Alexander A. Gusev

The effect of zinc-containing ferrous metallurgy wastes (blast and electric arc furnace dust) on mustard and sugar beet infected with Fusarium avenaceum was studied. The wastes did not increase fusarium wilt resistance; the proportion of wilted seedlings increased. However, they stimulated root growth, photosynthetic pigments, and biomass. Effectiveness depended on waste type, dose, and plant species.

Blast furnace sludge is a micro- and nano-dispersed metallurgical waste rich in iron and zinc, yet its accumulation poses a serious environmental challenge. Here we demonstrate its potential as a source of iron and zinc for sugar beet (Beta vulgaris L.), a crop with high micronutrient demand and economic importance. At application rates of 0.5–2 t ha⁻¹ in alluvial-meadow soils with neutral pH, the sludge increased root yield by up to 1.5-fold and sugar content by up to 1.4-fold compared to untreated controls. The optimal dose (0.1 g kg⁻¹ in greenhouse) significantly reduced the activity of oxidative stress markers—polyphenol oxidase (PPO) by 7.5-fold and peroxidase (POD) by 8-fold—indicating alleviation of cellular stress. The sludge also exhibited phytoprotective properties, reducing leaf necrosis under field conditions. A single application at these rates posed no food safety risks: lead and cadmium levels in beetroots and soil remained below international regulatory limits, and zinc accumulation in beetroots (≤10 mg kg⁻¹) was an order of magnitude below the FAO/WHO guideline. However, repeated annual applications would gradually increase soil zinc; preliminary screening suggests that applying 2 t ha⁻¹ annually could approach the soil MPC within 4–5 years under a linear accumulation scenario, necessitating long-term monitoring.

A study was conducted to investigate the effect of granulated blast furnace slag on the growth of downy birch (Betula pubescens Ehrh.) seedlings in model acidified substrates (pH 4.2–5.2). The addition of slag, whose main components are calcium, silicon, magnesium, and aluminum oxides, was shown to effectively neutralize soil acidity. Substrate deacidification to pH ~6.0 significantly stimulated plant growth: seedling height increased by 74% in a slightly acidic substrate (pH 5.2), and stem diameter by 38% in a strongly acidic substrate (pH 4.2), compared to control plants without slag. Normalizing pH also contributed to an increase in photosynthesis intensity and chlorophyll content to control levels, while simultaneously reducing the activity of antioxidant enzymes, indicating mitigation of oxidative stress. The results demonstrate a triple environmental benefit: safe disposal of industrial waste, improvement of the quality of acidic forest soils, and stimulation of forest plant growth, which contributes to the decarbonization of the metallurgical industry.

We studied the effect of copper oxide nanoparticles (CuO NPs) of elliptical shape, 80–100 nm in size (CuO 1) and flake-shaped, 100–500 nm in cross-sectional size and 10–20 nm in thickness (CuO 2), on sugar beet (Beta vulgaris L.) micro-sprouts of male-sterile (MS forms) and Owen-type sterility fixers (O-type) under tissue culture conditions in vitro. NPs were added to the nutrient growth medium at concentrations of 10 and 100 mg/L. We found a decrease in the growth indices of regenerants under the influence of NPs, regardless of the type of plants and particles. At the same time, the addition of 10 mg/L NPs significantly increased the multiplication coefficient. For MS-form plants, the maximum multiplication rate (+77% to the control) was observed with the introduction of CuO 1, while for O-type plants, an increase in the rate by 96% was noted in the variant with CuO 2. Analysis of copper bioaccumulation showed an increase in the element content in sugar beet microclones, and if a two-fold increase was noted for CuO 1, then in the case of CuO 2, the copper content increased 4 times for MS-form plants and 5 times for O-type plants. Thus, we have shown for the first time the prospects of using CuO NPs to increase the efficiency of the clonal micropropagation procedure of sugar beet plants. However, further studies of the safety of their use are required, which is associated with the identified accumulation of copper in regenerated plants.

