Recently, metal oxide nanoparticles (NPs) have attracted attention as promising components for the protection and stimulation of plant microclones in tissue culture in vitro. However, the effect of NPs on the genetic mechanisms underlying plant adaptive responses remains poorly understood. We studied the effect of column-shaped CuO NPs 50 nm in diameter and 70–100 nm in length at a concentration of 0.1–10 mg/L on the development of phytopathogenic fungi Alternaria alternata, Fusarium oxysporum, and Fusarium avenaceum in culture, as well as on the infection of downy birch micro-clones with phytopathogens and the level of genes expression associated with the formation of plant responses to stress induced by microorganisms. CuO NPs effectively suppressed the development of colonies of phytopathogenic fungi A. alternata and F. avenaceum (up to 68.42% inhibition at 10 mg/L CuO NPs) but not the development of a colony of F. oxysporum. Exposure to the NPs caused multidirectional responses at the level of plant genes transcription: 5 mg/L CuO NPs significantly increased the expression level of the LEA8 and MYB46 genes and decreased the expression of DREB2 and PAL. Infection with A. alternata significantly increased the level of MYB46, LEA8, PAL, PR-1, and PR-10 transcripts in birch micro-clones; however, upon exposure to a medium with NPs and simultaneous exposure to a phytopathogen, the expression of the MYB46, PR-1, and PR-10 genes decreased by 5.4 times, which is associated with a decrease in the pathogenic load caused by the effect of NPs and the simultaneous stimulation of clones in vitro. The results obtained can be used in the development of preparations based on copper oxide NPs for disinfection and stimulation of plant phytoimmunity during clonal micropropagation of tree crops.

Recent studies have shown that nanomaterials, including carbon nanotubes, are associated with a wide range of effects on living organisms, from stimulation to toxic effects. Plants are an important object of such research, which is associated with the potential use of carbon nanomaterials in agriculture and environmental protection. At the same time, the specific mechanisms of formation of plant resistance to the effects of carbon nanotubes remain not fully understood, especially in woody plants. Therefore, we studied the effect of aqueous colloids of multi-walled carbon nanotubes (MWCNTs) with an outer diameter of 10–30 nm and a length of about 2 μm at a concentration of 1, 10, 50, and 100 mg/L on morphometric parameters and the level of expression of stress resistance genes in Betula pubescens Ehrh. and B. pendula Roth. plants in greenhouse conditions. The results showed an increase in the length and diameter of the shoot in the studied plants. The dry biomass of the leaf increased by 30%, the stem by 42%, and the root by 49% when using MWCNTs at a concentration of 10 mg/L. The expression of the stress resistance genes DREB2 and PR-10 significantly increased under the influence of 1 mg/L MWCNTs on plants of both species. At the same time, the use of 100 mg/L nanoparticles led to a decrease in the studied parameters in Betula pendula, which may be associated with the negative effect of MWCNTs in high concentrations. The revealed positive effects of low concentrations of MWCNTs on morphometric parameters and stimulation of stress resistance genes by nanotubes open up prospects for their use in woody plant biotechnology.

The effects of using nanoparticles of copper oxide (5–40 nm) and silver (10–30 nm) in the clonal micropropagation of downy birch were studied. The addition of nanoparticles to WPM medium (Woody plant medium) at the stage of introducing explants into culture in vitro helps reduce the infection of explants by 15–25%, as well as increase their morphogenic potential. The use of colloidal solutions of CuO and Ag nanoparticles when transferring birch microplants to greenhouses reduces the number of plants infected by phytopathogens increases their survival rate by 25%. A decrease in the overall infectious load and an increase in the adaptive potential due to nanoparticles improves the main growth and development indicators of downy birch plants. At the stages of multiplication and rooting of birch microclones, the introduction of CuO and Ag nanoparticles into WPM contributed to decreased viability; deterioration in the appearance, development of shoots and leaves; and a decrease in the microclone multiplication coefficient. No positive effect of the introduction of nanoparticles on the number of rooted birch microplants in vitro was found. Note that under the action of CuO nanoparticles, in contrast to Ag nanoparticles, the birch root system became more branched, with a large number of lateral roots. The results can be applied when using CuO and Ag nanoparticles in the biotechnology of plant clonal micropropagation.

