In Vitro Analysis of Selected Antioxidant and Biological Properties of the Extract from Large-Fruited Cranberry Fruits.

This study investigated the in vitro antioxidant and biological properties of ethanol extracts obtained from the fruits of the highbush cranberry. The produced extracts exhibited a high content of polyphenols (1041.9 mg 100 g d.m.-1) and a high antioxidant activity (2271.2 mg TE g 100 d.m.-1 using the DPPH method, 1781.5 mg TE g 100 d.m.-1 using the ABTS method), as well as a substantial amount of vitamin C (418.2 mg 100 g d.m.-1). These extracts also demonstrated significant in vitro biological activity. Studies conducted on the Saccharomyces cerevisiae cellular model revealed the strong antioxidant effects of the extract, attributed to a significant reduction in the levels of reactive oxygen species (ROS) within the cells, confirming the utility of the extracts in mitigating oxidative stress. Moreover, inhibitory properties were demonstrated against factors activating metabolic processes characteristic of inflammatory conditions. It was observed that the cranberry extract inhibits the activity of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) non-selectively. Additionally, the extract was found to be a highly active inhibitor of acetylcholinesterase (AChE), potentially suggesting the applicability of this extract in the prevention of neurodegenerative diseases, including Alzheimer's disease.

Dual mechanism of silver nanoparticle-mediated upregulation of adipogenesis in mouse fibroblasts (3T3-L1) in vitro.

Silver nanoparticles (AgNPs) are widespread in the environment due to the increase in their application e.g. in medicine as part of hard-to-heal wound dressings. Many studies have revealed easy diffusion of AgNPs into deep skin layers through damaged epidermis and contact with e.g. fibroblasts. Therefore, the aim of this study was to evaluate the impact of small-size AgNPs (10 nm) in ppm concentrations on the adipogenesis process in mouse embryo fibroblasts (3T3-L1). The results showed a decrease in the metabolic activity, followed by an increase in the reactive oxygen species (ROS) level in a dose- and time-dependent manner (0-20 ppm). The increased caspase-3 activity was observed only at the highest concentration (20 ppm) of AgNPs. Further analysis showed the ability of the tested NPs to increase the lipid accumulation in adipocytes, similar to ROSI [peroxisome proliferator-activated receptor gamma (PPARγ) agonist], measured by Oil-Red-O staining. Moreover, the analyses evidenced the ability of AgNPs to increase the lipoxygenase activity and malondialdehyde levels, which is probably based on ROS-dependent enhancement of lipid hydroperoxidation. Lastly, a significant increase in the PPARγ, Adiponectin, Resistin, Vegf, and Serpine mRNA expression was shown 6 h after the induction of the differentiation process. Based on the obtained results, it can be concluded that small-size AgNPs increase adipogenesis via ROS- and PPARγ-based mechanisms with potential engagement of crosstalk with the aryl hydrocarbon receptor, which is important due to the widespread application of AgNPs in medicine. However, more studies are needed to elucidate the full mechanism of these NPs in the tested cell model in depth.

Physiological and Morphological Implications of Using Composts with Different Compositions in the Production of Cucumber Seedlings.

Compost has a broad application in terms of the improvement of the soil properties. This research work was conducted to present the molecular implications of using compost obtained from different substrates to improve soil parameters for cucumber seedlings cultivation. In the experiment, the following compost mixtures were used: sewage sludge (80%) + sawdust (20%); sewage sludge (40%) + sawdust (10%) + biodegradable garden and park waste (50%); biodegradable garden and park waste (90%) + sawdust (10%); sewage sludge (80%) + sawdust (20%) + Eisenia fetida; sewage sludge (40%) + sawdust (10%) + biodegradable garden and park waste (50%) + Eisenia fetida; biodegradable garden and park waste (90%) + sawdust (10%) + Eisenia fetida. The final substrate compositions consisted of compost mixtures and deacidified peat(O) (pH 6.97; Corg content-55%, N content-2.3%), serving as a structural additive, in different mass ratios (mass %). The produced plants underwent biometric and physiological measurements as well as enzymatic analyses of stress markers. Based on the conducted studies, it has been found that the substrate productivity depends not only on the content of nutrient components but also on their structure, which is moderated by the proportion of peat in the substrate. The most effective and promising substrate for cucumber seedling production was variant 2 (I), which consisted of 25% compost from sewage sludge (40%) + sawdust (10%) + biodegradable garden and park waste (50%) and 75% deacidified peat. Despite the richness of the other substrates, inferior parameters of the produced seedlings were observed. The analysis of the enzymatic activity of stress markers showed that these substrates caused stress in the plants produced. The study's results showed that this stress was caused by the presence of Eisenia fetida, which damaged the developing root system of plants in the limited volume of substrate (production containers). The adverse influence of Eisenia fetida on the plants produced could possibly be eliminated by thermal treatment of the compost, although this could lead to significant changes in composition.

