Simulated microgravity contributed to modification of callogenesis performance and secondary metabolite production in CannabisIndica

Low UV radiation influenced DNA methylation, gene regulation, cell proliferation, viability, and biochemical differentiation in the cell suspension cultures of Cannabis indica

The effect of low artificial Ultraviolet (UV) on the DNA methylation remains controversial. This study addresses how differential photoperiods of UV radiation affect the biochemical and molecular behaviors of Cannabis indica cell suspension cultures. The cell suspensions were illuminated with the compact fluorescent lamps (CFL), emitting a combination of 10% UVB, 30% UVA, and the rest visible wavelengths for 0, 4, 8, and 16 h. The applied photoperiods influenced cell morphological characteristics. The 4 h photoperiod was the most effective treatment for improving biomass, growth index and cell viability percentage while these indices remained non-significant in the 16 h treatment. The methylation-sensitive amplified polymorphism (MASP) assay revealed that the UV radiation was epigenetically accompanied by DNA hypermethylation. The light-treated cells significantly displayed higher relative expression of the cannabidiolic‌ acid synthase (CBDAS) and delta9-tetrahydrocannabinolic acid synthase (THCAS) genes about 4-fold. The expression of the olivetolic acid cyclase (OAC) and olivetol synthase (OLS) genes exhibited an upward trend in response to the UV radiation. The light treatments also enhanced the proline content and protein concentration. The 4 h illumination was significantly capable of improving the cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) concentrations, in contrast with 16 h. By increasing the illumination exposure time, the activity of the phenylalanine ammonia-lyase (PAL) enzyme linearly upregulated. The highest amounts of the phenylpropanoid derivatives were observed in the cells cultured under the radiation for 4 h. Taken collective, artificial UV radiation can induce DNA methylation modifications and impact biochemical and molecular differentiation in the cell suspensions in a photoperiod-dependent manner.

Methyl jasmonate conferred Arsenic tolerance in Thymus kotschyanus by DNA hypomethylation, stimulating terpenoid metabolism, and upregulating two cytochrome P450 monooxygenases

Arsenic (As) is a highly cytotoxic element impairing normal cellular functions, and its bioremediation has become one of the environmental concerns. This study explored the molecular and physiological responses of thyme (Thymus kotschyanus) seedlings to incorporating As (0 and 10 mgl-1) and methyl jasmonate (MJ; 0 and 10 µM) into the culture medium. The MJ treatment reinforced root system and mitigated the As cytotoxicity risk. MJ contributed to hypomethylation, a potential adaptation mechanism for conferring the As tolerance. Two cytochrome P450 monooxygenases, including CYP71D178 and CYP71D180 genes, were upregulated in response to As and MJ. The MJ treatment contributed to up-regulation in the γ-terpinene synthase (TPS) gene, a marker gene in the terpenoid metabolism. The As presence reduced photosynthetic pigments (chlorophylls and carotenoids), while the MJ utilization alleviated the As toxicity. The MJ supplementation increased proline accumulation and soluble phenols. The application of MJ declined the toxicity sign of As on the concentration of proteins. The activities of peroxidase, catalase, and phenylalanine ammonia-lyase (PAL) enzymes displayed an upward trend in response to As and MJ treatments. Taken collective, MJ can confer the As tolerance by triggering DNA hypomethylation, regulating CYPs, and stimulating primary and secondary metabolism, especially terpenoid.

