Green Synthesized Se Nanoparticle-mediated Alleviation of Salt Stress in Field Mustard TS-36 Variety

Lignin-containing cellulose nanofiber-selenium nanoparticle hybrid enhances tolerance to salt stress in rice genotypes

Soil salinization poses a significant challenge for rice farming, affecting approximately 20% of irrigated land worldwide. It leads to osmotic stress, ionic toxicity, and oxidative damage, severely hindering growth and yield. This study investigates the potential of lignin-containing cellulose nanofiber (LCNF)-selenium nanoparticle (SeNPs) hybrids to enhance salt tolerance in rice, focusing on two rice genotypes with contrasting responses to salt stress. LCNF-SeNP hybrids were synthesized using a microwave-assisted green synthesis method and characterized through FTIR, X-ray diffraction, SEM, TEM, and TGA. The effects of LCNF/SeNPs on seed germination, physiological responses, and gene expression were evaluated under varying levels of NaCl-induced salt stress. Results indicated that LCNF/SeNPs significantly enhanced the salt tolerance of the salt-sensitive genotype IR29, as evidenced by increased germination rates, reduced salt injury scores, and higher chlorophyll content. For the salt-tolerant genotype TCCP, LCNF/SeNPs improved shoot lengths and maintained elevated chlorophyll levels under salt stress. Furthermore, LCNF/SeNPs improved ion homeostasis in both genotypes by reducing the Na+/K+ ratio, which is crucial for maintaining cellular function under salt stress. Gene expression analysis revealed upregulation of key salt stress-responsive genes, suggesting enhanced stress tolerance due to the application of LCNF/SeNPs in both genotypes. This study underscores the potential of LCNF/SeNPs as a sustainable strategy for improving crop performance in saline environments.

Eco-Friendly Synthesis of Selenium Nanoparticles via Sternbergia candida: Enhancing Antioxidant Defense and Mitigating Salt Stress in Pepper (Capsicum annuum L.) Plants

Nanoparticles enhance agricultural applications with their bioactivity, bioavailability, and reactivity. Selenium mitigates the adverse effects of salinity on plant growth, boosting antioxidant defense, metabolism, and resilience to abiotic stress. Our study applied selenium nanoparticles to mitigate salinity-induced damage and support plant growth. We characterized green-synthesized nanoparticles and analyzed stress-related metabolites, antioxidant activities (DPPH, ABTS), phenolic content, and reducing powers (CUPRAC, FRAP). Nanoparticle applications reduced proline and MDA levels while boosting chlorophyll, carotenoids, antioxidant activity (DPPH, ABTS), and total phenolic content. An increase was also observed in CUPRAC and FRAP reducing capacities. In terms of phenolic content, the highest value was determined in SA1 (4.58±0.40 mg GAE g-1) application; DPPH free radical scavenging activity IC50 value was determined in A3 (0.13±0.007 mg mL-1) application, which was closest to the positive control. The lowest proline level was found in A3 (15.00±0.64 nmol g-1 FW) and the lowest MDA level was found in SA3 (10.08±0.42 nmol g-1). Comparing the results, green synthesis of selenium nanoparticles using Sternbergia candida (SC-SeNP) at different concentrations showed ameliorative effects on various parameters in plants, and it was determined that the effects of salt stress on pepper plants were reduced following SC-SeNP applications.

Antibacterial activity of selenium nanoparticles/copper oxide (SeNPs/CuO) nanocomposite against some multi-drug resistant clinical pathogens

BACKGROUND

Recent advances in nanomedicine have derived novel prospects for development of various bioactive nanoparticles and nanocomposites with significant antibacterial and antifungal properties. This study aims to investigate some characteristics of the novel Se-NPs/Cu2O nanocomposite such as morphological, physicochemical, and optical properties, as well as to assess the antibacterial activity of this fabricated composite in different concentrations against some MDR Gram-positive and Gram-negative clinical bacterial isolates.

METHODS

The Se-NPs/Cu2O nanocomposite was fabricated using the chemical deposition method. The fabricated nanocomposite was fully characterized by X-Ray diffraction analysis (XRD), fourier transforms infrared spectroscopy (FTIR), and transmission electron microscope (TEM). The antimicrobial activity of Se-NPs/Cu2O was investigated using the standard broth microdilution method. The fabricated Se-NPs/Cu2O nanocomposites were detected as stable and highly crystallized nanospheres with an average size of 98.6 nm.

