Although salinity inhibits plant growth, the use of a nitric oxide (NO) gasotransmitter can reduce its negative effects. In this study, the influence of 200 μM sodium nitroprusside (SNP) (donor of NO) on wheat plants (Triticum aestivum L., cv. Salavat Yulaev) in conditions of salinization (100 mM NaCl) was analyzed in pot experiments. Seed priming regulated the level of endogenous NO in normal and salinity conditions throughout the entire experiment (30 and 60 days). Salinity led to the strong accumulation of NO and H₂O₂, which is negative for plants, and significantly reduced leaf area and photosynthetic pigments (chlorophyll a and b and carotenoids). In addition, stress caused a drop in the content of reduced glutathione (GSH) and ascorbic acid (ASA), an accumulation of oxidized glutathione (GSSG), and significantly activated glutathione reductase (GR), ascorbate peroxidase (APX), and lipid peroxidation (LPO) in wheat leaves. SNP treatment significantly attenuated the negative effects of salinity on leaf area and photosynthetic pigments. An important indicator of reducing the damaging effect of salinity on treated plants is the stabilization of the content of GSH and ASA throughout the experiment (60 days). This condition has been associated with long-term modulation of GR and APX activity. Such an effect of 200 μM SNP may be related to its ability to reduce stress-induced accumulation of NO. Additional accumulation of proline also mitigated the negative effect of salinity on plants, and this also evidenced decreased LPO and H₂O₂ in them. For the first time, in natural growing conditions (small-scale field experiments), it was found that pre-sowing seed treatment with 200 μM SNP led to an improvement in the main yield indicators and an increase in the content of essential amino acids in wheat grains. Thus, SNP treatment can be used as an effective approach for prolonged protection of wheat plants under salinity and to improve grain yield and its quality.

Salicylic acid (SA) plays a crucial role in regulating plant growth and development and mitigating the negative effects of various stresses, including salinity. In this study, the effect of 50 μM SA on the physiological and biochemical parameters of wheat plants under normal and stress conditions was investigated. The results showed that on the 28th day of the growing season, SA pretreatment continued to stimulate the growth of wheat plants. This was evident through an increase in shoot length and leaf area, with the regulation of leaf blade width playing a significant role in this effect. Additionally, SA improved photosynthesis by increasing the content of chlorophyll a (Chl a) and carotenoids (Car), resulting in an increased TAP (total amount of pigments) index in the leaves. Furthermore, SA treatment led to a balanced increase in the levels of reduced glutathione (GSH) and oxidized glutathione (GSSG) in the leaves, accompanied by a slight but significant accumulation of ascorbic acid (ASA), hydrogen peroxide (H₂O₂), proline, and the activation of glutathione reductase (GR) and ascorbate peroxidase (APX). Exposure to salt stress for 28 days resulted in a reduction in length and leaf area, photosynthetic pigments, and GSH and ASA content in wheat leaves. It also led to the accumulation of H₂O₂ and proline and significant activation of GR and APX. However, SA pretreatment exhibited a long-term growth-stimulating and protective effect under stress conditions. It significantly mitigated the negative impacts of salinity on leaf area, photosynthetic pigments, proline accumulation, lipid peroxidation, and H₂O₂. Furthermore, SA reduced the salinity-induced depletion of GSH and ASA levels, which was associated with the modulation of GR and APX activities. In small-scale field experiments conducted under natural growing conditions, pre-sowing seed treatment with 50 μM SA improved the main indicators of grain yield and increased the content of essential amino acids in wheat grains. Thus, SA pretreatment can be considered an effective approach for providing prolonged protection to wheat plants under salinity and improving grain yield and quality.

Food insecurity is a top economic and national security concern in many countries, and scientists worldwide are working to increase crop productivity in order to address this issue. In line with this information, the present study aimed to test the possibility of improving the yield and fruit quality of two tomato cultivars, namely ‘Vspyshka’ and ‘Lyana’. The effect of LSL (light of sodium lamps—control) and the short additional 4 h treatment of nighttime LED lighting (LSL+night LED) with an increase in the proportion of red, blue, and far-red spectra on tomato fruit yield as well as its physiological, biochemical, and consumer attributes were compared in this study. The results suggested that LSL+night LED significantly increased soluble solids concentration, vitamin C content, and polyphenolic compounds of tomato fruits, taking into account the varietal characteristics. Moreover, a moderate to high relationship was also observed between the polyphenolic complex, vitamin C content, and antioxidant activity. It was concluded that the LSL+night LED could further enhance the relationship between polyphenols and antioxidants, as well as soluble solids concentration. LSL+night LED treatment also provided an increased accumulation of five essential amino acids associated with the taste characteristics of fruits, namely histidine, valine, threonine, licin, and the sum of isoleucine. In addition, the contents of lysine and methionine increased in the ‘Lyana’ cultivar. LSL+night LED treatment was also noted to have a less pronounced effect on the contents of aspartic acid and asparagine, as bio stimulators of plant growth processes, as well as the amino acids arginine, serine, glycine, and tyrosine, which were additionally consumed to restore photosynthesis. LSL+night LED treatment reduced the concentration of nitrates in fruits, which is a toxic element for human health. Overall, the results of the study are believed to be demanded in practical applications, with potential benefits in improving the elements of resource-saving technology for growing vegetable crops.

