# Multi-Omics Approaches to Study Molecular Mechanisms in _Camanabis sativa_
###### Abstract
\begin{table}
\begin{tabular}{c c} \hline \hline
**Abbreviations** & **Definition** \\ \hline CBC & Cannabichromene \\ CBCA & Cannabichromenic Acid \\ CBD & Cannabidiol \\ CBDA & Acidic Precursors of Cannabidiol \\ CBG & Cannabigerol \\ CBGA & Acidic Precursors of Cannabigerolic \\ CBDRx & High Cannabidiol Content Cannabis Cultivar \\ CNV & Copy Number Variation \\ DEG & Differentially Expressed Gene \\ DLLIME & Dispersive Liquid-Liquid Microextraction \\ DMAPP & Dimethylallyl Diphosphate \\ FN & Finola Cannabis Cultivar \\ GBS & Genotype By Sequencing \\ GC-EIMS & Gas Chromatography-Electron Impact Mass Spectrometry \\ GC-FID & Gas Chromatography-Flame Ionization Detection \\ GC-MS & Gas Chromatography-Mass Spectrometry \\ GFP & Gervani Diphosphate \\ GS & Genomic Selection \\ GWAS & Genome-Wide Association Study \\ HPLC & High Performance Liquid Chromatography \\ HRMS & High-Resolution Mass Spectrometry \\ HS-SPME & Headspace Solid-Phase Micro Extraction \\ IPP & Isopentenyl Diphosphate \\ ISO-Seq & Isoform Sequencing \\ JL & Jamaican Lion Cannabis Cultivar \\ LC-DAD & Liquid Chromatography-Diode Array Detector \\ LC-MS & Liquid Chromatography-Mass Spectrometry \\ MEP & Methylerthroit Phosphate \\ MS & Mass Spectrometry \\ NGS & Next Generation Sequencing \\ NMR & Nuclear Magnetic Resonance \\ OA & Olivetolic Acid \\ ORF & Open Reading Frames \\ PAVs & Presence/Absence Variations \\ PPFD & Photostynthetic Photon Flux Density \\ PK & Purple Kush Cannabis Cultivar \\ QTL & Quantitative Trait Loci \\ QQQ & Triple-Quadrupole Mass Spectrometry \\ qRT-PCR & Real time/Quantitative PCR—Polymerase Chain Reaction \\ RNA-Seq & RNA-Sequencing \\ ROS & Reactive Oxygen Species \\ SFE & Supercritical Fluid Extraction \\ SMRT & Single-Molecule Real-Time Sequencing \\ SNPs & Single Nucleotide Polymorphisms \\ \hline \hline \end{tabular}
\end{table} 
Table 1: List of abbreviations used in this manuscript. Within a given cannabis species, cultivars are categorised into groups based on their chemotype, from I to V, according to the number and ratio of main cannabinoids [16]. These compound profiles can be employed both as quality markers and fingerprints for cannabis standardization. Cannabis growth can be divided into four distinct phases: germination, seedling, vegetative and flowering stage. Each phase is characterised by its own photoperiod, environmental and nutritional needs [17]. Cannabis germinates, reaches maturity, reproduces and dies in one year in the wild. The flowers are unisexual, and therefore male and female individuals are distinct. However, hermaphrodites have often been documented [17; 18]. In general, males and females are not identified until the second week of the bloom cycle. Since only female inflorescences are used to produce extracts, once a male plant is identified, it is generally discarded. The vegetative phase is characterised by the greatest increase in biomass and overall growth. During this phase, roots extend considerably, leaves start growing and expanding to increase the photosynthetic area, and transpiration rises, so water intake increases as well. The reproductive phase of cannabis development involves massive hormonal changes induced by photoperiod and this can be enhanced by an increase in red and far-red wavelengths of light [17; 18]. In this phase, the first major increase in cannabinoid levels occurs in female inflorescences [17; 18]. Due to the legislation regulating cannabis cultivation, the cannabinoid biosynthetic pathway has not been characterized in detail, especially from a molecular and genetic perspective [19]. Conversely, many other major crop species have already been widely studied, especially after the development of next generation sequencing (NGS) technologies [19; 20]. The recent relaxation in legislation [21; 22], as well as the availability of the cannabis genomic sequence, consisting of a complex genome, containing 843 Mb and 818 Mb for male and female plants, respectively [23], is now facilitating research on this crop.