Influence of exogenous urea on photosynthetic pigments, 14CO2 uptake, and urease activity in Elodea densa-environmental implications

This paper analyzes the effect of exogenous urea in increased concentration gradient (0, 100, 500 and 1,000 mg L-1) on photosynthetic pigments (measured spectrophotometrically), uptake of 14CO2 (using radioisotope), and urease activity (by measuring ammonia with Nessler's reagent) in leaves of Elodea densa Planch. We have observed that low concentration of urea (100 mg L-1) stimulates the accumulation of photosynthetic pigments and intensifies photosynthesis in E. densa, whereas high concentration (1,000 mg L-1) suppresses these processes. Urease activity increased by approximately 2.7 and 8 fold when exogenous urea concentrations were 100 and 500 mg L-1, respectively. However, exogenous urea in high concentration (1,000 mg L-1) decreased urease activity by 1.5 fold compared to the control. The necessity of mitigating urea and other nitrogen-containing compounds (NH3 from urea) in water bodies has been discussed with emphasis on the potential for phytoremediation of urea using common water weed viz. E. densa. © 2013 Springer-Verlag Berlin Heidelberg

High dose of urea enhances the nickel and copper toxicity in Brazilian elodea (Egeria densa Planch. Casp.)

Selected cellular responses for urea (5 mM), Ni (100 μM), and Cu (100 μM) treatments and their combined effects on the leaves of a submerged macrophyte Brazilian elodea (Egeriadensa Planch. Casp.) were studied for 4 days. It was observed that the high dose of urea (5 mM) had a significant toxic effect on some physiological and biochemical characteristics of E. densa such as the content of chlorophyll a and the activities of catalase, ascorbate peroxidase, and guaiacol peroxidase. The elevated level of lipid peroxidation was accompanied by the accumulation of proline and ascorbate. A substantial increase in the amount of proline and urease activity was observed in Urea + Ni-treated leaves. The ascorbate content significantly increased in all the treated plants which correlated with ascorbate peroxidase activity. Urea with Cu ions affected the E. densa photosynthetic pigment system and urease activity adversely. The catalase activity was inhibited by the action of all the pollutants studied, especially in Urea + Cu-treated plants, whereas the peroxidases activity (APX and GPX) increased under the Cu and Urea + Cu action. The results presented indicate that the addition of the high dose of urea (5 mM) to the heavy metals studied may enhance the toxic effects in E. densa leaves, especially in the case of copper. © 2016, Botanical Society of Sao Paulo

Low-Molecular Antioxidants Help Rare Orchids to Survive in Serpentine Dumps

В статье представлены результаты исследования морфофизиологических и биохимических характеристик орхидеи Epipactis atrorubens, произрастающей в естественном лесном фитоценозе и техногенно нарушенных местообитаниях. Изучены параметры листовой пластинки, водный режим листьев, уровень перекисного окисления липидов, а также содержание фотосинтетических пигментов и низкомолекулярных антиоксидантов в листьях растений. Результаты исследования показали, что адаптивные структурные перестройки листа и активация системы антиоксидантной защиты определяют не только способность редкого вида орхидей выживать в неблагоприятных условиях, но и успешно адаптироваться к ним.The article presents the results of a study of morphophysiological and biochemical characteristics of the orchid Epipactis atrorubens, growing in natural forest community and technogenic habitats. Leaf mesostructure, water regime and biochemical features (level of lipid peroxidation, content of photosynthetic pigments and low molecular weight antioxidants) of plants have been studied. The present study showed that the adaptive leaf structural rearrangements and activation of antioxidant defense system determine not only the ability of a rare orchids to survive in negative conditions, but also to successfully adapt to them

Adaptive morphophysiological features of neottia ovata (Orchidaceae) contributing to its natural colonization on fly ash deposits

