Gold nanoparticle exposure induces growth and yield enhancement in Arabidopsis thaliana

Exploring the anticancer and antioxidant potential of gold nanoparticles synthesized from Pterocarpus marsupium bark extract against oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a disease of significant concern with higher mortality rates. Conventional treatment approaches have several drawbacks, leading to the opening of new research avenues in the field of nanoparticle-based cancer therapeutics. The study aimed at the synthesis of gold nanoparticles (Pm-AuNPs) from the aqueous bark extract of Pterocarpus marsupium, followed by its characterization and in vitro anticancer evaluation against OSCC. The synthesized Pm-AuNPs were characterized using UV-visible spectroscopy, particle size analyser, zeta potential, FTIR and SEM techniques. The anticancer potential of the Pm-AuNPs was evaluated against OSCC cell lines (SCC29b, SSC154 and OECM-1) through in vitro assays. The IC50 value was found to be 25 ± 1.2, 45 ± 1.5 and 75 ± 2.1 µg/mL for the three OSCC cell lines, elucidating Pm-AuNPs cytotoxic effects and mechanism of action. Intracellular ROS and SOX detection, mitochondrial transmembrane potential analysis and apoptosis detection were used to confirm the activity of Pm-AuNPs against OSCC. Acute toxicity studies on Wistar rats confirmed the non-toxic nature of the Pm-AuNPs at a higher dose concentration up to 2000 mg/kg body weight. The findings underscore Pm-AuNPs as promising candidates for future anticancer therapeutics, providing insights into their mechanism of action and therapeutic efficacy against OSCC.

Nanoprimers in sustainable seed treatment: Molecular insights into abiotic-biotic stress tolerance mechanisms for enhancing germination and improved crop productivity

Abiotic and biotic stresses during seed germination are typically managed with conventional agrochemicals, known to harm the environment and reduce crop yields. Seeking sustainable alternatives, nanotechnology-based agrochemicals leverage unique physical and chemical properties to boost seed health and alleviate stress during germination. Nanoprimers in seed priming treatment are advanced nanoscale materials designed to enhance seed germination, growth, and stress tolerance by delivering bioactive compounds and nutrients directly to seeds. Present review aims to explores the revolutionary potential of nanoprimers in sustainable seed treatment, focusing on their ability to enhance crop productivity by improving tolerance to abiotic and biotic stresses. Key objectives include understanding the mechanisms by which nanoprimers confer resistance to stresses such as drought, salinity, pests, and diseases, and assessing their impact on plant physiological and biochemical pathways. Key findings reveal that nanoprimers significantly enhance seedling vigor and stress resilience, leading to improved crop yields. These advancements are attributed to the precise delivery of nanomaterials that optimize plant growth conditions and activate stress tolerance mechanisms. However, the study also highlights the importance of comprehensive toxicity and risk assessments. Current review presents a novel contribution, highlighting both the advantages and potential risks of nanoprimers by offering a comprehensive overview of advancements in seed priming with metal and metal oxide nanomaterials, addressing a significant gap in the existing literature. By delivering advanced molecular insights, the study underscores the transformative potential of nanoprimers in fostering sustainable agricultural practices and responsibly meeting global food demands.

Nanomaterials in plant physiology: Main effects in normal and under temperature stress

Global climate change and high population growth rates lead to problems of food security and environmental pollution, which require new effective methods to increase yields and stress tolerance of important crops. Nowadays the question of using artificial chemicals is very relevant in theoretical and practical terms. It is important that such substances in low concentrations protect plants under stress conditions, but at the same time inflict minimal damage on the environment and human health. Nanotechnology, which allows the production of a wide range of nanomaterials (NM), provides novel techniques in this direction. NM include structures less than 100 nm. The review presents data on the methods of NM production, their properties, pathways for arrival in plants and their use in human life. It is shown that NM, due to their unique physical and chemical properties, can cross biological barriers and accumulate in cells of live organisms. The influence of NM on plant organism can be both positive and negative, depending on the NM chemical nature, their size and dose, the object of study, and the environmental conditions. This review provides a comparative analysis of the effect of artificial metal nanoparticles (NPm), the commonly employed NMs in plant physiology, on two important aspects of plant life: photosynthetic apparatus activity and antioxidant system function. According to studies, NM affect not only the functional activity of photosynthetic apparatus, but also structural organization of chloroplats. In addition, the literature analysis reflects the dual action of NM on oxidative processes, and antioxidant status of plants. These facts considerably complicate the ideas about possible mechanisms and further use of NPm in biology. In this regard, data on the effects of NM on plants under abiotic stressors are of great interest. Separate section is devoted to the use of NM as adaptogens that increase plant stress tolerance to unfavorable temperatures. Possible mechanisms of NM effects on plants are discussed, as well as the strategies for their further use in basic science and sustainable agriculture.

Nanopriming boost seed vigor: Deeper insights into the effect mechanism

Nanopriming, an advanced seed priming technology, is highly praised for its environmental friendliness, safety, and effectiveness in promoting sustainable agriculture. Studies have shown that nanopriming can enhance seed germination by stimulating the expression of aquaporins and increasing amylase production. By applying an appropriate concentration of nanoparticles, seeds can generate reactive oxygen species (ROS), enhance their antioxidant capacity, improve their response to oxidative stress, and enhance their tolerance to both biotic and abiotic stresses. This positive impact extends beyond the seed germination and seedling growth stages, persisting throughout the entire life cycle. This review offers a comprehensive overview of recent research progress in seed priming using various nanoparticles, while also addressing current challenges and future opportunities for sustainable agriculture.

The influence of Au-based nanoparticles on some physiological, biochemical and molecular characteristics of wheat plants during low temperature hardening

One of the most significant problems of the 21st century is the anthropogenic strain on the environment. The development of nanotechnology makes it possible to produce a variety of nanomaterials widely used in people's daily lives. However, nanomaterials can accumulate in ecosystems and spread through food chains. The environmental risks of nanoparticle proliferation are unclear. At the same time, certain nanoparticles act as adaptogens, improving plant tolerance to unfavorable stress factors. It is quite realistic to choose such experimental conditions, under which the effect on plant stress tolerance will be obvious and the accumulation of nanoparticles in tissues will be minimal. In this case, the main relevant factors are the type of nanoparticles, their concentration and their way of penetration into plants. We chose to study gold nanoparticles (Au-NPs), widely used in biomedical research. The concentration of Au-NPs was 20 μg/mL, which is considered safe for living organisms. The influence of Au-NPs on some physiological, biochemical and molecular characteristics of wheat plants during low temperature hardening was examined. The study of the photosynthetic apparatus and antioxidant system was the primary focus. The stimulating effect of Au-NPs on cold tolerance of wheat plants was shown. The results expand our knowledge of the processes by which nanoparticles impact plants and the potential applications of nanoparticles as adaptogens in science and agriculture.

Se-functionalized ZIF-8 nanoparticles: synthesis, characterization and disruption of biofilms and quorum sensing inSerratia marcescens

The majority of research on nanomaterials has been concentrated on metal nanoparticles since they are easily made and manipulated. Nanomaterials have shown a wide range of applications in biology. Nevertheless, their bioactivity declines due to their extreme susceptibility to and novel Se@ZIF-8 by chemical method. The sizes and morphologies of Se (0) and Se@ZIFchemical and physical stimuli. The goal of encapsulating these nanomaterials in a matrix is gradually being pursued, which boosts their affordability, stability, and usability. Metal-organic frameworks, often known as MOFs, have the potential to be the best platforms for encapsulating metal nanoparticles due to their well-defined frameworks, persistent porosity, and flexibility in modification. In this investigation, we report the synthesis and optimization of polyvinylpyrrolidone-stabilized Se(0) nanoparticles -8 were affected by the ratios of Se/Zn2+and [hmim]/Zn2+used. The optimized Se@ZIF-8 nanoparticles exhibited a particle size and zeta potential of 319 nm and -34 mv respectively. Transmission electron microscopy displayed spherical morphology for Se(0) nanoparticles, whereas the surface morphology of novel Se@ZIF-8 nanoparticles was drastically changed to hexagonal shaped structures with smooth surface morphologies in scanning electron microscopy (SEM). The DTA, TG/DTG, XRD analysis confirmed the presence of novel Se incorporated ZIF-8 nanoparticulate framework. The synthesized novel Se@ZIF-8 nanoparticles showed efficient antibacterial activity as evidenced by low MIC values. Interestingly, these Se@ZIF-8 NPs not only inhibited biofilm formation inS. marcescens,but also effectively eradicated mature biofilms by degrading the eDNA of the EPS layer. It was validated by confocal laser scanning microscopy and SEM analysis. It was observed that Se@ZIF-8 targeted the Quroum Sensing pathway and reduced its associated virulence factors production. This work opens up a different approach of Se@ZIF-8 nanoparticles as novel antibiotics to treat biofilm-associated infections caused byS. marcescensand offer a solution for antimicrobial resistance.

