Impacts of Silver Nanoparticles on Plants: A Focus on the Phytotoxicity and Underlying Mechanism

A Green Integrated Approach to Multifunctional Silver Nanoparticles Derived from Aronia melanocarpa

Background/Objectives: This study reports the green synthesis, optimization, characterization, and multifunctional evaluation of silver nanoparticles (AgNPs) using an ethanolic Aronia melanocarpa berry extract. The objective was to establish optimal synthesis conditions; assess the in vitro stability; and evaluate the antioxidant, photocatalytic, and photoprotective activities. Methods: The cytogenotoxic effects of the AgNPs were evaluated on Triticum aestivum roots. The AgNPs were synthesized via bioreduction using an ethanolic extract of A. melanocarpa under varied pH, AgNO3 concentration, extract/AgNO3 ratio, temperature, and stirring time, with optimization guided by UV-Vis spectral analysis. The AgNPs were further characterized by FTIR, DLS, TEM, and EDX. In vitro stability was evaluated over six months in different dispersion media (ultrapure water; 5% NaCl; and PBS at pH 6, 7, and 8). Biological assessments included antioxidant assays (lipoxygenase inhibition, DPPH radical scavenging, metal chelation, and hydroxyl radical scavenging), photocatalytic dye degradation, and SPF determination. Results: Optimal synthesis was achieved at pH 8, 3 mM AgNO3, extract/AgNO3 ratio of 1:9, 40 °C, and 240 min stirring. The AgNPs were spherical (TEM), well dispersed (PDI = 0.32), and highly stable (zeta potential = -40.71 mV). PBS pH 6 and 7 ensured the best long-term colloidal stability. The AgNPs displayed strong dose-dependent antioxidant activity, with superior lipoxygenase inhibition (EC50 = 18.29 µg/mL) and the effective photocatalytic degradation of dyes under sunlight. Photoprotective properties were confirmed through UV absorption analysis. The AgNPs showed a strong antimitotic effect on wheat root cells. Conclusions: The study demonstrates that A. melanocarpa-mediated AgNPs are stable, biologically active, and suitable for potential biomedical, cosmetic, and environmental applications, reinforcing the relevance of plant-based nanotechnology.

Ecotoxicity of fungal-synthesized silver nanoparticles: mechanisms, impacts, and sustainable mitigation strategies

The review investigates the ecotoxicological implications of fungal-synthesized silver nanoparticles (AgNPs), focusing on their behavior, transformations, and impacts across aquatic and terrestrial ecosystems. Advanced techniques, such as Single-Particle ICP-MS and Nanoparticle Tracking Analysis, reveal the persistence and biotransformation of AgNPs, including silver ion (Ag⁺) release and reactive oxygen species (ROS) generation. The review highlights species-specific bio-accumulation pathways in algae, soil microbes, invertebrates, and vertebrates, along with the limited biomagnification potential within trophic levels. Long-term exposure to AgNPs leads to reduced soil fertility, altered microbial communities, and inhibited plant growth, raising significant ecological concerns. Sustainable mitigation strategies, including bioremediation and advanced filtration systems, are proposed to reduce the environmental risks of AgNPs. This comprehensive analysis provides a framework for future ecological studies and regulatory measures, balancing the technological benefits of fungal-synthesized AgNPs with their environmental safety.

Ecotoxic effect of mycogenic silver nanoparticles in water and soil environment

Silver nanoparticles (AgNPs) are one of the most widely used nanomaterials due to their antimicrobial properties. Among the AgNPs synthesis methods, the biological route has become preferable because of its efficiency and eco-friendly character. Filamentous fungi can be successfully used in biosynthesis of AgNPs. The extensive application of AgNPs and their ever increasing production raise concerns about their environmental safety. AgNPs can be released during manufacturing processes or by leaching from AgNPs-supplemented products, and then enter the natural environment. Water and soil ecosystems are most exposed to the AgNPs presence. The present study aimed at evaluating the ecotoxicological potential of AgNPs derived from Gloeophyllum striatum fungus. The assessment was performed using organisms from water and soil ecosystems. Our results suggest that the presence of AgNPs can threaten the organisms inhabiting exposed ecosystems and the adverse effects of AgNPs differ depending on the organism species. Freshwater crustacean Daphnia magna was found to be the most sensitive among the tested species with EC50 values ranging 0.026-0.027 µg/mL after 48 h exposure. Crop plants were the least affected by the presence of AgNPs with EC50 values above tested AgNPs concentration range. Moreover, it was noted that ecotoxicological potential varied depending on the AgNPs synthesis scheme and these differences were the most visible in the case of S. polyrhiza.

