of cannabinoids extracted from plants has been popular research topic in recent years. China is one of the origins of cannabis and one of the few countries with wild cannabis plants. However, the genetic structure of Chinese cannabis and the degree of adaptive selection remain unclear.

RESULTS

The main morphological characteristics of wild cannabis in China were assessed. Based on whole-genome resequencing SNPs, Chinese cannabis could be divided into five groups in terms of geographical source and ecotype: wild accessions growing in the northwestern region; wild accessions growing in the northeastern region; cultivated accessions grown for fibre in the northeastern region; cultivated accessions grown for seed in northwestern region, and cultivated accessions in southwestern region. We further identified genes related to flowering time, seed germination, seed size, embryogenesis, growth, and stress responses selected during the process of cannabis domestication. The expression of flowering-related genes under long-day (LD) and short-day (SD) conditions showed that Chinese cultivated cannabis is adapted to different photoperiods through the regulation of Flowering locus T-like (FT-like) expression.

CONCLUSION

This study clarifies the genetic structure of Chinese cannabis and offers valuable genomic resources for cannabis breeding.

Developing Oligo Probes for Chromosomes Identification in Hemp (Cannabis sativa L.)

Hemp (Cannabis sativa L., 2n = 20) is a valuable crop that is successfully used as a food, technical and medicinal crop. It is a dioecious plant with an XX\XY sex determination system. Some chromosomes of C. sativa have almost the same lengths and centromeric indexes. Cytogenetic markers help to distinguish similar plant chromosomes, including sex chromosomes, which is important for the breeding process. Two repeats (CS-1 and CS-237) were used to develop labeled oligo-probes for rapid and low-cost oligo-FISH. These oligos can be recommended for use as cytological markers to distinguish sex chromosomes (X and Y) and somatic chromosome pairs 3, 6, and 8 by rapid oligo-FISH in a short time.

In planta Female Flower Agroinfiltration Alters the Cannabinoid Composition in Industrial Hemp (Cannabis sativa L.)

Industrial hemp is a diploid (2n = 20), dioecious plant, and an essential source of various phytochemical productions. More than 540 phytochemicals have been described, some of which proved helpful in the remedial treatment of human diseases. Therefore, further study of hemp phytochemicals in medicine is highly anticipated. Previously, we developed the vacuum agroinfiltration method, which allows the transient gene expression in hemp tissues including female flowers, where cannabinoids are produced and accumulated. In this study, we attempted to alter the composition of total CBD and THC. The RT-PCR and sanger sequence identified eleven copies of the CBDAS gene, two copies of the THCAS gene, and one CBCAS gene. Binary vectors were constructed to overexpress the CBDAS gene and silence the THCAS gene via RNA interference. The Transcript level of the CBDAS gene was increased by more than 10 times than the plants used as a control, which led to a 54% higher total CBD content. The silencing of the THCAS gene led to downregulation of the THCAS gene, with an 80% reduction in transcript levels, and total THC content was reduced to 43% compared with mock plant. These results suggest that hemp vacuum infiltration is highly effective for metabolic engineering of cannabinoids in hemp.

Evaluation of tetrahydrocannabinolic acid (THCA) synthase polymorphisms for distinguishing between marijuana and hemp

The Controlled Substances Act (CSA) classifies marijuana (Cannabis sativa) as a Schedule I illicit drug. However, the recent Agriculture Improvement Act of 2018 (U.S. Farm Bill) removed hemp from the definition of marijuana in the CSA, making it a legal crop. As a result, many hemp products are now available, including strains of hemp buds high in other cannabinoids such as cannabidiol (CBD) or cannabigerol (CBG). The genetic inheritance of chemical phenotype (chemotype) has been widely studied, with the tetrahydrocannabinolic acid (THCA) synthase gene at the forefront. Previous studies have speculated that there are two forms of the THCA gene, one that produces an active enzyme (present in marijuana) and one that cannot produce a functional enzyme (present in hemp). A DNA analysis method is desirable for determining crop type in sample types inconducive to chemical analysis, such as immature crops, trace residues, small leaf fragments, seeds, and root material. This study optimized and evaluated a previously reported single nucleotide polymorphism (SNP) assay for determining C. sativa crop type. Furthermore, the presence or absence of 15 cannabinoids, including THC and THCA, was reported in cannabis reference materials and 15 legal hemp flower samples. The SNP assay correctly identified crop type in most samples. However, several marijuana samples were classified as hemp, and several hemp seeds were classified as marijuana. Two strains of legal CBG hemp flowers were also classified as marijuana, indicating that factors other than the genetic variation of the THCA synthase gene should be considered when determining crop type.