Phytofabricated gold nanoparticles as modulators of salt stress responses in spinach: implications for redox homeostasis, biochemical and physiological adaptation

Introduction

The utilization of plant material for synthesizing nanoparticles effectively triggers physiological and biochemical responses in plants to combat abiotic stresses. Salt stress, particularly caused by NaCl, significantly affects plant morphology and physiology, leading to reduced crop yields. Understanding the mechanisms of salt tolerance is crucial for maintaining crop productivity.

Methods

In this study, we examined the effects of 150 μM spinach-assisted gold nanoparticles (S-AuNPs) on various parameters related to seed germination, growth attributes, photosynthetic pigments, stomatal traits, ion concentrations, stress markers, antioxidants, metabolites, and nutritional contents of spinach plants irrigated with 50 mM NaCl.

Results

Results showed that S-AuNPs enhanced chlorophyll levels, leading to improved light absorption, increased photosynthates production, higher sugar content, and stimulated plant growth under NaCl stress. Stomatal traits were improved, and partially closed stomata were reopened with S-AuNPs treatment, possibly due to K+/Na+ modulation, resulting in enhanced relative water content and stomatal conductance. ABA content decreased under S-AuNPs application, possibly due to K+ ion accumulation. S-AuNPs supplementation increased proline and flavonoid contents while reducing ROS accumulation and lipid peroxidation via activation of both non-enzymatic and enzymatic antioxidants. S-AuNPs also regulated the ionic ratio of K+/Na+, leading to decreased Na+ accumulation and increased levels of essential ions in spinach plants under NaCl irrigation.

Discussion

Overall, these findings suggest that S-AuNPs significantly contribute to salt stress endurance in spinach plants by modulating various physiological attributes.

Effects of Gold Nanoparticles on Mentha spicata L., Soil Microbiota, and Human Health Risks: Impact of Exposure Routes

Nanoparticles, due to their extensive production and application, can have significant consequences for the environment, including soil and plant pollution. Therefore, it is very important to assess how nanoparticles will affect plants depending on the exposure pathways. The effect of gold nanoparticles in a concentration range of 1-100 mg/L on Mentha spicata L. during a 28-day experiment was investigated. Two routes of nanoparticles exposure were applied: root and foliar. Transmission electron microscopy was used to characterize nanoparticles and their effect on plant leaves' ultrastructure. Gold content in soil and plant segments was determined using k0-neutron activation analysis. For root exposure, gold was mainly accumulated in soil (15.2-1769 mg/kg) followed by root systems (2.99-454 mg/kg). The maximum accumulation of gold in leaves (5.49 mg/kg) was attained at a nanoparticle concentration of 100 mg/L. Foliar exposure resulted in the maximum uptake of gold in leaves (552 mg/kg) and stems (18.4 mg/kg) at the highest applied nanoparticle concentration. The effect of nanoparticles on the Mentha spicata L. leaves' biochemical composition was assessed. Nanoparticles affected the content of chlorophyll and carotenoids and led to an increase in antioxidant activity. Root exposure to gold nanoparticles resulted in an increase in the number of starch grains in chloroplasts and also suppressed the activity of the soil microbiota. Gold extraction from mint leaves into herbal infusion varied from 2 to 90% depending on the concentration of nanoparticles in the solution and the exposure route. The health risk as a result of gold exposure via herbal tea intake was assessed through estimated daily intake. The hazard quotient values were found to be less than the cutoff, indicating that a cup of tea infusion should not cause a serious impact to human health.

Metallic nanoparticles and photosynthesis organisms: Comprehensive review from the ecological perspective

This review presents a comprehensive analysis of the ecological implications of metallic nanoparticles (MNPs) on photosynthetic organisms, particularly plants and algae. We delve into the toxicological impacts of various MNPs, including gold, silver, copper-based, zinc oxide, and titanium dioxide nanoparticles, elucidating their effects on the growth and health of these organisms. The article also summarizes the toxicity mechanisms of these nanoparticles in plants and algae from previous research, providing insight into the cellular and molecular interactions that underpin these effects. Furthermore, it discusses the reciprocal interactions between different types of MNPs, their combined effects with other metal contaminants, and compares the toxicity between MNPs with their counterpart. This review highlights the urgent need for a deeper understanding of the environmental impact, considering their escalating use and the potential risks they pose to ecological systems, especially in the context of photosynthetic organisms that are vital to ecosystem health and stability.

Au-Based Nanoparticles Enhance Low Temperature Tolerance in Wheat by Regulating Some Physiological Parameters and Gene Expression

One of the key problems of biology is how plants adapt to unfavorable conditions, such as low temperatures. A special focus is placed on finding ways to increase tolerance in important agricultural crops like wheat. Au-based nanoparticles (Au-NPs) have been employed extensively in this area in recent years. Au-NPs can be produced fast and easily using low-cost chemical reagents. When employed in microdoses, Au-NPs are often non-toxic to plants, animals, and people. In addition, Au-NPs mainly have favorable impacts on plants. In this study, we investigated the effect of Au-NP seed nanopriming (diameter 15.3 nm, Au concentration 5-50 µg mL-1) on cold tolerance, as well as some physiological, biochemical and molecular parameters, of cold-sustainable wheat (Triticum aestivum L.) genotype Zlata. The treatment with Au-NPs improved tolerance to low temperatures in control conditions and after cold hardening. Au-NPs treatment boosted the intensity of growth processes, the quantity of photosynthetic pigments, sucrose in leaves, and the expressions of encoded RuBisCo and Wcor15 genes. The potential mechanisms of Au-NPs' influence on the cold tolerance of wheat varieties were considered.

Zinc oxide nanoparticles influence on plant tolerance to salinity stress: insights into physiological, biochemical, and molecular responses

A slight variation in ecological milieu of plants, like drought, heavy metal toxicity, abrupt changes in temperature, flood, and salt stress disturbs the usual homeostasis or metabolism in plants. Among these stresses, salinity stress is particularly detrimental to the plants, leading to toxic effects and reduce crop productivity. In a saline environment, the accumulation of sodium and chloride ions up to toxic levels significantly correlates with intracellular osmotic pressure, and can result in morphological, physiological, and molecular alterations in plants. Increased soil salinity triggers salt stress signals that activate various cellular-subcellular mechanisms in plants to enable their survival in saline conditions. Plants can adapt saline conditions by maintaining ion homeostasis, activating osmotic stress pathways, modulating phytohormone signaling, regulating cytoskeleton dynamics, and maintaining cell wall integrity. To address ionic toxicity, researchers from diverse disciplines have explored novel approaches to support plant growth and enhance their resilience. One such approach is the application of nanoparticles as a foliar spray or seed priming agents positively improve the crop quality and yield by activating germination enzymes, maintaining reactive oxygen species homeostasis, promoting synthesis of compatible solutes, stimulating antioxidant defense mechanisms, and facilitating the formation of aquaporins in seeds and root cells for efficient water absorption under various abiotic stresses. Thus, the assessment mainly targets to provide an outline of the impact of salinity stress on plant metabolism and the resistance strategies employed by plants. Additionally, the review also summarized recent research efforts exploring the innovative applications of zinc oxide nanoparticles for reducing salt stress at biochemical, physiological, and molecular levels.

Ozone-induced oxidative stress alleviation by biogenic silver nanoparticles and ethylenediurea in mung bean (Vigna radiata L.) under high ambient ozone

Ground-level ozone (O3) is the most phytotoxic secondary air pollutant in the atmosphere, severely affecting crop yields worldwide. The role of nanoparticles (NP) in the alleviation of ozone-induced yield losses in crops is not known. Therefore, in the present study, we investigated the effects of biogenicB-AgNPs on the mitigation of ozone-induced phytotoxicity in mung bean and compared its results with ethylenediurea (EDU) for the first time. Two mung bean cultivars (Vigna radiata L., Cv. SML-668 and PDM-139) were foliar sprayed with weekly applications of B-AgNPs (0 = control, 10 and 25 ppm) and EDU (0 = control, 200 and 300 ppm) until maturation phase. Morphological, physiological, enzymatic, and non-enzymatic antioxidant data were collected 30 and 60 days after germination (DAG). The mean O3 and AOT40 values (8 h day-1) during the cultivation period were approximately 52 ppb and 4.4 ppm.h, respectively. More biomass was accumulated at the vegetative phase due to the impact of B-AgNPs and EDU, and more photosynthates were transported to the reproductive phase, increasing yield. We observed that the 10 ppm B-AgNPs treatment had a more noticeable impact on yield parameters and lower Ag accumulation in seeds for both cultivars. Specifically, SML-668 cultivar treated with 10 ppm B-AgNPs (SN1) showed greater increases in seed weight plant-1 (124.97%), hundred seed weight (33.45%), and harvest index (37.53%) in comparison to control. Our findings suggest that B-AgNPs can enhance growth, biomass, yield, and seed quality, and can improve mung bean ozone tolerance. Therefore, B-AgNPs may be a promising protectant for mung bean.