Role of Metal-Based Nanoparticles in Capsicum spp. Plants

Agriculture is a core activity in human civilization, constantly facing challenges with the main objective of increasing crop production; to solve this, different strategies and technologies have been used. Currently, metal-based nanoparticles (MNPs) have great potential to be used as agricultural inputs to mitigate the negative effects on crops caused by different stresses. However, studies about their impact on plants and agroecosystems require a comprehensive understanding of their effects. Chili pepper (Capsicum spp.) is a crop of global economic importance that could benefit from the use of MNPs in order to increase its production. The effects of MNPs depend on factors such as their composition, morphology, size, concentration, and application method. Both in vitro and greenhouse studies have demonstrated improvements in plant growth, response to abiotic stresses, and the induction of resistance to different pathogens. However, results vary considerably from one study to another, probably due to heterogeneity in synthesis, characterization, and application methods. This review examines recent findings about the effects of MNPs on chili pepper crops, focusing on growth, development, bioaccumulation, and response to biotic and abiotic stresses.

Diversity of copper-containing nanoparticles and their influence on plant growth and development

Copper (Cu) is an important microelement for plants, but in high concentrations it can be toxic. Cu-containing nanoparticles (Cu NPs) are less toxic, their use for plants is safer, more effective and economical than the use of Cu salts. This review presents detailed information on the chemical diversity of Cu NPs and various methods of their synthesis. The mechanisms of the effect of Cu NPs on plants are described in detail, and examples of research in this area are given. The main effects of Cu NPs on plants are reviewed including on their growth and development (organogenesis, mitosis, accumulation of biomass), biochemical processes (intensity of photosynthesis, antioxidant status and intensity of lipid peroxidation processes), gene expression, plant resistance to abiotic and biotic stress factors. The prospects of using Cu NPs as mineral fertilizers are shown by describing their stimulation effects on seed germination, plant growth and development, and on increase of plant resistance to stress factors. The protective effect of Cu NPs is often explained by their antioxidant activity. At the same time, there are a number of studies demonstrating the negative impact of Cu NPs on plant growth, development and the intensity of photosynthesis, depending on their concentration. Cu NPs have a pronounced antibacterial effect on bacterial phytopathogens of cultivated plants, as well as on a number of phytopathogenic fungi and nematodes. Thus, Cu NPs are promising agents for agriculture, while their effect on plants requires careful selection of optimal concentrations and comprehensive studies to avoid a toxic effect.

Speciation, distribution and environmental risk of dominant silver-containing nanoparticles in the Taihu Lake, China

Silver-containing nanoparticles (AgCNPs) have attracted increasing concerns because of their potential adverse effects on aquatic ecosystems. However, minimal information is available regarding their concentration, distribution, and speciation in the actual environment. In this work, different species of AgCNPs, including silver nanoparticles (AgNPs), silver chloride (AgCl NPs) and silver sulfide (Ag2S NPs) in water and sediment samples from Taihu Lake were analyzed by a multistep selective dissolution method combined with single-particle inductively coupled plasma mass spectrometry. The results showed that the concentrations of AgCNPs in the water and sediment of Taihu Lake were in the range of 0.61-3.10 × 107 particles/L and 0.57-1.41 × 109 particles/g, respectively, with mean particle sizes of 22.84 ± 1.62 nm and 20.10 ± 4.57 nm. Spatial distribution analysis indicated that AgCNPs were significantly concentrated in the northern areas of Taihu Lake. Ag2S NPs were found to be the predominant component in both water and sediment. Based on the toxicological data of AgNPs, the predicted no-effect concentration of AgNPs on freshwater species was calculated to be 0.03 μg/L. The calculated risk quotient based on the concentrations of AgNPs obtained from the species analysis was less than 0.01, indicating a low ecological risk posed by AgNPs in the Taihu Lake. This work is critical for reliable risk assessment and regulation of AgCNPs.

