Analysis of the genetic diversity of Chinese native Cannabis sativa cultivars by using ISSR and chromosome markers

Evidence of the Ability of Microsatellite Method to Distinguish Cannabis Strains with High Cannabinoid Content

Introduction: Cannabis is a plant with high potential for use in several sectors of the industry; however, it is also a controversial crop due to its tetrahydrocannabinol (THC) content. Moreover, the plant has a rather unclarified classification. Traditionally, two types of Cannabis have been distinguished, hemp as a source of fiber and low THC content, and marijuana with high THC levels, which is used as a drug. With the increasing use of CBD strains and wide range of commercially used THC strains, it is becoming paramount to be able to develop an easy and reliable method for Cannabis strain differentiation. The use of simple sequence repeat markers, or microsatellites, seems to be an applicable choice. Materials and Methods: In this study, 52 strains of Cannabis with variable cannabinoid content were collected from growers from different geographical regions and analyzed using 17 different microsatellite markers. For more precise differentiation, five strains were selected and a higher number of individuals of each were analyzed. Results: Fragment analysis and cluster analysis showed that when one to three individual plants per strain were analyzed, the method was able to classify these samples into distinguishable groups with similar gene structure. They also revealed that when a larger sample set was used (10 individual plants per strain), highly specific strain clusters could be fully discriminated. Conclusion: Our study involved the highest number of cannabinoid-rich strains up to now and showed that the microsatellite method can be used to reliably differentiate Cannabis strains and show their relationships.

Phytochemical differences of hemp (Cannabis sativa L.) leaves from different germplasms and their regulatory effects on lipopolysaccharide-induced inflammation in Matin-Darby canine kidney cell lines

The increasing demand of hemp (Cannabis sativa L.) has attracted more interest in exploring its phytochemical profile and bioactivities, such as anti-inflammatory effect. In this study, the phytochemicals of different hemp leaves were investigated, with the content order: total saponins content (TSC) > total alkaloids content (TAC) > total phenolics content (TPC) > total flavonoids content (TFC) > cannabinoids. Hemp leaves from Shanxi accumulated higher flavonoids and cannabinoids (i.e., THC, CBD, and CBN), while phenolics were more abundant in those from Hunan. A lipopolysaccharide (LPS)-induced inflammatory Matin-Darby canine kidney (MDCK) cell model was established to evaluate the anti-inflammatory effects of hemp leaf extracts. Hemp leaf extracts, especially the D129 and c7, significantly increased cell viability of LPS-induced inflammatory MDCK cells, and D132 significantly decreased the secretion of pro-inflammatory cytokines (TNF-α and IL-6) and the lactate dehydrogenase (LDH) activity. Except for c12, other hemp leaf extracts obviously decreased the cell morphological damage of LPS-induced inflammatory MDCK cells. The correlation analysis revealed that cannabinol (CBN) and TPC showed the strongest correlation with anti-inflammatory activities, and hierarchical clustering analysis also showed that hemp germplasms from Shanxi might be good alternatives to the common cultivar Ym7 due to their better anti-inflammatory activities. These results indicated that hemp leaves were effective in LPS-induced inflammatory MDCK cells, and flavonoids and cannabinoids were potential geographical markers for distinguishing them, which can provide new insights into the anti-inflammatory effect of hemp leaves and facilitate the application of hemp leaves as functional ingredients against inflammatory-related disorders.

Genome-wide development of insertion-deletion (InDel) markers for Cannabis and its uses in genetic structure analysis of Chinese germplasm and sex-linked marker identification

Background

Cannabis sativa L., a dioecious plant derived from China, demonstrates important medicinal properties and economic value worldwide. Cannabis properties have been usually harnessed depending on the sex of the plant. To analyse the genetic structure of Chinese Cannabis and identify sex-linked makers, genome-wide insertion-deletion (InDel) markers were designed and used.