A Roadmap from Functional Materials to Plant Health Monitoring (PHM)

Soft bioelectronics have great potential for the early diagnosis of plant diseases and the mitigation of adverse outcomes such as reduced crop yields and stunted growth. Over the past decade, bioelectronic interfaces have evolved into miniaturized conformal electronic devices that integrate flexible monitoring systems with advanced electronic functionality. This development is largely attributable to advances in materials science, and micro/nanofabrication technology. The approach uses the mechanical and electronic properties of functional materials (polymer substrates and sensing elements) to create interfaces for plant monitoring. In addition to ensuring biocompatibility, several other factors need to be considered when developing these interfaces. These include the choice of materials, fabrication techniques, precision, electrical performance, and mechanical stability. In this review, some of the benefits plants can derive from several of the materials used to develop soft bioelectronic interfaces are discussed. The article describes how they can be used to create biocompatible monitoring devices that can enhance plant growth and health. Evaluation of these devices also takes into account features that ensure their long-term durability, sensitivity, and reliability. This article concludes with a discussion of the development of reliable soft bioelectronic systems for plants, which has the potential to advance the field of bioelectronics.

Phytogenic nanoparticles: synthesis, characterization, and their roles in physiology and biochemistry of plants

Researchers are swarming to nanotechnology because of its potentially game-changing applications in medicine, pharmaceuticals, and agriculture. This fast-growing, cutting-edge technology is trying different approaches for synthesizing nanoparticles of specific sizes and shapes. Nanoparticles (NPs) have been successfully synthesized using physical and chemical processes; there is an urgent demand to establish environmentally acceptable and sustainable ways for their synthesis. The green approach of nanoparticle synthesis has emerged as a simple, economical, sustainable, and eco-friendly method. In particular, phytoassisted plant extract synthesis is easy, reliable, and expeditious. Diverse phytochemicals present in the extract of various plant organs such as root, leaf, and flower are used as a source of reducing as well as stabilizing agents during production. Green synthesis is based on principles like prevention/minimization of waste, reduction of derivatives/pollution, and the use of safer (or non-toxic) solvent/auxiliaries as well as renewable feedstock. Being free of harsh operating conditions (high temperature and pressure), hazardous chemicals and the addition of external stabilizing or capping agents makes the nanoparticles produced using green synthesis methods particularly desirable. Different metallic nanomaterials are produced using phytoassisted synthesis methods, such as silver, zinc, gold, copper, titanium, magnesium, and silicon. Due to significant differences in physical and chemical properties between nanoparticles and their micro/macro counterparts, their characterization becomes essential. Various microscopic and spectroscopic techniques have been employed for conformational details of nanoparticles, like shape, size, dispersity, homogeneity, surface structure, and inter-particle interactions. UV-visible spectroscopy is used to examine the optical properties of NPs in solution. XRD analysis confirms the purity and phase of NPs and provides information about crystal size and symmetry. AFM, SEM, and TEM are employed for analyzing the morphological structure and particle size of NPs. The nature and kind of functional groups or bioactive compounds that might account for the reduction and stabilization of NPs are detected by FTIR analysis. The elemental composition of synthesized NPs is determined using EDS analysis. Nanoparticles synthesized by green methods have broad applications and serve as antibacterial and antifungal agents. Various metal and metal oxide NPs such as Silver (Ag), copper (Cu), gold (Au), silicon dioxide (SiO2), zinc oxide (ZnO), titanium dioxide (TiO2), copper oxide (CuO), etc. have been proven to have a positive effect on plant growth and development. They play a potentially important role in the germination of seeds, plant growth, flowering, photosynthesis, and plant yield. The present review highlights the pathways of phytosynthesis of nanoparticles, various techniques used for their characterization, and their possible roles in the physiology of plants.

Mechanistic transcriptome comprehension of Chlamydomonas reinhardtii subjected to black phosphorus

Two-dimensional materials have recently gained significant awareness. A representative of such materials, black phosphorous (BP), earned attention based on its comprehensive application potential. The presented study focuses on the mode of cellular response underlying the BP interaction with Chlamydomonas reinhardtii as an algal model organism. We observed noticeable ROS formation and changes in outer cellular topology after 72 h of incubation at 5 mg/L BP. Transcriptome profiling was employed to examine C. reinhardtii response after exposure to 25 mg/L BP for a deeper understanding of the associated processes. The RNA sequencing has revealed a comprehensive response with abundant transcript downregulation. The mode of action was attributed to cell wall disruption, ROS elevation, and chloroplast disturbance. Besides many other dysregulated genes, the cell response involved the downregulation of GH9 and gametolysin within a cell wall, pointing to a shift to discrete manipulation with resources. The response also included altered expression of the PRDA1 gene associated with redox governance in chloroplasts implying ROS disharmony. Altered expression of the Cre-miR906-3p, Cre-miR910, and Cre-miR914 pointed to those as potential markers in stress response studies.

Inhibitory impact of MgO nanoparticles on oxidative stress and other physiological attributes of spinach plant grown under field condition

Green synthesis of NPs is preferred due to its eco-friendly procedures and non-toxic end products. However, unintentional release of NPs can lead to environmental pollution affecting living organisms including plants. NPs accumulation in soil can affect the agricultural sustainability and crop production. In this context, we report the morphological and biochemical response of spinach nanoprimed with MgO-NPs at concentrations, 10, 50, 100, and 150 µg/ml. Nanopriming reduced the spinach root length by 14-26%, as a result a reduction of 20-74% in the length of spinach shoots was observed. The decreased spinach shoot length inhibited the chlorophyll accumulation by 21-55%, thus reducing the accumulation of carbohydrates and yield by 46 and 49%, respectively. The reduced utilization of the total absorbed light further enhanced ROS generation and oxidative stress by 32%, thus significantly altering their antioxidant system. Additionally, a significant variation in the accumulation of flavonoid pathway downstream metabolites myricitin, rutin, kaempferol-3 glycoside, and quercitin was also revealed on MgO-NPs nanopriming. Additionally, NPs enhanced the protein levels of spinach probably as an osmoprotectant to regulate the oxidative stress. However, increased protein precipitable tannins and enhanced oxidative stress reduced the protein digestibility and solubility. Overall, MgO-NPs mediated oxidative stress negatively affected the growth, development, and yield of spinach in fields in a concentration dependent manner.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01391-9.

Unleashing the potential of nanoparticles on seed treatment and enhancement for sustainable farming

The foremost challenge in farming is the storage of seeds after harvest and maintaining seed quality during storage. In agriculture, studies showed positive impacts of nanotechnology on plant development, seed storage, endurance under various types of stress, detection of seed damages, and seed quality. Seed's response varies with different types of nanoparticles depending on its physical and biochemical properties and plant species. Herein, we aim to cover the impact of nanoparticles on seed coating, dormancy, germination, seedling, nutrition, plant growth, stress conditions protection, and storage. Although the seed treatment by nanopriming has been shown to improve seed germination, seedling development, stress tolerance, and seedling growth, their full potential was not realized at the field level. Sustainable nano-agrochemicals and technology could provide good seed quality with less environmental toxicity. The present review critically discusses eco-friendly strategies that can be employed for the nanomaterial seed treatment and seed enhancement process to increase seedling vigor under different conditions. Also, an integrated approach involving four innovative concepts, namely green co-priming, nano-recycling of agricultural wastes, nano-pairing, and customized nanocontainer storage, has been proposed to acclimatize nanotechnology in farming.