Nanomaterials in Agriculture: A Pathway to Enhanced Plant Growth and Abiotic Stress Resistance

Nanotechnology has emerged as a transformative field in agriculture, offering innovative solutions to enhance plant growth and resilience against abiotic stresses. This review explores the diverse applications of nanomaterials in agriculture, focusing on their role in promoting plant development and improving tolerance to drought, salinity, heavy metals, and temperature fluctuations. The method classifies nanomaterials commonly employed in plant sciences and examines their unique physicochemical properties that facilitate interactions with plants. Key mechanisms of nanomaterial uptake, transport, and influence on plants at the cellular and molecular levels are outlined, emphasizing their effects on nutrient absorption, photosynthetic efficiency, and overall biomass production. The molecular basis of stress tolerance is examined, highlighting nanomaterial-induced regulation of reactive oxygen species, antioxidant activity, gene expression, and hormonal balance. Furthermore, this review addresses the environmental and health implications of nanomaterials, emphasizing sustainable and eco-friendly approaches to mitigate potential risks. The integration of nanotechnology with precision agriculture and smart technologies promises to revolutionize agricultural practices. This review provides valuable insights into the future directions of nanomaterial R&D, paving the way for a more resilient and sustainable agricultural system.

Toxicity of copper oxide nanoparticles in barley: induction of oxidative stress, hormonal imbalance, and systemic resistances

BACKGROUND

Over the years, nanoparticles have emerged as a promising approach for improving crop growth, yield, and overall agricultural sustainability. However, there has been growing concern about the potential adverse effects of nanoparticles in the agricultural sector and the environment. The present study aimed to investigate the detrimental effects of high (1000 mg L-1) concentrations of copper oxide nanoparticles (CuO NPs) on barley seedlings. The equivalent concentrations of CuO bulk and the ionic form of copper were also used in the experiments for comparative analysis. CuO NPs were characterized by Field Emission-Scanning Electron Microscopy, Dynamic Light Scattering, Zeta Potential analysis, and X-ray Diffraction prior to the application. Barley seedlings were subjected to the foliar application of CuO NP, CuO bulk, ionic Cu, and control group. The presence of CuO NPs in barley leaves was confirmed 72 hours after treatment by energy-dispersive X-ray analysis.

RESULTS

The results showed a CuO NPs treatment led to an impairment of nutrient balance in barley leaves. An increase in hydrogen peroxide content followed by the higher specific activity of catalase and ascorbate peroxidase was also observed in response to CuO NPs, CuO bulk, and Cu2+ ions. The profile of phytohormones including auxins (IAA and IBA), Gibberellins (GA1, GA4, and GA9), abscisic acid (ABA), ethylene (ET), and jasmonic acid (JA) significantly affected by CuO NPs, CuO bulk, and Cu2+ ions. The transcripts of the PR1 gene involved in systemic acquired resistance (SAR) and LOX-1 and PAL involved in induced systemic resistance (ISR) were significantly upregulated in response to CuO NPs treatment.

CONCLUSION

Our findings suggest that the systemic resistances in barley seedlings were induced by higher accumulation of ABA, ET, and JA under CuO NPs treatment. The activation of systemic resistances indicated the involvement of both SAR and SAR pathways in the response to CuO NPs in barley.

Mineral Composition Analysis of Red Horse-Chestnut (Aesculus × Carnea) Seeds and Hydroalcoholic Crude Extract Using ICP OES

This study presents findings on the metal and metalloid composition of red horse-chestnut (Aesculus × carnea, AXC) seeds, determined by the ICP OES technique. Samples were collected from five AXC plants located in Modena (Italy) over four consecutive years (2016-2019). The seeds underwent proximate analysis, which included measurements of moisture content, proteins, lipids, carbohydrates, ash, and elemental composition. The analysis revealed consistent values for these parameters throughout the study period. The metal content of the AXC seeds can be categorized into two groups: (i) major components, with concentrations ranging from 1 to <1500 mg/100 g dry basis (d.b.), where K was identified as the most abundant element, and (ii) minor constituents, with concentrations between 1 and <1000 μg/100 g d.b., with Li, Mo, and Ti at the lower concentration limit. Comparative analyses were performed using literature data on AHP and AHH seeds, which, like AXC, belong to the Sapindaceae family and were collected from the same area and period. A hydroalcoholic extract of AXC seeds was prepared annually and characterized, with results compared to a commercial product (AXC_herb). AXC extracts had approximately 30% higher analyte concentrations than AXC_herb, while AXC seeds showed 20-30% higher metal and metalloid levels than AHP and AHH.