RESULTS

The Se-NPs/Cu2O nanocomposite showed a potent antimicrobial activity with MIC values ranged from 6.25 to 12.5 µg/ml for Gram-positive isolates, and 25 to 50 µg/ml for gram-negative isolates. The bactericidal activity was higher for gram-negative isolates with MBC/MIC ratios of 1-2 µg/ml for gram-negative, versus 8 µg/ml for gram positive pathogens.

CONCLUSION

These findings would support further research in development of a novel Se-NPs/Cu2O nanocomposite as a promising alternative therapeutic option for improving the quality of patients' management.

Selenium - An environmentally friendly micronutrient in agroecosystem in the modern era: An overview of 50-year findings

Agricultural productivity is constantly being forced to maintain yield stability to feed the enormously growing world population. However, shrinking arable and nutrient-deprived soil and abiotic and biotic stressor (s) in different magnitudes put additional challenges to achieving global food security. Though well-defined, the concept of macro, micronutrients, and beneficial elements is from a plant nutritional perspective. Among various micronutrients, selenium (Se) is essential in small amounts for the life cycle of organisms, including crops. Selenium has the potential to improve soil health, leading to the improvement of productivity and crop quality. However, Se possesses an immense encouraging phenomenon when supplied within the threshold limit, also having wide variations. The supplementation of Se has exhibited promising outcomes in lessening biotic and abiotic stress in various crops. Besides, bulk form, nano-Se, and biogenic-Se also revealed some merits and limitations. Literature suggests that the possibilities of biogenic-Se in stress alleviation and fortifying foods are encouraging. In this article, apart from adopting a combination of a conventional extensive review of the literature and bibliometric analysis, the authors have assessed the journey of Se in the "soil to spoon" perspective in a diverse agroecosystem to highlight the research gap area. There is no doubt that the time has come to seriously consider the tag of beneficial elements associated with Se, especially in the drastic global climate change era.

Expression of sucrose metabolizing enzymes in different sugarcane varieties under progressive heat stress

Studying the thermal stress effect on sucrose-metabolizing enzymes in sugarcane is of great importance for understanding acclimation to thermal stress. In this study, two varieties, S2003-US-633 and SPF-238, were grown at three different temperatures ( ± 2°C): 30°C as a control, 45°C for various episodes of high temperature treatments and recovery conditions at 24, 48 and 72 hours. Data showed that reducing sugar content increased until the grand growth stage but sharply declined at the maturity stage in both cultivars. On the other hand, sucrose is enhanced only at the maturity stage. The expression of all invertase isozymes declined prominently; however, the expression of SPS was high at the maturity stage. Hence, the sucrose accumulation in mature cane was due to increased SPS activity while decreased invertase isozymes (vacuolar, cytoplasmic and cell wall) activities at maturity stage in both cultivars. Heat shock decreased the sucrose metabolizing enzymes, sucrose content and sugar recovery rate in both cultivars. In contrast, heat-shock treatments induced maximum proline, MDA, H2O2 and EC in both cultivars. Notably, this is the first report of diverse invertase isozyme molecular weight proteins, such as those with 67, 134 and 160 kDa, produced under heat stress, suggesting that these enzymes have varied activities at different developmental stages. Overall, S2003-US-633 performs better than the cultivar SPF-238 under heat stress conditions at all development stages, with increased sucrose content, enzyme expression, proline and sugar recovery rate. This work will provide a new avenue regarding sugarcane molecular breeding programs with respect to thermal stress.

Review on Pesticide Abiotic Stress over Crop Health and Intervention by Various Biostimulants

Plants are essential for life on earth, and agricultural crops are a primary food source for humans. For the One Health future, crop health is crucial for safe, high-quality agricultural products and the development of future green commodities. However, the overuse of pesticides in modern agriculture raises concerns about their adverse effects on crop resistance and product quality. Recently, biostimulants, including microecological bacteria agents and nanoparticles, have garnered worldwide interest for their ability to sustain plant health and enhance crop resistance. This review analyzed the effects and mechanisms of pesticide stress on crop health. It also investigated the regulation of biostimulants on crop health and the multiomics mechanism, combining research on nanoselenium activating various crop health aspects conducted by the authors' research group. The paper helps readers understand the impact of pesticides on crop health and the positive influence of various biostimulants, especially nanomaterials and small molecules, on crop health.