The Combination of Gold and Silver Food Nanoparticles with Gluten Peptides Alters the Autophagic Pathway in Intestinal Crypt-like Cells

Metallic nanoparticles (mNPs) are widely used as food additives and can interact with gliadin triggering an immune response, but evaluation of the effects on crypts, hypertrophic in celiac subjects, is still lacking. This study evaluated the effects of gold and silver mNPs in combination with gliadin on crypt-like cells (HIEC-6). Transmission electron microscopy (TEM) was used to evaluate gliadin-mNP aggregates in cells. Western blot and immunofluorescence analysis assessed autophagy-related molecule levels (p62, LC3, beclin-1, EGFR). Lysosome functionality was tested with acridine orange (AO) and Magic Red assays. TEM identified an increase in autophagic vacuoles after exposure to gliadin + mNPs, as also detected by significant increments in LC3-II and p62 expression. Immunofluorescence confirmed the presence of mature autophagosomes, showing LC3 and p62 colocalization, indicating an altered autophagic flux, further assessed with EGFR degradation, AO and Magic Red assays. The results showed a significant reduction in lysosomal enzyme activity and a modest reduction in acidity. Thus, gliadin + mNPs can block the autophagic flux inducing a lysosomal defect. The alteration of this pathway, essential for cell function, can lead to cell damage and death. The potential effects of this copresence in food should be further characterized to avoid a negative impact on celiac disease subjects.

Fungi-mediated synthesis of nanoparticles: characterization process and agricultural applications

In the field of nanotechnology, the use of biologically active products from fungi for the reduction and synthesis of nanoparticles as an alternative to toxic chemicals has received extensive attention, due to their production of large quantities of proteins, high yields, easy handling, and the low toxicity of the residues. Fungi have become valuable tools for the manufacture of nanoparticles in comparison with other biological systems because of their enhanced growth control and diversity of metabolites, including enzymes, proteins, peptides, polysaccharides, and other macro-molecules. The ability to use different species of fungi and to perform the synthesis under different conditions enables the production of nanoparticles with different physicochemical characteristics. Fungal nanotechnology has been used to develop and offer products and services in the agricultural, medicinal, and industrial sectors. Agriculturally, it has found applications in plant disease management, crop improvement, biosensing, and the production of environmentally friendly, non-toxic pesticides and fertilizers to enhance agricultural production in general. The subject of this review is the application of fungi in the synthesis of inorganic nanoparticles, characterization, and possible applications of fungal nanoparticles in the diverse agricultural sector. The literature shows potential uses of fungi in biogenic synthesis, enabling the production of nanoparticles with different physiognomies. © 2023 Society of Chemical Industry.

Transcriptomic hallmarks of in vitro TiO2 nanotubes toxicity in Chlamydomonas reinhardtii

Recently, more accessible transcriptomic approaches have provided a new and deeper understanding of environmental toxicity. The present study focuses on the transcriptomic profiles of green microalgae Chlamydomonas reinhardtii exposed to new industrially promising material, TiO₂ nanotubes (NTs), as an example of a widely used one-dimensional nanomaterial. The first algal in vitro assay included 2.5 and 7.5 mg/L TiO₂ NTs, resulting in a dose-dependent negative effect on biological endpoints. At a working concentration of 7.5 mg/L, RNA-sequencing showed a mainly negative effect on the cells. In summary, the results indicated metabolic disruption, ^{such as ATP loss, damage to mitochondria and chloroplasts, loss of solutes due to permeated membranes,} and cell wall damage. Moreover, apoptosis-induced transcripts were detected. Interestingly, reactivation of transposons was observed. In signalling and transcription pathways, including chromatin remodelling and locking, the annotated genes were downregulated.

Biosynthesis and characterization of nanoparticles, its advantages, various aspects and risk assessment to maintain the sustainable agriculture: Emerging technology in modern era science

The current review aims to gain knowledge on the biosynthesis and characterization of nanoparticles (NPs), their multifactorial role, and emerging trends of NPs utilization in modern science, particularly in sustainable agriculture, for increased yield to solve the food problem in the coming era. However, it is well known that an environment-friendly resource is in excessive demand, and green chemistry is an advanced and rising resource in exploring eco-friendly processes. Plant extracts or other resources can be utilized to synthesize different types of NPS. Hence NPs can be synthesized by organic or inorganic molecules. Inorganic molecules are hydrophilic, biocompatible, and highly steady compared to organic types. NPs occur in numerous chemical conformations ranging from amphiphilic molecules to metal oxides, from artificial polymers to bulky biomolecules. NPs structures can be examined by different approaches, i.e., Raman spectroscopy, optical spectroscopy, X-ray fluorescence, and solid-state NMR. Nano-agrochemical is a unification of nanotechnology and agro-chemicals, which has brought about the manufacture of nano-fertilizers, nano-pesticides, nano-herbicides, nano-insecticides, and nano-fungicides. NPs can also be utilized as an antimicrobial solution, but the mode of action for antibacterial NPs is poorly understood. Presently known mechanisms comprise the induction of oxidative stress, the release of metal ions, and non-oxidative stress. Multiple modes of action towards microbes would be needed in a similar bacterial cell for antibacterial resistance to develop. Finally, we visualize multidisciplinary cooperative methods will be essential to fill the information gap in nano-agrochemicals and drive toward the usage of green NPs in agriculture and plant science study.

Nanotechnological approaches for management of soil-borne plant pathogens

Soil borne pathogens are significant contributor of plant yield loss globally. The constraints in early diagnosis, wide host range, longer persistence in soil makes their management cumbersome and difficult. Therefore, it is crucial to devise innovative and effective management strategy to combat the losses caused by soil borne diseases. The use of chemical pesticides is the mainstay of current plant disease management practices that potentially cause ecological imbalance. Nanotechnology presents a suitable alternative to overcome the challenges associated with diagnosis and management of soil-borne plant pathogens. This review explores the use of nanotechnology for the management of soil-borne diseases using a variety of strategies, such as nanoparticles acting as a protectant, as carriers of actives like pesticides, fertilizers, antimicrobials, and microbes or by promoting plant growth and development. Nanotechnology can also be used for precise and accurate detection of soil-borne pathogens for devising efficient management strategy. The unique physico-chemical properties of nanoparticles allow greater penetration and interaction with biological membrane thereby increasing its efficacy and releasability. However, the nanoscience specifically agricultural nanotechnology is still in its toddler stage and to realize its full potential, extensive field trials, utilization of pest crop host system and toxicological studies are essential to tackle the fundamental queries associated with development of commercial nano-formulations.

Nanomaterials biotransformation: In planta mechanisms of action

Research on engineered nanomaterials (ENMs) exposure has continued to expand rapidly, with a focus on uncovering the underlying mechanisms. The EU largely limits the number and the type of organisms that can be used for experimental testing through the 3R normative. There are different routes through which ENMs can enter the soil-plant system: this includes the agricultural application of sewage sludges, and the distribution of nano-enabled agrochemicals. However, a thorough understanding of the physiological and molecular implications of ENMs dispersion and chronic low-dose exposure remains elusive, thus requiring new evidence and a more mechanistic overview of pathways and major effectors involved in plants. Plants can offer a reliable alternative to conventional model systems to elucidate the concept of ENM biotransformation within tissues and organs, as a crucial step in understanding the mechanisms of ENM-organism interaction. To facilitate the understanding of the physico-chemical forms involved in plant response, synchrotron-based techniques have added new potential perspectives in studying the interactions between ENMs and biota. These techniques are providing new insights on the interactions between ENMs and biomolecules. The present review discusses the principal outcomes for ENMs after intake by plants, including possible routes of biotransformation which make their final fate less uncertain, and therefore require further investigation.

Interaction between nanomaterials and the innate immune system across evolution

Interaction of engineered nanomaterials (ENMs) with the immune system mainly occurs with cells and molecules of innate immunity, which are present in interface tissues of living organisms. Immuno-nanotoxicological studies aim at understanding if and when such interaction is inconsequential or may cause irreparable damage. Since innate immunity is the first line of immune reactivity towards exogenous agents and is highly conserved throughout evolution, this review focuses on the major effector cells of innate immunity, the phagocytes, and their major sensing receptors, Toll-like receptors (TLRs), for assessing the modes of successful versus pathological interaction between ENMs and host defences. By comparing the phagocyte- and TLR-dependent responses to ENMs in plants, molluscs, annelids, crustaceans, echinoderms and mammals, we aim to highlight common recognition and elimination mechanisms and the general sufficiency of innate immunity for maintaining tissue integrity and homeostasis.

