Phytogenic Selenium Nanoparticles Elicited the Physiological, Biochemical, and Antioxidant Defense System Amelioration of Huanglongbing-Infected ‘Kinnow’ Mandarin Plants

Antioxidant activity, metabolic profiling, in-silico molecular docking and ADMET analysis of nano selenium treated sesame seed bioactive compounds as potential novel drug targets against cardiovascular disease related receptors

Sesame (Sesamum indicum) is abundant in a diverse range of lignans, including sesamin, and γ-tocopherol, constituting a cluster of bioactive phenolic compound used for food and medicinal purposes. Cardiovascular diseases remain a leading global health challenge, demanding vigilant prevention and innovative treatments. This study was carried out to evaluate the effect of plant mediated SeNPs on sesame metabolic profile and to screen and check the effect bioactive compounds against CVD via molecular drug docking technique. Three sesame germplasms TS-5, TH-6 and Till-18 were treated with varying concentrations (10, 20, 30, 40 and 50 ppm) of plant-mediated selenium nanoparticles (SeNPs). There were three groups of treatments group-1 got only seed pretreatments of SeNPs, Group-2 with only foliar applications of SeNPs and Group-3 with both seed pretreatments and foliar applications of SeNPs. It was found that plants treated with 40 ppm of SeNPS in group 3 exhibited the highest total phenolic and flavonoid content. Total phenolic content at T4 was highest for TS-5 (134%), TH-6 (132%), and Till-18 (112%). LCMS analysis revealed a total of 276 metabolites, with phenolics, flavonoids, and free fatty acids being most abundant. KEGG analysis indicated enrichment in free fatty acid and phenylalanine tryptophan pathways. ADMET analysis and virtual screening resulted in total of five metabolic compounds as a potential ligand against Hemoglobin beta subunit. Lowest binding energy was achieved by Delta-Tocopherol (-6.98) followed by Lactoflavin (-6.20) and Sesamin (-5.00). Lipinski rule of five revealed that all the compounds completely safe to be used as drug against CVD and specifically for HBB. It was concluded that bioactive compounds from sesame could be an alternative source of drug for CVD related problems and especially for HBB.

Exposure of Caralluma tuberculata to biogenic selenium nanoparticles as in vitro rooting agent: Stimulates morpho-physiological and antioxidant defense system

The commercial-scale production of Caralluma tuberculata faces significant challenges due to lower seed viability and sluggish rate of root growth in natural conditions. To overcome these obstacles, using phyto-mediated selenium nanomaterials as an in vitro rooting agent in plant in vitro cultures is a promising approach to facilitate rapid propagation and enhance the production of valuable therapeutic compounds. This study aimed to investigate the impact of phytosynthesized selenium nanoparticles (SeNPs) on the morphological growth attributes, physiological status, and secondary metabolite fabrication in in vitro propagated Caralluma tuberculata. The results demonstrated that a lower dose of SeNPs (100 μg/L) along with plant growth regulators (IBA 1 mg/L) had an affirmative effect on growth parameters and promoted earliest root initiation (4.6±0.98 days), highest rooting frequency (68.21±5.12%), number of roots (6.3±1.8), maximum fresh weight (710±6.01 mg) and dry weight (549.89±6.77 mg). However, higher levels of SeNPs (200 and 400 μg/L) in the growth media proved detrimental to growth and development. Further, stress caused by SeNPs at 100 μg/L along with PGRs (IBA 1 mg/L) produced a higher level of total chlorophyll contents (32.66± 4.36 μg/ml), while cultures exposed to 200 μg/L SeNPs alone exhibited the maximum amount of proline contents (10.5± 1.32 μg/ml). Interestingly, exposure to 400 μg/L SeNPs induced a stress response in the cultures, leading to increased levels of total phenolic content (3.4 ± 0.052), total flavonoid content (1.8 ± 0.034), and antioxidant activity 82 ± 4.8%). Furthermore, the combination of 100 μg/L SeNPs and plant growth regulators (1 mg/L IBA) led to accelerated enzymatic antioxidant activities, including superoxide dismutase (SOD = 4.4 ± 0.067 U/mg), peroxidase dismutase (POD = 3.3 ± 0.043 U/mg), catalase (CAT = 2.8 ± 0.048 U/mg), and ascorbate peroxidase (APx = 1.6 ± 0.082 U/mg). This is the first report that highlights the efficacy of SeNPs in culture media and presents a promising approach for the commercial propagation of C. tuberculata with a strong antioxidant defense system in vitro.

