Introducing the glycyrrhizic acid and glabridin rich genotypes from the cultivated Iranian licorice (Glycyrrhiza glabra L.) populations to exploit in production systems.

Currently, the stable, uniform, and highly efficient production of raw materials for pharmaceutical companies has received special attention. To meet these criteria and reduce harvesting pressure on the natural habitats of licorice (Glycyrrhiza glabra L.), cultivation of this valuable plant is inevitable. In the present study, to introduce the glycyrrhizic acid (GA)- and glabridin-rich genotypes from cultivated Iranian licorice, forty genotypes from eight high-potential wild populations were cultivated and evaluated under the same environmental conditions. The GA content varied from 5.00 ± 0.04 mg/g DW (TF2 genotype) to 23.13 ± 0.02 mg/g DW (I5 genotype). The highest and lowest glabridin content were found in the K2 (0.72 ± 0.021 mg/g DW) and M5 (0.02 ± 0.002 mg/g DW) genotypes, respectively. The rutin content in the leaves of the studied genotypes varied from 1.27 ± 0.02 mg/g DW in E4 to 3.24 ± 0.02 mg/g DW in BO5 genotypes. The genotypes from the Ilam population were characterized by higher vegetative growth and yield traits in the aerial parts and roots. The average root dry yield was 2.44 tons per hectare (t/ha) among the studied genotypes and a genotype from Ilam (I5) yielded the maximum value (3.08 ± 0.034 t/ha). The highest coefficient of variation among the genotypes was observed for leaf width (CV = 34.9%). The GA and glabridin-rich genotypes introduced in this study can be used in the future breeding programs to release new bred licorice cultivars.

Phytochemistry of Oliveria decumbens Vent. (Apiaceae) and its therapeutic potential: A systematic review.

Oliveria decumbens Vent., an annual herb resistant to harsh environmental conditions, is an aromatic medicinal plant of the Apiaceae family. O. decumbens has numerous pharmacological, food and feed, and cosmetic applications. This species is endemic to Iran, Iraq, and Turkey. Published literature, available until 30 November 2022 on the morphology, phytochemistry, and bioactivity of O. decumbens, has been reviewed, and appraised for the potential therapeutic potential of this species, utilizing the databases, Web of Science, Google Scholar, PubMed, and Dictionary of Natural Products. The search term used was O. decumbens. Some manuscripts were issued on the chemical components of O. decumbens essential oil (EO) and various extracts. The EO of O. decumbens was evaluated for its chemical composition and medicinal potential against various diseases. Thymol and carvacrol constituted the primary oxygenated monoterpenes detected in substantial amounts within the EO. Additionally, diverse metabolites of O. decumbens were examined for their bactericidal, antioxidant, larvicidal, and immunomodulatory effects. This review article discusses morphology, phenology, and geographical distribution of O. decumbens and presents a critical appraisal of its phytochemistry and therapeutic potential as documented in the published literature.

Effects of summer savory (Satureja hortensis L.) and sweet corn (Zea mays L. saccharata) intercropping on crop production and essential oil profiles of summer savory.

A 2-year field experiment evaluated the effects of sweet corn-summer savory intercropping on crop productivity and essential oil (EO) composition of summer savory. Five cropping patterns of Corn 100%:Savory 0%, C75:S25, C50:S50, C25:S75, and C0:S100 were tested. The highest corn yield (2,440 kg ha-1) was obtained in a corn monoculture, but was not significantly different from C75:S25 or C50:S50. However, in both years the highest savory yield was obtained in S100 (793.3 g m-2 and 816.6 g m-2, respectively). Savory yields decreased as the proportion of corn increased. The land equivalent ratios in C25:S75, C50:S50, and C75:S25 were 1.54 ± 0.07, 1.56 ± 0.03, and 1.35 ± 0.1, respectively. Monocropped savory had the highest EO value followed by C25:S75 and C50:C50. However, no significant differences were found among these three treatments. Gas chromatography-mass spectrometry (GC-MS) analysis showed that the major components were carvacrol (35.88%-42.96%), γ-terpinene (18.45%-20.03%), ρ-cymene (11.77%-12.24%), and α-terpinene (2.75%-3.96%). The highest amount of carvacrol was recorded in C25:S75 (42.96%). This study suggests that intercropping of corn and savory represents an effective sustainable strategy, especially for smallholders, as a way to increase their overall land productivity and to improve the quality of savory's EO.

