Getting to the heart of cannabis health risks.

In this issue of Cell, Wei et al. show that the increased cardiovascular risks associated with cannabis use are mediated by proinflammatory cannabinoid 1 (CB1) receptor signaling, which can be ameliorated with the natural antioxidant agent genistein.

Cannabinoid receptor 1 antagonist genistein attenuates marijuana-induced vascular inflammation.

Epidemiological studies reveal that marijuana increases the risk of cardiovascular disease (CVD); however, little is known about the mechanism. Δ9-tetrahydrocannabinol (Δ9-THC), the psychoactive component of marijuana, binds to cannabinoid receptor 1 (CB1/CNR1) in the vasculature and is implicated in CVD. A UK Biobank analysis found that cannabis was an risk factor for CVD. We found that marijuana smoking activated inflammatory cytokines implicated in CVD. In silico virtual screening identified genistein, a soybean isoflavone, as a putative CB1 antagonist. Human-induced pluripotent stem cell-derived endothelial cells were used to model Δ9-THC-induced inflammation and oxidative stress via NF-κB signaling. Knockdown of the CB1 receptor with siRNA, CRISPR interference, and genistein attenuated the effects of Δ9-THC. In mice, genistein blocked Δ9-THC-induced endothelial dysfunction in wire myograph, reduced atherosclerotic plaque, and had minimal penetration of the central nervous system. Genistein is a CB1 antagonist that attenuates Δ9-THC-induced atherosclerosis.

Cannabinoid treatments in epilepsy and seizure disorders.

Cannabis has been used to treat convulsions and other disorders since ancient times. In the last few decades, preclinical animal studies and clinical investigations have established the role of cannabidiol (CBD) in treating epilepsy and seizures and support potential therapeutic benefits for cannabinoids in other neurological and psychiatric disorders. Here, we comprehensively review the role of cannabinoids in epilepsy. We briefly review the diverse physiological processes mediating the central nervous system response to cannabinoids, including Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol, and terpenes. Next, we characterize the anti- and proconvulsive effects of cannabinoids from animal studies of acute seizures and chronic epileptogenesis. We then review the clinical literature on using cannabinoids to treat epilepsy, including anecdotal evidence and case studies as well as the more recent randomized controlled clinical trials that led to US Food and Drug Administration approval of CBD for some types of epilepsy. Overall, we seek to evaluate our current understanding of cannabinoids in epilepsy and focus future research on unanswered questions.

Crystal Structure of the Human Cannabinoid Receptor CB1.

Cannabinoid receptor 1 (CB1) is the principal target of Δ9-tetrahydrocannabinol (THC), a psychoactive chemical from Cannabis sativa with a wide range of therapeutic applications and a long history of recreational use. CB1 is activated by endocannabinoids and is a promising therapeutic target for pain management, inflammation, obesity, and substance abuse disorders. Here, we present the 2.8 Å crystal structure of human CB1 in complex with AM6538, a stabilizing antagonist, synthesized and characterized for this structural study. The structure of the CB1-AM6538 complex reveals key features of the receptor and critical interactions for antagonist binding. In combination with functional studies and molecular modeling, the structure provides insight into the binding mode of naturally occurring CB1 ligands, such as THC, and synthetic cannabinoids. This enhances our understanding of the molecular basis for the physiological functions of CB1 and provides new opportunities for the design of next-generation CB1-targeting pharmaceuticals.

Δ9-THC-caused synaptic and memory impairments are mediated through COX-2 signaling.

Marijuana has been used for thousands of years as a treatment for medical conditions. However, untoward side effects limit its medical value. Here, we show that synaptic and cognitive impairments following repeated exposure to Δ(9)-tetrahydrocannabinol (Δ(9)-THC) are associated with the induction of cyclooxygenase-2 (COX-2), an inducible enzyme that converts arachidonic acid to prostanoids in the brain. COX-2 induction by Δ(9)-THC is mediated via CB1 receptor-coupled G protein ßγ subunits. Pharmacological or genetic inhibition of COX-2 blocks downregulation and internalization of glutamate receptor subunits and alterations of the dendritic spine density of hippocampal neurons induced by repeated Δ(9)-THC exposures. Ablation of COX-2 also eliminates Δ(9)-THC-impaired hippocampal long-term synaptic plasticity, working, and fear memories. Importantly, the beneficial effects of decreasing ß-amyloid plaques and neurodegeneration by Δ(9)-THC in Alzheimer's disease animals are retained in the presence of COX-2 inhibition. These results suggest that the applicability of medical marijuana would be broadened by concurrent inhibition of COX-2.

