bluuebunny/crossref_metadata_2025 huggingface dataset:
Modification of Fе/Gd Superlattices Crystal Structure by Hydrogenation
Authors: Likhachev I. A. , Subbotin I. A. , Chesnokov Yu. M. , Devyaterikov D. I. , Kondratev O. A. , Ryzhova A. A. , Salamatov Yu. A. , Milyaev M. A. , Vasilev A. L. , Kravtsov E. A. , Pashaev E. M.
Published: April 2024

Abstract—Structural studies of multilayer magnetic nanostructures formed by alternating layers of transition (Fe) and rare earth (Gd) metals placed in a hydrogen atmosphere at a temperature of 100°C have been carried out. When hydrogen is absorbed by rare earth metals, crystalline phases GdHx arise (form), the microstructural features of which were studied by X-ray diagnostics and electron microscopy.
Cultivar-Specific Effect of Chitosan on Chitinase and Glucanase Activity in the Roots of Garlic Allium sativum L.
Authors: Filyushin M. A. , Shagdarova B. Ts. , Il’ina A. V. , Kochieva E. Z. , Shchennikova A. V. , Varlamov V. P.
Published: April 2024

Chitosan is a natural polysaccharide and, when applied externally, is able to stimulate both growth and defense of the plant, enhancing its resistance to abiotic stresses and suppressing the development of many phytopathogens. Immune response includes the activation of defense proteins, carbohydrases such as chitinases and glucanases, which are also known to participate in the regulation of morphogenesis. In this study, for the first time, the effect of treatment with unfractionated (hydrolysate) chitosan of low (CH1) and medium (CH2) molecular weight on chitinase and glucanase activities, as well as on the expression of chitinase and -1,3-glucanase genes in the roots of two cultivars of garlic Allium sativum L. differing by resistance to Fusarium rot was examined. It was shown that the effect of chitosans on the enzymatic activity and expression of the genes encoding -1,3-glucanases (AsPR2a, AsPR2b, and AsPR2c) and chitinases (AsCHI1, AsCHI3, AsCHI7, AsCHI17, and AsCHI23) is cultivar-specific, which may be due to different susceptibility of the cultivars to Fusarium. The expression pattern of chitinase genes AsCHI10, AsCHI27, and AsCHI34, similar between varieties, suggested their involvement in root tissue morphogenesis. The results indicated a greater stimulatory effect of CH2 in comparison with CH1 on chitinase and glucanase activity. The stronger inhibitory influence of CH2 (as compared with CH1) on the expression of chitinase and -1,3-glucanase genes correlated with the lower fungicidal effect of CH2 on Fusarium proliferatum. The findings may be used in breeding biotechnology to increase the resistance of garlic to Fusarium.
Physiological Role of pH-Dependent Structural Transition in Oxygen-Evolving Complex of PSII
Authors: Semin Boris K. , Davletshina Lira N. , Loktyushkin Aleksey V. , Lovyagina Elena R.
Published: April 2024

Photosystem II (PSII) of the photosynthetic apparatus in oxygenic organisms contains a catalytic center that performs one of the most important reactions in bioenergetics: light-dependent water oxidation to molecular oxygen. The catalytic center is a Mn4CaO5 cluster consisting of four cations of manganese and one calcium cation linked by oxygen bridges. The authors reported earlier that a structural transition occurs at pH 5.7 in the cluster resulting in changes in manganese cation(s) redox potential and elevation of the Mn‑clus-ter resistance to reducing agents. The discovered effect was examined in a series of investigations that are reviewed in this work. It was found that, at pH 5.7, Fe(II) cations replace not two manganese cations as it happens at pH 6.5 but only one cation; as a result, a chimeric Mn3Fe1 cluster is produced. In the presence of exogenous calcium ions, membrane preparations of PSII with such a chimeric cluster are capable of evolving oxygen in the light (at a rate of approximately 25% of the rate in native PSII). It was found that photoinhibition that greatly depends on the processes of oxidation or reduction at pH 5.7 slows down as compared with pH 6.5. PSII preparations were also more resistant to thermal inactivation at pH 5.7 than at pH 6.5. However, in PSII preparations lacking manganese cations in the oxygen-evolving complex, the rates of photoinhibition at pH 6.5 and 5.7 did not differ. In thylakoid membranes, protonophores that abolish the proton gradient and increase pH in the lumen (where the manganese cluster is located) from 5.7 to 7.0 considerably elevated the rate of PSII photoinhibition. It is assumed that the structural transition in the Mn-cluster at pH 5.7 is involved in the mechanisms of PSII defense against photoinhibition.
Changes in Composition and Content of Lipophilic Compounds in the Seedlings of Triticum aestivum L. Treated with Stress Phytohormones
Authors: Renkova A. G. , Khabibrakhmanova V. R. , Chasov A. V. , Valitova J. N. , Galeeva E. I. , Minibayeva F. V.
Published: April 2024