Comparative Study of Antimicrobial Activity of Silver, Gold, and Silver/Gold Bimetallic Nanoparticles Synthesized by Green Approach

Nanotechnology is one of the most recent technologies. It is uncertain whether the production of small-size nanoparticles (NPs) can be achieved through a simple, straightforward, and medicinally active phytochemical route. The present study aimed to develop an easy and justifiable method for the synthesis of Ag, Au, and their Ag/Au bimetallic NPs (BNPs) by using Hippeastrum hybridum (HH) extract, and then to investigate the effects of Ag, Au, and their Ag/Au BNPs as antimicrobial and phytotoxic agents. Ag, Au, and their Ag/Au BNPs were characterized by UV-visible spectroscopy, FT-IR spectroscopy, XRD, EDX, and SEM analysis. XRD analysis conferring to the face of face-centered cubic crystal structure with an average size of 13.3, 10.72, and 8.34 nm of Ag, Au, and Ag/Au BNPs, respectively. SEM showed that Ag, Au, and Ag/Au BNPs had spherical morphologies, with calculated nano measurements of 40, 30, and 20 nm, respectively. The EDX analysis confirmed the composition of elemental Ag signal of the HH-AgNPs with 22.75%, Au signal of the HH-AuNPs with 48.08%, Ag signal with 12%, and Au signal with 38.26% of the Ag/Au BNPs. The Ag/Au BNPs showed an excellent antimicrobial efficacy against Gram-positive Staphylococcus aureus, Actinomycetes meriye, Bacillus cereus, Streptococcus pyogenes, Methicillin-resistant Staphylococcus aureus, Micrococcus luteus, Streptococcus pneumonia, and Gram-negative Klebsiella pneumonia, Escherichia coli, and Serratia marcescens bacterial strains, as well as against three fungal strains (Aspergillus niger, Aspergillus fumigatus, and Aspergillus flavus) compared to HH extract, HH-AgNPs, and HH-AuNPs. However, further investigations are recommended to be able to minimize potential risks of application.

Priming with gold nanoparticles leads to changes in the photosynthetic apparatus and improves the cold tolerance of wheat

Nanotechnologies provide a great platform for researching nanoparticles effects on living organisms including plants. This work shows the stimulating effect of seed priming with gold nanoparticles (AuNPs) on photosynthetic apparatus of Triticum aestivum seedlings. It was found using inductively coupled plasma-atomic emission and mass spectrometry that AuNPs (the average diameter of 15.3 nm, concentration of 20 μg ml^-1) penetrated into the seeds, but were not found in seedling leaves. Ultrastructural changes in chloroplasts were found using transmission electron microscopy in plants grown from treated seeds: increases in the size of plastids, starch grains, grana in chloroplasts, and the number of thylakoids in grana. The intensity of photosynthesis, the content of chlorophylls, and the portion of unsaturated fatty acids in the composition of total leaf lipids were increased in treated AuNPs plants. This study demonstrates that revealed changes determined the increased tolerance of wheat to low temperature. The adaptive significance of these changes, possible mechanisms of the AuNPs effects on plants and future perspectives of study are discussed. This is the first report showing nanopriming with AuNPs as a new method to study the mechanisms of stress tolerance.

Alleviating the adverse effects of salinity on Roselle plants by green synthesized nanoparticles

In the present study, an eco-friendly process was made for the rapid synthesis of silver nanoparticles using aqueous leaf extract of Hibiscus sabdariffa. The process was characterized by Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible and X-ray diffraction (XRD). These green silver nanoparticles (NPs) were used for mitigating the adverse effects of salinity on seed germination and growth parameters in plants. Accordingly, two experiments were conducted. In the first experiment, seven concentrations of green silver NPs and nine levels of NaCl:CaCl were apptoed on seeds for germination, and their effects were evaluated. In the second experiment, three concentrations of green silver NPs and NaCl were hypothesized to affect plant growth parameters. Seed germination, plant height, leaf, and root fresh and dry weights, as well as relative water content (RWC), decreased significantly under salt stress. However, green silver NPs intervened by alleviating the adverse effects of stress. Accordingly, green silver NPs were beneficial due to (1) activation of the antioxidant system by enhancing antioxidant enzymes such as catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD), and superoxide dismutase (SOD); (2) increase in the amounts of proline, soluble sugars and carbohydrates for osmoprotection; (3) improvements in flavonoid and anthocyanin contents. Real-time PCR showed that flavonoid and anthocyanin contents increased because of higher expressions in chalcone synthase (CHS), flavanone 3-hydroxylase (F3H), and anthocyanidin synthase (ANS) genes. In conclusion, green silver NPs offered an eco-friendly application for further research on agricultural development.

Gold nanoparticles as adaptogens increazing the freezing tolerance of wheat seedlings

The intensive development of nanotechnology led to the widespread application of various nanoparticles and nanomaterials. As a result, nanoparticles enter the environment and accumulate in ecosystems and living organisms. The consequences of possible impact of nanoparticles on living organisms are not obvious. Experimental data indicate that nanoparticles have both toxic and stimulating effects on organisms. In this study, we demonstrated for the first time that gold nanoparticles can act as adaptogens increasing plant freezing tolerance. Priming winter wheat (Triticum aestivum L., var. Moskovskaya 39, Poaceae) seeds for 1 day in solutions of gold nanoparticles (15-nm diameter, concentrations of 5, 10, 20, and 50 µg/ml) led to an increase in freezing tolerance of 7-day-old wheat seedlings. A relationship between an increase in wheat freezing tolerance and changes in some important indicators for its formation-growth intensity, the activity of the photosynthetic apparatus and oxidative processes, and the accumulation of soluble sugars in seedlings-was established. Assumptions on possible mechanisms of gold nanoparticles effects on plant freezing tolerance are discussed.

Recent Advances in Metal-Based Nanoparticle-Mediated Biological Effects in Arabidopsis thaliana: A Mini Review

The widespread application of metal-based nanoparticles (MNPs) has prompted great interest in nano-biosafety. Consequently, as more and more MNPs are released into the environment and eventually sink into the soil, plants, as an essential component of the ecosystem, are at greater risk of exposure and response to these MNPs. Therefore, to understand the potential impact of nanoparticles on the environment, their effects should be thoroughly investigated. Arabidopsis (Arabidopsis thaliana L.) is an ideal model plant for studying the impact of environmental stress on plants’ growth and development because the ways in which Arabidopsis adapt to these stresses resemble those of many plants, and therefore, conclusions obtained from these scientific studies have often been used as the universal reference for other plants. This study reviewed the main findings of present-day interactions between MNPs and Arabidopsis thaliana from plant internalization to phytotoxic effects to reveal the mechanisms by which nanomaterials affect plant growth and development. We also analyzed the remaining unsolved problems in this field and provide a perspective for future research directions.

Nano-priming as emerging seed priming technology for sustainable agriculture-recent developments and future perspectives

Nano-priming is an innovative seed priming technology that helps to improve seed germination, seed growth, and yield by providing resistance to various stresses in plants. Nano-priming is a considerably more effective method compared to all other seed priming methods. The salient features of nanoparticles (NPs) in seed priming are to develop electron exchange and enhanced surface reaction capabilities associated with various components of plant cells and tissues. Nano-priming induces the formation of nanopores in shoot and helps in the uptake of water absorption, activates reactive oxygen species (ROS)/antioxidant mechanisms in seeds, and forms hydroxyl radicals to loosen the walls of the cells and acts as an inducer for rapid hydrolysis of starch. It also induces the expression of aquaporin genes that are involved in the intake of water and also mediates H2O2, or ROS, dispersed over biological membranes. Nano-priming induces starch degradation via the stimulation of amylase, which results in the stimulation of seed germination. Nano-priming induces a mild ROS that acts as a primary signaling cue for various signaling cascade events that participate in secondary metabolite production and stress tolerance. This review provides details on the possible mechanisms by which nano-priming induces breaking seed dormancy, promotion of seed germination, and their impact on primary and secondary metabolite production. In addition, the use of nano-based fertilizer and pesticides as effective materials in nano-priming and plant growth development were also discussed, considering their recent status and future perspectives.

