A Recent Update on the Impact of Nano-Selenium on Plant Growth, Metabolism, and Stress Tolerance

Nanopriming with phytofabricated selenium nanoparticles alleviates arsenite-induced oxidative stress in Spinacia oleracea L

Arsenic (As) contamination of agricultural soil has become a major concern due to its adverse effects on plant growth and human health. Selenium nanoparticles (SeNPs), a novel selenium (Se) source, are characterised by their exceptional biocompatibility, degradability, and bioactivities. In the present study, SeNPs were biogenically synthesised and further characterised using UV-visible spectroscopy, XRD, FTIR, and TEM analysis. Different concentrations of the synthesised SeNPs were used to treat Spinacia oleracea L. (spinach) seeds to determine their impact on growth profile, gas exchange, photosynthetic pigments, oxidative stress, and antioxidant enzyme status upon arsenite (AsIII) treatment. The findings revealed that SeNP supplementation at a concentration of 100 µM (SeNPs100) led to a significant reduction in As accumulation by twofold in roots and 1.5-fold in leaves when compared to plants exposed to AsIII100 (µM) alone. Interestingly, the photosynthetic efficiency was also remarkably enhanced upon SeNPs100 treatment, associated with increased activities of the defence enzymes (ascorbate peroxidase, catalase, and glutathione peroxidase) in the AsIII + SeNP-exposed spinach plants as compared to AsIII treatment alone. Overall, the present study highlights the potential of biogenic SeNP supplementation in promoting plant growth and mitigating As toxicity in spinach under AsIII stress. This study could have significant implications for the use of SeNPs as a nanofertiliser in regions grappling with As-contaminated soils for sustainable agriculture and human health.

Unveiling Green Synthesis and Biomedical Theranostic paradigms of Selenium Nanoparticles (SeNPs) - A state-of-the-art comprehensive update

The advancements in nanotechnology, pharmaceutical sciences, and healthcare are propelling the field of theranostics, which combines therapy and diagnostics, to new heights; emphasizing the emergence of selenium nanoparticles (SeNPs) as versatile theranostic agents. This comprehensive update offers a holistic perspective on recent developments in the synthesis and theranostic applications of SeNPs, underscoring their growing importance in nanotechnology and healthcare. SeNPs have shown significant potential in multiple domains, including antioxidant, anti-inflammatory, anticancer, antimicrobial, antidiabetic, wound healing, and cytoprotective therapies. The review highlights the adaptability and biocompatibility of SeNPs, which are crucial for advanced disease detection, monitoring, and personalized treatment. Special emphasis is placed on advancements in green synthesis techniques, underscoring their eco-friendly and cost-effective benefits in biosensing, diagnostics, imaging and therapeutic applications. Additionally, the appraisal scrutinizes the progressive trends in smart stimuli-responsive SeNPs, conferring their role in innovative solutions for disease management and diagnostics. Despite their promising therapeutic and prophylactic potential, SeNPs also present several challenges, particularly regarding toxicity concerns. These challenges and their implications for clinical translation are thoroughly explored, providing a balanced view of the current state and prospects of SeNPs in theranostic applications.

Nano-selenium and compost vitalized morpho-physio-biochemical, antioxidants and osmolytes adjustment in soybean under tannery effluent polluted soil

The aim of this work was to investigate the impact of nano selenium (N-Se) and compost on the growth, photosynthesis, enzymes activity, compatible solutes and metals accumulation in soybean grown under tannery effluent polluted soil. The plants were exposed to compost application (no compost and compost addition) and foliar application of N-Se (0, 25, 50, and 75 mg L-1). The results showed the addition of compost in soil and foliar applied N-Se alleviated the toxic effect of tannery effluent polluted soil. Furthermore, foliar application of N-Se with basal compost supply significantly improved antoxidant enzymes activity in soybean grown in tannery effluent polluted soil. Addition of compost increased the root dry weight (46.43%) and shoot dry weight (33.50 %), relative water contents by (13.74 %), soluble sugars (15.99 %), stomatal conductance (gs) (83.33 %), intercellular CO2 concentration (Ci) (23.34 %), transpiration rate (E) (12.10 %) and decreased the electrolyte leakage (27.96 %) and proline contents by (20.34 %). The foliage application of N-Se at the rate of 75 mg L-1 showed the most promising results in control and compost amended tannery effluent polluted soil. The determined health risk index (HRI) values were recorded less than 1 for both adults and children under the application of compost and N-Se. In summary, the combined use of N-Se at 75 mg L⁻1 and basal supply of compost is an effective strategy for enhancing soybean productivity while minimizing the potential risks of metal accumulation in soybean grains grown in tannery effluent polluted soil.