Exposure of plants to biotic and abiotic stress agents causes changes in the composition and content of metabolites of different chemical nature, including lipophilic compounds. One of the ways to simulate a stress situation is plant treatment with exogenous phytohormones. This work deals with investigation of organ specificity of composition of lipophilic compounds and changes in their content in wheat Triticum aestivum L. seedlings treated with exogenous stress hormones: abscisic acid (ABA), salicylic acid (SA), and methyl jasmonate (MeJA). It was found that roots and leaves of wheat seedlings have identical composition of lipophilic compounds but their content considerably differed. In the leaves, the quantity of hydrocarbons, including squalene, as well as triterpenes, sterols, and phosphatidyl choline, was much greater than in the roots. In the leaves, glycoceramides of type 1 containing a FA residue with -hydroxyl group predominated; on the contrary, glycoceramides of type 2 whose FA residues lack -hydroxyl group prevailed in the roots. Moreover, lipid extracts from the leaves contain lipophilic pigments (chlorophylls a and b and carotenoids) and hydrophobic phenolic compounds in the form of hydroxycinnamic acids. Treatment with stress phytohormones brings about considerable changes in growth characteristics, the rate of photosynthesis, and the profile of lipophilic compounds in wheat seedlings depending on the plant organ and the chemical nature of the phytohormone. In the case of ABA and MeJA, the growth of roots and leaves was suppressed, the level of nonphotochemical quenching rose, and the content of photosynthetic pigments changed. An unexpected effect was observed upon treatment with MeJA that raised the level of cholesterol and phosphatidyl serine. SA was notable for organ-specific changes in the content of products of mevalonate pathway, triterpenes, and sterols. Thus, the simulation of stress conditions by means of treatment of wheat seedlings with exogenous phytohormones strongly affected the composition of lipophilic compounds. Specific changes in lipid composition induced by hormones may contribute to adaptive structural transformations of cellular membranes, whereas changes in the content of hydrophobic phenolic metabolites and photosynthetic pigments may reinforce antioxidant defense of plants under stress conditions.
Effect of NaCl on the Lipid Profile of Detergent-Resistant membranes of the Chloroplasts and Mitochondria of Euhalophyte Plants
Authors: Nesterov V. N. , Bogdanova E. S. , Rozentsvet O. A.
Published: April 2024

The effect of 1 M NaCl on the lipid profile of detergent-resistant chloroplast membranes was studied. sts and mitochondria of salt-accumulating halophyte plants – Salicornia perennans Willd. And Suaeda salsa (L.) Pall. (family Amaranthaceae). The composition of lipids and fatty acids in detergent-resistant membranes differs from the membrane lipids of chloroplasts and mitochondria by a large number of cerebrosides and sterols. Under the given salinity conditions, S. perennans experienced many a fold increase in the proportion of cerebrosides in the composition of detergent-resistant chloroplast membranes, and in S. salsa is found in detergent-resistant mitochondrial membranes. The opposite effect was observed in relation to sterols: a decrease in their relative content under the action of salt. Received data indicate the participation of detergent-resistant membranes in the interaction of chloroplast cells and mitochondria in the cellular response of halophytes to salinity.
Age and Adaptive Changes in the Photosynthetic Apparatus of Leaves in Winter Green Herbaceous Plant Ajuga reptans L. in the Natural Conditions of the Taiga Zone
Authors: Dymova O. V. , Zakhozhiy I. G. , Golovko T. K.
Published: April 2024

The formation and functioning of the photosynthetic apparatus (PSA) is under the general control of the plant organism and constantly changing environmental conditions. The authors studied age-related and adaptive changes in the pigment complex, spectral properties, and the state of photosystem II (PSII) leaves of partial shoots of a summer-winter-green herbaceous perennial Ajuga reptans L. (bugle) in connection with overwintering. Rosette leaves of a new generation appearing in May–June quickly accumulated photosynthetic pigments and formed PSA with a maximal quantum efficiency of PSII (Fv/Fm) and actual quantum yield of PSII (ФPSII). In autumn (September–October), the content of chlorophylls was 10 mg/g dry weight, the value of Fv/Fm was 0.8 rel. units, and the level of ФPSII at PAR 130 µmol quanta/(m2 s) was approximately 0.7 rel. units. Overwintered leaves contained half as much photosynthetic pigments, accumulated a significant amount of anthocyanins, and were characterized by low photochemical activity and a high level of de-epoxidation of pigments of the violaxanthin cycle. With the resumption of active vegetation of plants (May), a partial restoration of the pigment pool and the repair of PSA of overwintered leaves were noted, as evidenced by an increase in the quantum yield PSII. The completion of the leaf life cycle was accompanied by a decrease in ФPSII up to 0.5 rel. units and a sharp increase in the thermal dissipation of absorbed excitation energy (NPQ) to 0.9 rel. units. Seasonal changes of spectral properties of leaves and photochemical reflectance indices generally corresponded to the dynamics content pigments and the efficiency of the use of light in photosynthesis. The results obtained indicate a significant transformation of the structural and functional organization of PSA in the ontogeny of overwintering leaves. The genetically fixed property of winter green plants to preserve leaves is based on the ability of their PSA to restore functional activity after the shock impact of overwintering, which is facilitated by a complex of adaptive and protective mechanisms.
Continuous Lighting Increases Yield and Nutritional Value and Decreases Nitrate Content in Brassicaceae Microgreens
Authors: Shibaeva T. G. , Rubaeva A. A. , Sherudilo E. G. , Titov A. F.
Published: April 2024