This study focuses on refining in vitro propagation protocols for red currant cultivars of the Ribes genus and evaluating the role of LED lighting in the adaptation of microplants. The cultivars ‘Red Lake’, ‘Englische Grosse Weisse’, ‘Marmeladnitsa’, and ‘Podarok Leta’ were successfully introduced into in vitro culture during their dormancy phase using 0.1% HgCl₂ as a sterilizing agent. The period of spring introduction is not very efficient in connection with the intensive development of saprophytic microflora and weak morphogenesis microplants. Using 0.01% C₉H₉HgNaO₂S sterilizer resulted in a decrease in the necrosis percentage, but an increase in mold proportion. The preparation of the plants with 12% H₂O₂ was considered environmentally not effective enough to obtain a large number of healthy microplants. The use of 12% H₂O₂ resulted in increased necrosis rates by 24.76% compared to 0.01% C₉H₉HgNaO₂S and 0.1% HgCl₂ sterilizers. The variety specificity of Ribesia plants in terms of the content of MS and LF nutrient media components was determined by the survival rate of explants, the formation of additional micro-shoots, and the morphological development. The MS medium with the addition of 1 mg∙L⁻¹ BAP decreased the percentage of mold and necrosis infection and provided a high percentage of viable plants with optimal growth and reproduction rate. In contrast, the LF medium with the same concentration of 6-BAP resulted in poor explant quality and leaf chlorosis at later stages. The study also investigated the effects of different LED light spectra on morphological and physiological traits. For ‘Red Lake’ and ‘Englische Grosse Weisse’, RWUV-A (625–740 nm) lighting enhanced biomass and chlorophyll (Chl a and Chl a + b) accumulation, while the White (W) spectrum benefited ‘Podarok Leta’. Conversely, the RW spectrum with minimal green and no ultraviolet light restricted growth and photosynthetic pigment accumulation across all cultivars, promoting compact plant structures. The RWUV-A lighting condition resulted in the highest NDVI values across all cultivars, indicating an improved physiological status and biomass accumulation. These findings underscore the importance of refining the microclonal reproduction protocols for Ribesia subgenus representatives, emphasizing the genotype-specific light modulation during the proliferation stage. The study highlights the utility of the MS medium and tailored light conditions in enhancing the effectiveness of propagation techniques for producing high-quality planting material.

The effect of white and additional red and blue LED lighting at night (Blue-NLL, Red-NLL) and during the pre-harvest period (Blue-P-hLL, Red-P-hLL) on morphological and physiological parameters, elemental composition, content of polyphenols, and essential oils of purple basil cultivars ‘Ararat’ and green basil ‘Tonus’ grown in the hydroponic conditions of the climatic chamber was studied. The height of the plants was determined by the variety and the LED irradiation period. The highest purple basil plants were obtained in the variant with Blue-NLL illumination; the highest green basil plants were obtained under Blue-P-hLL and Red-P-hLL. The red spectrum, regardless of the lighting period and variety, increased the area and number of leaves, biomass, and vegetative productivity. Significant changes in the elemental composition of the vegetative mass of basil varieties were determined by the period of exposure to the red spectrum. Red-P-hLL stimulated the absorption and accumulation of Mg, Ca, S, and P from the nutrient solution, and Red-P-hLL reduced the nitrate content by more than 30.00%. Blue-NLL lighting increased the content of quercetin, rosmarinic acid, and essential oil and reduced the nitrate content in the vegetative mass by more than 40.00%. The effectiveness of the white LED was observed in increasing the vegetative mass of ‘Tonus’. The results of this study will be in demand in the real sector of the economy when improving resource-saving technologies for growing environmentally friendly leafy vegetable crops with improved chemical composition and high vegetative productivity.

The aim of the study is to investigate the effect of biofertilizers based on adaptive PGPR bacteria on the rooting process of thyme cuttings and to evaluate the impact of LED irradiation on the quality indicators of common thyme biomass. The object of the study was common thyme (Thymus vulgaris L.), variety Krymrozovets, bred by the Federal State Budgetary Scientific Institution Research Institute of Agriculture of Crimea. The rooting ability of common thyme cuttings taken from mother plants was assessed using PGPR bacteria under controlled conditions of a closed agroecosystem. At the rooting stage using the Arthobacter mysorens monoculture, 76 % of cuttings took root on a peat substrate, which corresponded to the control variant (82 %); on a mineral wool substrate, an increase in the survival rate of cuttings by 1.8 times (65 %) was observed compared to the control (36 %). Treatment of thyme cuttings with a consortium of PGPR bacilli Bacillus sp. reduced survival on both peat and mineral wool substrates compared to the control. When studying the effect of LED irradiation on the qualitative indices of common thyme biomass, differences in the accumulation of essential oil and in the synthesis of amino acids were observed. The highest yield of essential oil (1.01 %) was recorded when treating with PAR of 230 mmol/m2s, the lowest (0.46 %) – when using PAR of 106 mmol/m2s. The total content of amino acids (arginine, lysine, phenyla¬lanine, leucine + isoleucine, valine, proline, threonine and alanine) in the biomass of thyme grown under reduced irradiance (106 mmol/m2s) was 23.9 % higher than in plants grown under increased irradiance (230 mmol/m2s).Among all the analyzed amino acids, leucine + isoleucine (Leu + Ile) predominate with a total content from 901.1 (PAR – 230 mmol/m2s) to 1055.2 (PAR – 106 mmol/m2s) mg/100 g. To achieve optimal quality parameters of the obtained raw materials, it is recommended to grow plants under conditions of reduced LED irradiation at a PAR of 106 mmol/m2s of a closed agroecosystem.