Examining the Correlation between the Inorganic Nano-Fertilizer Physical Properties and Their Impact on Crop Performance and Nutrient Uptake Efficiency

The physical properties of nano-fertilizers (NFs) are important in determining their performance, efficacy, and environmental interactions. Nano-fertilizers, due to their small size and high surface area-to-volume ratio, enhance plant metabolic reactions, resulting in higher crop yields. The properties of nano-fertilizers depend on the synthesis methods used. The nanoparticle's nutrient use efficiency (NUE) varies among plant species. This review aims to analyze the relationship between the physical properties of NF and their influence on crop performance and nutrient uptake efficiency. The review focuses on the physical properties of NFs, specifically their size, shape, crystallinity, and agglomeration. This review found that smaller particle-sized nanoparticles exhibit higher nutrient use efficiency than larger particles. Nano-fertilizer-coated additives gradually release nutrients, reducing the need for frequent application and addressing limitations associated with chemical fertilizer utilization. The shapes of nano-fertilizers have varying effects on the overall performance of plants. The crystalline structure of nanoparticles promotes a slow release of nutrients. Amorphous nano-fertilizers improve the NUE and, ultimately, crop yield. Agglomeration results in nanoparticles losing their nanoscale size, accumulating on the outer surface, and becoming unavailable to plants. Understanding the physical properties of nano-fertilizers is crucial for optimizing their performance in agricultural applications.

Antioxidant and Hypoglycemic Potential of Phytogenic Selenium Nanoparticle- and Light Regime-Mediated In Vitro Caralluma tuberculata Callus Culture Extract

In vitro plant cultures have emerged as a viable source, holding auspicious reservoirs for medicinal applications. This study aims to delineate the antioxidant and hypoglycemic potential of phytosynthesized selenium nanoparticle (SeNP)- and light stress-mediated in vitro callus cultures of Caralluma tuberculata extract. The morphophysicochemical characteristics of biogenic SeNPs were assessed through a combination of analytical techniques, including UV-visible spectrophotometry, scanning electron microscopy, energy-dispersive X-rays, Fourier transform infrared spectrometry, and zeta potential spectroscopy. The antioxidative potential of the callus extract 200 and 800 μg/mL concentrations was assessed through various tests and exhibited pronounced scavenging potential in reducing power (26.29%), ABTS + scavenging (42.51%), hydrogen peroxide inhibition (37.26%), hydroxyl radical scavenging (40.23%), and phosphomolybdate (71.66%), respectively. To inspect the hypoglycemic capacity of the callus extract, various assays consistently demonstrated a dosage-dependent relationship, with higher concentrations of the callus extract exerting a potent inhibitory impact on the catalytic sites of the alpha-amylase (78.24%), alpha-glucosidase (71.55%), antisucrase (59.24%), and antilipase (74.26%) enzyme activities, glucose uptake by yeast cells at 5, 10, and 25 mmol/L glucose solution (72.18, 60.58 and 69.33%), and glucose adsorption capacity at 5, 10, and 25 mmol/L glucose solution (74.37, 83.55, and 86.49%), respectively. The findings of this study propose selenium NPs and light-stress-mediated in vitro callus cultures of C. tuberculata potentially operating as competitive inhibitors. The outcomes of the study were exceptional and hold promising implications for future medicinal applications.

Constructing network structures to enhance stability and target deposition of selenium nanoparticles via amphiphilic sodium alginate and alkyl glycosides

Dietary selenium (Se) supplementation has recently received increasing attention; however, Selenium nanoparticles (SeNPs) exhibit poor stability and tend to aggregate in aqueous solution. Therefore, enhancing the stability of SeNPs and their effective delivery to plants remain challenging. In this study, sodium alginate (SA) and lysozyme (LZ) were reacted via the wet-heat Maillard reaction (MR) to obtain amphiphilic alginate-based polymers (SA-LZ). Alkyl glycosides (APG) were introduced into SA-LZ to enhance the deposition of SeNPs in leaves. Thus, a renewable and degradable polysaccharide-based material (SA-LZ/APG) loaded with Se formed an amphiphilic alginate-based-based shell with a Se core. Notably, the encapsulation of SeNPs into a polysaccharide base (SA-LZ/APG) increased the stabilization of SeNPs and resulted in orange-red, zero-valent, monoclinic and spherical SeNPs with a mean diameter of approximately 43.0 nm. In addition, SA-LZ/APG-SeNPs reduced the interfacial tension of plant leaves and increased the Se content of plants compared to the blank group. In vitro studies have reported that SA-LZ/APG-SeNPs and SA-LZ-SeNPs have significantly better clearance of DDPH and ABTS than that of APG-SeNPs. Thus, we believe that SA-LZ/APG is a promising smart delivery system that can synergistically enhance the stability of SeNPs in aqueous solutions and improve the bioavailability of Se nutrient solutions.

Contributions of selenium-oxidizing bacteria to selenium biofortification and cadmium bioremediation in a native seleniferous Cd-polluted sandy loam soil

Selenium (Se) is a trace element that is essential for human health. Daily dietary Se intake is governed by the food chain through soil-plant systems. However, the cadmium (Cd) content tends to be excessive in seleniferous soil, in which Se and Cd have complex interactions. Therefore, it is a great challenge to grow crops containing appreciable amounts of Se but low amounts of Cd. We compared the effects of five Se-transforming bacteria on Se and Cd uptake by Brassica rapa L. in a native seleniferous Cd-polluted soil. The results showed that three Se-oxidizing bacteria (LX-1, LX-100, and T3F4) increased the Se content of the aboveground part of the plant by 330.8%, 309.5%, and 724.3%, respectively, compared to the control (p < 0.05). The three bacteria also reduced the aboveground Cd content by 15.1%, 40.4%, and 16.4%, respectively (p < 0.05). In contrast, the Se(IV)-reducing bacterium ES2-45 and weakly Se-transforming bacterium LX-4 had no effect on plant Se uptake, although they did decrease the aboveground Cd content. In addition, the three Se-oxidizing bacteria increased the Se available in the soil by 38.4%, 20.4%, and 24.0%, respectively, compared to the control (p < 0.05). The study results confirm the feasibility of using Se-oxidizing bacteria to simultaneously enhance plant Se content and reduce plant Cd content in seleniferous Cd-polluted soil.