Microgreens of four species of the family Brassicaceae (broccoli, mizuna, radish, and arugula) were grown under 16- and/or 24-h photoperiod conditions. In the first series of experiments, the daily light integral (DLI) was different (15.6 and 23.3 mol m–2 day–1 at PAR 270 µmol m–2 s–1), while it was the same (15.6 mol m–2 day–1 at PAR 270 µmol m–2 s–1 and 180 µmol m–2 s–1) in the second. In the third series of experiments, continuous lighting was used only in the last three days before harvesting. The results obtained showed that broccoli, mizuna, radish, and arugula plants in the early phases of growth are resistant to continuous lighting and do not show typical signs of leaf photodamage. In all three series of experiments, microgreens of all four species grown under 24-h photoperiod had a higher yield and nutritional value (higher content of substances with antioxidant properties—anthocyanins, flavonoids, carotenoids, and proline—as well as increased activity of antioxidant enzymes) and a lower content of nitrates compared to plants grown under 16-h photoperiod. It was concluded that it is possible through the use of continuous lighting without increasing energy costs (while maintaining the DLI) to increase the yield and nutritional value of the studied species of microgreens and reduce their nitrate content compared to the standard 16-h photoperiod. In addition, an increase in nutritional value and a decrease in nitrate content is also possible with the use of continuous lighting (as an agricultural practice) for several days immediately before harvesting.
Increasing the Resistance of Wheat to Oil Pollution Using Endophytic Bacteria Bacillus subtilis
Authors: Kuramshina Z. M. , Sattarova L. R. , Maksimov I. V.
Published: April 2024

The effect of treatment of wheat seeds with a suspension culture of cells of endophytic bacteria of the strain Bacillus subtilis 26D and lines B. subtilis 26D+n, selected for tolerance to crude oil components, on the growth and biochemical characteristics of wheat plants Triticum aestivum L. in conditions of oil pollution of the soil was studied. It has been shown that seed inoculation with the line B. subtilis 26D+n stimulated the growth of seedlings and suppressed the development of oxidative stress under conditions of exposure to oil pollution in plants in comparison with the control and plants inoculated with the strain B. subtilis 26D. Accordingly, bacteria B. subtilis 26D+n contributed to more successful growth of wheat plants on oil-contaminated soils, which can be used to stimulate the growth of plants in such areas and to return some of them to economic circulation.
Effect of Mosaic Knockout of Phytoene Desaturase Gene NtPDS on Biosynthesis of Carotenoids in Nicotiana tabacum L.
Authors: Nezhdanova A. V. , Slugina M. A. , Kulakova A. V. , Kamionskaya A. M. , Kochieva E. Z. , Shchennikova A. V
Published: April 2024

Carotenoids are essential participants in photosynthesis and photo protection as well as growth, development, and stress response in plants. Phytoene desaturase (PDS; EC 1.3.5.5) is an enzyme that catalyzes the first stage of desaturation of 15-cis-phytoene (a precursor to all carotenoids). In this work, we examined for the first time the effect of PDS knockout in the genome of Nicotiana tabacum L. using the CRISPR-Cas9 system on activity of downstream genes involved in biosynthesis of carotenoids. Nine transgenic lines of tobacco were obtained with a mosaic editing of gene NtPDS; three versions of indels (350^351→ins^g#, 350^351→ins^t#, and t351→del(1nt)#) in the exon II resulting in the synthesis of a shortened non-functional version of the protein. The lines were characterized by spotted, green-white pigmentation of the leaves, altered flowering time and morphology as well as a reduced content of carotenoids and chlorophylls in the leaf tissue. A rise in the level of transcripts of phytoene synthase gene NtPSY2 was shown in late-flowering lines as compared to control material. Edited line L29 with the latest flowering showed a considerable increase in the level of transcripts of downstream structural genes of carotenogenesis. A reduction in the carotenoid content in the leaves with mosaic editing was accompanied by a decrease in the level of expression of MADS-box gene NtSEP1, the product of which presumably participates in regulation of transcription of the carotenoid biosynthesis genes. The obtained results may be used for further studies of regulation of biosynthesis of carotenoids and apocarotenoids in Solanaceae.
Effect of Elevated CO2 and Temperature on Plants with Different Type of Photosynthesis: Quinoa (C3) and Amaranth (C4)
Authors: Rakhmankulova Z. F. , Shuyskaya E. V. , Prokofieva M. Yu. , Saidova L. T. , Voronin P. Yu.
Published: April 2024

The thermal stability of plants with different types of photosynthesis Chenopodium quinoa Willd. (C3) and Amaranthus retroflexus L. (C4-NAD) to short-term elevated temperature (35°С, eT) at ambient (400 ppm, aCO2) and elevated (800 ppm, eCO2) CO2 concentration was investigated. Growth parameters, water, proline, and MDA content, CO2/H2О gas exchange parameters, the functioning of PS I and PS II, and the content of key photosynthetic (Rubisco, PEPC) and photorespiratory (GDC) enzymes were analyzed. Under control conditions, C4-type plants, compared with the C3-type, show higher values of dry biomass growth, intensity of visible photosynthesis, transpiration, and PS I activity and lower proline content. The photosynthetic and stomatal apparatus of both types was sensitive to eT, which manifested itself in a decrease in the intensity of apparent photosynthesis and transpiration. In addition, suppression of light reactions (PS II) and intensity of photorespiration (according to GDC) was observed in the C3-species and an increase in the content of proline in the C4-species. Under eCO2 conditions, the C3-species showed a decrease in the intensity of photorespiration, while oxidative stress (twofold increase in the content of MDA) was accompanied by reduced intensity of apparent photosynthesis, transpiration, and increased intensity of dark mitochondrial respiration in the C4-species. A softening effect of eCO2 on thermal stability data for C3- and C4-plants was not established. With the combined action of eCO2 and eT, both types exhibited oxidative stress, reduced efficiency of PS II and apparent photosynthesis, and activation of dark respiration. However, differences were also observed: oxidative stress was accompanied by a decrease in the increase in dry biomass and water content in tissues, as well as suppression of photorespiration, in the C3-species, while there was a decrease in the intensity of transpiration and an increase in the content of PEPC in the C4-species. Reduced WUE with combined action of eCO2 and eT in plants of the C4-species was less significant than the C3-species. The different response of quinoa plants (C3) and amaranth (C4) on the combined effect of climatic factors of elevated temperature and CO2 concentration is discussed.
Content of Gentiopicroside in Natural Populations of Gentiana cruciata L., Growing in the Territory of the Republic of Tatarstan
Authors: Khusnetdinova L. Z. , Akulov A. N. , Dubrovnaya S. A. , Timofeeva O. A. , Mukhametshina R. M.
Published: April 2024