Special Issue Physiological and Molecular Responses of Plants to Engineered Nanomaterials

Engineered nanomaterials (ENMs), by definition materials with a size between 1 and 100 nm, are becoming an important part of the economy and thanks to their many fields of applications, from photovoltaic cells to fertilizers, are increasingly coming into contact with plants and with the environment in general [...].

Modulations of wheat growth by selenium nanoparticles under salinity stress

Salinity stress is a prominent environmental factor that presents obstacles to the growth and development of plants. When the soil contains high salt concentrations, the roots face difficulties in absorbing water, resulting in water deficits within the plant tissues. Consequently, plants may experience inhibited growth, decreased development, and a decline in biomass accumulation. The use of nanoparticles has become a popular amendment in recent times for the alleviation of salinity stress. The study investigated the biological approach for the preparation of Se nanoparticles (NP) and their effect on the growth of wheat plants under saline conditions. The leaf extract of lemon (Citrus limon L.) was used for the green synthesis of selenium nanoparticles (Se-NPs). The synthesized NPs were characterized by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) and were applied foliar in the range of 0.01%, 0.05% and 0.1% on wheat plants. Results showed that 0.1% SeNP alone exhibited a significantly higher yield per plant, biomass per plant, 1000 grains weight, chlorophyll a, chlorophyll b and total chlorophyll over the SS (salt stress) control. A significant decline in MDA and H2O2 also validated the effectiveness of 0.1% SeNP over the SS control.

From nature to nanotechnology: The interplay of traditional medicine, green chemistry, and biogenic metallic phytonanoparticles in modern healthcare innovation and sustainability

As we navigate the modern era, the intersection of time-honoured natural remedies and contemporary scientific approaches forms a burgeoning frontier in global healthcare. For generations, natural products have been foundational to health solutions, serving as the primary healthcare choice for 80% to 85% of the world's population. These herbal-based, nature-derived substances, significant across diverse geographies, necessitate a renewed emphasis on enhancing their quality, efficacy, and safety. In the current century, the advent of biogenic phytonanoparticles has emerged as an innovative therapeutic conduit, perfectly aligning with principles of environmental safety and scientific ingenuity. Utilizing green chemistry techniques, a spectrum of metallic nanoparticles including elements such as copper, silver, iron, zinc, and titanium oxide can be produced with attributes of non-toxicity, sustainability, and economic efficiency. Sophisticated herb-mediated processes yield an array of plant-originated nanomaterials, each demonstrating unique physical, chemical, and biological characteristics. These attributes herald new therapeutic potentials, encompassing antioxidants, anti-aging applications, and more. Modern technology further accelerates the synthesis of natural products within laboratory settings, providing an efficient alternative to conventional isolation methods. The collaboration between traditional wisdom and advanced methodologies now signals a new epoch in healthcare. Here, the augmentation of traditional medicine is realized through rigorous scientific examination. By intertwining ethical considerations, cutting-edge technology, and natural philosophy, the realms of biogenic phytonanoparticles and traditional medicine forge promising pathways for research, development, and healing. The narrative of this seamless integration marks an exciting evolution in healthcare, where the fusion of sustainability and innovation crafts a future filled with endless possibilities for human well-being. The research in the development of metallic nanoparticles is crucial for unlocking their potential in revolutionizing fields such as medicine, catalysis, and electronics, promising groundbreaking applications with enhanced efficiency and tailored functionalities in future technologies. This exploration is essential for harnessing the unique properties of metallic nanoparticles to address pressing challenges and advance innovations across diverse scientific and industrial domains.

Nano-selenium enhances melon resistance to Podosphaera xanthii by enhancing the antioxidant capacity and promoting alterations in the polyamine, phenylpropanoid and hormone signaling pathways

Powdery mildew is one of the main problematic diseases in melon production, requiring the use of chemical pesticides with disease-resistant cultivars for control. However, the often rapid acquisition of fungicidal resistance by mildew pathogens makes this practice unsustainable. The identification of crop treatments that can enhance resistance to powdery mildew resistance is therefore important to reduce melon crop attrition. This study indicates that the application of Nano-Se can reduce the powdery mildew disease index by 21-45%. The Nano-Se treatment reduced reactive oxygen species (ROS) and malondialdehyde (MDA) accumulation, with increases in glutathione (GSH), proline and 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH). Increases were also observed in the activities and transcriptional levels of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD). Assays with four different cultivars of melon with differing levels of mildew resistance demonstrated that relative to the control, the Nano-Se treatment resulted in larger responses to mildew infection, including increases in the levels of putrescine (PUT; 43-112%) and spermine (SPM; 36-118%), indoleacetic acid (IAA; 43-172%) and salicylic acid (SA; 24-73%), the activities of phenylalanine ammonium lyase (PAL), trans-cinnamate 4-hydroxylase (C4H) and 4-coumarate: Co A ligase (4CL) of the phenylpropanoid pathway (22-38%, 24-126% and 19-64%, respectively). Key genes in the polyamine and phenylpropanoid pathway were also upregulated. These results indicate that the foliar application of Nano-Se improved melon defenses against powdery mildew infection, with a significant reduction in mildew disease development.