In previous decades, some species of the Orchidaceae family have been found growing in man-made habitats. Neottia ovata is one of the most widespread orchids in Europe, however it is quite rare in Russia and is included in several regional Red Data Books. The purpose of this study was to compare the chemical composition and morphophysiological parameters of N. ovata from two forest communities of the Middle Urals, Russia: natural and transformed (fly ash dump of Verkhnetagil’skaya Thermal Power Station) for determining orchid adaptive features. The content of most of the studied metals in the underground parts (rhizome + roots) of N. ovata was considerably higher than in the leaves, which diminished the harmful effect of toxic metals on the aboveground organs. The adaptive changes in the leaf mesostructure of N. ovata such as an increase in epidermis thickness, the number of chloroplasts in the cell, and the internal assimilating surface were found for the first time. The orchids from the fly ash deposits were characterized by a higher content of chlorophyll b and carotenoids than plants from the natural forest community that evidenced the compensatory response on the decrease in chlorophyll a. The ability of N. ovata from the transformed habitat to maintain a relatively favorable water balance and stable assimilation indexes further contribute to its high viability. The study of orchid adaptive responses to unfavorable factors is necessary for their successful naturalization and introduction into a new environment. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The reported study was partly funded by RFBR and the Government of Sverdlovsk region, project number 20-44-660011 and the Ministry of Science and Higher Education of the Russian Federation as part of state task of the Ural Federal University, FEUZ-2020-0057

Leaf Mesophyll Structure and Photosynthetic Activity in Calla palustris L. from Natural Habitats with Different Level of Technogenic Pollution

A study of leaf structure and CO2 assimilation rate was conducted on the emergent plant Calla palustris L. from natural habitats with different levels of technogenic pollution (the Sak-Elga River, upstream and downstream of the Karabash copper smelter, Chelyabinsk region, Russia). It was found that both chlorophyll a content andthe rate of CO2 assimilation decreased twofold in plants from the downstream site. No significant changes were observed in leaf mesophyll structure and the volume of aerenchyma in the leaf. It was shown that in plants from strongly contaminated site, the decrease in spongy mesophyll cell volume was compensated by the increase in their number, whereas the decrease in the number of chloroplasts per cell was accompanied by a growth in volume. It is concluded that the changes in the numerical and dimensional characteristics of mesophyll cells and chloroplasts provide for the viability of C. palustris under prolonged technogenic impact and demonstrate the plasticity of the photosynthetic apparatus. Keywords: emergent plant, heavy metals, adaptation, leaf structure, CO2 uptak

Adaptive Redox Reactions Promote Naturalization of Rare Orchid Epipactis atrorubens on Serpentine Dumps Post Asbestos Mining

Epipactis atrorubens (Hoffm.) Besser. is a regionally rare orchid species with highly ornamental properties due to its very beautiful bright flowers, therefore it is of considerable interest as a horticultural plant for use in botanical gardens and greenhouses. The objective of the research was to assess metal accumulation and some pro-and antioxidant reactions in E. atrorubens, colonizing serpentine dumps post asbestos mining. Additionally, some physicochemical properties of substrates, microbiotic characteristics and water status were investigated in orchids growing on two serpentine dumps and in a natural forest habitat of the Middle Urals, Russia. The dump substrates were characterized by the strong stoniness and the high content of Mg, Ni, Cr and Co (by 1.8 times on average) compared to the natural habitat. In these sites, E. atrorubens was characterized by increased mycorrhization. In the rhizome and roots of E. atrorubens the concentrations of most metals studied were considerably higher (more than 4 times on average) than in the leaves. It was found that orchids colonizing serpentine dumps produced more lipid peroxidation products (by 1.4 times on average) in the leaves which was accompanied by the more active synthesis of such non-enzymatic antioxidants as ascorbate, free proline, soluble phenolic compounds (including flavonoids) and non-protein thiols. The study suggests that non-enzymatic antioxidants increased the adaptive potential of E. atrorubens and contributed to its naturalization on serpentine dumps post asbestos mining. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.20-44-660011; Russian Foundation for Basic Research, РФФИ; Ministry of Education and Science of the Russian Federation, Minobrnauka; Ural Federal University, UrFU: FEUZ-2020-0057Funding: The reported study was partly funded by RFBR and the Government of Sverdlovsk region, project number 20-44-660011 and the Ministry of Science and Higher Education of the Russian Federation as part of state task of the Ural Federal University, FEUZ-2020-0057