This report contains the results of quantitative analysis of primary iridoid gentiopicroside, phenolic compounds, and flavonoids in the shoots, rhizomes, and roots of cross gentian (Gentiana cruciata L.) plants collected in natural phytocenoses of Alekseevskii, Zelenodol’skii, and Apastovskii raions in the Republic of Tatarstan. The content of phenolic compounds and flavonoids in herbs was determined spectrophotometrically. It was shown that the greatest content of phenolic compounds and flavonoids in above-ground parts was 19.4 and 10.80 mg/g in Zelenodol’skii and Alekseevskii raions and that in the rhizomes and roots was 8.53 and 1.96 mg/g in Apastovskii raion. By the method of high-performance liquid chromatography, it was shown that the greatest quantity of gentiopicroside (more than 9%) was accumulated in the underground part of plants, whereas the above-ground part contained approximately 6% of this compound. Thus, cross gentian growing in plant communities located in these raions differed in the content of biologically active substances, which probably depended on the joint effect of ecological and cenotic characteristics of habitats. The results of phytochemical analysis suggest that Apastovskii raion in the Republic of Tatarstan may be a promising locality for picking and preparing medicinal herbs with a high content of main iridoid gentiopicroside.
Plant Anthocyanins: Structure, Biosynthesis Regulation, Functions, and Ecology
Authors: Golovko T. K.
Published: April 2024

The review summarizes current information about anthocyanins (AnC) and their localization in various plant organs and tissues. The pathways and regulation of AnC biosynthesis, the functional significance, and ecological role of these compounds in metabolism and adaptation of plants to environmental conditions are considered. Data on the induction of AnC synthesis under the action of stress factors and during plant growth and development are summarized. Special attention is given to the role of AnC in protection of the photosynthetic apparatus. The prospects for further research and the use of AnC as indicators of plant organism’s state are discussed. The importance of these compounds for humans and human health is mentioned.
Influence of Growth Regulators and Different Spectra of Monochromatic Radiation on the Growth and Biosynthetic Characteristics of Callus Culture of Ipomoea batatas (L.) Lam.
Authors: Yugay Yu. A. , Grishchenko O. V. , Vasyutkina E. A. , Grigorchuk V. P. , Chukhlomina E. N. , Tsydeneshieva Zh. L. , Kudinova O. D. , Yaroshenko Yu. L. , Degtyarenko A. I. , Subbotin E. P. , Bulgakov V. P. , Kulchin Yu. N. , Shkryl Yu. N.
Published: April 2024

The work studied the influence of plant growth regulators as well as the effect of monochromatic radiation of different spectral composition on the growth and accumulation of secondary metabolites in the callus culture of sweet potato (Ipomoea batatas L.). It was found that auxin analogues in low concentrations (0.5 mg/L) significantly stimulated the growth of cell biomass, while the effect of 4-chlorophenoxyacetic acid (4-CPA) was more pronounced (stimulation 16 times) than that of 2,4-dichlorophenoxyacetic acid (2,4-D) (13.5 times stimulation). Both the increase in the concentration of 2,4-D and 4-CPA in the medium and the addition of cytokinin, 6-benzylaminopurine (BAP), led to a significant inhibition of culture growth (up to three times). In contrast to 2,4-D, the addition of 4-CPA led to an eightfold increase in the total content of polyphenolic compounds in cultured cells. Activating effect of 4-CPA on the biosynthetic characteristics of I. batatas cell culture persisted even with the addition of BAP, while an increase in the concentration of 4‑CPA led to the leveling of the activating effect. Monochromatic radiation—white, red (660 and 630 nm), yellow, green, and blue (440 and 460 nm) light—inhibited growth (up to 1.5 times) and the total accumulation of secondary metabolites in I. batatas cells (up to 1.8 times). At the same time, the white, bright blue, and red spectra differentially activated the formation of individual compounds 3,4-dicaffeoylquinic acid and 3-feruloyl-5-caffeoylquinic acid. Thus, the authors have established that both auxin analogues and spectral radiation exhibit different effects on the growth and biosynthetic characteristics of the I. batatas calli.
Phenolic Compounds of Plants Bidens tripartita (L.) and Bidens pilosa (L.) from Different Locations
Authors: Bimenyindavyi E. , Khusnetdinova L. Z. , Timofeeva O. A.
Published: April 2024