Selenium Modification of Natural Products and Its Research Progress

The selenization of natural products refers to the chemical modification method of artificially introducing selenium atoms into natural products to interact with the functional groups in the target molecule to form selenides. Nowadays, even though scientists in fields involving organic selenium compounds have achieved numerous results due to their continuous investment, few comprehensive and systematic summaries relating to their research results can be found. The present paper summarizes the selenization modification methods of several kinds of important natural products, such as polysaccharides, proteins/polypeptides, polyphenols, lipids, and cyclic compounds, as well as the basic principles or mechanisms of the selenizing methods. On this basis, this paper explored the future development trend of the research field relating to selenized natural products, and it is hoped to provide some suggestions for directional selenization modification and the application of natural active ingredients.

Effect of Soil Acidification on the Production of Se-Rich Tea

Selenium (Se)-enriched tea is a well-regarded natural beverage that is often consumed for its Se supplementation benefits. However, the production of this tea, particularly in Se-abundant tea plantations, is challenging due to soil acidification. Therefore, this study aimed to investigate the effects of changes in Se under acidified soil conditions. Eight tea plantation soil monitoring sites in Southern Jiangsu were first selected. Simulated acid rain experiments and experiments with different acidification methods were designed and soil pH, as well as various Al-ion and Se-ion concentrations were systematically determined. The data were analyzed using R statistical software, and a correlation analysis was carried out. The results indicated that as the pH value dropped, exchangeable selenium (Exc-Se) and residual selenium (Res-Se) were transformed into acid-soluble selenium (Fmo-Se) and manganese oxide selenium (Om-Se). As the pH increased, exchange state aluminum (Alex) and water-soluble aluminum (Alw) decreased, Fmo-Se and Om-Se declined, and Exc-Se and Res-Se increased, a phenomenon attributed to the weakened substitution of Se ions by Al ions. In the simulated acid rain experiment, P1 compared to the control (CK), the pH value of the YJW tea plantation decreased by 0.13, Exc-Se decreased by 4 ug mg-1, Res-Se decreased by 54.65 ug kg-1, Fmo-Se increased by 2.78 ug mg-1, and Om-Se increased by 5.94 ug mg-1 while Alex increased by 28.53 mg kg-1. The decrease in pH led to an increase in the content of Alex and Alw, which further resulted in the conversion of Exc-Se to Fmo-Se and Om-Se. In various acidification experiments, compared with CK, the pH value of T6 decreased by 0.23, Exc-Se content decreased by 8.35 ug kg-1, Res-Se content decreased by 40.62 ug kg-1, and Fmo-Se content increased by 15.52 ug kg-1 while Alex increased by 33.67 mg kg-1, Alw increased by 1.7 mg kg-1, and Alh decreased by 573.89 mg kg-1. Acidification can trigger the conversion of Exc-Se to Fmo-Se and Om-Se, while the content of available Se may decrease due to the complexation interplay between Alex and Exc-Se. This study provides a theoretical basis for solving the problem of Se-enriched in tea caused by soil acidification.

Effects of High Doses of Selenate, Selenite and Nano-Selenium on Biometrical Characteristics, Yield and Biofortification Levels of Vicia faba L. Cultivars

Faba bean (Vicia faba L.) has spread worldwide as an excellent source of proteins. To evaluate the efficiency of Se biofortification, four cultivars of V. faba (Belorussian, Russian Black, Hangdown Grünkernig, and Dreifach Weiβe) were foliar treated with 1.27 mM solutions of nano-Se, sodium selenate, and sodium selenite. Yield, protein, and Se contents were greatly affected by genetic factors and chemical form of Se. Selenium biofortification levels were negatively correlated with Se concentration in control plants and increased according to the following sequence: nano-Se < sodium selenite < sodium selenate. Contrary to selenate and selenite, nano-Se showed a growth-stimulating effect, improving yield, seed weight, and pod number. Pod thickness decreased significantly as a result of nano-Se supply and increased by 1.5-2.3 times under selenate and selenite supply. The highest Se concentrations were recorded in the seeds of Se-fortified cv. Belorussian and the lowest one in those of Se-treated Hangdown Grünkernig. Protein accumulation was varietal dependent and decreased upon 1.27 mM selenate and selenite treatment in the cvs. Hangdown Grünkernig and Dreifach Weiβe. The results indicate the high prospects of nano-Se supply for the production of faba bean seeds with high levels of Se.