Defense Mechanisms Induced by Celery Seed Essential Oil against Powdery Mildew Incited by Podosphaera fusca in Cucumber.

This study aimed to evaluate the effectiveness of essential oil extracted from celery (Apium graveolens) seeds (CSEO) for the control of powdery mildew of cucumber (Cucumis sativus) incited by Podosphaera fusca and to investigate the metabolic and genetic defense mechanisms triggered by the treatment with this essential oil in cucumber seedlings. The main compounds in the CSEO as determined by gas chromatography-mass spectrometry (GC-MS) analysis were d-limonene, 3-butyl phthalide, ß-selinene, and mandelic acid. The treatment with CSEO led to an increase in the content of both chlorophyll and phenolic/flavonoid compounds in cucumber leaves. In greenhouse tests, the application of CSEO reduced by 60% the disease severity on leaves of cucumber plants and stimulated the activity of defense-related enzymes such as ß-1,3-glucanase, chitinase, phenylalanine ammonia-lyase, peroxidase, and polyphenol oxidase. Moreover, treatment with CSEO induced overexpression of ß-1,3-glucanase, chitinase, and phenylalanine ammonia-lyase genes. A highly significant correlation was found between the ß-1,3-glucanase, chitinase, and phenylalanine ammonia-lyase enzymatic activities and the relative expression of the corresponding encoding genes in both inoculated and non-inoculated cucumber seedlings treated with the essential oil. Overall, this study showed that CSEO is a promising eco-friendly candidate fungicide that can be exploited to control cucumber powdery mildew.

Essential Oil Variability of Superior Myrtle (Myrtus communis L.) Accessions Grown under the Same Conditions.

Myrtle (Myrtus communis L., Myrtaceae) has numerous applications in pharmacology, food technology, and cosmetic industry. The current research aimed at measuring variations in the leaf essential oil (EO) compositions of 14 superior myrtle accessions originating in natural habitats of south Iran. The plants were grown under greenhouse conditions. Fresh leaf samples were harvested in June 2021. Based on dry matter, the extractable amount of EO in the accessions ranged from 0.42% (BN2) to 2.6% (BN5). According to GC/MS analysis, the major compounds in the EO were α-pinene (2.35-53.09%), linalyl acetate (0-45.3%), caryophyllene oxide (0.97-21.8%), germacrene D (0-19.19%), α-humulene (0-18.97%), 1,8-cineole (0-18.0%), limonene (0-17.4%), and p-cymene (0-13.2%). These myrtle accessions were classified into four groups, including I: caryophyllene oxide/germacrene D/α-humulene/methyl eugenol chemotype; II: α-pinene/p-cymene/α-humulene and (E)-ß-caryophyllene; III: α-pinene/1,8-cineole, and linalool; IV: linalyl acetate/γ-terpinene/1,8, cineole/limonene. These classifications were established by considering the main EO components using hierarchical cluster analysis (HCA) and principal component analysis (PCA). In summary, this study provided new insights into available opportunities of selecting suitable genotypes for commercial cultivation purposes and planning breeding programs in the future.

Photosynthesis and chlorophyll fluorescence of Iranian licorice (Glycyrrhiza glabra l.) accessions under salinity stress.