Molecular Mechanisms of Early Flowering in Tomatoes Induced by Manganese Ferrite (MnFe2O4) Nanomaterials

Nanomaterials (NMs) have demonstrated enormous potential to improve agricultural production. Ten mg L^-1 of customized manganese ferrite (MnFe₂O₄) NMs was selected as the optimal dose based on its outstanding effects on promoting tomato flowering and production. After the foliar application before flowering, MnFe₂O₄ NMs increased the leaf chlorophyll content by 20 percent, and significantly upregulated the expressions of ferredoxin, PsaA, and PsbA in leaves, likely by serving as an electron donor, leading to a significant increase in photosynthesis efficiency by 13.3%. Long distance transport of sucrose was then confirmed by the upregulation of sucrose transporter SUT1 and SUT2 in NM-treated leaves and meristems. The genes associated with gibberellin biosynthesis, including GA20ox2, GA20ox3, and SIGAST, and a flowering induction gene SFT, were also significantly upregulated. Importantly, the flowering time was 13 days earlier by MnFe₂O₄ NMs over the control. At the reproductive stage, MnFe₂O₄ NMs increased pollen activity and ovule size, leading to the significant increase in fruit number per plant, single fruit weight, and fruit weight per plant by 50%, 30%, and 75%, respectively. Metabolically, a significant increase of glucose-6-phosphate, phenylalanine, rutin, and ascorbic acid (vitamin C), as well as a significant decrease of tomatine and methionine, demonstrates an increased nutritional value of the tomato fruits. A verified companion field experiment showed an increase of 84.1% in total tomato production with the MnFe₂O₄ NM amendment. These findings provide support for the early flowering and yield improvement in nano-enabled agricultural systems.

Nanomaterials coupled with microRNAs for alleviating plant stress: a new opening towards sustainable agriculture

Plant growth and development is influenced by their continuous interaction with the environment. Their cellular machinery is geared to make rapid changes for adjusting the morphology and physiology to withstand the stressful changes in their surroundings. The present scenario of climate change has however intensified the occurrence and duration of stress and this is getting reflected in terms of yield loss. A number of breeding and molecular strategies are being adopted to enhance the performance of plants under abiotic stress conditions. In this context, the use of nanomaterials is gaining momentum. Nanotechnology is a versatile field and its application has been demonstrated in almost all the existing fields of science. In the agriculture sector, the use of nanoparticles is still limited, even though it has been found to increase germination and growth, enhance physiological and biochemical activities and impact gene expression. In this review, we have summarized the use and role of nanomaterial and small non-coding RNAs in crop improvement while highlighting the potential of nanomaterial assisted eco-friendly delivery of small non-coding RNAs as an innovative strategy for mitigating the effect of abiotic stress.

Morphological, Histological and Ultrastructural Changes in Hordeum vulgare (L.) Roots That Have Been Exposed to Negatively Charged Gold Nanoparticles

In recent years, there has been an impressive development of nanotechnology. This has resulted in the increasing release of nanomaterials (NM) into the environment, thereby causing the risk of an uncontrolled impact on living organisms, including plants. More studies indicated the biotoxic effect of NM on plants, including crops. The interaction of nanoparticles (NP) with food crops is extremely important as they are a link to the food chain. The objective of this study was to investigate the effect of negatively charged gold nanoparticles (-) AuNP (at two concentrations; 25 µg/mL or 50 µg/mL) on barley (Hordeum vulgare L.) root development. Morphological, histological and ultrastructural analyses (with the use of stereomicroscope, bright filed microscope and transmission electron microscope) revealed that regardless of the concentration, (-) AuNP did not enter into the plant body. However, the dose of (-) AuNP proved to be important for the plant’s response because different morphological, histological and ultrastructural changes were observed in the treated roots. The NP treatment caused: red root colouration, a local increase in the root diameter and a decreased formation of the root hair cells (on morphological level), damage to the rhizodermal cells, vacuolisation of the cortical cells, a detachment of the cell files between the cortical cells, atypical divisions of the cells, disorder of the meristem organisation (on the histological level), the appearance of periplasmic space, numerous vesicles and multivesicular bodies, electron-dense spots in cytoplasm, alterations in the structure of the mitochondria, breakdown of the tonoplast and the plasmalemma (on the ultrastructural level).

Influence of Gold Nanoparticles on the Tolerance of Wheat to Low Temperature

It was shown for the first time that the treatment of winter wheat (Triticum aestivum L.) seeds with gold nanoparticles (average diameter 15.3 nm; solution concentration 20 μg/mL) increases plant tolerance to low temperature. It was found that an increase in tolerance under the influence of nanoparticles is accompanied by a number of changes depending on temperature conditions. In optimal temperature conditions, gold nanoparticles stimulated plant growth and the activity of the photosynthetic apparatus, whereas in conditions of low-temperature hardening (2°C, 7 days) they inhibited growth but maintained photosynthetic activity, contributing to the accumulation of soluble sugars (cryoprotectants) in the leaves. It is concluded that gold nanoparticles can be considered as adaptogens that increase plant tolerance to low temperatures; however, their effectiveness in this role and the subtle mechanisms of action require further study.

A comprehensive review of impacts of diverse nanoparticles on growth, development and physiological adjustments in plants under changing environment

The application of nanotechnology in agriculture includes the use of nanofertilizers, nanopesticides, and nanoherbicides that enhance plant nutrition without disturbing the soil texture and protect it against microbial infections. Thus, nanotechnology maintains the plant's health by maintaining its soil health. The use of nanoparticles (NPs) in agriculture reduces the chemical spread and nutrient loss and boosts crop yield and productivity. Effect of NPs varies with their applied concentrations, physiochemical properties, and plant species. Various NPs have an impact on the plant to increase biomass productivity, germination rate and their physiology. Also, NPs change the plant molecular mechanisms by altering gene expression. Metal and non-metal oxides of NPs (Au, Ag, ZnO, Fe₂O₃, TiO₂, SiO₂, Al₂O₃, Se, carbon nanotubes, quantum dots) exert an important role in plant growth and development and perform an essential role in stress amelioration. On the other hand, other effects of NPs have also been well investigated by observing their role in growth suppression and inhibition of chlorophyll and photosynthetic efficiency. In this review, we addressed a description of studies that have been made to understand the effects of various kind of NPs, their translocation and interaction with the plants. Also, the phytoremediation approaches of contaminated soil with combined use of NPs for sustainable agriculture is covered.

Influence of metallic, metallic oxide, and organic nanoparticles on plant physiology

Nanotechnology is a research area that has experienced tremendous development given the enormous potential of nanoparticles (NPs) to influence almost all industries and conventional processes. NPs have been extensively used in agriculture to improve plant physiology, production, and nutritional values of plant-based products. The large surface area and small size are some of the desired attributes for NPs that can substantially ameliorate plants' physiological processes, thereby improving crop production. Nevertheless, the results derived from such research have not always been positive as NPs have been shown, in some cases, to negatively affect plants due to their potentially toxic nature. These toxic effects depend upon the size, concentration, nature, zeta potential, and shape of nanoparticles, as well as the used plant species. The most common response of plants under NPs toxicity is the activation of antioxidant systems and the production of secondary metabolites. The mitigation of such NPs-induced stress highly varies depending on the amount of NPs applied to the plant growth stage and the environmental conditions. On the contrary, higher photosynthetic rates, higher chlorophyll, and proline content, improved homeostasis, hormonal balance, and nutrient assimilation are the favorable physiological changes after NPs applications. Alternatively, NPs do not always exhibit positive or negative impacts on plants, and no physiological influences are sometimes observed. Considering such diversity of responses after the use of NPs on plants, this review summarizes the progress made in nanotechnology on the influence of different NPs in plant physiology through the use of indexes like seed germination, root and shoot morphology, photosynthesis, and their impact when used as carriers of cell signaling molecules such as nitric oxide (NO). Understanding the intimate dynamics of nanoparticle toxicity in plants can prove to be fruitful for the development of areas like agronomy, horticulture, plant pathology, plant physiology, etc. That, in return, can assist to ensure agricultural sustainability. Similarly, this may also help to pave the way to combat the drastic climate change and satisfy growing food demands for the ever-increasing world population. Further studies on molecular and genetic levels can certainly broaden the current understanding of NPs-plant interactions and devise the respective mitigation strategies for environmental safety.

Cross-examination of engineered nanomaterials in crop production: Application and related implications

The review presents the current knowledge on the development and implementation of nanotechnology in crop production, giving particular attention to potential opportunities and challenges of the use of nano-sensors, nano-pesticides, and nano-fertilizers. Due to the size-dependent properties, e.g. high reactivity, targeted and controlled delivery of active ingredients, engineered nanomaterials (ENMs) are expected to be more efficient agrochemicals than conventional agents. Growing production and usage of ENMs result in the spread of ENMs in the environment. Because plants constitute an important component of the agri-ecosystem, they are subjected to the ENMs activity. A number of studies have confirmed the uptake and translocation of ENMs by plants as well as their positive/negative effects on plants. Here, these endpoints are briefly summarized to show the diversity of plant responses to ENMs. The review includes a detailed molecular analysis of ENMs-plant interactions. The transcriptomics, proteomics and metabolomics tools have been very recently employed to explore ENMs-induced effects in planta. The omics approach allows a comprehensive understanding of the specific machinery of ENMs occurring at the molecular level. The summary of data will be valuable in defining future studies on the ENMs-plant system, which is crucial for developing a suitable strategy for the ENMs usage.