Advancing food safety with biogenic silver nanoparticles: Addressing antimicrobial resistance, sustainability, and commercial viability

The escalating threat of antimicrobial resistance (AMR), particularly among foodborne pathogens such as Escherichia coli, Salmonella enterica, and Listeria monocytogenes, necessitates innovative solutions beyond conventional antimicrobials. Silver nanoparticles (AgNPs) have garnered significant attention for their broad-spectrum antimicrobial efficacy, ability to target multidrug-resistant strains, and versatile applications across the food sector. This review critically examines AgNPs' integration into food safety strategies, including their roles in antimicrobial food packaging, agricultural productivity enhancement, and livestock disease mitigation. Key advancements in eco-friendly synthesis methods, leveraging algae, agricultural byproducts, and microbial systems, are highlighted as pathways to address scalability, sustainability, and cost constraints. However, the potential risks of silver bioaccumulation, environmental toxicity, and regulatory challenges present significant barriers to their widespread implementation. By reviewing cutting-edge research, this review provides a comprehensive analysis of AgNP efficacy, safety, and commercial viability, proposing a roadmap for overcoming current limitations. It calls for collaborative, interdisciplinary efforts to bridge technological, ecological, and regulatory gaps, positioning AgNPs as a transformative solution for combating AMR and ensuring global food security.

Nano-delivery platforms for bacterial gene transformation: suitability and challenges

Nano-scale particles (NPs) have gained increased interest as non-viral vectors for nucleic acid delivery due to their ability to penetrate through unabraded cell membranes. The previous studies performed have evaluated the nanomaterials for their microbial transformation proficiency but have not compared the relative efficacy. The present study aims to identify the most proficient nano-delivery vehicle among the chemically synthesized/functionalized non-metal oxide, metal/metal oxide, and carbon-based (carbon nanotube (CNT), graphene oxide (GO)) nanomaterial(s) (NMs) for the transformation of two gram-negative bacteria, i.e., Escherichia coli and Agrobacterium tumefaciens. The microscopy and spectroscopy studies helped to identify the interaction, adhesion patterns, transformation efficiencies, better delivery, and expression of the target gfp gene by use of NMs. Loading of pgfp on all NMs imparted protection to DNAse I attack except ZnO NPs with maximum by chitosan, layered double hydroxide (LDH), and GO NM-plasmid DNA conjugates. The CNTs and GO significantly enhanced the extra- and intra-cellular protein content, respectively, in both bacteria. However, GO and CNT significantly decreased the cell viability in a time-dependent manner while AuNPs exhibited negligible cell toxicity. Therefore, this study identified the comparative efficiency of metal/metal oxide, non-metal oxide, and carbon nanomaterials with AuNPs as the most biosafe while LDH and chitosan NPs being the most proficient alternative tools for the genetic transformation of gram-negative bacteria by simple incubation method.

A review on green synthesis of silver nanoparticles (SNPs) using plant extracts: a multifaceted approach in photocatalysis, environmental remediation, and biomedicine

A sustainable and viable alternative for conventional chemical and physical approaches is the green production of silver nanoparticles (SNPs) using plant extracts. This review centers on the diverse applications of plant-mediated SNPs in biomedicine, environmental remediation, and photocatalysis. Ocimum sanctum (tulsi), Curcuma longa (turmeric), and Azadirachta indica (neem) and many others are plant extracts that have been used as stabilizing and reducing agents because of their extensive phytochemical profiles. The resulting SNPs have outstanding qualities, such as better photocatalytic degradation of organic dyes like methylene blue, antibacterial efficacy towards multidrug-resistant pathogens, biocompatibility for possible therapeutic applications, and regulated magnitude (10-50 nm), enhanced rigidity, and tunable surface plasmon resonance. Significant effects of plant extract type, amount, and synthesis parameters on the physical and functional characteristics of SNPs are revealed by key findings. Along with highlighting important issues and potential paths forward, this review also underlines the necessity of scalable production, thorough toxicity evaluations, and investigating the incorporation of SNPs into commercial applications. This work highlights how plant-based SNPs can be used to address global environmental and biological concerns by straddling the division between sustainable chemistry and nanotechnology.