Acute cannabinoids impair working memory through astroglial CB1 receptor modulation of hippocampal LTD.

Impairment of working memory is one of the most important deleterious effects of marijuana intoxication in humans, but its underlying mechanisms are presently unknown. Here, we demonstrate that the impairment of spatial working memory (SWM) and in vivo long-term depression (LTD) of synaptic strength at hippocampal CA3-CA1 synapses, induced by an acute exposure of exogenous cannabinoids, is fully abolished in conditional mutant mice lacking type-1 cannabinoid receptors (CB(1)R) in brain astroglial cells but is conserved in mice lacking CB(1)R in glutamatergic or GABAergic neurons. Blockade of neuronal glutamate N-methyl-D-aspartate receptors (NMDAR) and of synaptic trafficking of glutamate α-amino-3-hydroxy-5-methyl-isoxazole propionic acid receptors (AMPAR) also abolishes cannabinoid effects on SWM and LTD induction and expression. We conclude that the impairment of working memory by marijuana and cannabinoids is due to the activation of astroglial CB(1)R and is associated with astroglia-dependent hippocampal LTD in vivo.

Structure-based identification of a G protein-biased allosteric modulator of cannabinoid receptor CB1.

Cannabis sativa is known for its therapeutic benefit in various diseases including pain relief by targeting cannabinoid receptors. The primary component of cannabis, Δ9-tetrahydrocannabinol (THC), and other agonists engage the orthosteric site of CB1, activating both Gi and ß-arrestin signaling pathways. The activation of diverse pathways could result in on-target side effects and cannabis addiction, which may hinder therapeutic potential. A significant challenge in pharmacology is the design of a ligand that can modulate specific signaling of CB1. By leveraging insights from the structure-function selectivity relationship (SFSR), we have identified Gi signaling-biased agonist-allosteric modulators (ago-BAMs). Further, two cryoelectron microscopy (cryo-EM) structures reveal the binding mode of ago-BAM at the extrahelical allosteric site of CB1. Combining mutagenesis and pharmacological studies, we elucidated the detailed mechanism of ago-BAM-mediated biased signaling. Notably, ago-BAM CB-05 demonstrated analgesic efficacy with fewer side effects, minimal drug toxicity and no cannabis addiction in mouse pain models. In summary, our finding not only suggests that ago-BAMs of CB1 provide a potential nonopioid strategy for pain management but also sheds light on BAM identification for GPCRs.

Adverse Impact of Cannabis on Human Health.

Cannabis, the most commonly used recreational drug, is illicit in many areas of the world. With increasing decriminalization and legalization, cannabis use is increasing in the United States and other countries. The adverse effects of cannabis are unclear because its status as a Schedule 1 drug in the United States restricts research. Despite a paucity of data, cannabis is commonly perceived as a benign or even beneficial drug. However, recent studies show that cannabis has adverse cardiovascular and pulmonary effects and is linked with malignancy. Moreover, case reports have shown an association between cannabis use and neuropsychiatric disorders. With growing availability, cannabis misuse by minors has led to increasing incidences of overdose and toxicity. Though difficult to detect, cannabis intoxication may be linked to impaired driving and motor vehicle accidents. Overall, cannabis use is on the rise, and adverse effects are becoming apparent in clinical data sets.

Cannabis and synaptic reprogramming of the developing brain.

Recent years have been transformational in regard to the perception of the health risks and benefits of cannabis with increased acceptance of use. This has unintended neurodevelopmental implications given the increased use of cannabis and the potent levels of Δ9-tetrahydrocannabinol today being consumed by pregnant women, young mothers and teens. In this Review, we provide an overview of the neurobiological effects of cannabinoid exposure during prenatal/perinatal and adolescent periods, in which the endogenous cannabinoid system plays a fundamental role in neurodevelopmental processes. We highlight impaired synaptic plasticity as characteristic of developmental exposure and the important contribution of epigenetic reprogramming that maintains the long-term impact into adulthood and across generations. Such epigenetic influence by its very nature being highly responsive to the environment also provides the potential to diminish neural perturbations associated with developmental cannabis exposure.

The why behind the high: determinants of neurocognition during acute cannabis exposure.