Bidens tripartita L. and Bidens pilosa L. are potential sources of biologically active substances with antimicrobial, antidiabetic, anticancer, anti-inflammatory, antioxidant, and other activities. These types of strings are widely used in different countries in phytomedicine. It was established that the studied species are rich in a variety of phenolic compounds, and plants growing in temperate continental (Tatarstan) and tropical (Burundi) climates differ slightly in the content of phenolic compounds, which indicates a genetically determined narrow amplitude of variability in the metabolism of these species. Qualitative analysis of phenolic compounds showed that the studied plant species synthesize certain groups of compounds for adaptation to specific environmental conditions. Kirimiro in the Republic of Burundi and Spassky raion in the Republic of Tatarstan can be considered as promising areas for growing and collecting the plant species under study. Temperature, altitude, rainfall, and soil composition are key factors affecting phenolic content in B. pilosa and B. tripartita plants.
Sterol Composition of Lichen Peltigera canina When Exposed to Unfavorable Temperatures
Authors: Valitova Yu. N. , Khabibrakhmanova V. R. , Babaev V. M. , Uvaeva V. L. , Khairullina A. F. , Rakhmatullina D. F. , Galeeva E. I. , Swid M. A. , Minibayeva F. V.
Published: April 2024

Currently, special attention is paid to the study of the mechanisms of stress resistance of extremophile organisms that can survive in extreme conditions. Such organisms include lichens, which are symbiotic associations of fungi and algae and/or cyanobacteria. The high stress resistance of lichens is due to the presence of a wide range of biologically active metabolites, including sterols. It is known that lichens have a diverse and unique sterol composition, different from that of fungi and algae. Sterol-mediated biochemical mechanisms of stress resistance in lichens have not been fully studied and not systematized. Temperature stress is quite common for lichens, which often grow in unfavorable conditions. It is known that dry lichen thalli are able to withstand temperature changes over large ranges, while hydrated thalli are much more sensitive to unfavorable temperatures. In this work, stress-induced changes in respiratory activity and membrane stability index (MSI), as well as the sterol profile of hydrated lichen thalli, of Peltigera canina (L.) Willd. under the influence of elevated (+40°С) and low (–20°С) temperatures was investigated. It was shown that unfavorable temperatures caused a suppression of respiration rate and a decrease in the MSI of lichen thalli. Chromatomass spectrometric analysis showed the presence of P. canina ergosterol, dehydroergosterol, episterol, lichesterol, and fungisterol. Under the influence of both stress factors, there was a decrease in the level of ergosterol and an increase in the proportion of episterol. Under cold stress conditions, the proportion of dehydroergosterol also increased, the proportion of lichesterol decreased, and the relative content of the more saturated sterol fungisterol remained at the control level. It can be assumed that stress-induced changes in the sterol profile of lichens under low-temperature exposure create an optimal balance of sterols in membranes, which provides conditions for the deployment of a successful strategy leading to the adaptation of the lichen to the action of a stressor.
Changes in the Content of Carotenoids in Moss Shoots Hylocomium splendens Hedw. under Conditions of Temperature Stress
Authors: Renkova A. G. , Khabibrakhmanova V. R. , Gurjanov O. P. , Galeeva E. I. , Mazina A. B. , Minibayeva F. V.
Published: April 2024

The ability of plants to adapt to unfavorable living conditions is a necessary condition for the survival of plants, the preservation of the genotype, and the maintenance of flora diversity. A promising approach to solving the problem of increasing plant resistance is to study the mechanisms of stress resistance of “extremophiles”, including mosses, higher nonvascular plants. The relative simplicity of their anatomical structure and ability to survive in unfavorable environmental conditions make these evolutionarily ancient plants ideal models for studying adaptation mechanisms. It is known that the functional activity of the photosynthetic apparatus can change dynamically under the influence of stress factors. In this work, we conducted a study of stress-induced changes in the content of carotenoids in the forest moss Hylocomium splendens Hedw. under temperature stress conditions. We have identified the main carotenoids of H. splendens moss. It has been established that the relative content of lutein, β-carotene, and zeaxanthin increased under the influence of negative and elevated temperatures, while the total content of carotenoids decreased under temperature stress. It was shown that 1 h of exposure to unfavorable temperatures led to a significant decrease in nonphotochemical quenching of chlorophyll fluorescence a, with stronger changes observed when exposed to negative temperatures. Transcript level analysis of HsLUT1, one of the key genes for lutein biosynthesis, showed a significant increase of four to five times under temperature stress. Thus, our data revealed that changes in the expression of the carotenoid biosynthesis gene are accompanied by changes in their content under temperature stress. The data obtained expand our knowledge of resistance mechanisms in bryophytes and will contribute to the understanding of evolutionary changes in stress resistance in higher plants.
Synthesis and Study of the Properties of Porous Carbon–Carbon Nanocomposites with Nitrogen-Containing Carbon Nanofibers
Authors: Kryazhev Yu. G. , Pod”yacheva O. Yu. , Trenikhin M. V. , Gulyaeva T. I. , Anikeeva I. V. , Vol’fkovich Yu. M. , Rychagov A. Yu.
Published: April 2024