Results

In this study, a genome-wide analysis of insertion-deletion (InDel) polymorphisms was performed based on the recent genome sequences. In total, 47,558 InDels were detected between the two varieties, and the length of InDels ranged from 4 bp to 87 bp. The most common InDels were tetranucleotides, followed by pentanucleotides. Chromosome 5 exhibited the highest number of InDels among the Cannabis chromosomes, while chromosome 10 exhibited the lowest number. Additionally, 31,802 non-redundant InDel markers were designed, and 84 primers evenly distributed in the Cannabis genome were chosen for polymorphism analysis. A total of 38 primers exhibited polymorphisms among three accessions, and of the polymorphism primers, 14 biallelic primers were further used to analyse the genetic structure. A total of 39 fragments were detected, and the PIC value ranged from 0.1209 to 0.6351. According to the InDel markers and the flowering time, the 115 Chinese germplasms were divided into two subgroups, mainly composed of cultivars obtained from the northernmost and southernmost regions, respectively. Additional two markers, “Cs-I1–10” and “Cs-I1–15”, were found to amplify two bands (398 bp and 251 bp; 293 bp and 141 bp) in the male plants, while 389-bp or 293-bp bands were amplified in female plants. Using the two markers, the feminized and dioecious varieties could also be distinguished.

Conclusion

Based on the findings obtained herein, we believe that this study will facilitate the genetic improvement and germplasm conservation of Cannabis in China, and the sex-linked InDel markers will provide accurate sex identification strategies for Cannabis breeding and production.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07883-w.

Cannabis sativa: Interdisciplinary Strategies and Avenues for Medical and Commercial Progression Outside of CBD and THC

Cannabis sativa (Cannabis) is one of the world’s most well-known, yet maligned plant species. However, significant recent research is starting to unveil the potential of Cannabis to produce secondary compounds that may offer a suite of medical benefits, elevating this unique plant species from its illicit narcotic status into a genuine biopharmaceutical. This review summarises the lengthy history of Cannabis and details the molecular pathways that underpin the production of key secondary metabolites that may confer medical efficacy. We also provide an up-to-date summary of the molecular targets and potential of the relatively unknown minor compounds offered by the Cannabis plant. Furthermore, we detail the recent advances in plant science, as well as synthetic biology, and the pharmacology surrounding Cannabis. Given the relative infancy of Cannabis research, we go on to highlight the parallels to previous research conducted in another medically relevant and versatile plant, Papaver somniferum (opium poppy), as an indicator of the possible future direction of Cannabis plant biology. Overall, this review highlights the future directions of cannabis research outside of the medical biology aspects of its well-characterised constituents and explores additional avenues for the potential improvement of the medical potential of the Cannabis plant.

Antioxidant and antimicrobial activity of two standardized extracts from a new Chinese accession of non-psychotropic Cannabis sativa L

The purpose of this study was to evaluate the antioxidant and antimicrobial properties of two extracts from a new Chinese accession (G-309) of Cannabis sativa L. (Δ⁹ -tetrahydrocannabinol <0.2%) with high content of propyl side chain phytocannabinoids. Dried flowering tops, as such and after hydrodistillation of the essential oil, were extracted with acidic hexane to produce the Cannabis Chinese hexane extract 1 (CChHE1) and 2 (CChHE2), respectively. The phytochemical profile of CChHE1 and CChHE2 was investigated by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-diode array detector-electrospray ionization-tandem mass spectrometry (LC-DAD-ESI-MS/MS) analyses. The antioxidant properties were assessed by several in vitro cell-free assays. The antimicrobial activity was evaluated against Gram-positive and Gram-negative bacteria and the yeast Candida albicans. Phytochemical analyses highlighted a high content of cannabidivarinic acid (CBDVA) and tetraydrocannabivarinic acid (THCVA) in CChHE1, and cannabidivarin (CBDV) and tetraydrocannabivarin (THCV) in CChHE2. Both extracts showed remarkable antioxidant activity and strong antimicrobial properties (MIC 39.06 and MBC 39.06-78.13 μg/ml) against both ATCC and methicillin-resistant clinical strains of Staphylococcus aureus. In conclusion, standardized extracts of C. sativa Chinese accession could be promising for their possible use as novel antibacterial agents for the treatment of widespread S. aureus infections.