Deciphering the iPBS retrotransposons based genetic diversity of nanoparticles induced in Vitro seedlings of industrial hemp (Cannabis sativa L.)

BACKGROUND

The phytochemicals contained in hemp are highly significant and can be modified or altered by employing in vitro elicitors like nanoparticles (NPs). Application of NPs type, concentration, and treatment time regulate the germination, growth, and phytohemicals.

METHODS AND RESULTS

In vitro sterilized seeds of cannabis were augmented on Murashige and Skoog (MS) medium supplemented with silver (Ag) and titanium dioxide (TiO₂) nanoparticles at different concentrations (0, 200, 400, 800, 1200 and 1600 mg/L) for one month. Results revealed that supplementation of NPs resulted in reduced germination (%), root length and longer shoots and seedling fresh wt compared to control.

CONCLUSIONS

Maximum germination was recorded on MS medium supplemented with 1600 mg/L TiO₂NPs (92.50%) followed by 1600 mg/L AgNPs (80.00%). Supplementation of 800 mg/L AgNPs yielded longer shoots, roots, seedlings fresh weight, and chlorophyll-b contents compared to all other treatments. Whereas, maximum chlorophyll-a, carotenoids, and MDA contents were attributed to 1200 mg/L TiO₂NPs. PCR results using eight iPBS-retrotransposons primers yielded a total of 101 bands with 98 polymorphic bands. Whereas, minimum (0.28) and maximum (0.42) gene diversity was associated with 2095 and 2228 primers.

Combined use of specific length amplified fragment sequencing (SLAF-seq) and bulked segregant analysis (BSA) for rapid identification of genes influencing fiber content of hemp (Cannabis sativa L.)

Hemp (Cannabis sativa L.), an ancient crop, is a significant source of high-quality fiber that primarily caters to the textile industry worldwide. Fiber content is a crucial quantitative trait for evaluating fiber yield in hemp. Understanding the genetic mechanisms involved in hemp breeding is essential for improving yield. In this study, we developed 660 F1 plants from a cross between Jindao-15 (high fiber content fiber-use variety) and Fire No.1 (low fiber content fiber-use variety), and thirty plants each with high and low fiber content were selected from 305 monoecious plants of this population according to 5%-10% of population size for quantitative traits. The DNA from these plants was extracted to establish two bulk DNA pools and then subjected to the restriction digestion by the enzymes RsaI and HaeIII to obtain 314-364 bp digestion fragments and subjected to sequencing using specific length amplified fragment sequencing (SLAF-seq). Finally, we successfully developed 368,404 SLAF tags, which led to the detection of 25,133 high-quality SNPs. Combing with the resequencing results of parents, the SNPs of mixed pools were then subjected to the SNP-Index correlation algorithm, which revealed four candidate regions related to fiber content traits on Chromosome 1, with a length of 8.68 Mb and containing 389 annotated genes. The annotation information and the comparison results identified 15 genes that were highly likely to modulate the fiber content of hemp. Further, qPCR validation identified six genes (LOC115705530, LOC115705875, LOC115704794, LOC115705371, LOC115705688 and LOC115707511) that were highly positively correlated with influencing the hemp fiber content. These genes were involved in the transcription regulation, auxin and water transportion, one carbon and sugar metabolism. And non-synnoumous mutation SNPs which may play vital role in influencing the fiber content were detected in LOC115705875, LOC115704794, LOC115705688 and LOC115707511. Thus, our study highlights the importance of the combined use of SLAF-Seq and Bulked Segregant analysis (BSA) to locate genes related to hemp fiber content rapidly. Hence, our study provides novel mechanistic inputs for the fast identification of genes related to important agronomic traits of hemp and other crops catering to the textile industry.

Chemical Profiling and Characterization of Different Cultivars of Cannabis sativa L. Inflorescences by SPME-GC-MS and UPLC-MS

The chemical profile of the Cannabis sativa L. female inflorescences is rather complex being characterized by a large number of molecules belonging to different chemical classes. Considering the numerous applications in various fields, including the medical and pharmaceutical sectors, that have seen a large use of Cannabis genus in recent years, a precise characterization of the matrices is essential. In this regard, the application of adequate and suitable sampling and analysis techniques becomes important in order to provide an identification of the metabolites characterizing the profile of the sample under examination. The goal of this work is to provide additional information on the chemical composition of the inflorescences of five C. sativa different cultivars grown in Emilia Romagna (Italy) through the application of sophisticated analysis techniques such as Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry and Ultra-Performance Liquid Chromatography-Mass Spectrometry (SPME-GC-MS and UPLC-MS). The obtained data highlighted the presence of a high number of volatile and non-volatile compounds, thus allowing a comparative evaluation of the different samples. Furthermore, an in-depth statistical survey by Principal Components Analysis (PCA) and HeatMap, Hierarchical luster Analysis (HCA) and Partial Least Squares Discriminant Analysis (PLS-DA-VIP), was conducted to consider any correlations between the investigated cultivars. The findings of this study may help to provide more information on the C. sativa inflorescences useful for potential applications of their metabolites in scientific research.