Variability of Properties Modulating the Biosynthesis of Biologically Active Compounds in Young Barley Treated with Ozonated Water.

This paper presents the effects of irrigating barley plants with different type of water solutions saturated with gaseous ozone generated from atmospheric air. The study investigated the effects of the applied types of water on the modulation of the biosynthesis of selected bioactive compounds (content of total polyphenols, small molecule antioxidants, vitamin C) in the produced plant material. A number of transformations of reactive oxygen species (ROS) and nitrogen compounds have also been postulated; these are observed during the saturation of water with gaseous O3 and 30 min after the end of the process. It was shown that after the process of water saturation with gaseous O3, the gas later is converted to compounds with high oxidative potential and good stability; these, in turn, lead to the oxidation of oxidates generated from atmospheric nitrogen into nitrates, which exhibit fertilising properties. Thirty minutes after the process of H2O saturation with gaseous O3 was completed, the tests showed the highest concentrations of nitrates and the relatively high oxidative potential of the solution originating from H2O2 with a low concentration of the dissolved O3. This solution exhibited the highest activity modulating the biosynthesis of polyphenols, small molecule antioxidants and vitamin C in young barley plants. The resulting differences were significant, and they were reflected by 15% higher total polyphenol content, 35% higher antioxidative potential and 57% greater content of vitamin C compared to the control specimens (plants treated with fresh H2O).

Effect of postharvest nicotinamide treatment on NAD+ metabolism and redox status in strawberry fruit during storage.

The increased activity of PARP enzymes is associated with a deficiency of NAD+, as well as with a loss of NADPH and ATP, and consequent deterioration of the redox state in fruits. In this study, we checked whether treatment with nicotinamide (NAM) would affect PARP-1 expression and NAD+ metabolism in strawberry fruit during storage. For this purpose, strawberry fruits were treated with 10 mM NAM and co-treated with NAM and UV-C, and then stored for 5 days at 4 °C. Research showed that nicotinamide contributes to reducing oxidative stress level by reducing PARP-1 mRNA gene expression and the protein level resulting in higher NAD+ availability, as well as improving energy metabolism and NADPH levels in fruits, regardless of whether they are exposed to UV-C. The above effects cause fruits treated with nicotinamide to be characterised by higher anti-radical activity, and a lower level of reactive oxygen species in the tissue.

Edible coating enriched with cinnamon oil reduces the oxidative stress and improves the quality of strawberry fruit stored at room temperature.

BACKGROUND: The present study aimed to assess the impact of a starch/gelatine coating containing cinnamon oil on selected quality attributes and redox status in strawberry fruit stored at room temperature (72 h). RESULTS: Research showed that the application of cinnamon oil to an edible coating allows an improvement of the quality of strawberry fruit stored at room temperature. The cinnamon oil coating inhibits the development of yeast and mould, and reduces loss of soluble solids and ascorbic acid during 72 h storage at room temperature. Moreover, the coating with cinnamon oil clearly reduced the level of oxidative stress, which was manifested by a lower level of reactive oxygen species, as well as a lower activity of antioxidant enzymes. The elimination of oxidative stress in the cinnamon oil-coated fruit also contributed to lower PARP1 mRNA expression, inhibiting the metabolism of NAD+ and reducing ATP losses. CONCLUSION: The coating of strawberry fruit with a starch/gelatine biofilm containing cinnamon oil is an effective method for delaying postharvest senescence of fruit and the storage degradation of tissue. © 2023 Society of Chemical Industry.

Comprehensive Analysis of Highbush Blueberry Plants Propagated In Vitro and Conventionally.