While salinity is increasingly becoming a prominent concern in arable farms around the globe, various treatments can be used for the mitigation of salt stress. Here, the effective presence of Azotobacter sp. inoculation (A1) and absence of inoculation (A0) was evaluated on Iranian licorice plants under NaCl stress (0 and 200 mM) (S0 and S1, respectively). In this regard, 16 Iranian licorice (Glycyrrhiza glabra L.) accessions were evaluated for the effects on photosynthesis and chlorophyll fluorescence. Leaf samples were measured for photosynthetic pigments (via a spectrophotometer), stomatal and trichome-related features (via SEM), along with several other morphological and biochemical features. The results revealed an increase in the amount of carotenoids that was caused by bacterial inoculation, which was 28.3% higher than the non-inoculated treatment. Maximum initial fluorescence intensity (F0) (86.7) was observed in the 'Bardsir' accession. Meanwhile, the highest variable fluorescence (Fv), maximal fluorescence intensity (Fm), and maximum quantum yield (Fv/Fm) (0.3, 0.4, and 0.8, respectively) were observed in the 'Eghlid' accession. Regarding anatomical observations of the leaf structure, salinity reduced stomatal density but increased trichome density. Under the effect of bacterial inoculation, salinity stress was mitigated. With the effect of bacterial inoculation under salinity stress, stomatal length and width increased, compared to the condition of no bacterial inoculation. Minimum malondialdehyde content was observed in 'Mahabad' accession (17.8 µmol/g FW). Principle component analysis (PCA) showed that 'Kashmar', 'Sepidan', 'Bajgah', 'Kermanshah', and 'Taft' accessions were categorized in the same group while being characterized by better performance in the aerial parts of plants. Taken together, the present results generally indicated that selecting the best genotypes, along with exogenous applications of Azotobacter, can improve the outcomes of licorice cultivation for industrial purposes under harsh environments.

Evaluation of metabolites in Iranian Licorice accessions under salinity stress and Azotobacter sp. inoculation.

Licorice (Glycyrrhiza glabra L.) is an industrial medicinal plant that is potentially threatened by extinction. In this study, the effects of salinity (0 and 200 mM sodium chloride (NaCl)) and Azotobacter inoculation were evaluated on 16 licorice accessions. The results showed that salinity significantly reduced the fresh and dry biomass (FW and DW, respectively) of roots, compared to plants of the control group (a decrease of 15.92% and 17.26%, respectively). As a result of bacterial inoculation, the total sugar content of roots increased by 21.56% when salinity was applied, but increased by 14.01% without salinity. Salinity stress increased the content of glycyrrhizic acid (GA), phenols, and flavonoids in licorice roots by 104.6%, 117.2%, and 56.3%, respectively. Integrated bacterial inoculation and salt stress significantly increased the GA content in the accessions. Bajgah and Sepidan accessions had the highest GA contents (96.26 and 83.17 mg/g DW, respectively), while Eghlid accession had the lowest (41.98 mg/g DW). With the bacterial application, the maximum amounts of glabridin were obtained in Kashmar and Kermanshah accessions (2.04 and 1.98 mg/g DW, respectively). Bajgah and Kashmar accessions had higher amounts of rutin in their aerial parts (6.11 and 9.48 mg/g DW, respectively) when their roots were uninoculated. In conclusion, these results can assist in selecting promising licorice accessions for cultivation in harsh environments.

Microbial amelioration of salinity stress in endangered accessions of Iranian licorice (Glycyrrhiza glabra L.).

BACKGROUND: Glycyrrhiza glabra L. is a medicinal and industrial plant that has gone extinct due to different abiotic stress caused by climate change. To understand how the plant-associated microorganism can support this plant under salinity, we collected sixteen Iranian accessions of G. glabra L., inoculated their rhizomes with Azotobacter sp. (two levels, bacterial treatments, and no-bacterial treatments, and grown them under salinity stress (NaCl levels; 0, and 200 mM). RESULTS: Two accessions of Bardsir and Bajgah significantly showed higher resistant to salinity, for example by increasing crown diameter (11.05 and 11 cm, respectively) compared to an average diameter of 9.5 in other accessions. Azotobacter inoculation caused a significant increase in plant height and crown diameter. Among studied accessions, Kashmar (46.21%) and Ilam (44.95%) had the highest rate of membrane stability index (MSI). Evaluation of enzyme activity represented that bacterial application under salinity, increased polyphenol oxidase (PPO) (0.21 U mg-1 protein), peroxidase (POD) (3.09 U mg-1 protein U mg-1 protein), and phenylalanine ammonia-lyase (PAL) (17.85 U mg-1 protein) activity. Darab accession showed the highest increase (6.45%) in antioxidant potential compared with all studied accessions under Azotobacter inoculation. According to principal component analysis (PCA), it was found that the accession of Meshkinshahr showed a more remarkable ability to activate its enzymatic defense system under salt stress. Also, three accessions of Meshkinshahr, Eghlid, and Ilam were categorized in separated clusters than other accessions regarding various studied treatments. CONCLUSION: Analysis indicated that five accessions of Meshkinshahr, Rabt, Piranshahr, Bardsir, and Kermanshah from the perspective of induced systematic resistance are the accessions that showed a greater morphophysiological and biochemical outcome under salinity. This study suggested that, inoculation of with Azotobacter on selected accession can relieve salt stress and support industrial mass production under abiotic condition.