Current insights into the green synthesis, in planta characterization and phytoeffects of nickel nanoparticles and their agricultural implications

The intensifying production and release into the environment as well as the increasing potential in agricultural applications make the relationship between plants and nickel nanoparticles (Ni NPs) a relevant and timely topic. The aim of this review is to give an overview and discuss the latest findings about the relationship of Ni NPs and plants. Ni NPs can be synthesized using phytochemicals derived from plant parts in an environmentally friendly manner. There are several ways for these nanoparticles to enter plant cells and tissues. This can be demonstrated through various imaging and chemical mapping approaches (e.g., transmission electron microscopy, X-ray fluorescence spectroscopy etc.). NiO NPs affect plants at multiple levels, including subcellular, cellular, tissue, organ, and whole-plant levels. However, the effects of Ni NPs on plants' ecological partners (e.g., rhizobiome, pollinators) remain largely unknown despite their ecotoxicological significance. The main cause of the Ni NPs-triggered damages is the reactive oxygen species imbalance as a consequence of the modulation of antioxidants. In non-tolerant plants, the toxicity of NiO NPs can be mitigated by exogenous treatments such as the application of silicon, salicylic acid, or jasmonic acid, which induce defense mechanisms whereas Ni-hypertolerant plant species possess endogenous defense systems, such as cell wall modifications and nitrosative signaling against NiO NP stress. Research highlights the role of Ni NPs in managing fungal diseases, showcasing their antifungal properties against specific pathogens. Due to the essentiality of Ni, the application of Ni NPs as nanofertilizers might be promising and has recently started to come into view.

Plant extract-mediated biosynthesis of sulphur nanoparticles and their antibacterial and plant growth-promoting activity

This study reports green synthesis of sulphur nanoparticles using sodium thiosulfate pentahydrate (Na2S2O35H2O) and Cannabis sativa leaf extracts. X-ray diffraction (XRD) pattern and scanning electron microscopy (SEM) was employed to examine the crystallinity of the particles and morphological characteristics, proved both spherical and rod-shaped morphology of the S NPs having porous nature. The FTIR spectra revealed the interaction of the synthesized SNPs with the biomolecules present in the leaf extract. UV-VIS spectral investigations confirmed the production of SNPs from C. sativa leaf extract and that these SNPs can be used for visible region photocatalysis for the removal of pollutants from wastewater. Energy dispersive X-ray (EDX) spectrum of the SNP shows a single peak around 2.4 keV, confirmed S NPs purity. TEM image revealed the formation of mainly nanorods having a width of ∼20-25 nm and a length of 50-100 nm. Furthermore, some spherical particles (∼20-30 nm) were also formed. HRTEM image of the rod-shaped particles clearly shows the crystal fringe spacing of 0.38 nm. Further, disc diffusion method (DDM) was used to check the antibacterial activity of S NPs against gram-positive S. aureus (MTCC737) 18 ± 0.12 mm and gram-negative bacteria against E. coli (MTCC443) 21.5 ± 0.12 mm, A. salmonicida (MTCC1522) 19.1 ± 0.12 mm, K. pneumoniae (MTCC3384) 17.8 ± 0.10 mm. Among all the strains of bacteria, E. coli (MTCC443) showed a maximum zone of inhibition of 21.5 ± 0.12 mm and its antibacterial activity is somewhat like streptomycin sulfate. These SNPs also promote growth of C. sativa in pot experiment, resulting in a 30 % increase in biomass, 90 cm in shoot length and 28 cm in root length and higher fresh and dry weight (50g and 20g, respectively) with 1.0 mg mL-1 NPs treatment. In addition, SEM-EDX confirmed the accumulation of nanomaterial in plant leaves. This environmentally friendly approach to SNP synthesis using C. sativa extracts demonstrates both potent antibacterial properties and plant growth-promoting effects, making it a promising solution for agriculture and biomedicine.

Silicon Nanomaterials Enhance Seedling Growth and Plant Adaptation to Acidic Soil by Promoting Photosynthesis and Antioxidant Activity in Mustard (Brassica campestris L.)

Soil acidity is a divesting factor that restricts crop growth and productivity. Conversely, silicon nanomaterials (Si-NMs) have been praised as a blessing of modern agricultural intensification by overcoming the ecological barrier. Here, we performed a sequential study from seed germination to the yield performance of mustard (Brassica campestris) crops under acid-stressed conditions. The results showed that Si-NMs significantly improved seed germination and seedling growth under acid stress situations. These might be associated with increased antioxidant activity and the preserve ratio of GSH/GSSG and AsA/DHA, which is restricted by soil acidity. Moreover, Si-NMs in field regimes significantly diminished the acid-stress-induced growth inhibitions, as evidenced by increased net photosynthesis and biomass accumulations. Again, Si-NMs triggered all the critical metrics of crop productivity, including the seed oil content. Additionally, Si-NMs, upon dolomite supplementation, further triggered all the metrics of yields related to farming resilience. Therefore, the present study highlighted the crucial roles of Si-NMs in sustainable agricultural expansion and cropping intensification, especially in areas affected by soil acidity.