In vitro exposed magnesium oxide nanoparticles enhanced the growth of legume Macrotyloma uniflorum

Nanoparticles interact with plants to induce a positive, negative, or neutral effect on their growth and development. In this study, we document the positive influence of magnesium oxide (MgO) nanoparticles (NPs) on the morpho-biochemical parameters of Macrotyloma uniflorum (horse gram). Horse gram is a protein and polyphenol-rich legume crop. It is an important part of the human diet and nutrition. When exposed to MgO-NPs, a significant increment in the shoot-root length, fresh biomass, and chlorophyll content of horse gram was evident. Furthermore, there was a 4-20 and 18-127% increase in the accumulation of carbohydrate and protein content on MgO-NP exposure. The antioxidant potential was enhanced by 5-19% on NP treatment as a result of the increase in the accumulation of total polyphenolics. Total phenols and flavonoids were enhanced by 7-20 and 50-84% in the presence of MgO-NPs. The enzyme activity of SOD, CAT, and APX was also enhanced in MgO-NP-exposed horse gram. The observed alterations were also justified by the Pearson correlation. Overall, the MgO-NP-induced morpho-biochemical alterations in horse gram indicated their probable role as a nano-fertilizer. However, it further warrants the need to extensively investigate the responses of various other plant types to MgO-NPs before industry scale application.

Ecological safety with multifunctional applications of biogenic mono and bimetallic (Au-Ag) alloy nanoparticles

Recently, the design and biosynthesis of metallic nanoparticles (NPs) have drawn immense interest, but their very specific function and secondary toxic effects are major concern towards commercial application of NPs. That's why environment-friendly (nontoxic) NPs having multiple functions are extremely important. Herein, we report the mechanism of biosynthesis of mono and bimetallic (Au-Ag) alloy NPs and study their multifunctional (antioxidant, antifungal and catalytic) activity and ecotoxicological property. AgNPs exhibit phytotoxicity (at 100 μg/ml) on morphological characteristics of Lentil (during germination), while alloy and AuNPs are non-toxic (up to 100 μg/ml). In-vitro antioxidant response using DPPH methods reveals that alloy NPs (IC₅₀ = 55.8 μg/ml) possesses better antioxidant activity compared to the monometallic NPs (IC₅₀ = 73.6-82.6 μg/ml). In addition, alloy NPs displayed appreciable antifungal efficacy against a plant pathogenic fungus Gloeosporium musarum by structural damage to hyphae and conidia of the fungus. The catalytic performance of NPs for degradation of chlorpyriphos (CP) pesticide reveals that alloy NPs is more efficient in terms of rate constant (k = 0.405 d^-1) and half-life (T₅₀ = 1.71 d) compared to the monometallic counterparts (k = 0.115-0.178 d^-1; T₅₀ = 3.89-6.04 d). Degradation products of CP (3,5,6-trichloropyridinol and diethyl thiophosphate) are confirmed using mass spectrometry and based on that a degradation pathway has been suggested. Thus, these sustainable and ecological safe biogenic (Au-Ag) alloy NPs promise multiple applications as an antioxidant in the pharmaceutical sector, as a fungicide for disease control in agriculture, as a catalyst for remediation of toxic pollutants and in other pertinent areas.

The Effects of Several Metal Nanoparticles on Seed Germination and Seedling Growth: A Meta-Analysis

Using the proper means to improve seed germination is of great significance in agriculture and forestry. Here, a meta-analysis was used to examine whether metal nanoparticle treatments have a specific effect on the seed germination and seedling growth of agricultural species. Using the Web of Science (1950–2021), PubMed (1950–2021), and Scopus (1950–2021) databases, a paper search was conducted using the following items (“nanoparticles” and “seed germination”, “nanomaterials” and “seed germination”) to filter the references in the title, abstract, and keywords of the published articles. The results indicated that nanoparticle (NP) treatments had a significantly positive effect on the final germination percentage (FGP), with a mean difference (MD) (that is, the overall effect) of 1.97 (0.96, 2.98) for the silver (Ag)-NP subgroup, 1.21 (0.34, 2.09) for the other-NP subgroup, 1.40 (0.88, 1.92) for the total based on the NP types, 1.47 (0.85, 2.09) for the “Concentrations: < 50 mg/L” subgroup, and 1.40 (0.88, 1.92) for the total based on the NP concentrations. Similarly, root length (RL) was positively and significantly affected by NP treatment, with an MD (95% CI) of 0.92 (0.76, 1.09) for the zinc (Zn)-NP subgroup, 0.79 (0.65, 0.92) for the other-NP subgroup, 0.82 (0.72, 0.93) for the total based on the NP types, 0.90 (0.77, 1.04) for the “Concentrations: ≤ 50 mg/L” subgroup, 0.80 (0.60, 0.99) for the “Concentrations: > 50 mg/L” subgroup, and 0.82 (0.72, 0.93) for the total based on the NP concentrations. However, there was no statistical correlation between the nanoparticle concentrations and shoot length (SL), due to the inclusion of zero in the 95% CI of the overall effect. Therefore, Ag-NPs could increase the FGP more than other-NPs, while Zn-NPs enhanced RL more. Moreover, NPs at lower concentrations could improve the FGP and RL of crop species to a larger extent than NPs at higher concentrations. This meta-analysis can provide a reference for the nanoparticle treatment technology utilization in agricultural and forest seeds.

Metal/Metalloid-Based Nanomaterials for Plant Abiotic Stress Tolerance: An Overview of the Mechanisms

In agriculture, abiotic stress is one of the critical issues impacting the crop productivity and yield. Such stress factors lead to the generation of reactive oxygen species, membrane damage, and other plant metabolic activities. To neutralize the harmful effects of abiotic stress, several strategies have been employed that include the utilization of nanomaterials. Nanomaterials are now gaining attention worldwide to protect plant growth against abiotic stresses such as drought, salinity, heavy metals, extreme temperatures, flooding, etc. However, their behavior is significantly impacted by the dose in which they are being used in agriculture. Furthermore, the action of nanomaterials in plants under various stresses still require understanding. Hence, with this background, the present review envisages to highlight beneficial role of nanomaterials in plants, their mode of action, and their mechanism in overcoming various abiotic stresses. It also emphasizes upon antioxidant activities of different nanomaterials and their dose-dependent variability in plants' growth under stress. Nevertheless, limitations of using nanomaterials in agriculture are also presented in this review.

Recent Trends in Nano-Fertilizers for Sustainable Agriculture under Climate Change for Global Food Security

Nano-fertilizers (NFs) significantly improve soil quality and plant growth performance and enhance crop production with quality fruits/grains. The management of macro-micronutrients is a big task globally, as it relies predominantly on synthetic chemical fertilizers which may not be environmentally friendly for human beings and may be expensive for farmers. NFs may enhance nutrient uptake and plant production by regulating the availability of fertilizers in the rhizosphere; extend stress resistance by improving nutritional capacity; and increase plant defense mechanisms. They may also substitute for synthetic fertilizers for sustainable agriculture, being found more suitable for stimulation of plant development. They are associated with mitigating environmental stresses and enhancing tolerance abilities under adverse atmospheric eco-variables. Recent trends in NFs explored relevant agri-technology to fill the gaps and assure long-term beneficial agriculture strategies to safeguard food security globally. Accordingly, nanoparticles are emerging as a cutting-edge agri-technology for agri-improvement in the near future. Interestingly, they do confer stress resistance capabilities to crop plants. The effective and appropriate mechanisms are revealed in this article to update researchers widely.

Impact of silver nanoparticles as antibacterial agent derived from leaf and callus of Celastrus paniculatus Willd

Background

Celastrus paniculatus Willd. is a rich source of numerous active constituents such as celapanigin, celapagin, malkangunin, celapanin, zeylasteral, pristimerin, and zeylasterone which render medicinal properties to its various parts. Therefore, the present work provides a protocol for the synthesis of AgNPs from in vivo leaf and in vitro developed callus extract of C. paniculatus and both the extracts have great antibacterial potential, which may give immense support for the drug preparation using AgNPs prepared from this valuable medicinal plant.