Applications of cell- and tissue-specific 'omics to improve plant productivity

The individual tissues and cell types of plants each have characteristic properties that contribute to the function of the plant as a whole. These are reflected by unique patterns of gene expression, protein and metabolite content, which enable cell-type-specific patterns of growth, development and physiology. Gene regulatory networks act within the cell types to govern the production and activity of these components. For the broader organism to grow and reproduce successfully, cell-type-specific activity must also function within the context of surrounding cell types, which is achieved by coordination of signalling pathways. We can investigate how gene regulatory networks are constructed and function using integrative ‘omics technologies. Historically such experiments in plant biological research have been performed at the bulk tissue level, to organ resolution at best. In this review, we describe recent advances in cell- and tissue-specific ‘omics technologies that allow investigation at much improved resolution. We discuss the advantages of these approaches for fundamental and translational plant biology, illustrated through the examples of specialised metabolism in medicinal plants and seed germination. We also discuss the challenges that must be overcome for such approaches to be adopted widely by the community.

Accumulation of somatic mutations leads to genetic mosaicism in cannabis

Cannabis (Cannabis sativa L.) is typically propagated using stem cuttings taken from mother plants to produce genetically uniform propagules. However, producers anecdotally report that clonal lines deteriorate over time and eventually produce clones with less vigor and lower cannabinoid levels than the original mother plant. While the cause of this deterioration has not been investigated, one potential contributor is the accumulation of somatic mutations within the plant. To test this, we used deep sequencing of whole genomes (>50×) to compare the variability within an individual cannabis cultivar Honey Banana plant sampled at the bottom, middle, and top. We called over six million sequence variants based on a reference genome and found that the top had the most by a sizable amount. Comparing the variants among the samples uncovered that nearly 600,000 (34%) were unique to the top while the bottom only contained 148,000 (12%), and middle with 77,000 (9%) unique variants. Bioinformatics tools were used to identify mutations in critical cannabinoid-terpene biosynthesis pathways. While none were identified as high impact, four genes contained more than double the average level of nucleotide diversity (π) in or near the gene. Two genes code for essential enzymes required for the cannabinoid pathway while the other two are in the terpene pathways, demonstrating that mutations were accumulating within these pathways and could influence their function. Overall, a measurable number of intraplant genetic diversity was discovered that could impact long-term genetic fidelity of clonal lines and potentially contribute to the observed decline in vigor and cannabinoid content.

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

Medical cannabis (Cannabis sativa L.) is quickly becoming a central agricultural crop as its production has continued to increase globally. The recent release of the cannabis reference genomes provides key genetic information for the functional analysis of cannabis genes. Currently, however, the established tools for in vivo gene functional analysis in cannabis are very limited. In this study, we investigated the use of the tobacco rattle virus (TRV) as a possible tool for virus-induced gene silencing (VIGS) and virus-aided gene expression (VAGE). Using leaf photobleaching as a visual marker of PHYTOENE DESATURASE (PDS) silencing, we found that VIGS was largely restricted to the agro-infiltrated leaves. However, when agro-infiltration was performed under vacuum, VIGS increased dramatically, which resulted in intense PDS silencing and an increased photobleaching phenotype. The suitability of TRV as a vector for virus-aided gene expression (VAGE) was demonstrated by an analysis of DsRed fluorescence protein. Interestingly, a DsRed signal was also observed in glandular trichomes in TRV₂-DsRed-infected plants, which suggests the possibility of trichome-related gene function analysis. These results indicate that TRV, despite its limited spread, is an attractive vector for rapid reverse-genetics screens and for the analysis of gene function in cannabis.

