Utilization of arbuscular mycorrhizal fungi (AMF) for enhancing growth and development as well as production of essential oil in aromatic plants has been increasingly drawing research interest. In order to assess the AMF effects on different aromatic species, an open-field experiment was carried out using Artemisia dracunculus (tarragon), Lavandula angustifolia (lavender) and Hyssopus officinalis (hyssop). AMF stimulated the growth of tarragon and lavender plants, whereas hyssop showed a slight developmental slowing; nonetheless, a significant increase in essential oil content in the three species was seen. AMF application increased the biomass of A. dracunculus and H. officinalis by 20–35%. No differences in antioxidant activity and phenolics content were recorded at harvest between the control and AMF-inoculated plants, but the latter showed a significant increase in antioxidant status upon storage at high temperature and humidity compared to the untreated control. The enhancement of abiotic stress resistance during storage in plants inoculated with AMF was the highest in A. dracunculus, and the lowest in H. officinalis, while the untreated control plants showed a significant decrease in phenolics, ascorbic acid and chlorophyll content, as well as antioxidant activity, upon the abiotic stress. AMF inoculation differentially affected the mineral composition, increasing the accumulation of Se, I and Zn in A. dracunculus, and decreasing the levels of heavy metals and Co, Fe, Li, Mn in H. officinalis. Based on the outcome of the present research, AMF inoculation resulted in a significant enhancement of the overall performances of A. dracunculus, L. angustifolia and H. officinalis, and also in the improvement of plant antioxidant status upon storage in stress conditions.

The unique biological properties of A. annua have stimulated the research on its cultivation in different regions of the world. In this study, the effect of the Se and nano-Si supply on the yield, biochemical characteristics and mineral content of A. annua was investigated. Growth stimulation and a significant increase in the antioxidant status were recorded under Se and nano-Si foliar application. A decrease in the number of essential oil components and significant changes in the essential oil amount and composition led to significant phenophase shifts: nano-Si significantly stimulated eucalyptol and artemisia ketone accumulation and decreased germacrene D production, whereas Se demonstrated the opposite effect. A joint Se and nano-Si supply significantly decreased the camphor content and increased artemisia ketone and artemisinin levels by 1.3–1.5 times. Se/Si supplementation affected the macro- and microelements content, causing either a redistribution of leaves/stems elements (Al, Li and Zn) or a significant decrease in Ca, Mg, K, B, Cu, Fe and Mn concentrations in leaves, with no signs in growth inhibition or a decrease in the photosynthetic pigments content. The biofortification of A. annua with Se singly or in combination with nano-Si resulted in the synthesis of products with a Se content of as much as approximately 16% of the daily adequate Se consumption level (ACL) when using 5 g day⁻¹ as a spice, or 36% of ACL when using 50 mL of tea infusion (1:2, v/w). The results indicated a high possibility of Se and nano-Si application toward the regulation of A. annua growth, biochemical characteristics (including essential oil and artemisinin) and mineral content.

Among the plants that exhibit significant or established pharmacological activity, the genus Artemisia L. deserves special attention. This genus comprises over 500 species belonging to the largest Asteraceae family. Our study aimed at providing a comprehensive evaluation of the phytochemical composition of the ethanol extracts of five different Artemisia L. species (collected from the southwest of the Russian Federation) and their antimicrobial and nematocide activity as follows: A. annua cv. Novichok., A. dracunculus cv. Smaragd, A. santonica cv. Citral, A. abrotanum cv. Euxin, and A. scoparia cv. Tavrida. The study of the ethanol extracts of the five different Artemisia L. species using the methods of gas chromatography–mass spectrometry (GC–MS) and high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (HPLC–MS/MS) allowed establishing their phytochemical profile. The obtained data on the of five different Artemisia L. species ethanol extracts’ phytochemical composition were used to predict the antibacterial and antifungal activity against phytopathogenic microorganisms and nematocidal activity against the free-living soil nematode Caenorhabditis elegans. The major compounds found in the composition of the Artemisia L. ethanol extracts were monoterpenes, sesquiterpenes, flavonoids, flavonoid glycosides, coumarins, and phenolic acids. The antibacterial and antifungal activity of the extracts began to manifest at a concentration of 150 µg/mL. The A. dracunculus cv. Smaragd extract had a selective effect against Gram-positive R. iranicus and B. subtilis bacteria, whereas the A. scoparia cv. Tavrida extract had a selective effect against Gram-negative A. tumefaciens and X. arboricola bacteria and A. solani, R. solani and F. graminearum fungi. The A. annua cv. Novichok, A. dracunculus cv. Smaragd, and A. santonica cv. Citral extracts in the concentration range of 31.3–1000 µg/mL caused the death of nematodes. It was established that A. annua cv. Novichok affects the UNC-63 protein, the molecular target of which is the nicotine receptor of the N-subtype.