In vitro culture allows the production of numerous plants with both desirable and undesirable traits. To investigate the impact of the propagation method on highbush blueberry plants, an analysis was performed on four groups of differentially propagated plants: in vitro with axillary (TC-Ax) or adventitious shoots (TC-Ad), conventionally (SC) and using a mixed method (TC/SC). The analysis included plant features (shoot length and branching, chlorophyll and fluorescence and DNA methylation) and fruit properties (antioxidant compounds). The data obtained indicated significant differences between plants propagated conventionally and in vitro, as well as variations among plants derived from in vitro cultures with different types of explants. SC plants generally exhibited the lowest values of morphological and physiological parameters but produced fruits richest in antioxidant compounds. TC/SC plants were dominant in length, branching and fluorescence. Conversely, TC-Ax plants produced fruits with the lowest levels of antioxidant compounds. The methylation-sensitive amplified polymorphism (MSAP) technique was employed to detect molecular differences. TC-Ad plants showed the highest methylation level, whereas SC plants had the lowest. The overall methylation level varied among differentially propagated plants. It can be speculated that the differences among the analysed plants may be attributed to variations in DNA methylation.

Induction of Biosynthesis Antioxidant Molecules in Young Barley Plants by Trioxygen.

Young barley plants are a good source of bioactive compounds. This paper presents the effects of gaseous O3 (trioxygen or ozone) on the biosynthesis of compounds, determining the antioxidant potential of young barley plants. The total content of polyphenols was determined along with their profile, as well as total antioxidant potential and vitamin C content. The highest contents of these compounds were identified in young barley plants exposed to gaseous O3. The main bioactive compound, representing polyphenols, determined in the examined raw materials was saponarin (isovitexin 7-O-glucoside). The induction of increased biosynthesis of these molecules was directly linked to the modification of the activity of selected enzymes. The increased polyphenol content resulted from the modified activities of polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL). On the other hand, the oxidative effect of ozone on barley plants was reduced, owing to the modified activities of catalases (CAT), glutathione peroxidases (SOD) and guaiacol peroxidase (GPOX). Analysis of the results showed that by applying gaseous O3 at a dose of 50 ppm for 10 min, the contents of bioactive compounds can be maximised in a residue-free way by activating oxidative stress defence mechanisms.

Effects of Post-Harvest Ozone Treatment on Some Molecular Stability Markers of Amelanchier alnifolia Nutt. Fruit during Cold Storage.

Fruits of Amelanchier alnifolia Nutt. ex M. Roem. (Nutt.) are a good source of bioactive compounds and vitamins. Due to the fact that the berries are a soft fruit, they require special procedures to increase their molecular and mechanical stability during cold storage. The study investigated the effects of ozone treatment applied cyclically (every 24 h) on selected chemical and mechanical parameters of saskatoon berries kept in storage. For this purpose, measurements were performed to assess changes in some molecular markers such as antioxidant potential, content of vitamin C, and total polyphenols, as well as microbial stress and maximum destructive force under uniaxial compression of samples. The effectiveness of the storage process was also assessed in relation to the conditions used by determining the proportion of fruit affected by diseases occurring in storage. The findings show that ozone treatment led to increased content of bioactive compounds at the initial stages of storage and resulted in decreased loss of water and bioactive compounds at the later stages. Ultimately, irrespective of the conditions applied during ozone treatment, it was observed that the growth of micro-organisms on the fruit surface was inhibited, and as a result, storage losses during the relevant period were significantly reduced.

One-time ozone treatment improves the postharvest quality and antioxidant activity of Actinidia arguta fruit.

The major aim of this study was to check the effect of one-time ozonation on selected quality parameters and antioxidant status of Actinidia arguta fruit. For this purpose, A. arguta fruit was ozonated with gas at a concentration of 10 and 100 ppm, which was carried out successively for 5, 15 and 30 min. Next, the selected quality attributes, antioxidants level as well as NADPH and mitochondrial energy metabolism in mini-kiwi fruit after ozonation were analysed. Our research has shown that ozonation reduced the level of yeast and mould without affecting the content of soluble solids or acidity. In turn, ozonation clearly influenced the antioxidant activity and the redox status of the fruit. The ozonated fruit was characterised by a lower level of ROS due to the higher level of low molecular weight antioxidants, as well as the higher activity of superoxide dismutase and catalase. In addition, improved quality and antioxidant activity of the fruit were indirectly due to improved energy metabolism and NADPH level. The ozonated fruit showed a higher level of ATP, due to both higher activity of succinate dehydrogenase and higher availability of NADH. Moreover, the increased level of NAD+ and the activity of NAD+ kinase and glucose-6-phosphate dehydrogenase contributed to higher levels of NADPH in the fruit.

Ozonation process causes changes in PARP-1 expression and the metabolism of NADPH in strawberry fruit during storage.