Acute cannabis intoxication may induce neurocognitive impairment and is a possible cause of human error, injury and psychological distress. One of the major concerns raised about increasing cannabis legalization and the therapeutic use of cannabis is that it will increase cannabis-related harm. However, the impairing effect of cannabis during intoxication varies among individuals and may not occur in all users. There is evidence that the neurocognitive response to acute cannabis exposure is driven by changes in the activity of the mesocorticolimbic and salience networks, can be exacerbated or mitigated by biological and pharmacological factors, varies with product formulations and frequency of use and can differ between recreational and therapeutic use. It is argued that these determinants of the cannabis-induced neurocognitive state should be taken into account when defining and evaluating levels of cannabis impairment in the legal arena, when prescribing cannabis in therapeutic settings and when informing society about the safe and responsible use of cannabis.

Goods and Bads of the Endocannabinoid System as a Therapeutic Target: Lessons Learned after 30 Years.

The cannabis derivative marijuana is the most widely used recreational drug in the Western world and is consumed by an estimated 83 million individuals (∼3% of the world population). In recent years, there has been a marked transformation in society regarding the risk perception of cannabis, driven by its legalization and medical use in many states in the United States and worldwide. Compelling research evidence and the Food and Drug Administration cannabis-derived cannabidiol approval for severe childhood epilepsy have confirmed the large therapeutic potential of cannabidiol itself, Δ9-tetrahydrocannabinol and other plant-derived cannabinoids (phytocannabinoids). Of note, our body has a complex endocannabinoid system (ECS)-made of receptors, metabolic enzymes, and transporters-that is also regulated by phytocannabinoids. The first endocannabinoid to be discovered 30 years ago was anandamide (N-arachidonoyl-ethanolamine); since then, distinct elements of the ECS have been the target of drug design programs aimed at curing (or at least slowing down) a number of human diseases, both in the central nervous system and at the periphery. Here a critical review of our knowledge of the goods and bads of the ECS as a therapeutic target is presented to define the benefits of ECS-active phytocannabinoids and ECS-oriented synthetic drugs for human health. SIGNIFICANCE STATEMENT: The endocannabinoid system plays important roles virtually everywhere in our body and is either involved in mediating key processes of central and peripheral diseases or represents a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of the components of this complex system, and in particular of key receptors (like cannabinoid receptors 1 and 2) and metabolic enzymes (like fatty acid amide hydrolase and monoacylglycerol lipase), will advance our understanding of endocannabinoid signaling and activity at molecular, cellular, and system levels, providing new opportunities to treat patients.

Loss of daylength sensitivity by splice site mutation in Cannabis pseudo-response regulator.

Photoperiod insensitivity (auto-flowering) in drug-type Cannabis sativa circumvents the need for short day (SD) flowering requirements making outdoor cultivation in high latitudes possible. However, the benefits of photoperiod insensitivity are counterbalanced by low cannabinoid content and poor flower quality in auto-flowering genotypes. Despite recent studies in cannabis flowering, a mechanistic understanding of photoperiod insensitivity is still lacking. We used a combination of genome-wide association study and genetic fine-mapping to identify the genetic cause of auto-flowering in cannabis. We then used gene expression analyses and transient transformation assays to characterize flowering time control. Herein, we identify a splice site mutation within circadian clock gene PSEUDO-RESPONSE REGULATOR 37 (CsPRR37) in auto-flowering cannabis. We show that CsPRR37 represses FT expression and its circadian oscillations transition to a less repressive state during SD as compared to long days (LD). We identify several key circadian clock genes whose expression is altered in auto-flowering cannabis, particularly under non-inductive LD. Research into the pervasiveness of this mutation and others affecting flowering time will help elucidate cannabis domestication history and advance cannabis breeding toward a more sustainable outdoor cultivation system.

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.

Deep learning-based quantification and transcriptomic profiling reveal a methyl jasmonate-mediated glandular trichome formation pathway in Cannabis sativa.