The possibility of synthesizing carbon–carbon nanocomposites with nanofibers embedded in a carbon matrix by two-stage dehydrochlorination (under the action of alkali followed by carbonization) of a carbon-chain chloropolymer has been shown. Chlorinated polyvinyl chloride was used as the initial chloropolymer, and nitrogen-containing carbon nanofibers (N-CNFs) were used as a nanoscale component. The structure of the resulting nanocomposites was examined by electron microscopy and the texture parameters were studied using low-temperature nitrogen adsorption–desorption. The introduction of N-CNFs into the carbon matrix and the activation of the resulting carbon–carbon nanocomposite in an atmosphere of CO2 contributed to the formation of a micro- and mesoporous material with a specific surface area of ~1100 m2/g. It was shown that the resulting nanocomposites were characterized by high energy capacity and energy efficiency when tested as electrodes of electrochemical supercapacitors.
Changes in the Composition of Heavy Oil and the Structure of Asphaltenes upon Treatment with Isopropyl Alcohol
Authors: Korneev D. S. , Osnitskii E. M. , Voronetskaya N. G. , Pevneva G. S. , Klimenko L. S.
Published: April 2024

The interactions of the components of heavy oil from the Zyuzeevskoye field (Republic of Tatarstan) and isopropyl alcohol (IPA) at temperatures of 25, 65, and 100°C were studied. It was established that the temperature regime affected the density, composition, and structural group characteristics of the products of interactions between the oil and IPA. The density of the resulting products increased by 4 wt % (from 0.885 to 0.924 g/cm3) as the process temperature was increased to 100°C, and the concentration of resin–asphaltene substances also increased by 4 wt % in this case. It was shown using IR spectroscopy that the tentative concentration of paraffin fragments in the structure of asphaltenes increased significantly when the oil was treated with isopropanol at temperatures of 65–100°C, and the branching factor increased by a factor of 3, as compared to that of the initial asphaltenes. The observed changes were due to the incorporation of isopropyl fragments into the structure of asphaltene molecules upon the processing of heavy oil with IPA.
Composition of the Organic Compounds of Different Peat Types from the Southern Taiga Subzone of Western Siberia
Authors: Serebrennikova O. V. , Russkikh I. V. , Strel’nikova E. B. , Kharanzhevskaya Yu. A. , Fedorov D. V.
Published: April 2024

Acyclic (n-alkanes, n-alkan-2-ones, fatty acids, methyl esters of fatty acids, n-aldehydes, squalene, phyton, and phytol isomers) and cyclic (series of di- and triterpenoids, steroids, and tocopherols, phytonadione, and dihydroactinidiolide) organic compounds, many of which are biologically active, in peat samples raised bogs and fens of the southern taiga subzone of Western Siberia were studied using gas chromatography–mass spectrometry. Acyclic structures, among which n-alkan-2-ones were predominant, dominated in sedge and sedge-hypnum peat in contrast to Sphagnum peat, in which n-alkanes predominated. The distribution of pentacyclic triterpenoids, n-alkanes, n-alkan-2-ones, and methyl esters of fatty acids was largely determined by the botanical composition of peat.
Influence of In Situ Formed Nickel- and Cobalt-Containing Catalysts on the Mechanism of Conversion of Heavy Oil Asphaltenes
Authors: Urazov Kh. Kh. , Sviridenko N. N.
Published: April 2024

The influence of the amount of precursors of cobalt and nickel oxides on the composition and structure of catalytic cracking products of heavy oil from the Zyuzeevskoye field was studied. It was found that an increase in the amount of a loaded precursor led to the destruction of a larger amount of resin–asphaltene components and the yield of an IBP–360°C fraction. It was established that nickel-containing catalysts facilitated the destruction of 66% high-molecular-weight components, and cobalt-containing catalysts contributed to a low yield of by-products. The structural group analysis of initial oil asphaltenes and those formed after thermal and catalytic cracking was studied. A possible mechanism of the reactions was presented based on the experimental data.
Influence of the Mechanochemical Modification of Humic Acids on the Formation of Colloids in Solution
Authors: Yudina N. V. , Savel’eva A. V.
Published: April 2024

The colloid-chemical properties of humic acids (HAs) were studied depending on the mechanochemicalmodification of their structure. An increase in the amount of acidic ionogenic groups and hydrophilicfragments in the composition of modified HAs facilitated a decrease in the excess energy of surfacemolecules. In an alkaline solution, two types of colloids characterized by a decrease in the energy of adsorption and the constant of adsorption equilibrium were formed as the concentration of HAs was increased.
Granular Carbon Adsorbent Based on Soot and Synthetic Pitch
Authors: Kugatov P. V. , Ivashkina E. A. , Zhirnov B S.
Published: April 2024

A method for producing granular carbon adsorbent by stirring a suspension of soot in a solution of naphthalene (in heptane) in the presence of sulfuric acid was proposed. Experimental research together with mathematical processing of the results made it possible to propose a mechanism for the formation of spherical carbon granules from soot and naphthalene: in the course of intense mixing in the presence of concentrated sulfuric acid, a binder material was formed from naphthalene, and it was adsorbed on the surface of soot particles. The resulting particles with a thin layer of binding material on their surface stuck together in the field of centrifugal forces to form larger particles, which ultimately acquired a spherical shape and had a size of up to 5 mm. A comparison of the resulting carbon granules (from soot and synthetic pitch) with granules preparedby mixing soot and petroleum pitch showed that the proposed adsorbent had specific surface area and mechanical strength greater by factors of 1.5–2.
Development Dynamics of the Almond Willow’s Shoots on Different Levels Atmospheric Moisture
Authors: Afonin A. A.
Published: April 2024