In this study, the effect of ozonation process on the poly(ADP-ribose) polymerase 1 gene expression (PARP-1) and related the NADPH metabolism in strawberry fruit during storage was determined. Our results showed that ozonation with gas at both 10 and 100 ppm concentrations increased the expression of PARP-1 in the fruit during storage. Furthermore, the ozonation process initially increased the level of NAD+ and NADH in the fruit, which corresponds to a higher ATP level. The storage of the fruit in an ozone atmosphere also contributed to increased activity of the NAD+ kinase, leading to increased levels of NADP+ . In turn, the higher activity of glucose-6-phosphate dehydrogenase caused the ozonated fruit to show a higher level of NADPH. However, as the storage period extended and thus with increasing expression of PARP-1 in the ozonated fruit, the level of NAD+ decreased. In general, the ozonated fruit, which had a higher level of NADPH, showed a higher content of reduced glutathione, which in turn contributed to an increase in the antioxidant activity of the fruit and, ultimately, to a lower accumulation of reactive oxygen species.

Ozone Treatment Improves the Texture of Strawberry Fruit during Storage.

The major aim of this study was to check whether a cyclic ozonation process will affect the preservation of the texture of strawberries stored at room temperature. Strawberry fruit was stored for 3 days at room temperature and ozonated with gaseous ozone at a concentration of 10 and 100 ppm for 30 min, every 12 h of storage. Research showed that the ozonation process inhibited the texture deterioration of the fruit during storage. The positive effect of ozone was directly related to the inhibition of the activity of enzymes involved in the degradation of the fruit cell walls, as well as indirectly from the improved energy metabolism of the fruit. The higher level of energy charge corresponded to the higher resistance of ozonated fruit to abiotic stress, leading to the maintenance of the integrity of cell membranes and, consequently, to maintaining good hardness of the fruit throughout the storage period.

Epidermal Growth Factor-labeled liposomes as a way to target the toxicity of silver nanoparticles into EGFR-overexpressing cancer cells in vitro.

Silver nanoparticles (AgNPs) are the most toxic nanostructures for both cancer and healthy cells. Thus, their usefulness in the anticancer therapy is limited. Interestingly, the epidermal growth factor receptor (EGFR) is overexpressed in many cancer cells, e.g. in lung and tongue cancers. Therefore, the aim of this study was to develop a way to direct the cytotoxic effect of AgNPs against cancer cells, saving healthy ones by entrapping these NPs inside liposomes labeled with the epidermal growth factor (EGF-LipoAgNPs) and directing these structures into EGFR-overexpressing cancer cells. The obtained results showed spherical structures with a 107.9 nm size and - 16.60 mV zeta-potential. The UV-Vis scan and TEM images did not show free AgNPs in the solution. The obtained complexes were able to decrease the metabolic activity in the A549 and SCC-15 cells more effectively than native AgNPs. Furthermore, the ROS production, lactate dehydrogenase release, and caspase-9 and -3 activity were significantly increased after the treatment with EGF-LipoAgNPs for 24 and 48 h. The expression of genes encoding catalase, superoxide dismutase, and p53 protein increased significantly, while the KI67 gene expression decreased, especially in the A549 and SCC-15 cells. Moreover, the KI67 protein expression was lower than in the cells treated with native AgNPs, while catalase activity was decreased significantly after the treatment with the obtained complexes. In turn, SOD activity increased more efficiently in the EGFR-overexpressing cancer cells. In all tested parameters, EGF-LipoAgNPs exerted a lower toxic effect on the BJ cells than native AgNPs. Summarizing, the created liposomal system reduces the toxicity of AgNPs against normal human fibroblasts and enhances the toxic and proapoptotic effect of these NPs, which may be caused by improvement of their uptake by EGFR-overexpressing cancer cells.

Assessment of the Impact of the Application of a Quercetin-Copper Complex on the Course of Physiological and Biochemical Processes in Wheat Plants (Triticum aestivum L.) Growing under Saline Conditions.