Cannabis glandular trichomes (GTs) are economically and biotechnologically important structures that have a remarkable morphology and capacity to produce, store, and secrete diverse classes of secondary metabolites. However, our understanding of the developmental changes and the underlying molecular processes involved in cannabis GT development is limited. In this study, we developed Cannabis Glandular Trichome Detection Model (CGTDM), a deep learning-based model capable of differentiating and quantifying three types of cannabis GTs with a high degree of efficiency and accuracy. By profiling at eight different time points, we captured dynamic changes in gene expression, phenotypes, and metabolic processes associated with GT development. By integrating weighted gene co-expression network analysis with CGTDM measurements, we established correlations between phenotypic variations in GT traits and the global transcriptome profiles across the developmental gradient. Notably, we identified a module containing methyl jasmonate (MeJA)-responsive genes that significantly correlated with stalked GT density and cannabinoid content during development, suggesting the existence of a MeJA-mediated GT formation pathway. Our findings were further supported by the successful promotion of GT development in cannabis through exogenous MeJA treatment. Importantly, we have identified CsMYC4 as a key transcription factor that positively regulates GT formation via MeJA signaling in cannabis. These findings provide novel tools for GT detection and counting, as well as valuable information for understanding the molecular regulatory mechanism of GT formation, which has the potential to facilitate the molecular breeding, targeted engineering, informed harvest timing, and manipulation of cannabinoid production.

Cannabis Legalization and Detection of Tetrahydrocannabinol in Injured Drivers.

BACKGROUND: The effect of cannabis legalization in Canada (in October 2018) on the prevalence of injured drivers testing positive for tetrahydrocannabinol (THC) is unclear. METHODS: We studied drivers treated after a motor vehicle collision in four British Columbia trauma centers, with data from January 2013 through March 2020. We included moderately injured drivers (those whose condition warranted blood tests as part of clinical assessment) for whom excess blood remained after clinical testing was complete. Blood was analyzed at the provincial toxicology center. The primary outcomes were a THC level greater than 0, a THC level of at least 2 ng per milliliter (Canadian legal limit), and a THC level of at least 5 ng per milliliter. The secondary outcomes were a THC level of at least 2.5 ng per milliliter plus a blood alcohol level of at least 0.05%; a blood alcohol level greater than 0; and a blood alcohol level of at least 0.08%. We calculated the prevalence of all outcomes before and after legalization. We obtained adjusted prevalence ratios using log-binomial regression to model the association between substance prevalence and legalization after adjustment for relevant covariates. RESULTS: During the study period, 4339 drivers (3550 before legalization and 789 after legalization) met the inclusion criteria. Before legalization, a THC level greater than 0 was detected in 9.2% of drivers, a THC level of at least 2 ng per milliliter in 3.8%, and a THC level of at least 5 ng per milliliter in 1.1%. After legalization, the values were 17.9%, 8.6%, and 3.5%, respectively. After legalization, there was an increased prevalence of drivers with a THC level greater than 0 (adjusted prevalence ratio, 1.33; 95% confidence interval [CI], 1.05 to 1.68), a THC level of at least 2 ng per milliliter (adjusted prevalence ratio, 2.29; 95% CI, 1.52 to 3.45), and a THC level of at least 5 ng per milliliter (adjusted prevalence ratio, 2.05; 95% CI, 1.00 to 4.18). The largest increases in a THC level of at least 2 ng per milliliter were among drivers 50 years of age or older (adjusted prevalence ratio, 5.18; 95% CI, 2.49 to 10.78) and among male drivers (adjusted prevalence ratio, 2.44; 95% CI, 1.60 to 3.74). There were no significant changes in the prevalence of drivers testing positive for alcohol. CONCLUSIONS: After cannabis legalization, the prevalence of moderately injured drivers with a THC level of at least 2 ng per milliliter in participating British Columbia trauma centers more than doubled. The increase was largest among older drivers and male drivers. (Funded by the Canadian Institutes of Health Research.).

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 synthases7,8. 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.

Trends in U.S. Medical Cannabis Registrations, Authorizing Clinicians, and Reasons for Use From 2020 to 2022.