NMR, LC-MS Characterization of Rydingia michauxii Extracts, Identification of Natural Products Acting as Modulators of LDLR and PCSK9.

Rydingia michauxii (Briq.) Scheen and V.A.Albert (Lamiaceae) is used in Iranian traditional medicine to treat malaria, diabetes, hyperlipidemia, rheumatism and cardiovascular diseases. NMR and LC-DAD-MSn analyses were used to establish extract composition and phenylethanoid, flavonoid glycosides, lignans, labdane diterpenes and iridoids were identified and quantified. The main constituents were isolated, and structures were elucidated based on NMR, polarimetric and MS measurements. A new natural compound, ent-labda-8(17),13-dien-18-glucopyranosyl ester-15,16-olide is described here. The effects of ent-labda-8(17),13-dien-18-oic acid-15,16-olide (1), ent-labda-8(17),13-dien-18-glucopyranosyl es-ter-15,16-olide (2), antirrhinoside (3), echinacoside (4), verbascoside (5), and apigenin 6,8-di-C-glucoside (6), on the low-density lipoprotein receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9), were studied in the human hepatocarcinoma cell line Huh7. Among the six constituents, (3) showed the strongest induction of the LDLR (3.7 ± 2.2 fold vs. control) and PCSK9 (3.2 ± 1.5 fold vs. control) at a concentration of 50 µM. The in vitro observations indicated a potential lipid lowering activity of (3) with a statin-like mechanism of action.

The Essential Oil from Oliveria decumbens Vent. (Apiaceae) as Inhibitor of Breast Cancer Cell (MCF-7) Growth.

Oliveria decumbens Vent. is an aromatic and medicinal plant traditionally used in Iran for the treatment of infections, gastrointestinal diseases, cancer, and inflammation. This research was aimed at investigating the pharmacological potential of O. decumbens essential oil (OEO) and its main compounds, focusing on OEO's cytotoxic effects on MCF-7 breast cancer cells. OEO was obtained by hydro-distillation, and the chemical constituents were identified using GC-MS. Thymol, carvacrol, γ-terpinene, and p-cymene were the main OEO constituents. When MCF-7 cells were treated with OEO, the expressions of genes related to apoptosis (BIM and Bcl-2), tumor suppression (PTEN), and cell growth inhibition (AURKA), were evaluated using real-time PCR. Moreover, molecular docking was used for studying in silico the interaction of OEO principal compounds with PTEN and AURKA. The expression of AURKA was significantly reduced since the OEO treatment enhanced the expression of PTEN. Through in silico molecular docking, it was revealed that thymol, carvacrol, p-cymene, and γ-terpinene can activate PTEN and thus inhibit AURKA. Additionally, the DNA fragmentation assay, acridine orange/ethidium bromide (AO/EB) double-staining assay, and real-time PCR highlighted the fact that the OEO treatment could activate apoptosis and inhibit cell proliferation. Therefore, OEO is a viable candidate to be employed in the pharmaceutical industry, specifically as a possible agent for cancer therapy.

In Silico Evaluation of Iranian Medicinal Plant Phytoconstituents as Inhibitors against Main Protease and the Receptor-Binding Domain of SARS-CoV-2.