Due to the increasing use of nanomaterials in agriculture, the effects of copper(II) oxide nanoparticles (CuO NPs) on plants are of considerable interest. This study analyzes the effect of CuO NPs synthesized by chemical precipitation and electrical explosion of a wire, as well as a commercial CuO NP sample, all stabilized with the antimicrobial polymer polyhexamethylene biguanide hydrochloride (PHMB), on spring wheat (Triticum aestivum L.) seedlings. X-ray diffraction analysis and scanning electron microscopy have revealed significant differences among the samples in phase purity, particle size, and morphology (rod-shaped, spherical, and flake-like particles). Rod-shaped nanoparticles from the commercial sample exhibited the highest colloidal stability in aqueous dispersions. Bioassays have shown that all CuO NP dispersions enhanced seed germination and biomass accumulation, particularly in roots, while seedling length was reduced. The strongest stimulatory effect, including increased chlorophyll content and catalase activity, has been recorded for the commercial CuO NP sample at a concentration of 100 mg/kg. Copper accumulated predominantly in the above-ground parts of the plants. Overall, the results indicate that nanostructured CuO–PHMB complexes may represent an effective approach for improving the growth of spring wheat. However, long-term studies are needed to assess their ecological safety.

The effect of copper(II) oxide nanoparticles (CuO NPs) of various morphologies at concentrations of 10–200 mg L^–1 on the microshoots of the hybrid white poplar × aspen and downy birch was studied. Low NP concentrations increased sterility and stimulated growth, whereas high concentrations inhibited development. Nanospheres and nanoflakes reduced contamination more effectively than nanorods. For the white poplar × aspen hybrid, the use of nanoflakes at a concentration of 10 mg L^–1 was optimal for sterilization and stimulation of multiplication, while for birch, nanospheres at concentrations of 10–100 mg L^–1 were optimal for reducing contamination. White poplar × aspen exhibited higher resistance to the effects of CuO NPs, whereas birch was more sensitive to NP exposure. Overall, CuO NPs appear to be promising agents for micropropagation; however, further studies are required to minimize phytotoxic effects.

This study investigated the concentration-dependent effects of zinc oxide nanoparticles (ZnO NPs, 30–70 nm) on the freshwater microalga Lobosphaera sp. under different salinity conditions (0–4 g L⁻¹ NaCl). ZnO NPs demonstrated dual effects: low concentration (0.75 mg L⁻¹) enhanced growth and alleviated salt stress, while higher concentrations (7.5–75 mg L⁻¹) caused significant growth inhibition (up to 52%) and induced oxidative stress. Salinity did not significantly affect NPs aggregation patterns, and neither salinity nor aggregation degree influenced toxicity outcomes. NPs concentration plays a dominant role of toxicological effects. Dose-dependent increases in catalase activity and ROS-positive cells confirmed NPs-induced oxidative stress. Crucially, zinc bioaccumulation correlated with NPs concentration but dissociated from dissolved Zn²⁺ release, demonstrating particle-driven toxicity. Our findings challenge the ion-release paradigm and highlight the potential of low-dose ZnO nanoparticles as effective stress-protectors in algal biotechnology, offering new strategies for enhancing microalgal resilience under environmental stress.

One of the main difficulties preventing the widespread introduction of clonal micropropagation technology to obtain high-quality planting material for woody plants is the difficulty of obtaining an aseptically pure culture with high regenerative capacity. The article discusses the effects of copper oxide nanoparticle solutions (75-100 nm) stabi-lized by nonionic surfactants (Tween 20, Triton X100 and Polyhexamethylenebiguanide) on the stage of introducing the Poplar × aspen hybrid and downy birch 15-1 into in vitro culture. It is assumed that the introduction of nanoparti-cles into the Murasige-Skoog nutrient medium will reduce the microbial load of explants, as well as enhance plant growth and morphogenesis. The use of nanoparticle solutions does not replace traditional methods of explant steriliza-tion, but serves as an additional measure. In the course of the research, the optimal concentration of nanoparticles was determined – 5 mg/l, the use of which in the composition of the cultivation medium allows to increase the yield of ster-ile viable poplar explants by 16.7-26.7%, birch 30.0-36.7%. It was established that the greatest antagonistic effect on the surface (epiphytic) microflora is possessed by nanoparticles stabilized by Polyhexamethylenebiguanide – the yield of poplar and birch microshoots suitable for further stages of micropropagation is 66.7%. The use of this combination of nanoparticles allows to obtain a minimum number of non-viable cultures. Increasing the rate of aseptically viable explants using copper oxide nanoparticle solutions has a positive effect on the efficiency of clonal micropropagation by accelerating the microcloning process, reducing the time required to obtain finished planting material, and improving the quality of the product.