Phytomediated selenium nanoparticles and light regimes elicited in vitro callus cultures for biomass accumulation and secondary metabolite production in Caralluma tuberculata

Introduction

Caralluma tuberculata holds significant importance as a medicinal plant due to its abundance of bioactive metabolites, which offer a wide range of therapeutic potentials. However, the sustainable production of this plant is challenged by overexploitation, changes in natural conditions, slow growth rate, and inadequate biosynthesis of bioactive compounds in wild populations. Therefore, the current study was conducted to establish an in vitro based elicitation strategy (nano elicitors and light regimes) for the enhancement of biomass and production of secondary metabolites.

Methods

Garlic clove extract was employed as a stabilizing, reducing, or capping agent in the green formulation of Selenium nanoparticles (SeNPs) and various physicochemical characterization analyses such as UV visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-Ray (EDX) Spectroscopy, fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were performed. Furthermore, the effects of phytosynthesized SeNPs at various concentrations (0, 50, 100, 200, and 400 µg/L on callus proliferation and biosynthesis of medicinal metabolites under different light regimes were investigated.

Results and discussion

Cultures grown on Murashige and Skoog (MS) media containing SeNPs (100 µg/L), in a dark environment for two weeks, and then transferred into normal light, accumulated maximum fresh weight (4,750 mg/L FW), phenolic contents (TPC: 3.91 mg/g DW), flavonoid content (TFC: 2.04 mg/g DW) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity (85%). Maximum superoxide dismutase (SOD: 4.36 U/mg) and peroxide dismutase activity (POD: 3.85 U/mg) were determined in those cultures exposed to SeNPs (100 µg/L) under complete dark conditions. While the callus cultures proliferate on media augmented with SeNPs (200 µg/L) and kept under dark conditions for two weeks and then shifted to normal light conditions exhibited the highest catalase (CAT: 3.25 U/mg) and ascorbate peroxidase (APx: 1.93 U/mg) activities. Furthermore, LC-ESI-MS/MS analysis confirmed the effects of SeNPs and light conditions that elicited the antidiabetic metabolites (cumarins, gallic acid, caffeic acid, ferulic acid, catechin, querctin and rutin). This protocol can be scaled up for the industrial production of plant biomass and pharmacologically potent metabolites using in vitro callus cultures of C. tuberculata.

Opportunities for the use of selenium nanoparticles in agriculture

Due to the growing number of the world's population, there is an urgent need for high-quality food to meet global food security. Traditional fertilizers and pesticides face the problems of low utilization efficiency and possible hazards to non-target organisms. Selenium (Se) is an essential trace element for animals and humans. As a result, Se nanoparticles (SeNPs) have aroused intense interest and found opportunities in agricultural use. Herein, we summarized representative studies on the potential application of SeNPs in agriculture, including mitigating biotic and abiotic stresses in plants, promoting seed germination and plant growth, and improving Se contents and nutritional values in crops, and the underlying mechanisms were also discussed. Finally, future directions are highlighted to get a deep insight into this field.

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

Selenium (Se) is a microelement that plays an important nutrient role by influencing various physiological and biochemical traits in plants. It has been shown to stimulate plant metabolism, enhancing secondary metabolites and lowering abiotic and biotic stress in plants. Globally, the enormous applications of nanotechnology in the food and agricultural sectors have vastly expanded. Nanoselenium is more active than bulk materials, and various routes of synthesis of Se nanoparticles (Se-NPs) have been reported in which green synthesis using plants is more attractive due to a reduction in ecological issues and an increase in biological activities. The Se-NP-based biofortification is more significant because it increases plant stress tolerance and positively impacts their metabolism. Se-NPs can enhance plant resistance to various oxidative stresses, promote growth, enhance soil nutrient status, enhance plant antioxidant levels, and participate in the transpiration process. Additionally, they use a readily available, biodegradable reducing agent and are ecologically friendly. This review concentrates on notable information on the different modes of Se-NPs' synthesis and characterization, their applications in plant growth, yield, and stress tolerance, and their influence on the metabolic process.