The novel coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which initially appeared in Wuhan, China, in December 2019. Elderly individuals and those with comorbid conditions may be more vulnerable to this disease. Consequently, several research laboratories continue to focus on developing drugs to treat this infection because this disease has developed into a global pandemic with an extremely limited number of specific treatments available. Natural herbal remedies have long been used to treat illnesses in a variety of cultures. Modern medicine has achieved success due to the effectiveness of traditional medicines, which are derived from medicinal plants. The objective of this study was to determine whether components of natural origin from Iranian medicinal plants have an antiviral effect that can prevent humans from this coronavirus infection using the most reliable molecular docking method; in our case, we focused on the main protease (Mpro) and a receptor-binding domain (RBD). The results of molecular docking showed that among 169 molecules of natural origin from common Iranian medicinal plants, 20 molecules (chelidimerine, rutin, fumariline, catechin gallate, adlumidine, astragalin, somniferine, etc.) can be proposed as inhibitors against this coronavirus based on the binding free energy and type of interactions between these molecules and the studied proteins. Moreover, a molecular dynamics simulation study revealed that the chelidimerine-Mpro and somniferine-RBD complexes were stable for up to 50 ns below 0.5 nm. Our results provide valuable insights into this mechanism, which sheds light on future structure-based designs of high-potency inhibitors for SARS-CoV-2.

Phytotoxic Potential and Phenolic Profile of Extracts from Scrophularia striata.

A large number of plants produce secondary metabolites known as allelochemicals that are capable of inhibiting the germination of competitive species. This process is known as allelopathy and is mediated by several classes of chemicals, among which phenolic compounds are the most frequent. Thus, plant allelochemicals can be used to control weeds in agricultural systems. In the present work, we analyzed the phenolic profile and phytotoxic potential of different extracts (pure water or water: ethanol 50:50) from Scrophularia striata plants that were collected from two ecological regions in Iran (Pahleh and Lizan). The total polyphenolic content (TPC), as evaluated by the Folin-Ciocolteau method, ranged from 28.3 mg/g in the aqueous extract obtained from the Lizan ecotype to 39.6 mg/g in the hydroalcoholic extract obtained from the Pahleh ecotype. Moreover, HPLC analysis was aimed at determining the content of eight phenolic compounds, namely eugenol, rosmarinic acid, hesperetin, hesperedin, trans-ferulic acid, vanillin, and caffeic acid. According to the results, rosmarinic acid appeared to be the most abundant component. The phytotoxic activities of S. striata extracts were examined on the seed germination of a crop species, Lepidium sativum, and two weeds, Chenopodium album and Malva sylvestris. All extracts showed inhibitory effects on these species. The efficiency of these inhibitory effects depended on the type of plant species, origin, and concentration of extract. The highest phytotoxic activity was caused by approximately 1% concentration of extract. The most susceptible weed was M. sylvestris. The extracts that were obtained from the Pahleh ecotype, notably the hydroalcoholic ones, showed higher phytotoxicity against L. sativum, C. album and M. sylvestris. These results encourage further studies to support the use of S. striata as a source of bioherbicides.

Variation in essential oil composition of Rydingia michauxii at the three developmental stages.

In this study, the essential oil composition of Rydingia michauxii was evaluated during the dormant, vegetative and flowering stages. The major chemical constituents of R. michauxii at the dormant stage were eugenol (36.81%), eugenol acetate (21.02%), and carvacrol (9.35%). While the main chemical constituents for the vegetative stage were carvacrol (16.08%), eugenol (13.23%), cumin aldehyde (9.63%), and linalool (8.28%). In addition, carvacrol (14.20%), eugenol (8.98%), δ-cadinene (8.90%), caryophyllene oxide (8.43%) and n-hexadecanoic acid (7.07%) were the major volatile components during the flowering stage. Variation in chemical compositions of R. michauxii during the various developmental stages might be affected by environmental and climatic factors.

Metabolic and genes expression analyses involved in proline metabolism of two rose species under drought stress.

