The method of somatic embryogenesis could be used for industrial production of clonal planting material. For this reason special attention is paid to the studies of various genetic disorders that arise in vitro because of their possibility to be inherited by the vegetative offsprings. In our investigation the levels of somaclonal variability and mixoploidy in callus colonies and plantlets of six embryogenic lines of Norway spruce (Picea abies (L.) Karst.) were studied. ½ LM nutrient medium supplemented with sucrose and glutamine was used at different stages of plant tissues and plantlets in vitro cultivation. Growth regulators 2,4-D, 6-BAP, ABA, IMC and activated carbon were added to nutrient media if necessary. Microsatellite analysis of samples was carried out using five EST-SSR markers Pa28, Pa33, Pa56, Pa47, Pa52. It was shown that in samples of three of the six embryogenic lines, more than two (three or four) allelic variants were identified at the Pa28 locus. In a number of cases, the tissues studied have pronounced signs of mixoploidy. Appropriate microsatellite analysis of samples collected from 33 middle-aged trees of Norway spruce from naturally formed forest stand was additionally carried out in order to compare the results with the data obtained earlier. Only two plants showed the presence of triploid cells, indicating a significantly lower level of genomic or chromosomal aberrations than observed in in vitro cultures.

The article presents the results of a genetic evaluation of the diversity of allelic variants of the PaLAR3 gene promoter, which determines some stages of flavonoid metabolism in Norway spruce (Picea abies (L.) H. Karst.). The activity of production of flavan-3,4-diol-(+)-catechin derivatives depends on the structure of the PaLAR3 gene promoter and affects the formation of resistance of Norway spruce to spruce root rot, a condition induced by the phytopathogenic fungus Heterobasidion parviporum Niemelä & Korhonen.

The experimental material for the research was collected from 950 trees of European spruce during the period 2017–2023. These trees were growing in various regions of Belarus both in forest seed plantations of the 1st and 2nd generation and in forest crops.

A molecular genetic analysis of the PaLAR3 gene promoter revealed eight amplicon size variants belonging to two major allele groups: A (A – 470 bp, A₁ – 488 bp) – susceptible phenotype of spruce to H. parviporum; B (B – 345 bp, B₁ – 342 bp, C – 376 bp, C₁ – 394 bp, D – 331 bp, and D₁ – 339 bp) – resistant phenotype. The analysis of the occurrence of allelic variants among all the trees studied showed that the susceptible A allele group (65.40 %), and A allele (62.75 %) directly had the highest representation. Group B (34.60 %), included the dominant allele variant B (32.35 %) and its rare variants, with an incidence of less than 1 %.

Given that wheat endosperm comprises 65–85 % starch, its content significantly influences the weight of the grain. In the present study, a total of 40 common wheat lines with the genetic material of Triticum dicoccoides, T. dicoccum, T. durum, T. spelta, and T. kiharae, in addition to their parent forms, were collected for genetic analysis. The objective was to study the polymorphism of nine genes that control starch synthesis to identify the association of allelic variants of these genes with productivity traits in Belarus. Furthermore, the study sought to assess the influence of alien genetic material on wheat productivity. A polymorphism was not detected only for TaCWI-5D and TaAGP-L-1B genes. The genes TaSus2-2B, TaSus1-7A, TaCWI-4A, TaAGP-S1-7A, and TaBT1-6B significantly contributed to the variability of the thousand kernel weight, while TaSus2-2A, TaSus1-7A, and TaCWI-4A were associated with the grain number per spike and TaSus2-2A and TaSus2-2B with the productive tillering. The favorable haplotypes frequency in wheat relatives was slightly lower than that of varieties, while in introgressive lines it was at the level of varieties. The introgression of the alien genetic material into the wheat genome did not adversely affect the main productivity indicator – the thousand kernel weight, which on average, during the 4-year period, was significantly higher in introgression lines (38.51 g) than in varieties (36.91 g).

Nickel (Ni) is an essential trace element for higher plants, being a part of urease, glyoxylases and hydrogenases. However, in high concentrations, this metal exerts a pronounced toxic effect. Levels of Ni²⁺ that are toxic to plants (>10^–5 M) are typical for soils formed from volcanic rocks, near mining and metallurgical plants, landfills, waste disposal sites. Elevated nickel levels are also recorded in the soils of Belarus. In the presented work, we examined the effect of a range of toxic Ni²⁺ concentrations (0.3–2 mM NiCl₂) on the expression of a number of important stress response genes in model plants Arabidopsis thaliana (L.) Heynh., as well as the effect of a natural plant protective agent, L-histidine (His), which is intensively synthesized by plants under nickel stress and is able to bind Ni²⁺, on this process. In the experiments conducted using the Real-Time Polymerase Chain Reaction (RT-PCR) method, it was found that the introduction of Ni²⁺ into the culture medium caused a dose-dependent increase in the relative expression of genes encoding glutathione reductase (GR1), NADPH oxidase (RBOHC), Ca²⁺-dependent protein kinase (CPK6), catalase (CAT2) and outward-rectifying K⁺ channel (GORK1). The maximum increase was observed upon treatment with 2 mM Ni²⁺, relative transcript levels were 5.9, 5.0, 3.0, 2.8 and 2.2 times higher than in control for RBOHC, GR1, CPK6, CAT2 and GORK1 respectively. In the case of the genes encoding poly(ADP-ribose)-polymerase (PARP1), cyclin B2 (CYCB2), and Cu/Zn-superoxide dismutase (CSD2), the transcript levels increased at low Ni²⁺ concentrations and then decreased at higher Ni²⁺ concentrations in the medium. The introduction of His, in conjunction with Ni²⁺, prevented the Ni²⁺-induced change in gene expression. Thus, it was demonstrated that A. thaliana plants respond to excess Ni²⁺ by inducing the expression of enzymatic antioxidants, proteins involved in redox- and Ca²⁺-mediated cellular signaling. This response is accompanied by alterations in the systems of control cell division and DNA replication, which can be regulated by exogenous His.