Salt stress is one of the main stressors limiting plant growth and yield. As a result of salt stress, unfavorable changes in the photosynthesis process take place, leading to a decrease in plant productivity. Therefore, it is necessary to use biologically active substances that reduce the effects of this stress. An example of such a substance is quercetin, classified as a flavonoid, which plays an important role in alleviating the effects of salt stress, mainly by the inactivation of reactive oxygen species (ROS) and by improvement of the photosynthesis process. A study was made of the effect of the quercetin-copper complex (Q-Cu (II)), which has a stronger antioxidant effect than pure quercetin. By means of a pot experiment, the influence of solutions of the Q-Cu (II) complex (100 mg∙L-1 [Q1], 500 mg∙L-1 [Q2] and 1000 mg∙L-1 [Q3]) on the physiological and biochemical processes occurring in wheat plants subjected to salt stress was investigated. The plants were given two sprays of Q-Cu (II) solution, and their physiological parameters were examined both 1 and 7 days after each application of this solution. The level of ROS and the activity of antioxidant enzymes (catalase [CAT], superoxide dismutase [SOD] and guaiacol peroxidase [GPOX]) were also determined. It has been shown that spraying with Q2 and Q3 solutions improves the chlorophyll content, the values of chlorophyll fluorescence parameters (the photochemical efficiency of PS II [Fv/Fm], the maximum quantum yield of primary photochemistry [Fv/F0], and the performance index of PS II [PI]), and gas exchange (net photosynthetic rate [Pn], stomatal conductance [gs], transpiration rate [E] and intercellular CO2 concentration [Ci]). As a result of the application of Q2 and Q3 solutions, the level of ROS and the activity of the antioxidant enzymes tested decreased, which means that these concentrations are most effective in counteracting the effects of salt stress.

Triclosan (TCS) affects the level of DNA methylation in the human oral squamous cell carcinoma (SCC-15) cell line in a nontoxic concentration.

The oral cancer is presumably caused by genetic factors and exposure to substances derived from cosmetics and disinfectants. Triclosan (TCS) is widely spread in many consumer products and oral care products. Since TCS can affect DNA methylation, which is one of the key mechanisms of gene expression that may lead to cancerogenesis, it is necessary to study this mechanism in oral cell carcinoma. The aim of the present study was to evaluate the impact of TCS on metabolic parameters, oxidative stress, gene expression, and DNA methylation and hydroxymethylation in the SCC-15 cell line. The experiments have shown TCS toxicity to SCC-15 cells only in the highest concentrations of 50 and 100 µM. TCS in a wide range of concentrations increases ROS production and caspase-3 activity. Our experiments have shown that TCS in the nontoxic concentrations of 10 µM exerts an impact on SOD2 mRNA expression and SOD activity in the SCC-15 cell line. Finally, our experiments have demonstrated that 6-h treatment with TCS decreases the mRNA expression of DNMT3A and DNMT3B. After 72-h exposure to TCS, an increased level of 5-methylcytosine and 5-hydroxymethylcytosine was observed in the SCC-15 cell line, but it was abolished by the NAC treatment. However, it is very likely that these results can be an effect of TET enzyme activity, especially in the case of the decrease in 5mC and the increase in 5hmC after the 48-h exposure to TCS, which was accompanied with a decrease in the mRNA expression of DNMT3A and DNMT3B.

Changes in the activity of flavanone 3ß-hydroxylase in blueberry fruit during storage in ozone-enriched atmosphere.

BACKGROUND: The present study aimed to determine whether the ozonation process affects the flavonoid biosynthesis in highbush blueberry (Vaccinum corymbosum L.) fruit. Flavanone 3ß-hydroxylase (F3H) was used as a marker of the flavonoid biosynthesis pathway. The activity of F3H, the expression of gene encoding F3H and the antioxidant status in blueberries treated with ozone at a concentration of 15 ppm for 30 min, every 12 h of storage, and maintained at 4 °C for 4 weeks were investigated. RESULTS: The results showed that ozonation process increases the expression of the F3H gene after 1 week of storage, which translates into a higher catalytic capacity of protein, as well as a higher content of flavonoids and total antioxidant potential of ozonated blueberries compared to non-ozonated fruits. CONCLUSION: The present study provides experimental evidence indicating that ozone treatment in proposed process conditions positively affects flavonoid metabolism in highbush blueberry fruit leading to the maintainance of the high quality of the fruit during storage. © 2021 Society of Chemical Industry.

The Modification of Substrate in the Soilless Cultivation of Raspberries (Rubus Idaeus L.) as a Factor Stimulating the Biosynthesis of Selected Bioactive Compounds in Fruits.