An investigation was conducted to assess proline anabolism and catabolism pathway genes under drought stress. Treatments were irrigation in three levels (25, 50 and 100% field capacity) at 1, 3, 6 and 12 d and two rose species (Rosa canina L. and Rosa damascene Mill.). The results showed that the potential for proline accumulation in R. damascena was higher than R. canina under drought. Simultaneous with proline accumulation, expression of P5CS and P5CR genes increased from 1 to 12 d under 50% FC whereas their expression had an increasing trends from 1 to 6 d at 25% FC and expression of both genes decreased at 12 d in both species. The highest accumulation of proline was observed under 25% FC at 12 d, but expression of genes involved in proline synthesis main pathway decreased on this day. Furthermore, expression of genes (PDH and P5CDH) involved in proline catabolism pathway decreased in 50% FC from 1 to 12 d while their expression remarkably decreased from 1 to 6 d and increased at 12 d under 25% FC. These findings showed that under conditions of 50 and 25% FC, arginine accumulation resulted in the increased expression of the ARG gene, which led to ornithine production. Furthermore, ornithine accumulation increased OAT expression. Therefore, it seems that OAT-induced P5C is transported from the mitochondria to the cytosol and reduced to proline by the P5CR.

Regulation of stomatal aperture in response to drought stress mediating with polyamines, nitric oxide synthase and hydrogen peroxide in Rosa canina L.

To assess the role of genes involved in polyamines synthesis, nitric oxide synthase (NOS), copper amine oxidase activity (CuAO) and hydrogen peroxide (H2O2) in regulation of stomatal aperture to drought stress in Rosa canina L., a study was performed at three irrigating levels (25%, 50%, and 100% field capacity) with three replications at 1, 3, 6 and 12 days. The results showed that putrescine (Put) accumulation occurred under both 50% and 25% FC at 1 d. Furthermore, the role of the Put direct biosynthesis pathway ornithine decarboxylase (ODC) was more effective under 50% FC whereas in the 25% FC the Put indirect production pathway (agmatine iminohydrolase (AIH), N-carbamoyl putrescine amidohydrolase (CPA) and arginine decarboxylase (ADC)) was more effective. HPLC results showed that the accumulation of spermidine (Spd) and spermine (Spm) is consistent with the expression of S-adenosyl methionine decarboxylase (SAMDC), spermidine synthase (SPDS) and spermine synthase (SPMS) genes. Spd accumulation under both 50% and 25% FC occurred on the 3 d and then decreased in the other days. Spm content showed an increasing trend from 6 d under 50% FC and from 3 d under 25% FC. Our results suggest that among the measured polyamines, Put oxidation through CuAO activity increased resulted in an increase in H2O2 production. The H2O2 accumulation also as a secondary messenger led to enhance in NOS gene expression. Increase in NOS gene expression can act as a signal resulting in stomatal closure.

The Variability of Thymol and Carvacrol Contents Reveals the Level of Antibacterial Activity of the Essential Oils from Different Accessions of Oliveria decumbens.

Oliveria decumbens (Apiaceae) is an aromatic herb traditionally employed in the Persian medicine for the treatment of infectious and gastrointestinal disorders. In the present study, we analyzed the chemical composition of essential oils obtained from different Iranian populations and evaluated their efficacy on a panel of human pathogens (Staphylococcus aureus and Escherichia coli), probiotic (Bacillus subtilis), and phytopathogens (Clavibacter michiganensis, Curtobacterium flaccumfaciens, Xanthomonas citri, and Agrobacterium tumefaciens). The gas chromatographic-mass spectrometry analysis put in evidence four main volatile constituents such as thymol (20.3-36.4%), carvacrol (18.8-33.1%), γ-terpinene (10.6-25.9%), and p-cymene (9.5-17.3%), though with significant variability from an essential oil to another. Notably, the oils from the populations sited in Nourabad Mamasani and Dehdasht showed the highest amount of the phenolic monoterpenes thymol (36.4 and 35.2%, respectively) and carvacrol (33.1 and 30.6%, respectively). The antibacterial activity of O. decumbens essential oils was assessed by the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods, showing high activity for the samples from Nourabad Mamasani and Dehdasht populations exhibiting high level of the above phenolics. The obtained MIC and MBC values (mg/ml) were in the ranges 0.0625-2 mg/ml and 1-16 mg/ml, respectively. Noteworthy, in some cases, the antibacterial activity of O. decumbens essential oils was higher than that of chloramphenicol used as positive control. The average MBCs displayed by the O. decumbens samples showed that C. flaccumfaciens had the highest sensitivity to the essential oils. Based on these results, our work shed light on selected O. decumbens populations deserving proper breeding and cultivation strategies in order to warrantee production of bioactive essential oils to be used at pharmaceutical and agricultural level to combat several pathogens.

