The reactive oxygen species content, the activity of phenolic peroxidase, and the expression levels of genes encoding certain defense proteins were studied in potato seedlings grown on a substrate with the addition of a preparation based on B. subtilis and infected with potato virus Х. The accumulation of reactive oxygen species and the induction of the defense system components in potato leaves treated with this preparation and infected are shown. Less viral material was detected in experimental samples of potato seedlings compared with control untreated with B. subtilis.

The content of phenolic compounds and flavonoids in separate organs and aerial parts of Bidens species growing in different regions of Belarus was studied (alien species – Bidens frondosus L. and Bidens connatus Willd., native species – Bidens tripartitus L.). It was found that the leaves were characterized by the maximum accumulation of total phenolic compounds and total flavonoids. The accumulation of these metabolites decreased in the row of “leaves – inflorescences – stems and roots”. Approximately 14 % of phenolic compounds in leaves and inflorescences were flavonoids. The accumulation of phenolic compounds in the aerial parts of B. frondosus, B. connatus and B. tripartitus, depending on the growing conditions, varied from 60, 55, 90 to 155, 130, 115 mg/g dry weight, flavonoids – from 7, 11, 8 to 20, 15, 19 mg/g dry weight, correspondingly. B. frondosus and B. connatus demonstrated a wider range of variation in the sum of phenolic compounds than B. tripartitus. A comparative analysis of the total phenolic accumulation in plants of different species collected in geographically close localities showed the absence of significant differences in the content of the studied secondary metabolites in alien and native species of Bidens.

The efficiency of electron carriers in thylakoid membranes untreated and exposed to heat 7-day-old barley seedlings was evaluated with PAM fluorescence. Darkness–light transitional states in chloroplasts after heat exposure are studied. Thermoinduced changes in linear and cyclic electron transport chain of chloroplasts are revealed. The activation of NADPH-dependent electron flux after exposure to elevated temperatures is shown. We assumed that ΔрН of thylakoid membranes employed the regulatory role in the distribution of electron flows and the adaptation of the photosynthetic apparatus to stressful effects.

The accumulation of carotenoids (carotenogenesis) in the cells of Haematococcus pluvialis (strain IBCE H-17) upon cultivation in nutrient media deficient in nutrient elements (N and K + P) is shown. K and P deficiency in nutrient medium led to accumulation of astaxanthin, β-carotene, anteraxanthin, zeaxanthin and violaxanthin after 18 days of cultivation, while the amount of neoxanthin and lutein was at the control level. Carotenogenesis under such conditions was accompanied by high levels of chlorophyll (a + b). The use of nutrient medium deficient in N led to the accumulation of astaxanthin and, to a lesser extent, β-carotene in haematococcus cells, while lutein, anteraxanthin, zeaxanthin, violaxanthin and neoxanthin levels were lower or the same as control. N deficiency caused the decrease in amount of chlorophyll (a + b). Nitrogen deficiency was 4.3 times more effective than control medium and 1.8 times more effective than combined potassium and phosphorus deficiency in promoting astaxanthin accumulation.

The results of study of the components of Monarda fistulosa L. essential oil under chemicals are shown. The experiment was made at the Central botanical garden of the National academy of sciences of the Republic of Belarus since 2011 till 2013. The research conditions involved using of nitrogen, phosphoric and potassium fertilizers on limed and nonlimed fields. Essential oil was determined in air-dry material with hydrodistillation method applying Ginsberg apparatus. The component composition of essential oil was investigated using chromatograph “Agilent Technologies 7820 A” with a flame ionization detector. Components those were important for quality of essential oil were studied in different stages of ontogenesis. Accumulation dynamics of γ-terpinen, p-cymene and linalool was depended on random factor. Accumulation of geraniol, 1.8-cineole, thymol and carvacrol was M-shaped curve under growth doses of mineral fertilizers. Ranked rows of the variants of fertilizer application on the basis of changes in mass fractions thymol, carvacrol, 1,8-cineole and geraniol were built. Analyzing of these data gives possible to grow Monarda fistulosa L. and to use its essential oil for pharmaceutical, food and perfumery-cosmetic industries.