The article provides an analysis of the modern trends in the rational use of fast-growing shrub willows. The almond willow (Salix triandra) is considered a source of wicker for weaving, as well as a species performing important ecosystem functions. The purpose of the research was to identify the influence of uneven precipitation distribution on the growth and development of the S. triandra shoots. The test site had a genetically aligned model inbred-clonal population of S. triandra. One-year willow saplings grown from unrooted cuttings were chosen as a study material. The development dynamics of S. triandra shoots was studied in four clones and in two different years with excessive moisture. The second year of observations differed from the previous one by an excess of precipitation during the cuttings rooting. Under experimental conditions, the maximum length of annual shoots was 210–220 cm, regardless of the year of observation. The cyclicality was determined in the shoots’ daily growth’s variations. The full seasonal development cycle of shoots includes four multi-day cycles. The second and third multi-day cycles are characterised by the greatest daily growth of shoots in the first half of summer. The maximum daily growth in both years of observation was 4.1–4.9 cm/day and occurred in early summer. The spring and late summer daily growth of most shoots did not exceed 2.3–2.7 cm/day. In the second year of observation, the late-summer daily growth (on average 1.9 cm/day) was slightly higher than in the first year (on average 1.6 cm/day). The synchronization of the shoots development in the beginning of summer was revealed, regardless of the year of observation and the clones’ factor. Excessive moisture during the rooting of cuttings lead to a shift in the peak values of daily growth at a later date. Against the background of an uneven distribution of precipitation, the influence of the clones’ factor on the seasonal dynamics of daily growth was revealed. When studying the growth and development of shoots in S. triandra clones, it is necessary to take into account the uneven distribution of precipitation in the first half of the vegetation period.
Phytocenotic and Biotopic Parameters Affect the Condition of European Spruce Cultures during the Establishment Stage in the South-East of the Leningrad Region
Authors: Koptseva Ye. M. , Kuzmina Yu. V. , Sorokina I. A. , Bushkovskiy A. A.
Published: April 2024

In the Boksitogorskiy district of the Leningrad oblast, the study was conducted regarding the influence of phytocenotic parameters (crowns density, height, herbage density, moss cover) and biotopic parameters (illumination, acidity, moisture and soil richness) on the morphometric parameters and vitality of European spruce (Picea abies (L.) H. Karst.) BRT (bare root trees) and RBT (root-balled trees) seedlings during the establishment phase under contrasting growing conditions: under the sparse aspen canopy left in clearings and in open spaces, outside the influence of tree crowns. The positive effect of undercanopy cultivation on the safety and viability of seedlings of both types has been statistically proven; with RBT seedlings having the best indicators of vitality and growth along the main axis. However, the herbaceous layer’s height and density under these conditions adversely affected the branching of seedlings. Unlike the undercanopy conditions, when growing in the open, the condition of seedlings was more susceptible to the influence of abiotic factors. Under these conditions, a close positive correlation was found between the viability of seedlings with BRT and the main soil parameters (humidity, acidity, and nitrogen supply). Due to the better illumination on plots without canopies, seedlings with BRT had consistently high growth rates along the main axis. Under these conditions, the grass cover at the stage of spruce establishment was found to have a protective effect, maintaining a more optimal moisture regime and shading the seedlings. The practicality of using the RBT cultures in open spaces was still substantiated, since they were less susceptible to the negative influence of factors.
The Correlation between the Radial Growth of Coniferous Trees and the Normalised Difference Vegetation Index
Authors: Soukhovolsky V. G. , Kovalev A. V. , Voronin V. I. , Oskolkov V. A. , Ivanova Yu. D.
Published: April 2024

This work is dedicated to analysing of the nature of the relationship between the radial growth of trees and remote sensing data. The calculations performed showed that there are certain connections between the satellite data and the values of the first differences in the widths of tree rings, but the strength of these correlations depends on the uniformity of the plantation trees’ radial growth processes. The less synchronous in time are the series of the first differences in the widths of the tree rings (FD WTR), the weaker are the connections between the remote sensing data and the radial increment. Another factor influencing the nature of the relationship between the satellite data and the radial growth is damage to trees. Thus, weak or lacking links between satellite and field data can still be observed and the reason for this is the heterogeneity in growth processes periods of different trees in the stand.
The Role of Greenery in Adaptation of Urban Ecosystems to Climate Change
Authors: Semenyuk O. V. , Telesnina V. M. , Bogatyryov L. G. , Baranova O. Yu.
Published: April 2024