A Review of Sustainable Use of Biogenic Nanoscale Agro-Materials to Enhance Stress Tolerance and Nutritional Value of Plants

Climate change is more likely to have a detrimental effect on the world's productive assets. Several undesirable conditions and practices, including extreme temperature, drought, and uncontrolled use of agrochemicals, result in stresses that strain agriculture. In addition, nutritional inadequacies in food crops are wreaking havoc on human health, especially in rural regions of less developed countries. This could be because plants are unable to absorb the nutrients in conventional fertilizers, or these fertilizers have an inappropriate or unbalanced nutrient composition. Chemical fertilizers have been used for centuries and have considerably increased crop yields. However, they also disrupt soil quality and structure, eventually impacting the entire ecosystem. To address the situation, it is necessary to develop advanced materials that can release nutrients to targeted points in the plant-soil environment or appropriate receptors on the leaf in the case of foliar applications. Recently, nanotechnology-based interventions have been strongly encouraged to meet the world's growing food demand and to promote food security in an environmentally friendly manner. Biological approaches for the synthesis of nanoscale agro-materials have become a promising area of research, with a wide range of product types such as nanopesticides, nanoinsecticides, nanoherbicides, nanobactericides/fungicides, bio-conjugated nanocomplexes, and nanoemulsions emerging therefrom. These materials are more sustainable and target-oriented than conventional agrochemicals. In this paper, we reviewed the literature on major abiotic and biotic stresses that are detrimental to plant growth and productivity. We comprehensively discussed the different forms of nanoscale agro-materials and provided an overview of biological approaches in nano-enabled strategies that can efficiently alleviate plant biotic and abiotic stresses while potentially enhancing the nutritional values of plants.

Phytomediated Selenium Nanoparticles Improved Physio-morphological, Antioxidant, and Oil Bioactive Compounds of Sesame under Induced Biotic Stress

Vegetable oil consumption is expected to reach almost 200 billion kilograms by 2030 in the world and almost 2.97 million tons in Pakistan. A large quantity of edible oil is imported annually from other countries to fill the gap between local production and consumption. Compared to other edible oil crops such as soybean, rapeseed, peanut and olive, sesame has innately higher (55%) oil content, which makes it an excellent candidate to be considered to meet local edible oil production. Oil seed crops, especially sesame, are affected by various pathogens, which results in decreased oil production with low quality oil. Selenium nanoparticles (SeNPs) work synergistically, as it has antifungal activity along with improving plant growth. Different concentrations of SeNPs were used, on three different varieties of sesame (TS-5, TH-6, and Till-18). Plant growth and development were accelerated by SeNPs, which ultimately led to an increase in crop yield. Morphological parameters revealed that SeNPs resulted in a growth increase of 55.7% in root length, 48% increase in leaf number/plant, and 38% in stem diameter. Out of three sesame varieties, TS-5 seedlings treated with 40 mg/L SeNPs showed 96.7% germination and 53% SVI at 40 mg/L. Sesame varieties dramatically increased antioxidant capability using SeNPs, resulting in 147% increase in SOD and 140% increase in POD enzyme units in TH-6 and 76% elevation in CAT enzymes in TS-5 (mean ± S.E). GCMS analysis revealed that bioactive compound I, sesamin, sesamol, and tocopherol contents were increased along with enhanced production of different unsaturated fatty acids. Kegg pathway analysis and MSEA revealed that these compounds were mainly involved in biosynthesis of unsaturated fatty acids, suggesting that SeNPs have elicited the biosynthesis of unsaturated fatty acids such as oleic acid, linoleic acid, and α-linoleic acid. This study concluded that SeNPs (40 mg/L) have an excellent capability to be used for crop improvement along with better oil quality.

Comparative Study of Antimicrobial and Antioxidant Potential of Olea ferruginea Fruit Extract and Its Mediated Selenium Nanoparticles