Содержание фенольных соединений в листьях Platanthera bifolia из естественной и трансформированных экосистем на разных стадиях развития орхидеи

The representatives of the family Orchidaceae Juss. are often used as a source of natural antioxidants, including phenolic compounds, which play an important role in plant resistance under stressful conditions. This study investigates the content of lipid peroxidation products and soluble phenolic compounds in flowering plants of Platanthera bifolia (L.) Rich. growing in natural (forest park) and transformed (fly ash dumps of Thermal Power Stations) ecosystems of the Middle Urals, Russia, as well as the content of flavonoids at different stages of orchid development. Research has shown that in disturbed habitats, P. bifolia is capable of forming abundant populations containing a significant portion of the flowering plants. Additionally, flowering orchids from fly ash dumps contained an average 20 % more lipid peroxidation products, which indicated a shift in the redox balance towards oxidative processes. An increase by 2.4 times on average in the content of phenolic compounds, particularly flavonoids, was observed at all developmental stages of the plants growing in the transformed ecosystems. Regardless of the growing conditions, the non-flowering mature individuals were characterized by a minimum content of flavonoids, probably due to pre-generative metabolic restructuring. Yet, in the period of orchid blooming, the flavonoid content in their leaves increased again in all study sites. At the same time, the flavonoid proportion of the total soluble phenolic compounds was 42 % in the natural habitat, increasing to 66 % on average in the transformed ecosystems. Thus, flavonoids are involved in the protective adaptive responses of P. bifolia, not only ensuring the survival of this orchid but also contributing to the implementation of its ontogenetic program. © Siberian Federal University. All rights reserved.Acknowledgments. The reported study was partly funded by RFBR and the Government of the Sverdlovsk Region, project number 20-44-660011 and the Ministry of Science and Higher Education of the Russian Federation as part of State Task of the Ural Federal University, FEUZ-2020-0057. The authors are grateful to the reviewers, DSc Pozolotina V.N. (Institute of Plant and Animal Ecology Ural Branch of the RAS, Ekaterinburg) and DSc Dymova O.V. (Institute of Biology of Komi Scientific Centre of the Ural Branch of RAS, Syktyvkar) for valuable comments that helped improve this paper and to Dr. Tripti (Ural Federal University, Ekaterinburg, Russia) for editing of the English language

Редокс-реакции у Hydrocharis morsus-ranae L. в условиях техногенной нагрузки

Aquatic ecosystems are very sensitive to industrial impacts, and, therefore, it is increasingly important to study the mechanisms underlying the tolerance of aquatic organisms to water pollution. Heavy metals (HMs) are among the most common and toxic pollutants of aquatic ecosystems. They have a particularly strong effect on macrophytes, which are in close contact with the aquatic environment and can accumulate metals in considerable quantities. Hydrocharis morsus-ranae L. is a floating macrophyte (pleistophyte) with a high capacity for accumulation of HMs. The aim of the present study was to assess the effect of industrial pollution on the redox reactions in H. morsus-ranae and to identify the role of low molecular weight antioxidants in adaptation of this macrophyte to unfavorable conditions. A comparative analysis of the physiological and biochemical characteristics of H. morsus-ranae from two (reference and impacted) water bodies was carried out. The study revealed an increased level of lipid peroxidation products in the leaves of H. morsus-ranae under industrial impact, which indicates oxidative stress. Nevertheless, this floating plant demonstrated fairly high resistance to adverse conditions, due to the synthesis of non-enzymatic antioxidants such as proline and soluble protein thiols. Revealing the response of macrophytes to pollution of water bodies will help predict the state of aquatic ecosystems with an increase in anthropogenic pressure. © Siberian Federal University. All rights reserved.Acknowledgements. The reported study was partly funded by RFBR and the Government of the Sverdlovsk Region, project number 20–45–660014. The authors are grateful to the reviewer, Prof., D. Sc. Golovko T. K. (Institute of Biology of Komi Scientific Centre of the Ural Branch of RAS, Syktyvkar) for valuable comments that helped improve this paper and to Dr. Tripti (Ural Federal University, Ekaterinburg, Russia) for editing the English language