Essential Oil Chemical Variability in Oliveria decumbens (Apiaceae) from Different Regions of Iran and Its Relationship with Environmental Factors.

Oliveria decumbens Vent. (Apiaceae) is an annual herb resistant to harsh environmental conditions, which has got numerous pharmacological, food and feed, and cosmetic applications. In the present study, the variation in the essential oil (EO) content and composition of twelve O. decumbens populations growing wild in several habitats of Iran was studied. The EO contents varied from 2.71% (Darab) to 8.52% (Behbahan) on a dry matter basis, where the latter population revealed to be the highest source of essential oil reported so far in this species. Gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS) analysis revealed that carvacrol (18.8-51.8%), thymol (20.3-38.7%), γ-terpinene (0.9-28.8%), p-cymene (1.6-21.3%) and myristicin (0.8-9.9%) were the major volatile compounds in all the investigated populations. The EO content had a strong and significant positive correlation with temperature (r = 0.62) and sand content (r = 0.73), but a strong and significant negative correlation with altitude (r = -0.61). On the other hand, the rising altitude led to an increase in thymol content. Cluster and principal component analyses placed the samples from different regions into two main groups based on the main EO components, including thymol/carvacrol type and γ-terpinene/thymol/carvacrol/p-cymene type. This study provides valuable information for identifying chemotypes in O. decumbens as well as insight into planning a domestication and cultivation program.

Role of genes and metabolites involved in polyamines synthesis pathways and nitric oxide synthase in stomatal closure on Rosa damascena Mill. under drought stress.

In order to evaluate the genes involved in polyamines synthesis pathway and the role of nitric oxide synthase (NOS) and H2O2 in stomatal closure under drought stress, a research conducted with three irrigation levels (100, 50 and 25% field capacity) at 1, 3, 6 and 12 days on Rosa damascena Mill. HPLC and qPCR results showed that putrescine (Put) accumulation occurred at first day in both 50 and 25% of field capacity and then decreased the other days. Furthermore, Put accumulation in the indirect pathway (ADC, AIH and CPA) was more effective related to the direct pathway (ODC) under severe stress. Increased expression of genes involved in production of spermidine (Spd) and spermine (Spm) i.e., SAMDC, SPDS and SPMS correlated with the highest accumulation of Spd and Spm under 50% FC at 6 d and 25% FC at 12 d, respectively. Moreover, results showed that Put reduction simultaneously accumulated H2O2, which subsequently increased NOS expression suggesting a key signal for stomatal closure.

Essential oil composition of Rydingia michauxii (Briq.) Scheen & V.A. Albert endemic of Iran.

The chemical composition of the essential oil (EO) obtained from the aerial parts of Rydingia michauxii (Briq.) Scheen & V.A. Albert was analysed by gas chromatography and gas chromatography/mass spectrometry (GC/MS). Eighty components were identified in the oil with caryophyllene oxide (20.1%), trans-verbenol (10.2%), linalool (5.3%) and humulene epoxide II (4.6%) as main constituents. We reported here the chemical compositions of R. michauxii EOs from southern Zagros of Iran with a distinct chemical profile for the first time.

Essential oil composition of Ajuga comata Stapf. from Southern Zagros, Iran.

The chemical composition of essential oil obtained from the aerial parts of Ajuga comata Stapf. was analyzed by GC and GC/MS. Thirty-seven components were identified in the oil. (E)-ß-caryophyllene (30.9%), caryophyllene oxide (24.9%), (E)-ß-farnesene (12.6%), ß-eudesmol (3.2%), δ-cadinene (3.1%) and germacrene D (3.0%) were the main compounds in the EOs. The chemical composition of A. comata Stapf. from the Southern Zagros of Iran is reported for the first time.