In order to develop proposals for managing the functioning of the city’s green frame, a study has been carried out, regarding tree plantations and their litter layers, as well as some aspects of the urban ecosystems’ biological cycle of as part of the optimisation of the carbon footprint. The topic’s relevance is due to the global warming and the need to identify sources of direct and indirect anthropogenic impact on the carbon balance, as well as the need to assess the contribution of carbon emissions to the atmosphere of urban areas. The litter, despite its small contribution to the total carbon stock of the ecosystem, is the most mobile horizon, connecting vegetation and mineral soil horizons, thus its typology and properties are the most important characteristics that can be used to monitor urban ecosystems. It has been established that in urban ecosystems, compared to the natural analogues, there is an increase in the biological cycle intensity, which is associated with the following factors: a shift in the ratio of tree species in the city’s green frame towards a significant increase in the proportion of deciduous trees, the use of a greenery maintenance system and the destructive impact of recreation on litter layers. The percentage decrease in the amount of carbon in the litter of coniferous plantations as a result of recreational impact is 20–57%, in the case of the leaf litter collection – up to 90%, while in absolute terms the loss of carbon reserves is comparable and equal to 20–23 kg/100 m2 (we note that that the litter variant of larch plantations shows the absolute values of carbon losses 3 times higher). All studied variants of urban greenery subject to pronounced anthropogenic impact, demonstrate a decrease in the biological cycle isolation compared to undisturbed ones. A change in the organic matter circulation direction in urban ecosystems towards its depositing as a part of terrestrial detritus can be implemented both by regulating the intensity of the greenery maintenance, and by reducing its loss during recreation – design solutions for the organisation of landscape objects with the diversion of visitors’ transit flows from the locations of conifers ecosystems.
Aphid Species Composition in Three Parks of Saint-Petersburg and Leningrad Region in 2021
Authors: Berim M. N.
Published: April 2024

Due to the high harmfulness of aphids inhabiting trees and shrubs in the St. Petersburg’s and the Leningrad Region’s park areas, it becomes necessary to monitor the dynamics of the numbers and species composition of this group of insects. During the vegetation season of 2021, the species composition of aphids was determined in three parks in St. Petersburg and the Leningrad Region: Sosnovsky forest park, Pavlovsky and Gatchina parks. The material was taken directly from plants and caught using an entomological net. A total of 16 species were identified. In the Sosnovsky forest park, 10 species were identified, in the Pavlovsky park – 12, in the Gatchinsky park – 9 species. Two species were found on coniferous trees, the rest – on the deciduous ones. Species such as dogwood aphid (Anoecia corni F.), bird cherry-oat aphid (Rhopalosiphum padi L.), silver birch aphid (E-uceraphis betulae gr. sp.), common oak aphid (Tuberculatus annulatus Hart.), black bean aphid (Aphis fabae Scop.), rose aphid (Macrosiphum rosae L.) were found in all three parks, the rest – in one or two parks. Dogwood aphid, bird cherry-oat aphid, silver birch aphid, black bean aphid and rose aphid were observed in massively large colonies on a significant number of host trees. In other species, small colonies were found on separate trees; finally, for some species only single individuals were caught. In the first half of September, the number of aphids was relatively low.
Analysis of the Stocks and Conditions of Harvesting for Forest Berries with Considering Their Spatial Distribution and Availability
Authors: Kolycheva A. A. , Chumachenko S. I. , Kiseleva V. V. , Agol’cov A. Ju.
Published: April 2024

Within the framework of the multi-purpose forest management concept, the resource and economic potential of harvesting wild berries was analyzed under different forest management scenarios. As a tool for forecasting and analysis, scenario-based simulation was used to model the forest ecosystems dynamics under the clearcut and the selective felling management types. The object of research is the Pashe-Kapetskoe district forestry of the Leningrad Region, the calculation was carried out for a period of 120 years. Based on the forest condition types’, species composition and simulated illumination at the ground level data, the potential productivity of wild berries was calculated. The most productive resources on the territory were bilberry and lingonberries, the predicted yield of which reaches 25–48 t/ha and 7–15 t/ha respectively. Zoning of the territory was carried out according to the resources availability for industrial harvesting, taking into account the interests of the local population. 37–48% of the wild berries harvest was available for industrial harvesting, about 30% was allocated for the needs of the local population, and 27–36% of the resource remained in economically inaccessible areas. The most promising was the scenario with artificial restoration of 50% of the clearcut areas and a full maintenance cycle. For this scenario, the maximum profitability was predicted from both the food resources procurement (4.1–5.7 million rubles per year) and the harvesting of timber.
Siberian Larch Reproduction Using the Somatic Embryogenesis Biotechnology
Authors: Tretyakova I. N. , Park M. E.
Published: April 2024

The biotechnology of somatic embryogenesis in vitro, combined with genomic selection and cryopreservation is used to create varietal genetically tested fast-growing plantations (Multi-Varietal Forestry program (MVF), Park, 2014, 2016, 2018). In 2008, the Sukachev Forest Institute of the Siberian Branch of the RAS has developed for the first time the biotechnology of somatic embryogenesis for Siberian larch (Larix sibirica Ledeb.) and obtained 42 proliferating cell lines consisting of embryonal-suspensor mass (ESM). The age of cell lines reaches 13 years. Significant variability was observed between cell lines in the number and size of globular embryos in proliferating embryogenic cultures, and in the ability of somatic embryos to mature and germinate. In different cell lines, the number of globular somatic embryos per 1 g of ESMs fresh weight ranges from 2040 to 11103, with 10 to 1220 embryos maturing. The regenerants germinate in a growth chamber, and plantlets of individual cell lines grow successfully in a greenhouse and then in the soil of the forest nursery at the Forest Institute’s Pogorelsky Bor station. Genotyping of clones at microsatellite loci showed their complete genetic identity to the cell line from which they were obtained. In cloned Siberian larch trees at the age of seven, the initiation of generative organs forming occurred. Thus, at present, it is possible to quickly implement the MVF program for plantation forestry in Russia.