This article presents information on the influence of pre-sowing treatment of Larix × eurolepis Henry. seeds by physical factors, such as atmospheric pressure dielectric barrier discharge plasma (DBD), low-pressure high-frequency discharge plasma (HF), high-frequency electromagnetic field (HF EMF), and placing seeds in a vacuum environment on seed germination and the morphometric parameters of 3-year-old seedlings.

A stimulatory effect on the germination of Larix × eurolepis seeds was observed, which depends on the specific treatment factor and the duration of exposure.

Treating the seeds with physical factors affected the growth and development of seedlings. Treating the seeds with atmospheric pressure dielectric barrier discharge plasma (DBD) for three minutes was observed to have the most significant impact on growth, crown diameter, needle length, and plant height, which reduced those parameters by more than fourfold. This seed treatment can be utilized for breeding purposes to obtain dwarf plants.

It was found that there is considerable variation in needle color among seedlings, particularly evident when seeds are placed in a vacuum environment for 15 minutes. In addition to typical light green needles, seedlings with various combinations of green, white, gray, and blue colors in their needle coloration were observed.

An improved biotechnological method for producing 6-thio-2′-deoxyguanosine, a modified nucleoside exhibiting a uniquely broad spectrum of antitumor activity, has been developed. The one-pot preparative method involves incubation of 6-thioguanine and 2′-deoxythymidine at 45 °C in phosphate buffer in the presence of recombinant Escherichia coli thymidine phosphorylase and purine nucleoside phosphorylase. This method is distinct from the known analogue method in that 2′-deoxythymidine and 6-thioguanine are added to the reaction mixture in amounts that far exceed their water solubility. Utilizing the disclosed method of producing 6-thio-2′-deoxyguanosine increases yield of the end product based on the starting 2′-deoxythymidine from 14.6 to 33.5 % compared to the known prototype method and raises volumetric yield of the end product from 4.13 to 75.8 g/l of the reaction mixture. This significantly improves the efficiency of using a unit volume of the bioreactor. The proposed technology is high-tech and can be successfully applied under largescale production conditions.

The combined effect of nutrient deficiency in the cultivation medium of Dunaliella salina IBCE D-1 strain and high-intensity light is more effective than the effect of nutrient deficiency alone in inducing the accumulation of carotenoids in algae cells. At the same time, nitrogen deficiency in the nutrient medium leads to greater production of β-carotene by cells than potassium and phosphorus deficiency. A predominant suppression of photosystem 2 (PS2) activity was observed in D. salina cells cultured on a nitrogen-deficient medium was established in comparison with to the control and variant with potassium and phosphorus deficiency. This may be a key factor in triggering increased synthesis of β-carotene in algae cells, as an antioxidant that prevents excessive accumulation of reactive oxygen species in chloroplasts, in particular, singlet molecular oxygen, the generation of which increases when components are damaged or the functioning of PS2 complexes is disrupted.

Obesity can lead to thyroid dysfunction in male rats, as shown in our primary studies. The aim of this work was to study the morpho-functional state of the thyroid gland in diet-induced visceral obesity and variants of its non-drug correction in female Wistar rats.

The experiments involved six groups of animals. Rats were fed either a standard diet (StD) or a high-calorie diet (HCD), which induced visceral obesity. Obesity was corrected by switching from HCD to StD and/or by treadmill running. The following animal groups were utilized in the study: 1) “StD” – 16 weeks; 2) “HCD” – 16 weeks; 3) “HCD/StD” – 8/8 weeks; 4) “StD + running” – 16/8 weeks; 5) “HCD + running” – 16/8 weeks; 6) “HCD/StD + running” – 8/8 weeks.

An increase in thyroxine (T4) levels was observed in the blood serum of female rats in the HCD group. At the same time, thyroperoxidase (TPO) activity and malonic dialdehyde (MDA) content in thyroid tissue decreased, and morphological signs of thyroid hypofunction were observed. The most complete recovery of TPO activity and morpho-functional characteristics of thyroid tissue was observed during the transition from HCD to StD. Moderate physical activity against the background of HCD had a positive effect on some morphometric characteristics of the thyroid, but did not restore the values of TPO and MDA. With combined correction of obesity (HCD/StD + running), a partial restoration of the organ histostructure with normalisation of TPO activity, but not MDA, was observed.

Thus, diet-induced visceral obesity is accompanied by an increase in blood thyroxine levels, yet morphological and biochemical signs of decreased functional activity of the thyroid gland tissue develop. A successful correction of visceral obesity, accompanied by the restoration of thyroid structure and function, can be achieved by transitioning from HCD to StD.