Evaluation of the Effects of High Silver and Copper Nanoparticle Concentrations on Vaccinium myrtillus L. under Field Conditions

The extensive development of nanotechnologies has allowed nanoparticles to impact living systems through different pathways. The effect of single exposure to high concentrations of silver and copper nanoparticles (50-200 mg/L) on Vaccinium myrtillus L. under field conditions was investigated. Nanoparticle uptake in different segments of Vaccinium myrtillus L. was assessed by applying inductively coupled plasma-atomic emission spectroscopy and a particle-induced X-ray emission technique. Copper nanoparticles mainly accumulated in the roots and leaves, while silver nanoparticles showed a higher affinity for the roots and berries. The nanoparticles' effects on the pigments and antioxidant activity of the plant's leaves were also evaluated. The possible human health risk associated with the consumption of nanoparticle-contaminated berries was assessed. The results indicated that the consumption of berries contaminated with nanoparticles presented a low risk for human health.

Effect of silver nanoparticles foliar application on the nutritional properties of potato tubers

The aim of presented study was to test nutritional properties of potato tubers and silver ions accumulation pattern after foliar application of silver nanoparticles (AgNPs) during potato vegetation. Potato plants were sprayed with different concentration of Ag nanoparticles (0.1, 1.0 and 10 mg·dm-3) synthesized with incorporation with sodium dodecyl sulphate (SDS) and sodium citrate as stabilizing agent. The lowest amounts of silver ions were transported to the tubers after spraying with AgNPs synthesized with SDS, rather than with citrate. Nevertheless silver ions accumulation in tubers was negligible. SDS method of synthesis was more favourable in terms of nutritional properties of potato tubers. The highest tested concentration of AgNPs_SDS had a favourable effect on a variety of macro- and micronutrients, ascorbic acid and soluble sugars. In turn, lower concentrations of AgNPs_SDS increased the content of phenolic compounds and free radical scavenging efficiency of tubers. These correlations were also confirmed by Principal Component Analysis.

Unveiling influences of metal-based nanomaterials on wheat growth and physiology: From benefits to detriments

Metal-based nanomaterials (MNs) are widely used in agricultural production. However, our current understanding of the overall effects of MNs on crop health is insufficient. A global meta-analysis of 144 studies involving approximately 2000 paired observations was conducted to explore the impacts of MNs on wheat growth and physiology. Our analysis revealed that the MN type plays a key role in influencing wheat growth. Ag MNs had significant negative effects on wheat growth and physiology, whereas Fe, Ti, and Zn MNs significantly increased wheat biomass and photosynthesis. Our study also observed a clear dose-specific effect, with a decrease in wheat shoot biomass with increasing MN concentrations. Meanwhile, MNs with small sizes (<25 nm) have no significant impacts on wheat growth. Furthermore, both the root and foliar applications significantly improved wheat growth, with no considerable differences. Using a machine learning approach, we found that the MN type was the main driving factor affecting wheat shoot biomass, followed by MN dose and size. Overall, wheat growth and physiology can be negatively influenced by specific MNs, for which a high dose and small size should be avoided in practical applications. Therefore, our study can provide insights into the future design and safe use of MNs in agriculture and increase the public acceptance of nano-agriculture.

Nutrient strengthening and lead alleviation in Brassica Napus L. by foliar ZnO and TiO2-NPs modulating antioxidant system, improving photosynthetic efficiency and reducing lead uptake