Results

High frequencies of calli induced from leaves and its counterpart, i.e., the natural part leaf were selected as the experimental materials for the green synthesis. The collected data exhibited gradual color variations started with whitish color, creamish, and after 8 weeks it ultimately turns into a solid mass of brownish callus. The silver nanoparticles (AgNPs) were synthesized using in vivo fresh leaves and in vitro developed callus extracts with an indication of brown colored complex. Further confirmation of AgNPs synthesis in both the samples was done using UV-visible spectral analysis followed by X-ray diffraction (XRD) analysis, Fourier transformation infrared spectroscopy (FTIR), and scanning electron microscopic (SEM) analysis.

Conclusion

The antibacterial activity of both extracts reflected the presence of the zone of inhibition in both gram-positive and gram-negative bacteria. AgNPs derived from callus extract showed better results with 24.00 ± 1.00 mm zones of inhibition. This protocol deserves the recognition of the antibacterial potential of AgNPs synthesized from CP plant extracts.

Interactions of nanoparticles and salinity stress at physiological, biochemical and molecular levels in plants: A review

Salinity stress is one of the most destructive non-biological stresses in plants that has adversely affected many agricultural lands in the world. Salinity stress causes many morphological, physiological, epigenetic and genetic changes in plants by increasing sodium and chlorine ions in the plant cells. The plants can alleviate this disorder to some extent through various mechanisms and return the cell to its original state, but if the salt dose is high, the plants may not be able to provide a proper response and can die due to salt stress. Nowadays, scientists have offered many solutions to this problem. Nanotechnology is one of the most emerging and efficient technologies that has been entered in this field and has recorded very brilliant results. Although some studies have confirmed the positive effects of nontechnology on plants under salinity stress, there is no the complete understanding of the relationship and interaction of nanoparticles and intracellular mechanisms in the plants. In the review paper, we have tried to reach a conclusion from the latest articles that how NPs could help salt-stressed plants to recover their cells under salt stress so that we can take a step towards clearing the existing ambiguities for researchers in this field.

Growth-Promoting Gold Nanoparticles Decrease Stress Responses in Arabidopsis Seedlings

The global economic success of man-made nanoscale materials has led to a higher production rate and diversification of emission sources in the environment. For these reasons, novel nanosafety approaches to assess the environmental impact of engineered nanomaterials are required. While studying the potential toxicity of metal nanoparticles (NPs), we realized that gold nanoparticles (AuNPs) have a growth-promoting rather than a stress-inducing effect. In this study we established stable short- and long-term exposition systems for testing plant responses to NPs. Exposure of plants to moderate concentrations of AuNPs resulted in enhanced growth of the plants with longer primary roots, more and longer lateral roots and increased rosette diameter, and reduced oxidative stress responses elicited by the immune-stimulatory PAMP flg22. Our data did not reveal any detrimental effects of AuNPs on plants but clearly showed positive effects on growth, presumably by their protective influence on oxidative stress responses. Differential transcriptomics and proteomics analyses revealed that oxidative stress responses are downregulated whereas growth-promoting genes/proteins are upregulated. These omics datasets after AuNP exposure can now be exploited to study the underlying molecular mechanisms of AuNP-induced growth-promotion.

Effect of Fe3O4 nanoparticles on seed germination in tobacco

Many studies on the toxicity of nanoparticles (NPs) have reported different levels of toxicity for various types of NPs. This study aimed to examine the morpho-ultrastructural impact of iron oxide (Fe3O4) NPs on seed germination in tobacco (Nicotiana tabacum var. Turkish) using different sizes and concentrations of nanoparticles. Seeds were allowed to germinate in the presence of (Fe3O4) NPs of three different sizes (5, 10, and 20 nm) at three different concentrations 3, 10, and 30 mg/L for each size. Seeds were assessed using light and transmission microscopy. Radical lengths and seed germination rate were significantly affected (positively or negatively) in all NPs-treated seeds compared to control seeds. The radical lengths in 5 nm-treated seeds (30 mg/L concentration) and 10 nm-treated seeds (10 and 30 mg/L concentrations) were significantly shorter than control seeds. In contrast, the radical lengths in 10 nm-treated seeds (3 mg/L concentration) and 20 nm-treated seeds (10 mg/L concentration) were significantly longer than control seeds. Most NPs-treated seeds exhibited significant higher seed germination except for seeds treated with 5 nm NPs (3 mg/L concentration). Moreover, thick and thin micrographs of radicles and leaflets of 5 nm NPs-treated seeds (30 mg/L concentration) and 10 nm NPs (30 mg/L concentration) showed structural and ultrastructural deformation. Thus, these findings confirm that the toxicity and the bioaccumulation of (Fe3O4) NPs were size and concentration dependent.

Biosynthesis and Characterization of ZnO Nanoparticles Using Ochradenus arabicus and Their Effect on Growth and Antioxidant Systems of Maerua oblongifolia

Zincoxide nanoparticles (ZnO NPs) are among the most produced and used nanomaterials worldwide, and in recent times these nanoparticles have also been incorporate in plant science and agricultural research. The present study was planned to synthesize ZnO NPs biologically using Ochradenus arabicus leaves and examine their effect on the morphology and physiology properties of Maerua oblongifolia cultured in vitro. ZnO NPs were characterized by UV-visible spectroscopy (UV-vis), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy, which demonstrated hexagonal shape nanoparticles of size ranging from 10 to 50 nm. Thus, the study uncovered an efficient, eco-friendly and simple technique for biosynthesis of multifunctional ZnO NPs using Ochradenus arabicus following growth of Maerua oblongifolia shoots in different concentrations of ZnO NPs (0, 1.25, 2.5, 5, 10, or 20 mg L^-1) in Murashige and Skoog medium. Remarkable increases in plant biomass, photosynthetic pigments, and total protein were recorded up to a concentration of 5 mg L^-1; at the same time, the results demonstrated a significant reduction in lipid peroxidation levels with respect to control. Interestingly, the levels of proline and the antioxidant enzyme catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) activities were increased significantly in response to all ZnO NP treatments. These findings indicate that bioengineered ZnO NPs play a major role in accumulation of biomass and stimulating the activities of antioxidant enzymes in plant tissues. Thus, green-synthesized ZnO NPs might be of agricultural and medicinal benefit owing to their impacts on plants in vitro.

Cross-Species Comparisons of Nanoparticle Interactions with Innate Immune Systems: A Methodological Review

Many components of the innate immune system are evolutionarily conserved and shared across many living organisms, from plants and invertebrates to humans. Therefore, these shared features can allow the comparative study of potentially dangerous substances, such as engineered nanoparticles (NPs). However, differences of methodology and procedure between diverse species and models make comparison of innate immune responses to NPs between organisms difficult in many cases. To this aim, this review provides an overview of suitable methods and assays that can be used to measure NP immune interactions across species in a multidisciplinary approach. The first part of this review describes the main innate immune defense characteristics of the selected models that can be associated to NPs exposure. In the second part, the different modes of exposure to NPs across models (considering isolated cells or whole organisms) and the main endpoints measured are discussed. In this synergistic perspective, we provide an overview of the current state of important cross-disciplinary immunological models to study NP-immune interactions and identify future research needs. As such, this paper could be used as a methodological reference point for future nano-immunosafety studies.

Effects of metal nanoparticle-mediated treatment on seed quality parameters of different crops

The increasing population of the world requires novel techniques to feed everyone, which can replace or work along with traditional methods to increase production of agricultural crops. In recent times, nanotechnology is considered as a promising and emerging approach to be incorporated in agriculture to improve productivity of different crops by the administration of nanoparticles through seed treatment, foliar spray on plants, nano-fertilizers for balanced crop nutrition, nano-herbicides for effective weed control, nanoinsecticides for plant protection, early detection of plant diseases and nutrient deficiencies using diagnostics kits, and nano-pheromones for effective monitoring of pests. Further, distinct nanoparticles with unique physicochemical and biological properties are used in agriculture to increase the percentage of seed germination, which is the initial step to increase the crop yield. In the context of agricultural crops, nanoparticles have both positive effects on seed quality parameters, such as germination percentage, seedling length, seedling dry weight and vigor indices, as well as negative impacts of causing toxicity toward the environment. Thus, the aim of this review article is to provide a comprehensive overview on the effects of super-dispersive metal powders, such as zinc, silver, and titanium nanoparticles on the seed quality parameters of different crops. In addition, the drawback of conventional seed growth enhancers, impact of metal nanoparticles toward seeds, and mechanism of nanoparticles to increase seed germination were also discussed.