BACKGROUND: As medical cannabis availability increases, up-to-date trends in medical cannabis licensure can inform clinical policy and care. OBJECTIVE: To describe current trends in medical cannabis licensure in the United States. DESIGN: Ecological study with repeated measures. SETTING: Publicly available state registry data from 2020 to 2022. PARTICIPANTS: People with medical cannabis licenses and clinicians authorizing cannabis licenses in the United States. MEASUREMENTS: Total patient volume and prevalence per 10 000 persons in the total population, symptoms or conditions qualifying patients for licensure (that is, patient-reported qualifying conditions), and number of authorizing clinicians. RESULTS: In 2022, of 39 jurisdictions allowing medical cannabis use, 34 reported patient numbers, 19 reported patient-reported qualifying conditions, and 29 reported authorizing clinician numbers. Enrolled patients increased 33.3% from 2020 (3 099 096) to 2022 (4 132 098), with a corresponding 23.0% increase in the population prevalence of patients (175.0 per 10 000 in 2020 to 215.2 per 10 000 in 2022). However, 13 of 15 jurisdictions with nonmedical adult-use laws had decreased enrollment from 2020 to 2022. The proportion of patient-reported qualifying conditions with substantial or conclusive evidence of therapeutic value decreased from 70.4% (2020) to 53.8% (2022). Chronic pain was the most common patient-reported qualifying condition in 2022 (48.4%), followed by anxiety (14.2%) and posttraumatic stress disorder (13.0%). In 2022, the United States had 29 500 authorizing clinicians (7.7 per 1000 patients), 53.5% of whom were physicians. The most common specialties reported were internal or family medicine (63.4%), physical medicine and rehabilitation (9.1%), and anesthesia or pain (7.9%). LIMITATION: Missing data (for example, from California), descriptive analysis, lack of information on individual use patterns, and changing evidence base. CONCLUSION: Enrollment in medical cannabis programs increased overall but generally decreased in jurisdictions with nonmedical adult-use laws. Use for conditions or symptoms without a strong evidence basis continues to increase. Given these trends, more research is needed to better understand the risks and benefits of medical cannabis. PRIMARY FUNDING SOURCE: National Institute on Drug Abuse of the National Institutes of Health.

Cannabis for chronic pain: cardiovascular safety in a nationwide Danish study.

BACKGROUND AND AIMS: A rising number of countries allow physicians to treat chronic pain with medical cannabis. However, recreational cannabis use has been linked with cardiovascular side effects, necessitating investigations concerning the safety of prescribed medical cannabis. METHODS: Using nationwide Danish registers, patients with chronic pain initiating first-time treatment with medical cannabis during 2018-21 were identified and matched 1:5 to corresponding control patients on age, sex, chronic pain diagnosis, and concomitant use of other pain medication. The absolute risks of first-time arrhythmia (atrial fibrillation/flutter, conduction disorders, paroxysmal tachycardias, and ventricular arrhythmias) and acute coronary syndrome were reported comparing medical cannabis use with no use. RESULTS: Among 1.88 million patients with chronic pain (46% musculoskeletal, 11% cancer, 13% neurological, and 30% unspecified pain), 5391 patients claimed a prescription of medical cannabis [63.2% women, median age: 59 (inter-quartile range 48-70) years] and were compared with 26 941 control patients of equal sex- and age composition. Arrhythmia was observed in 42 and 107 individuals, respectively, within 180 days. Medical cannabis use was associated with an elevated risk of new-onset arrhythmia {180-day absolute risk: 0.8% [95% confidence interval (CI) 0.6%-1.1%]} compared with no use [180-day absolute risk: 0.4% (95% CI 0.3%-0.5%)]: a risk ratio of 2.07 (95% CI 1.34-2.80) and a 1-year risk ratio of 1.36 (95% CI 1.00-1.73). No significant association was found for acute coronary syndrome [180-day risk ratio: 1.20 (95% CI 0.35-2.04)]. CONCLUSIONS: In patients with chronic pain, the use of prescribed medical cannabis was associated with an elevated risk of new-onset arrhythmia compared with no use-most pronounced in the 180 days following the initiation of treatment.

A protocol for rapid generation cycling (speed breeding) of hemp (Cannabis sativa) for research and agriculture.

Hemp (Cannabis sativa) is a highly versatile crop with a multitude of applications, from textiles, biofuel and building material to high-value food products for consumer markets. Furthermore, non-hallucinogenic cannabinoids like cannabidiol (CBD), which can be extracted from female hemp flowers, are potentially valuable pharmacological compounds. In addition, hemp has high carbon sequestration potential associated with its rapid growth rate. Therefore, the hemp industry is gaining more traction and breeding hemp cultivars adapted to local climate conditions or bred for specific applications is becoming increasingly important. Here, we present a method for the rapid generation cycling (speed breeding) of hemp. The speed breeding protocol makes use of the photoperiod sensitivity of Cannabis. It encompasses vegetative growth of the plants for 2 weeks under continuous light, followed by 4 weeks under short-day conditions, during which flower induction, pollination and seed development proceed, and finally a seed ripening phase under continuous light and water stress. With the protocol described here, a generation time of under 9 weeks (61 days) from seed to seed can be achieved. Furthermore, our method synchronises the flowering time of different hemp cultivars, thus facilitating crosses between cultivars. The extremely short generation time will enable hemp researchers and breeders to perform crosses in a time-efficient way and generate new hemp cultivars with defined genetic characteristics over a short period of time.