Raspberry fruits are a valuable source of bioactive compounds. The study used the modification of the substrate (coconut fibre), consisting of the use of various organic and mineral additives, in the soilless cultivation of raspberries. The additives influenced the biosynthesis of bioactive compounds in the raspberry fruits by modifying the sorption properties and the abundance of the substrate. The influence of the additives on the content of polyphenols was determined as well as their profile (UPLC-MS), antioxidant potential (ABTS), vitamin C content, and the activity of selected enzymes that are markers of stress and resistance to abiotic factors. In the study, a significant effect of these additives was observed on the biosynthesis of polyphenols in raspberry fruit. The highest increase in the content of these compounds in relation to the control sample (substrate-100% coconut fibre), namely 37.7%, was recorded in the case of fruit produced on coconut substrate enriched with sheep wool. These fruits were also characterised by a significantly different profile of these compounds. These changes were caused by readily available ammonium nitrogen and free amino acids in the decomposition of proteins contained in the sheep wool. This was confirmed by the recorded content of chlorophyll SPAD in the plant leaves and the activity of selected enzymes, which proves a low level of stress and good condition of the plants.

Characterisation of Some Phytochemicals Extracted from Black Elder (Sambucus nigra L.) Flowers Subjected to Ozone Treatment.

Elderflowers are a well-known source of bioactive compounds. The amount of isolated bioactive compounds may be increased by applying various abiotic and biotic factors. Gaseous ozone (10 and 100 ppm) was used in the process of preparing flowers. Next, the flowers were treated with sugar syrup to extract bioactive compounds. It was shown that this treatment, including the influence of extraction temperature, significantly affects the contents of polyphenols (liquid chromatography-mass spectrometry (LC-MS) methods) and vitamin C, as well as the antioxidant potential (cupric reducing antioxidant capacity (CUPRAC method)), the profile of volatile substances (head space-solid-phase microextraction (HS-SPME methods)) and the colour of the syrup (Commission Internationale de l'Eclairage (CIE) L*a*b* methods). The findings show that an increased dose of ozone and higher extraction temperature applied in the process of syrup production resulted in higher contents and different compositions of bioactive compounds. The highest contents of bioactive compounds were identified in syrup obtained from raw material treated with ozone for 15 min (concentration = 10 ppm) and extraction with sugar syrup at a temperature of 60 °C.

The Effect of Exogenous Application of Quercetin Derivative Solutions on the Course of Physiological and Biochemical Processes in Wheat Seedlings.

Quercetin, classified as a flavonoid, is a strong antioxidant that plays a significant role in the regulation of physiological processes in plants, which is particularly important in the case of biotic and abiotic stresses. The study investigated the effect of the use of potassium quercetin solutions in various concentrations (0.5%, 1.0%, 3.0% and 5.0%) on the physiological and biochemical properties of wheat seedlings. A pot experiment was carried out in order to determine the most beneficial dose of this flavonoid acting as a bio-stimulant for wheat plants. Spraying with quercetin derivative solutions was performed twice, and physiological measurements (chlorophyll content and fluorescence as well as gas exchange) were carried out on the first and seventh days after each application. The total phenolic compounds content and the total antioxidant capacity were also determined. It was shown that the concentrations of potassium quercetin applied have a stimulating effect on the course of physiological processes. In the case of most of the tested physiological parameters (chlorophyll content and fluorescence and gas exchange) and the total antioxidant capacity, no significant differences were observed in their increase as a result of application with concentrations of 3.0 and 5.0%. Therefore, the beneficial effect of quercetin on the analysed parameters is already observed when spraying with a concentration of 3.0%.

Physiological Response of Maize Plants (Zea mays L.) to the Use of the Potassium Quercetin Derivative.

Plant production technologies based solely on the improvement of plants themselves face obstacles resulting from the natural limitations of the biological potential of varieties. Therefore, new substances are sought that positively influence the growth and development of plants and increase resistance to various biotic and abiotic stresses, which also translates into an increase in obtained yields. The exogenous application of various phytoprotectants shows great promise in terms of cost effectiveness compared to traditional breeding methods or transgenic approaches in relation to increasing plant tolerance to abiotic stresses. Quercetin is a strong antioxidant among phenolic compounds, and it plays a physiological and biochemical role in plants. As such, the aim of this research was to assess the effect of an aqueous solution of a quercetin derivative with potassium, applied in various concentrations (0.5%, 1.0%, 3.0% and 5.0%), on the efficiency of the photosynthetic apparatus and biochemical properties of maize. Among the tested variants, compared to the control, the most stimulating effect on the course of physiological processes (PN, gs, ci, CCI, Fv/Fm, Fv/F0, PI) in maize leaves was found in 3.0 and 5.0% aqueous solutions of the quercetin derivative. The highest total antioxidant capacity and total content of polyphenolic compounds were found for plants sprayed with 5.0% quercetin derivative solution; therefore, in this study, the optimal concentration could not be clearly selected.