THC and CBD Fingerprinting of an Elite Cannabis Collection from Iran: Quantifying Diversity to Underpin Future Cannabis Breeding

Cannabis (Cannabis sativa L.) has a rich history of human use, and the therapeutic importance of compounds produced by this species is recognized by the medical community. The active constituents of cannabis, collectively called cannabinoids, encompass hundreds of distinct molecules, the most well-characterized of which are tetrahydrocannabinol (THC) and cannabidiol (CBD), which have been used for centuries as recreational drugs and medicinal agents. As a first step to establish a cannabis breeding program, we initiated this study to describe the HPLC-measured quantity of THC and CBD biochemistry profiles of 161 feral pistillate cannabis plants from 20 geographical regions of Iran. Our data showed that Iran can be considered a new region of high potential for distribution of cannabis landraces with diverse THC and CBD content, predominantly falling into three groups, as Type I = THC-predominant, Type II = approximately equal proportions of THC and CBD (both CBD and THC in a ratio close to the unity), and Type III = CBD-predominant. Correlation analysis among two target cannabinoids and environmental and geographical variables indicated that both THC and CBD contents were strongly influenced by several environmental-geographical factors, such that THC and CBD contents were positively correlated with mean, min and max annual temperature and negatively correlated with latitude, elevation, and humidity. Additionally, a negative correlation was observed between THC and CBD concentrations, suggesting that further studies to unravel these genotype × environment interactions (G × E interactions) are warranted. The results of this study provide important pre-breeding information on a collection of cannabis that will underpin future breeding programs.

Industry-Based Misconceptions Regarding Cross-Pollination of Cannabis spp

Cross-pollination of commercial crops has been an ongoing issue in many species. Cannabis spp. encompasses the classifications of marijuana [high in Δ⁹-tetrahydrocannabinol (THC)] and hemp (below 0.3% THC). As such, cannabis is the most recent crop facing the dilemma of cross-pollination and is leading to litigation. These litigations are driven by the large misunderstanding of the impacts of cross-pollination within the cannabis industry. The misconception is that if hemp is cross-pollinated by high THC cannabis, the hemp will become "hot" (high in THC) thereby rendering the crop illegal under the 2018 Farm Bill. However, there are many factors that contribute to the amount of THC a plant may produce. This article examines and refutes the misconception of cross-pollination increasing THC levels by highlighting several methods of how THC may become high in a given hemp crop.

Metabolomics Analysis Revealed the Characteristic Metabolites of Hemp Seeds Varieties and Metabolites Responsible for Antioxidant Properties

Hemp seeds are rich in metabolites such as protein, lipids and flavonoids, which are beneficial to health and can be used as a nutritional supplement. Few studies have focused on the metabolites of different hemp seed varieties. In the current study, using widely targeted metabolomics based on UHPLC-QQQ-MS/MS, we compared the metabolomes of seeds from seven hemp varieties with different uses. A total of 1,001 metabolites, including 201 flavonoids, 86 alkaloids, and 149 phenolic acids, were identified. Flavonoids, organic acids, alkaloids, lipids, and fatty acids with high nutritional value are important to investigate the differences between hemp accessions. By using weighted gene co-expression network analysis (WGCNA), six modules of closely related metabolites were identified. And, we identified the metabolite characteristics and hub metabolites of each variety. Then, we experimentally determined antioxidant activity of seven varieties and demonstrated that alkaloids, flavonoids, phenolic acids, terpenes, and free fatty acids are responsible for the antioxidant activity of hemp seeds. Our research provides useful information for further investigation of the chemical composition of hemp seeds.

Application of High-Throughput Sequencing on the Chinese Herbal Medicine for the Data-Mining of the Bioactive Compounds

The Chinese Herbal Medicine (CHM) has been used worldwide in clinic to treat the vast majority of human diseases, and the healing effect is remarkable. However, the functional components and the corresponding pharmacological mechanism of the herbs are unclear. As one of the main means, the high-throughput sequencing (HTS) technologies have been employed to discover and parse the active ingredients of CHM. Moreover, a tremendous amount of effort is made to uncover the pharmacodynamic genes associated with the synthesis of active substances. Here, based on the genome-assembly and the downstream bioinformatics analysis, we present a comprehensive summary of the application of HTS on CHM for the synthesis pathways of active ingredients from two aspects: active ingredient properties and disease classification, which are important for pharmacological, herb molecular breeding, and synthetic biology studies.

Contents of Cannabinoids in Hemp Varieties Grown in Maryland

Coincident with the cannabis legalization and the increased interest in the medicinal use of the plant, the cannabis marketplace and farming have seen tremendous growth. It is reported that there are more than 2000 cannabis varieties available to customers. However, the data that is available to the growers and breeders regarding the cannabinoid contents of various varieties remains low. Here, a high-performance liquid chromatography (HPLC) method was developed and validated for the simultaneous separation and determination of 11 cannabinoids. A total of 104 hemp bud materials belonging to 20 varieties were collected from farms in the state of Maryland and analyzed with the HPLC method. The contents of the 11 cannabinoids in various varieties were compared and discussed, highlighting the varieties that showed a high yield of cannabinoids and good consistency that are more appropriate for cannabinoid production.