The study is the first to examine the combined use of blast-furnace sludge as a source of microelements and converter slag as a soil-deoxidizing agent in oat (Avena sativa L.) cultivation in sod-podzolic soils. It has been established that blast-furnace sludge is a highly dispersed waste, which contains about 50% iron, 7% zinc, and a small amount of calcium, silicon, magnesium, aluminum, and sulfur. Hazardous components such as lead, arsenic, etc., are not detected. Converter slag comprises porous granules up to 3 mm in size, consisting mainly of calcium compounds (CaO, Ca(CO)₃, CaSiO₃, CaFe₂O₄) and a small amount of Mn, Al, and Mg trace elements. In a laboratory experiment, blast-furnace sludge increased the germination of oats by 5–10%, regardless of the addition of a deoxidizer (slag), but at the same time suppressed the growth of stem length by a maximum of 18% at 1 g∙kg⁻¹. The addition of slag raised substrate pH and increased the index by 8% at a sludge concentration of 0.1 g∙kg⁻¹. Root length in deoxidizer-free variants increased by 50–60% and with the addition of slag by 27–47%. Root dry mass also increased under the addition of sludge by 85–98%; however, the addition of slag reduced the indicator to the control level. In a field experiment with the combined application of waste, an increase in yield by more than 30% was shown. When soil was treated with slag and sludge, the height of plants increased by an average of 18%. It should be noted that the introduction of waste did not affect the quality of the grain. The use of slag increased the lead content in the soil, which is probably due to the sorption properties of calcium compounds in the slag, since lead was not found in the analyzed waste. Presumably, lead is sorbed by slag from the lower soil horizons, concentrating and immobilizing it in the upper layer. This version is supported by the absence of lead accumulation in straw and oat grain. The zinc-containing sludge increased the content of this element by 33% in the soil, as well as by 6% in straw and by 14% in grain. Thus, we found that the studied metallurgical wastes can be used as nutrients for agriculture, both individually and jointly. Overall, the proposed approach will contribute both to reducing the amount of accumulated waste and to improving the efficiency and sustainability of agricultural production and CO₂ sequestration. However, the features of the accumulation of heavy metals in soil and plants under the influence of the analyzed types of waste require more in-depth study, including within the framework of long-term field experiments.

The article discusses the effect of copper oxide (CuO) and silver (Ag) nanoparticles on expression of genes asr3, icdh, PR-1, PR-10, DREB2, used as markers of the development of stress tolerance, in poplar in vitro clones of the “POK” variety under conditions of artificial infection with the filamentous ascomycete Alternaria alternata. The exposure to the phytopathogen activates the asr3, icdh, PR-1, PR-10, DREB2 genes in microclones on a medium without nanoparticles, which indicates development of adaptation mechanisms in them. The expression indicators of stress tolerance marker genes in in vitro clones on a medium with CuO and Ag nanoparticles were reduced or did not exceed the values obtained for plants on a medium without nanoparticles. The observed suppression of the stress response under cultivation with CuO and Ag may be governed by the inhibitory effect of nanoparticles on the development of Alternaria alternata, as well as their influence on the development processes of poplar in vitro clones of the POK variety, which is associated with the peculiarities of the plant genotype and the concentration of nanoparticles.

Due to the growing population of Earth, the problem of providing food comes to the fore. Therefore, the search for new, economically available sources of trace elements for crop production is relevant. One of these potential sources is blast-furnace sludge: highly dispersed metallurgical waste, the industrial processing of which is difficult due to its high zinc content. We studied the effect of blast-furnace sludge on rapeseed plants in laboratory, greenhouse, and field experiments and also assessed the accumulation of sludge components in plant organs. The studied sludge sample consisted of micron and submicron particles containing compounds of iron, silicon, aluminum, zinc, calcium, and sulfur. Used concentrations: laboratory—0.01, 0.1, 1%, 10, and 100 g L⁻¹; greenhouse—0.01, 0.1, 1, 10, and 100 g kg⁻¹; field—0.5, 2, and 4 t ha⁻¹. During a laboratory experiment, a decrease in the germination of rapeseed seeds exposed to 0.01, 0.1, 10, and 100 g L⁻¹ waste was observed, but 1 g L⁻¹ promoted the increase of this indicator by 7% regarding control (0 g L⁻¹). While inhibiting seed germination, the sludge had a beneficial effect on the vegetative performance of plants. Reverse effects were noted in the greenhouse experiment as an increase in seed germination (introduction of 1 g kg⁻¹ of sludge to the substrate caused maximum stimulation) and a decrease in rapeseed morphometric parameters were observed. However, at a concentration of 10 g kg⁻¹, the root mass increased by 43% and the stem mass by 63%. In the same group, the highest content of chlorophylls was noted. The number of pods in all experimental groups of plants was less than in control (0 g kg⁻¹) plants, but at the same time, in the variants of 0.01 and 1 g kg⁻¹, the weight of seeds was noticeably increased, by 15.6 and 50%, respectively. Under the conditions of the field experiment, the sludge had a positive effect on the indicators of biological and economic productivity. Thus, exposure to 0.5 and 2 t ha⁻¹ of sludge significantly increased the dry matter and leaf area. The highest values of photosynthetic capacity were recorded at a dose of 2 t ha⁻¹. The maximum increase in yield was ensured by the introduction of sludge at a concentration of 0.5 and 2 t ha⁻¹. The sludge dose of 4 t ha⁻¹, which was also used, either had no effect or suppressed the development of the analyzed traits. The study of the accumulation of zinc and iron in the organs of plants showed the absence of a pronounced dose-dependent accumulation of zinc in the organs of rapeseed, while for iron, an increase in the content of the element in the organs of plants associated with an increase in the concentration of sludge in the soil was recorded. Our results demonstrate the promise of further research and development of methods for the agricultural use of highly dispersed sludge from wet gas cleaning of blast furnace production.