The trends in the distribution and occurrence of the freshwater crayfish in the water bodies of the Neman River basin are presents. It has been shown that both native species: the noble and the narrow-clawed crayfish are declined and/or are displaced with rapidly expanding its range the invasive spiny-cheek crayfish. In recent years the alien species was found in isolated gravel pits and lakes, where it could be transferred only by the human activity. These findings confirm the need of the education about the threats posed by the invasive species on the native biodiversity especially with the local community, which is an obligatory practice for protection the native species in the area expanded with non-native crayfish species. Further, to increase the likelihood of the local biodiversity conservation it is highly needed to undertake targeted actions aimed at resettling endangered populations into waterbodies unavailable for the invasive spiny-cheek crayfish expansion.

It was established that the treatment of clover seeds with radio frequency (RF) electromagnetic field and low pressure (200 Pa) RF plasma excited at a frequency of 5.28 MHz has a stimulating effect both on the germination of seeds and on the growth and development of plants grown in laboratory and field conditions. Plasma treatment for 5 min led to the greatest stimulation of seed germination and germination energy, a significant increase in the biomass of shoots and roots. At the same time, the content of phenolic compounds and flavonoids in plant leaves decreased.

It was shown the irradiation of aqueous solutions of thiamine and riboflavin with ultraviolet UVA (315–400 nm) and visible light (λ > 400 nm) leads to oxidation of thiamine to thiochrome and oxodihydrothiochrome. In absence of riboflavin in aerobic conditions thiamine oxidation to thiochrome was mainly due to reaction with singlet oxygen. Under anaerobic conditions, thiamine in the presence of riboflavin was photostable and UV and visible light irradiation of their aqueous solutions did not result in thiamine oxidation. Under aerobic conditions, thiochrome was oxidized to form oxodihydrothiohrome in reactions with singlet oxygen and riboflavin in triplet states. Under anaerobic conditions, oxidation of thiochrome to oxodihydrothiochrome occurred due to reaction with riboflavin in triplet state. Possible mechanisms of the damage of cellular eye structures due to inactivation of thiamine-dependent enzymes on exposure to intensive UVA and visible light in the presence of endogenous photosensitizer riboflavin are discussed.

The article summarizes the many years of experience in introducing into Belarus over 200 decorative forms of 60 species of conifers. Provides information on the biological characteristics of growth and development, resistance to diseases and pests in comparison with the main species.

It is substantiated a new methodological approach to identifying perspective plants, based on taking into account the genotypic characteristics of the growth and development of most stable in Belarus cultivars. This approach reduces the time for their initial assessment to 5–6 years. An assessment is made of the regenerative ability of stem cuttings and technological procedures have been developed that made it possible to organize the cultivation of planting material of perspective plants in Belarus.

The results of a comparative study of the main characteristics of the biochemical composition of fruits of the same age of generative plants of 5 introduced varieties of V. corymbosum of different ripening dates – early ripening Weymouth, mid-ripening Bluecrop and Concord, late ripening Elizabeth and Atlantic obtained by traditional (stem-cuttings) and microclonal vegetative methods are presented. A significant effect of the propagation method on the biochemical composition of the fruits, the degree of which was determined by the chemical nature of its components and the plant genotype, was established. In the fruits of cloned plants, depending on the genotype, ambiguous changes in the range of 5–40 %, relative to traditional plants, in the content of solids, free organic, ascorbic and hydroxycinnamic acids, soluble sugars and pectin substances, as well as the index of sugar acid index, were revealed. For most varieties, a common trend in the nature of differences between cloned and traditional plants in the accumulation of bioflavonoids was shown, consisting in the increase in the first case of their total number by 5–27 %, including 6–34 % of anthocyanin pigments. The greatest positive effect of the microclonal propagation method on the content of P-vitamins in fruits of late ripening varieties, especially Atlantik, was found, with a 3–6 times lesser degree of similar influence in Weymouth and Concord varieties, against the background of the prevailing negative effect in mid-ripening Bluecrop. With the relative stability of the ratio of the components of the P-vitamin complex of blueberry fruits to the tested propagation methods, significant shifts were revealed in the composition of their anthocyanin complex in cloned plants of early ripening and especially mid-ripening varieties towards a decrease in the proportion of anthocyanins proper and an increase in that of leukoanthocyanins, compared to traditional plants, reaching 1.5–1.6-fold value in Concord variety with the opposite direction of less pronounced shifts in late-ripening varieties.