Separation and non-separation methods for the analysis of cannabinoids in Cannabis sativa L

Cannabis sativa L. is a plant known all over the world, due to its history, bioactivity and also social impact. It is chemically complex with an astonishing ability in the biosynthesis of many secondary metabolites belonging to different chemical classes. Among them, cannabinoids are the most investigated ones, given their pharmacological relevance. In order to monitor the composition of the plant material and ensure the efficacy and safety of its derived products, extraction and analysis of cannabinoids play a crucial role. In this context, in addition to a conventional separation method based on HPLC with UV/DAD detection, a new strategy based on a non-separation procedure, such as ¹³C-qNMR, may offer several advantages, such as reduced solvent consumption and simultaneous acquisition of the quali/quantitative data related to many analytes. In the light of all the above, the aim of this work is to compare the efficiency of the above-mentioned analytical techniques for the study of the main cannabinoids in different samples of cannabis inflorescences, belonging to fibre-type, recreational and medical varieties. The ¹³C-qNMR method here proposed for the first time for the quantification of both psychoactive and non-psychoactive cannabinoids in different cannabis varieties provided reliable results in comparison to the more common and consolidated HPLC technique.

Traditional uses of Cannabis: An analysis of the CANNUSE database

ETHNOPHARMACOLOGICAL RELEVANCE

Cannabis is one of the most versatile genera in terms of plant use and has been exploited by humans for millennia. Nowadays, Cannabis is the centre of many scientific studies, most of them focusing on chemical composition and medicinal values. While new and varied applications are continuously being developed, the knowledge surrounding less common uses of the plant is slowly disappearing.

AIM OF THE REVIEW

We have analysed diversity of global data of Cannabis traditional uses, to investigate if certain plant parts are significantly associated with particular Cannabis use. We wanted to uncover potential associations between the plant parts used for the treatment of different body systems and ailments.

MATERIALS AND METHODS

We have analysed the extensive database of Cannabis traditional uses (CANNUSE). This database contains 2330 data entries of Cannabis ethnobotanical uses from over 40 countries across the world. The dataset was divided into five general groups based on the type of use: medicinal, alimentary, psychoactive, fibre and other uses. Given the abundance of human medicinal uses, detailed analysis was done on the subset of 1167 data entries. We analysed the relationship between 16 body system categories and ailments treated with Cannabis plant parts. We used a Pearson's chi-square and Fisher's exact test, to determine which Cannabis parts are characteristic of treatment for specific ailments.

RESULTS

In this dataset, the majority of reports were represented by medicinal (75.41%), followed by psychoactive (8.35%) and alimentary (7.29%) use. The most commonly used plant parts were leaf (50.51%), seed (15.38%) and inflorescence (11.35%). We found that different Cannabis plant parts were significantly associated with different uses; the leaf was typically used for medicinal, seed for alimentary and inflorescence for psychoactive use. Regarding the human medicinal uses, most common were reports for treatments of the digestive system and nutritional disorders (17.66%), nervous system and mental disorders (16.24%), followed by pain and inflammations (12.21%). We found a significant relationship between the use of certain Cannabis parts and treatment of ailments and body systems categories; leaf was significantly associated with treatment of two categories: skin and subcutaneous tissue disorders and circulatory system and blood disorders; seed use was associated with musculoskeletal system disorders and traumas; while inflorescence use shows a statistical support for treatment of nervous system and mental disorders.

CONCLUSION

Several pharmaceutical companies are intensely working on developing new drugs with isolated chemical compounds or crude extracts, almost exclusively from Cannabis inflorescences. However, our review revealed that use of leaf or seed in traditional medicine is often more important than use of inflorescence for the treatment of certain ailments. A review of traditional medicine provides a body of knowledge and an initial pathway to identify landraces and plant parts that could have an important role in future medicinal research. We are confident that traditional medicine still has a large potential for modern medicine. As more information on Cannabis diversity (genetics, biochemistry, and clinical studies) becomes available, ethnobotanical data are poised to be of much greater significance.

Analysis of Sequence Variability and Transcriptional Profile of Cannabinoid synthase Genes in Cannabis sativa L. Chemotypes with a Focus on Cannabichromenic acid synthase

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.