Nanotechnology, the science of the recent era, has diverse applications in agriculture. Selenium (Se) is a non-metal and an essential micronutrient for animals and humans. In this study, selenium nanoparticles (SeNPs) were biosynthesized by using Olea ferruginea fruit extracts. The size, shape, chemical nature, and identification of functional groups involved in the synthesis of SeNPs were studied by UV-visible spectroscopy, Scanning Electron Microscope (SEM), and Fourier Transform Infra-Red (FTIR) spectrometry. SeNP synthesis was confirmed by an absorption peak at 258 nm by UV-visible spectroscopy. SEM showed that SeNPs were spherical, smooth, and between 60 and 80 nm in size. FTIR spectrometry confirmed the presence of terpenes, alcohols, ketones, aldehydes, and esters as well as phyto-constituents, such as alkaloids and flavonoids, that possibly act as reducing or capping agents of SeNPs in an aqueous solution of Olea ferruginea. Antimicrobial activity was examined against bacterial pathogens, such as Klebsiella pneumonia, Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermitis, as well as fungal pathogens, such as Aspergillus niger and Fusarium oxysporum, by using the well-diffusion method. Antioxidant activity was observed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, ABTs assay, and reducing power assay. At a higher concentration of 400 ppm, biosynthesized SeNPs showed an inhibition zone of 20.5 mm, 20 mm, 21 mm, and 18.5 mm against Klebsiella pneumonia, Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermitis, respectively. Similarly, SeNPs also demonstrated a zone of inhibition against Aspergillus niger and Fusarium oxysporum of 17.5 and 21 mm, respectively. In contrast to Olea ferruginea fruit extracts, Olea ferruginea-mediated SeNPs demonstrated strong antimicrobial activity. By performing the DPPH, ABTs, and reducing power assay, SeNPs showed 85.2 ± 0.009, 81.12 ± 0.007, and 80.37 ± 0.0035% radical scavenging potential, respectively. The present study could contribute to the drug development and nutraceutical industries.

Unveiling Antimicrobial and Insecticidal Activities of Biosynthesized Selenium Nanoparticles Using Prickly Pear Peel Waste

In the current study, prickly pear peel waste (PPPW) extract was used for the biosynthesis of selenium nanoparticles through a green and eco-friendly method for the first time. The biosynthesized SeNPs were characterized using UV-Vis, XRD, FTIR, TEM, SEM, EDX, and mapping. Characterization results revealed that biosynthesized SeNPs were spherical, polydisperse, highly crystalline, and had sizes in the range of 10–87.4 nm. Antibacterial, antifungal, and insecticidal activities of biosynthesized SeNPs were evaluated. Results revealed that SeNPs exhibited promising antibacterial against Gram negative (E. coli and P. aeruginosa) and Gram positive (B. subtilis and S. aureus) bacteria where MICs were 125, 125, 62.5, and 15.62 µg/mL, respectively. Moreover, SeNPs showed potential antifungal activity toward Candida albicans and Cryptococcus neoformans where MICs were 3.9 and 7.81 µg/mL, respectively. Furthermore, tested crud extract and SeNPs severely induced larvicidal activity for tested mosquitoes with LC50 and LC90 of 219.841, 950.087 mg/L and 75.411, 208.289 mg/L, respectively. The fecundity and hatchability of C. pipiens mosquito were significantly decreased as applied concentrations increased either for the crude or the fabricated SeNPs extracts. In conclusion, the biosynthesized SeNPs using prickly pear peel waste have antibacterial, antifungal, and insecticidal activities, which can be used in biomedical and environmental applications.

Green Biosynthesis of Selenium Nanoparticles Using Orange Peel Waste: Characterization, Antibacterial and Antibiofilm Activities against Multidrug-Resistant Bacteria

There is an increase of pathogenic multidrug-resistant bacteria globally due to the misuse of antibiotics. Recently, more scientists used metal nanoparticles to counteract antibacterial resistance. In this study, orange peel waste (OPW) was used for selenium nanoparticles’ (Se-NPs) biosynthesis through the green and ecofriendly method, and their applications as antibacterial and antibiofilm agents. Green biosynthesized Se-NPs were characterized using FTIR, XRD, SEM, EDAX, and TEM. Characterization results revealed that biosynthesized Se-NPs were highly crystalline, spherical, and polydisperse, and had sizes in the range of 16–95 nm. The biosynthesized Se-NPs were evaluated as antibacterial and antibiofilm activities against multidrug-resistant bacteria. Results illustrated that Se-NPs exhibited potential antibacterial activity against Gram-positive bacteria (S. aureus ATCC 29213 and biofilm-producing clinical isolates of S. aureus) and Gram-negative bacteria (Pseudomonas aeruginosa PAO1, MDR, biofilm, and quorum-sensing and producing clinical isolates of MDR P. aeruginosa, MDR E. coli, and K. pneumonia). Moreover, results illustrated that S. aureus ATCC 29213 was the most sensitive bacteria to Se-NPs at 1000 µg/mL, where the inhibition zone was 35 mm and MIC was 25 µg/mL. Furthermore, Se-NPs at 0.25 and 0.5 MIC decreased the biofilm significantly. The largest inhibition of biofilm was noticed in MDR K. pneumonia, which was 62% and 92% at 0.25 and 0.5 MIC, respectively. In conclusion, Se-NPs were successfully biosynthesized using OPW through the green method and had promising antibacterial and antibiofilm activity against multidrug-resistant bacteria, which can be used later in fighting resistant bacteria.