With the anticipated foliar application of nanoparticles (NPs) as a potential strategy to improve crop production and ameliorate heavy metal toxicity, it is crucial to evaluate the role of NPs in improving the nutrient content of plants under Lead (Pb) stress for achieving higher agriculture productivity to ensure food security. Herein, Brassica napus L. grown under Pb contaminated soil (300 mg/kg) was sprayed with different rates (0, 25, 50, and 100 mg/L) of TiO2 and ZnO-NPs. The plants were evaluated for growth attributes, photosynthetic pigments, leaf exchange attributes, oxidant and antioxidant enzyme activities. The results revealed that 100 mg/L NPs foliar application significantly augmented plant growth, photosynthetic pigments, and leaf gas exchange attributes. Furthermore, 100 mg/L TiO2 and ZnO-NPs application showed a maximum increase in SPAD values (79.1%, 68.9%). NPs foliar application (100 mg/L TiO2 and ZnO-NPs) also substantially reduced malondialdehyde (44.3%, 38.3%), hydrogen peroxide (59.9%, 53.1%), electrolyte leakage (74.8%, 68.3%), and increased peroxidase (93.8%, 89.1%), catalase (91.3%, 84.1%), superoxide dismutase (81.8%, 73.5%) and ascorbate peroxidase (78.5%, 73.7%) thereby reducing Pb accumulation. NPs foliar application (100 mg/L) significantly reduced root Pb (45.7%, 42.3%) and shoot Pb (84.1%, 76.7%) concentration in TiO2 and ZnO-NPs respectively, as compared to control. Importantly, macro and micronutrient analysis showed that foliar application 100 mg/L TiO2 and ZnO-NPs increased shoot zinc (58.4%, 78.7%) iron (79.3%, 89.9%), manganese (62.8%, 68.6%), magnesium (72.1%, 93.7%), calcium (58.2%, 69.9%) and potassium (81.5%, 68.6%) when compared to control without NPs. The same trend was observed for root nutrient concentration. In conclusion, we found that the TiO2 and ZnO-NPs have the greatest efficiency at 100 mg/L concentration to alleviate Pb induced toxicity on growth, photosynthesis, and nutrient content of Brassica napus L. NPs foliar application is a promising strategy to ensure sustainable agriculture and food safety under metal contamination.

Interaction of plants and metal nanoparticles: Exploring its molecular mechanisms for sustainable agriculture and crop improvement

Metal nanoparticles offer promising prospects in agriculture, enhancing plant growth and ensuring food security. Silver, gold, copper, and zinc nanoparticles possess unique properties making them attractive for plant applications. Understanding molecular interactions between metal nanoparticles and plants is crucial for unlocking their potential to boost crop productivity and sustainability. This review explores metal nanoparticles in agriculture, emphasizing the need to understand these interactions. By elucidating mechanisms, it highlights the potential for enhancing crop productivity, stress tolerance, and nutrient-use efficiency, contributing to sustainable agriculture and food security. Quantifying benefits and risks reveal significant advantages. Metal nanoparticles enhance crop productivity by 20% on average and reduce disease incidence by up to 50% when used as antimicrobial agents. They also reduce nutrient leaching by 30% and enhance soil carbon sequestration by 15%, but concerns about toxicity, adverse effects on non-target organisms, and nanoparticle accumulation in the food chain must be addressed. Metal nanoparticles influence cellular processes including sensing, signaling, transcription, translation, and post-translational modifications. They act as signaling molecules, activate stress-responsive genes, enhance defense mechanisms, and improve nutrient uptake. The review explores their catalytic role in nutrient management, disease control, precision agriculture, nano-fertilizers, and nano-remediation. A bibliometric analysis offers insights into the current research landscape, highlighting trends, gaps, and future directions. In conclusion, metal nanoparticles hold potential for revolutionizing agriculture, enhancing productivity, mitigating environmental stressors, and promoting sustainability. Addressing risks and gaps is crucial for their safe integration into agricultural practices.

Effects of particle size on toxicity, bioaccumulation, and translocation of zinc oxide nanoparticles to bok choy (Brassica chinensis L.) in garden soil

The indiscriminate use of zinc oxide nanoparticles (ZnO NPs) in daily life can lead to their release into soil environment. These ZnO NPs can be taken up by crops and translocated to their edible part, potentially causing risks to the ecosystem and human health. In this study, we conducted pot experiments to determine phytotoxicity, bioaccumulation and translocation depending on the size (10 - 30 nm, 80 - 200 nm and 300 nm diameter) and concentration (0, 100, 500 and 1000 mg Zn/kg) of ZnO NPs and Zn ion (Zn2+) in bok choy, a leafy green vegetable crop. After 14 days of exposure, our results showed that large-sized ZnO NPs (i.e., 300 nm) at the highest concentration exhibited greater phytotoxicity, including obstruction of leaf and root weight (42.5 % and 33.8 %, respectively) and reduction of chlorophyll a and b content (50.2 % and 85.2 %, respectively), as well as changes in the activities of oxidative stress responses compared to those of small-sized ZnO NPs, although their translocation ability was relatively lower than that of smaller ones. The translocation factor (TF) values decreased as the size of ZnO NPs increased, with TF values of 0.68 for 10 - 30 nm, 0.55 for 80 - 200 nm, and 0.27 for 300 nm ZnO NPs, all at the highest exposure concentration. Both the results of micro X-ray fluorescence (μ-XRF) spectrometer and bio-transmission electron microscopy (bio-TEM) showed that the Zn elements were mainly localized at the edges of leaves exposed to small-sized ZnO NPs. However, the Zn elements upon exposure to large-sized ZnO NP were primarily observed in the primary veins of leaves in the μ-XRF data, indicating a limitation in their ability to translocate from roots to leaves. This study not only advances our comprehension of the environmental impact of nanotechnology but also holds considerable implications for the future of sustainable agriculture and food safety.