Antimitotic effects of <i>Cysticercus tenuicollis</i> protoscolexes extract at administration to mice and their negative consequences for organism

The purpose of the research is studying of Cysticercus tenuicollis protoscolexes extract effects on cell division at different routes of administration to mice and evaluation of the associated negative effects.Materials and methods. C. tenuicollis were obtained from spontaneously infected sheep in Kabardino-Balkarian Republic. C. tenuicollis protoscolexes were washed, crushed and homogenized. Protein extraction was performed with phosphate buffered saline pH 7.2–7.4. C. tenuicollis extract was administered intraperitoneally and intravenously to mice males at the dose level of 80 μg protein/animal. The control group of mice was intravenously injected with 0.1 ml of saline. At hours 3; 6; 24 and 48 post extract administration mice were euthanized. Bone marrow samples were taken from experimental and control mice for preparation of microscopic preparations to assess mitotic activity in a given cell population. The mitotic index was determined, all stages of mitosis were recorded. At the above time points blood samples were taken from mice to determine the main hematological parameters post intravenous and intraperitoneal administration of C. tenuicollis extract. The main hematological parameters of mice were determined using hematological analyzer MicroCC-20 Plus (High Technology, Inc. (USA)); leukocyte formula – by the generally accepted method. Samples of liver, kidneys, spleen, mesenteric lymph nodes and testes were taken from experimental and control animals for macroscopic and microscopic studies.Results and discussion. C. tenuicollis protoscolices extract leads to inhibition of cell division in the population bone marrow and testes cells in mice when administered intravenously and intraperitoneally at the dose level of 80 μg/animal manifested in accumulation of metaphases and decrease of other stages. At both routes of administration a decrease in leukocyte counts was noted. The observed microscopic changes in testes, spleen and lymph nodes either reflect the consequences of extract antimitotic effect or the immune response to the administration of C. tenuicollis extract

Effects of <i>Trichinella spiralis</i> and <i>Echinococcus multilocularis</i> extracts after single and multiple injections on mitosis and hematological and biochemical parameters of mice

The purpose of the research is to study effects of Trichinella spiralis and Echinococcus multilocularis extracts on mitosis in a bone marrow cell population, and on hematological and biochemical blood parameters of mice after single and multiple intraperitoneal injections.Materials and methods. The experiment was conducted on outbred male mice. The T. spiralis and E. multilocularis extracts were administered intraperitoneally once or multiple times daily for 10 days at a dose of 80 μg/mouse. Bone marrow cell isolation, microscopic preparations, mitotic index and individual stage determination were made as described in the literature (Ford C. E., Hamerton J. L., 1956). The mouse main peripheral blood parameters were determined with a MicroCC-20 Plus hematological analyzer, and the leucogram was determined by a conventional method. Biochemical blood parameters of the mice were determined with a Clima MC-15 analyzer.Results and discussion. The T. spiralis and E. multilocularis extracts after a single intraperitoneal injection at a dose of 80 μg/ mouse had a pronounced negative effect on the mouse bone marrow cell mitosis with the cell division terminated in the metaphase and a decreased proportion of other mitosis stages. Characteristics were detected of the effects made by the T. spiralis and E. multilocularis extracts on the mouse bone marrow cell mitosis after multiple administration for 10 days. In the reinjection mode of the test extracts to the mice, hematological and biochemical parameters did not change