Genetic Diversity and Population Structure of Cannabis Based on the Genome-Wide Development of Simple Sequence Repeat Markers

Cannabis has been used as a source of nutrition, medicine, and fiber. However, lack of genomic simple sequence repeat (SSR) markers had limited the genetic research on Cannabis species. In the present study, 92,409 motifs were identified, and 63,707 complementary SSR primer pairs were developed. The most abundant SSR motifs had six repeat units (36.60%). The most abundant type of motif was dinucleotides (70.90%), followed by trinucleotides, tetranucleotides, and pentanucleotides. We randomly selected 80 pairs of genomic SSR markers, of which 69 (86.25%) were amplified successfully; 59 (73.75%) of these were polymorphic. Genetic diversity and population structure were estimated using the 59 (72 loci) validated polymorphic SSRs and three phenotypic markers. Three hundred ten alleles were identified, and the major allele frequency ranged from 0.26 to 0.85 (average: 0.56), Nei’s genetic diversity ranged from 0.28 to 0.82 (average: 0.56), and the expected heterozygosity ranged from 0.28 to 0.81 (average: 0.56). The polymorphism information content ranged from 0.25 to 0.79 (average: 0.50), the observed number of alleles ranged from 2 to 8 (average: 4.13), and the effective number of alleles ranged from 0.28 to 0.81 (average: 0.5). The Cannabis population did not show mutation-drift equilibrium following analysis via the infinite allele model. A cluster analysis was performed using the unweighted pair group method using arithmetic means based on genetic distances. Population structure analysis was used to divide the germplasms into two subgroups. These results provide guidance for the molecular breeding and further investigation of Cannabis.

Promising in vitro antioxidant, anti-acetylcholinesterase and neuroactive effects of essential oil from two non-psychotropic Cannabis sativa L. biotypes

The aim of this study was to compare the micro-morphological features of two different non-drug Cannabis sativa L. biotypes (Chinese accession G-309 and one fibrante variety) and to evaluate the phytochemical profile as well as some biological properties of the essential oils (EOs) obtained by hydrodistillation of dried flowering tops. After a micro-morphological evaluation by scanning electron microscopy, the phytochemical composition was analysed by GC-FID and GC-MS analyses. Antioxidant and anti-acetylcholinesterase properties were investigated by several in vitro cell-free assays, while neuroactive effects were evaluated on mouse cortical neuronal as well as human iPS cell-derived central nervous system cells grown on MEA chips. Both EOs showed strong antioxidant properties mainly attributable to the high content of hydroxylated compounds as well as significant anti-acetylcholinesterase activities (IC₅₀ 74.64 and 57.31 μg/ml for Chinese accession and fibrante variety, respectively). Furthermore, they showed a concentration-dependent inhibition of spontaneous electrical activity of human and mouse neuronal networks, with the fibrante variety, which showed the best activity (MFR, IC₅₀ 0.71 and 10.60 μg/ml, respectively). The observed biological activities could be due to a synergic effect between terpenes and phytocannabinoids, although in vivo studies, which clarify the molecular mechanism, are still lacking.

OFP1 Interaction with ATH1 Regulates Stem Growth, Flowering Time and Flower Basal Boundary Formation in Arabidopsis

Ovate Family Protein1 (OFP1) is a regulator, and it is suspected to be involved in plant growth and development. Meanwhile, Arabidopsis Thaliana Homeobox (ATH1), a BEL1-like homeodomain (HD) transcription factor, is known to be involved in regulating stem growth, flowering time and flower basal boundary development in Arabidopsis. Previous large-scale yeast two-hybrid studies suggest that ATH1 possibly interact with OFP1, but this interaction is yet unverified. In our study, the interaction of OFP1 with ATH1 was verified using a directional yeast two-hybrid system and bimolecular fluorescence complementation (BiFC). Our results also demonstrated that the OFP1-ATH1 interaction is mainly controlled by the HD domain of ATH1. Meanwhile, we found that ATH1 plays the role of transcriptional repressor to regulate plant development and that OFP1 can enhance ATH1 repression function. Regardless of the mechanism, a putative functional role of ATH1-OFP1 may be to regulate the expression of the both the GA20ox1 gene, which is involved in gibberellin (GA) biosynthesis and control of stem elongation, and the Flowering Locus C (FLC) gene, which inhibits transition to flowering. Ultimately, the regulatory functional mechanism of OFP1-ATH1 may be complicated and diverse according to our results, and this work lays groundwork for further understanding of a unique and important protein⁻protein interaction that influences flowering time, stem development, and flower basal boundary development in plants.