Silicon nanoparticles (SiNPs) stimulated secondary metabolism and mitigated toxicity of salinity stress in basil (Ocimum basilicum) by modulating gene expression: a sustainable approach for crop protection

The underlying mechanisms through which silicon oxide nanoparticles (SiNPs) can confer salinity resistance to plants are poorly understood. This study explored the efficacy of supplementing nutrient solution with SiNPs (20-30 nm; 10 mg kg-1 soil) to stimulate metabolism and alleviate the risks associated with salinity (0.73 g kg-1 soil) in basil seedlings. For this purpose, variations in photosynthetic indices, proline osmoprotectant, antioxidant markers, phenylpropanoid metabolism, and transcriptional behaviors of genes were investigated. SiNPs increased shoot fresh weight (38%) and mitigated the risk associated with the salinity stress by 14%. SiNPs alleviated the inhibitory effects of salinity on the total chlorophyll concentration by 15%. The highest increase (twofold) in proline content was recorded in the SiNP-treated seedlings grown under salinity. The nano-supplement enhanced the activity of enzymatic antioxidants, including peroxidase (2.5-fold) and catalase (4.7-fold). SiNPs induced the expression of gamma-cadinene synthase (CDS) and caffeic acid O-methyltransferase (COMT) genes by 6.5- and 18.3-fold, respectively. SiNPs upregulated the eugenol synthase (EGS1) and fenchol synthase (FES) genes by six- and nine-fold, respectively. Salinity transcriptionally downregulated the geraniol synthase (GES) gene, while this gene displayed an upward trend in response to SiNPs by eight-fold. The nano-supplement transcriptionally stimulated the R-linalool synthase (LIS) gene by 3.3-fold. The terpinolene synthase (TES) gene displayed a similar trend to that of the GES gene. The highest expression (25-fold) of the phenylalanine ammonia-lyase (PAL) gene was recorded in seedlings supplemented with SiNPs. The physiological and molecular assessments demonstrated that employing SiNPs is a sustainable strategy for improving plant primary/secondary metabolism and crop protection.

Alteration in the callogenesis, tropane alkaloid formation, and gene expression in Hyoscyamus niger under clinorotation

This study aimed to investigate the effects of clinorotation induced by 2-D clinostat on the growth, tropane alkaloid production, gene expression, antioxidant capacity, and cellular defense responses in the callus tissue of Hyoscyamus niger. Callus induction was conducted by putting hypocotyl explants in the MS culture medium supplemented with 1 mgL-1 2,4-D and 1 mgL-1 BAP growth regulators. The sub-cultured calli were placed on a clinostat for 0, 3, 7, and 10 days (2.24 × 10-5 g on the edge of the callus ring). Clinorotation significantly increased callus fresh weight, dry weight, protein, carbohydrate, and proline contents compared to the control, and their maximum contents were obtained after 7 and 10 days. H2O2 level enhanced under clinorotation with a 76.3% rise after 10 days compared to control and positively affected the atropine (77.1%) and scopolamine (69.2%) productions. Hyoscyamine 6-beta hydroxylase and putrescine N-methyltransferase gene expression involved in the tropane alkaloid biosynthesis were upregulated markedly with 14.2 and 17.1-folds increase after 10 days of clinorotation, respectively. The expressions of jasmonic acid, mitogen-activated protein kinase, and ethylene-responsive element-binding transcription factor were upregulated, and the activity of peroxidase and catalase showed a 72.7 and 80% rise after 10 days. These findings suggest that microgravity can enhance callogenesis by stimulating the ROS level, which can impact the antioxidant enzymes, tropane alkaloid formation, and gene expression.

Carboxylic acid-functionalized multiwalled carbon nanotubes (COOH-MWCNTs) improved production of atropine in callus of Datura inoxia by influencing metabolism, gene regulation, and DNA cytosine methylation; an in vitro biological assessment