БИОЛОГИЧЕСКИ АКТИВНЫЕ ВЕЩЕСТВА ЛИСТЬЕВ ЛАВРА БЛАГОРОДНОГО

The article presents the results of morphological-anatomical, morphometric and histochemical studies of the aerial part of Melissa officinalis L., a selection variety sample from the collection of Nikitsky Botanical Garden – National Science Center (NBG-NSC) of the Russian Academy of Sciences, Republic of Crimea. The data on the morphology, histochemistry and morphometry of the main diagnostic microscopic signs of the Melissa officinalis L. herb, which are crucial for establishing the authenticity of medicinal plant materials, and also show the localization of secretion of metabolites and the heterogeneous nature of Melissa essential oil, have been obtained.The aim. Is to determine the microdiagnostic signs and biometric characteristics of the Melissa officinalis L. variety sample, introduced in Nikitsky Botanical Garden, to study the possibility of using histochemical reactions for the analysis of tissues and secretory structures of the studied species.Materials and methods. The plant material was provided by Nikitsky Botanical Garden. The study of microscopic signs, morphometric characteristics as well as histochemical tests, were performed according to the methods of the State Pharmacopoeia of the Russian Federation, XIII edition, using a Micromed-1 light microscope, a Micromed Micrometer 3 LUM fluorescent microscope and a Digital Eyepiece microscope camera MD 3.2 digital camera. The photos were edited in the program Paint. NET.3.5.11.Results. The main diagnostic microscopic signs of the herb of the Melissa officinalis L. selection variety sample can be called as follows: simple unicellular conical, nonbranching hairs, simple multicellular conical hairs, capitate hairs with a multicellular leg and a funnel-shaped head and with a unicellular leg and a spherical head, essential oil glands of a radial-type with 6-8 excretory cells. These signs have been diagnosed in the crushed raw materials. A quantitative assessment of the morphological and anatomical signs of the leaf (leaf thickness, height of the cells of the upper and lower epidermis, stoma density per 1 mm² of the epidermis), stem, calyx and corolla was carried out. The size of cells, stoma, trichomes, as well as the frequency of the location of trichomes have been analyzed, too. The presence and localization of lipids, polysaccharides, phenolic compounds, flavonoids, essential oil, terpenoids, alkaloids in tissues and trichomes of the herb have been studied by histochemical methods using light and fluorescent microscopy.Conclusion. Morphological and anatomical study of the herb of the Melissa officinalis L. selection variety sample from the Nikitsky Botanical Garden collection has been carried out, diagnostically significant microscopic signs of raw materials have been revealed and their biometric characteristics have been established. For the first time the localization of characteristic secreted biologically active substances in the tissues and secretory structures of the herb has been studied by histochemical methods. The results of the experimental studies complement the scientific literature data and can be used to confirm the authenticity, identification and standardization of the aerial parts of this variety sample.

The importance of using the barks of trees and shrubs as powerful natural antioxidants suggests the necessity to evaluate the effect of different environmental factors on bark extracts’ quality. The determination of total antioxidant activity (AOA) and polyphenol content (TP) in the bark of 58 tree and shrub species from 7 regions differing in mean annual temperature, insolation, humidity, salinity level, and altitude was performed. The above stress factors positively affected bark AOA but did not have a statistically significant effect on TP. The bark of trees grown in the seashore proximity was characterized by significantly higher AOA than samples gathered in other areas, similarly to the trees grown at high altitude. The bark antioxidant status of 18 species was described for the first time. New sources of powerful antioxidants were represented by the ornamental shrubs Cornus sanguinea and Cornus alba, which showed the highest AOA (169–171 mg GAE g⁻¹ d.w.). Among the typical halophytes, Calligonum and Tamarix had high AOA (172 and 85 mg GAE g⁻¹ d.w.), while in the bark of tamarisk, an Se accumulator, an Se concentration of about 900 µg kg⁻¹ d.w. was recorded. A significant positive correlation was found between leaves and bark AOA in the Karadag Nature Reserve’s deciduous trees (r = 0.898, p < 0.01). The relationship between bark AOA and TP was highly significant (r = 0.809; p < 0.001) for all samples except the mountainous ones. The results of the present research revealed new opportunities in successive bark utilization.