Assessment of Genetic Diversity and Population Structure in Iranian Cannabis Germplasm

Cannabis sativa has a complex history reflected in both selection on naturally occurring compounds and historical trade routes among humans. Iran is a rich resource of natural populationswhich hold the promise to characterize historical patterns of population structure and genetic diversity within Cannabis. Recent advances in high-throughput DNA sequencing technologies have dramatically increased our ability to produce information to the point that it is now feasible to inexpensively obtain population level genotype information at a large scale. In the present investigation, we have explored the use of Genotyping-By-Sequencing (GBS) in Iranian cannabis. We genotyped 98 cannabis samples 36 from Iranian locations and 26 accessions from two germplasm collections. In total, 24,710 high-quality Single Nucleotide Polymorphisms (SNP) were identified. Clustering analysis by Principal Component Analysis (PCA) identified two genetic clusters among Iranian populations and fineSTRUCTURE analysis identified 19 populations with some geographic partitioning. We defined Iranian cannabis in two main groups using the results of the PCA and discovered some strong signal to define some locations as population according to fineSTRUCTURE analyses. However, single nucleotide variant analysis uncovered a relatively moderate level of variation among Iranian cannabis.

Cannabis in Chinese Medicine: Are Some Traditional Indications Referenced in Ancient Literature Related to Cannabinoids?

Cannabis sativa L. (Cannabaceae) has a long history of utilization as a fiber and seed crop in China, and its achenes (“seeds”) as well as other plant parts have been recorded in Chinese medical texts for nearly 2000 years. While the primary applications of cannabis in Chinese medicine center around the use of the achenes, ancient indications for the female inflorescence, and other plant parts include conditions such as pain and mental illness that are the subject of current research into cannabinoids such as cannabidiol (CBD) and Δ⁹-tetrahydrocannabinol (THC). However, little previous research has been conducted to analyze the Chinese medical literature in light of recent advances in the pharmacology and taxonomy of cannabis, and most of the relevant Chinese historical records have not yet been translated into Western languages to facilitate textual research. Furthermore, many key questions remain unresolved in the Chinese literature, including how various traditional drug names precisely correspond to different plant parts, as well as the implications of long-term selection for fiber-rich cultivars on the medical applications of cannabis in Chinese medicine. In this article, prominent historical applications of cannabis in Chinese medicine are chronologically reviewed, and indications found in ancient Chinese literature that may relate to cannabinoids such as CBD and Δ⁹-THC are investigated.

A Belated Green Revolution for Cannabis: Virtual Genetic Resources to Fast-Track Cultivar Development

Cannabis is a predominantly diecious phenotypically diverse domesticated genus with few if any extant natural populations. International narcotics conventions and associated legislation have constrained the establishment, characterization, and use of Cannabis genetic resource collections. This has resulted in the underutilization of genepool variability in cultivar development and has limited the inclusion of secondary genepools associated with genetic improvement strategies of the Green Revolution. The structured screening of ex situ germplasm and the exploitation of locally-adapted intraspecific traits is expected to facilitate the genetic improvement of Cannabis. However, limited attempts have been made to establish the full extent of genetic resources available for pre-breeding. We present a thorough critical review of Cannabis ex situ genetic resources, and discuss recommendations for conservation, pre-breeding characterization, and genetic analysis that will underpin future cultivar development. We consider East Asian germplasm to be a priority for conservation based on the prolonged historical cultivation of Cannabis in this region over a range of latitudes, along with the apparent high levels of genetic diversity and relatively low representation in published genetic resource collections. Seed cryopreservation could improve conservation by reducing hybridization and genetic drift that may occur during Cannabis germplasm regeneration. Given the unique legal status of Cannabis, we propose the establishment of a global virtual core collection based on the collation of consistent and comprehensive provenance meta-data and the adoption of high-throughput DNA sequencing technologies. This would enable representative core collections to be used for systematic phenotyping, and so underpin breeding strategies for the genetic improvement of Cannabis.