Atropine is a well-known tropane alkaloid commonly employed in medicine class called anticholinergics. This study intends to address biochemical and molecular responses of Datura inoxia calluses to fortifying culture medium with carboxylic acid-functionalized multi-walled carbon nanotubes (COOH-MWCNTs). The application of MWCNTs influenced callogenesis performance and biomass in a dose-dependent manner. The MWCNT at 5 mgL-1 resulted in the highest biomass of calluses by 57%. While, MWCNTs at high concentrations were accompanied by cytotoxicity. On the other hand, MWCNTs at concentrations above 100 mgL-1 exhibited cytotoxicity, decreased callogenesis performance, and reduced Atropine biosynthesis. The MWCNTs increased the activity of phenylalanine ammonia-lyase (PAL) and catalase enzymes. The concentrations of proline and soluble phenols displayed upward trends in response to using MWCNTs. According to the HPLC assessment, enriching culture medium with MWCNTs at 5 mgL-1 elicited Atropine production in calluses by 64%. The quantitative PCR assessment referred to the upregulation in the transcription of the PAL gene. The expression of ornithine decarboxylase (ODC) and putrescine N-methyltransferase 1 (PMT) genes were also upregulated in calluses cultured in a medium supplemented with MWCNTs. Methylation Sensitive Amplification Polymorphism (MSAP) technique indicated that employing MWCNTs altered the DNA methylation profile, reflecting epigenetic modification. Overall, engineering plant cells with MWCNTs as a nano-elicitor can be suggested for large-scale synthesis of industrially-valuable secondary metabolites.

Zinc oxide nanoparticles (ZnONPs) influenced seed development, grain quality, and remobilization by affecting the transcription of microRNA 171 (miR171), miR156, NAM, and SUT genes in wheat (Triticum aestivum): a biological advantage and risk assessment study

Limited studies have been conducted on the role of microRNAs (miRs) and transcription factors in regulating plant cell responses to nanoparticles. This study attempted to address whether the foliar application of zinc oxide nanoparticles (ZnONPs; 0, 10, 25, and 50 mgL^-1) can affect miRs, gene expression, and wheat grain quality. The seedlings were sprayed with ZnONPs (0, 10, 25, and 50 mgL^-1) or bulk counterpart (BZnO) five times at 72 h intervals. The application of ZnONPs at 10 mgL^-1 increased the number of spikelets and seed weight, while the nano-supplement at 50 mgL^-1 was accompanied by severe restriction on developing spikes and grains. ZnONPs, in a dose-dependent manner, transcriptionally influenced miR156 and miR171. The expression of miR171 showed a similar trend to that of miR156. The ZnONPs at optimum concentration upregulated the NAM transcription factor and sucrose transporter (SUT) at transcriptional levels. However, the transcription of both NAM and SUT genes displayed a downward trend in response to the toxic dose of ZnONPs (50 mgL^-1). Utilization of ZnONPs increased proline and total soluble phenolic content. Monitoring the accumulation of carbohydrates, including fructan, glucose, fructose, and sucrose, revealed that ZnONPs at 10 mgL^-1 modified the source/sink communication and nutrient remobilization. The molecular and physiological data revealed that the expression of miR156 and miR171 is tightly linked to seed grain development, remobilization of carbohydrates, and genes involved in nutrient transportation. This study establishes a novel strategy for obtaining higher yields in crops. This biological risk assessment investigation also displays the potential hazard of applying ZnONPs at the flowering developmental phase.

Regulation of DNA Methylation by Cannabidiol and Its Implications for Psychiatry: New Insights from In Vivo and In Silico Models

Cannabidiol (CBD) is a non-psychotomimetic compound present in cannabis sativa. Many recent studies have indicated that CBD has a promising therapeutic profile for stress-related psychiatric disorders, such as anxiety, schizophrenia and depression. Such a diverse profile has been associated with its complex pharmacology, since CBD can target different neurotransmitter receptors, enzymes, transporters and ion channels. However, the precise contribution of each of those mechanisms for CBD effects is still not yet completely understood. Considering that epigenetic changes make the bridge between gene expression and environment interactions, we review and discuss herein how CBD affects one of the main epigenetic mechanisms associated with the development of stress-related psychiatric disorders: DNA methylation (DNAm). Evidence from in vivo and in silico studies indicate that CBD can regulate the activity of the enzymes responsible for DNAm, due to directly binding to the enzymes and/or by indirectly regulating their activities as a consequence of neurotransmitter-mediated signaling. The implications of this new potential pharmacological target for CBD are discussed in light of its therapeutic and neurodevelopmental effects.