In cloned plants (with the exception of the Bluecrop variety), the integral level of the nutritional and vitamin value of the fruits was found to be 2.6–4.4 times higher than their traditional counterparts by a total of 14 indicators of the biochemical composition when the varieties were arranged in accordance with a decrease in the degree of data differences in the series: Atlantik > Elizabeth > Weymouth > Concord > Bluecrop, in which late ripe varieties of blueberries were characterized by the greatest advantages.

The aim of this research was to analyze the effect of soil moisture regime on the intensity of ¹³⁷Cs transfer into cereals using spring wheat as a model species. Accumulation of ¹³⁷Cs in shoots of spring wheat grown on soil substrates differ by water and nutrients content was analyzed. The investigated water regimes were 40 % (insufficient moisture supply), 70 % (optimal moisture supply) and 85 % (excessive moisture supply) of full moisture capacity of the soils; substrates with optimal and low content of essential mineral nutrients were used in the experiment. The plants were grown in a chamber with controlled climate conditions. Increasing water content in the soil from 40 to 85 % of the total moisture capacity significantly reduces the ¹³⁷Cs content in plants. The shape of the relationship between soil moisture and the soil-to-plant transfer of ¹³⁷Cs depends on the agrochemical characteristics of the soil. The difference in the radioisotope accumulation in the shoots of wheat grown on extreme water regimes is about four times when substrate with optimum content of nutrients was used. The difference is less than two times when substrate with a low content of essential nutrients was used; moreover, there are no differences between the 70 and 85 % variants on a substrate with low content of nutrients. The revealed dependencies cannot be explained by the change in the share of bioavailable forms of ¹³⁷Cs in the soil since it does not significantly change in soils with different moisture regimes.

It is known that bacterial purine nucleoside phosphorylase (PNPase), unlike mammalian PNPase, is capable of phosphorolytic cleavage of adenosine and its derivatives to form free nitrogen bases. This makes it possible to use bacterial PNPase (provided the problem of delivering this enzyme or its gene to target cells is solved) as a prodrug therapy for cancer. In addition, PNPase in a tumor bed can destroy extracellular adenosine, which is known to protect cancer cells from antitumor immunity.

As a result of the study, a new strain of Escherichia coli was constructed, producing a chimeric protein whose molecule consists of a homologous PNPase fused to human annexin A5, a protein showing affinity for cancer cells.

The production capacity of the producer strain of the chimeric protein “Annexin-PNPase” with respect to PNPase calculated from the results of the inosine phosphorolysis reaction, was 10,200 units/ml of culture liquid. The obtained strain is intended for creation of a technology for obtaining new antitumor preparations.

The reduction in the area occupied by the petrophytic steppes of the European part of Russia, including in the Samara region, due to alienation under agricultural land and high anthropogenic pressure, led to a decrease in the total number of plant species in the steppe and mountain-steppe flora. The current state of the species of these phytocenotic groups in the regions also depends on the ecological and biological characteristics of the representatives.

The object of study is Atraphaxis frutescens (L.) C. Koch (Polygonaceae). On the territory of the Samara Pre-Volga and Trans-Volga regions, the structure and current state of 21 coenopopulations were studied. In the course of the work, traditional population-ontogenetic techniques and recommendations were used. The heterogeneity of the ontogenetic spectra was revealed, the regional basic ontogenetic spectrum of Atraphaxis frutescens cenopopulations, the main demographic parameters (including the age-effectiveness criterion L. A. Zhivotovsky was used to determine the type of cenopopulations) were determined. Based on data on the population structure, the protection efficiency of Atraphaxis frutescens as part of nature monuments of regional significance is analyzed in comparison with other valuable natural complexes that do not have conservation status. It has been established that with low and medium load on the vegetation cover, natural monuments are able to ensure the preservation of the species in the region. Significant differences in the ontogenetic spectra of coenopopulations in and beyond protected areas were not noted. In the coenopopulations of A. frutescens in protected areas, there is a slight increase in the number of old generative plants (31.4 %) and a decrease in the proportion of subsenile individuals (7.1 %). The average area of the geographical population on the territory of protected natural complexes is 850 m², the average number is 2011.7 generative individuals; outside the protected areas, the population area is 275 m² and the number of individuals is 642.4.

Thus, natural monuments contribute to better conservation of the area of the geographical population, ensure the stability of the number of individuals and spatial distribution, including the formation of large aggregations of individuals and a more even distribution of recorded aggregations.