Beneficial role of Coronatine on the morphological and physiological responses of Cress Plants (Lepidium sativum) exposed to Silver Nanoparticle

BACKGROUND

Silver nanoparticles are widely used in various fields such as industry, medicine, biotechnology, and agriculture. However, the inevitable release of these nanoparticles into the environment poses potential risks to ecosystems and may affect plant productivity. Coronatine is one of the newly identified compounds known for its beneficial influence on enhancing plant resilience against various stress factors. To evaluate the effectiveness of coronatine pretreatment in mitigating the stress induced by silver nanoparticles on cress plants, the present study was carried out.

RESULTS

Our findings indicated a decrease in multiple growth parameters, proline content, chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in cress plants exposed to silver nanoparticle treatment. This decline could be attributed to the oxidative stress induced by the presence of silver nanoparticles in the plants. Conversely, when coronatine treatment was applied, it effectively mitigated the reduction in growth parameters and pigments induced by the silver nanoparticles. Furthermore, we observed an increase in silver content in both the roots and shoot portions, along with elevated levels of malondialdehyde (MDA) content, hydrogen peroxide (H2O2), anthocyanins, glutathione (GSH), and antioxidant enzyme activities in plants exposed to silver nanoparticles. Concurrently, there was a decrease in total phenolic compounds, ascorbate, anthocyanins, and proline content. Pre-treatment of cress seeds with coronatine resulted in increased levels of GSH, total phenolic compounds, and proline content while reducing the silver content in both the root and shoot parts of the plant.

CONCLUSIONS

Coronatine pre-treatment appeared to enhance both enzymatic and non-enzymatic antioxidant activities, thereby alleviating oxidative stress and improving the response to stress induced by silver nanoparticles.

Nanomaterials in the environment and their pragmatic voyage at various trophic levels in an ecosystem

In the development of nanotechnology, nanomaterials (NMs) have a huge credential in advancing the existing follow-ups of analytical and diagnosis techniques, drug designing, agricultural science, electronics, cosmetics, sports, textiles and water purification. However, NMs have also grasped attention of researchers onto their toxicity. In the present review, initially the development of notable NMs such as metal and metal-oxide nanoparticles (NPs), magnetic NPs, carbon-based NMs and quantum dots intended to be commercialized along with their applications are discussed. This is followed by the current scenario of NMs in the environment to widen the outlook on the concentration of NPs in the environmental compartments and the frequency of organism exposed to NPs at varied trophic levels. In order to understand the physiochemical and morphological significance of NPs in exhibiting toxicity, fate of NPs in the environment is briefly deliberated. This is further geared-up to glance in-sightedly on the organisms starting from primary producer to primary consumer, secondary consumer, tertiary consumer and decomposers encountering NPs in their habitual niche. The state of NPs to which organisms are exposed, mechanism of NP uptake and toxicity, anomalies faced at each trophic level, concentration of NPs that is liable to cause toxicity and, biotransfer of NPs to the next generation and trophic level are detailed. Finally, the future prospects on bioaccumulation and biomagnification of NP-based products are conversed. Thus, the review would be noteworthy in unveiling the significance of NPs in forthcoming years combined with threat towards each organism in an ecosystem.

Agrochemical-free genetically modified and genome-edited crops: Towards achieving the United Nations sustainable development goals and a 'greener' green revolution

Sustainable farming on ever-shrinking agricultural land and declining water resources for the growing human population is one of the greatest environmental and food security challenges of the 21st century. Conventional, age-old organic farming practices alone, and foods based on costly cellular agriculture, do not have the potential to be upscaled to meet the food supply challenges for feeding large populations. Additionally, agricultural practices relying on chemical inputs have a well-documented detrimental impact on human health and the environment. As the available farming methods have reached their productivity limits, new approaches to agriculture, combining friendly, age-old farming practices with modern technologies that exclude chemical interventions, are necessary to address the food production challenges. Growing genetically modified (GM) crops without chemical inputs can allow agricultural intensification with reduced adverse health and environmental impacts. Additionally, integrating high-value pleiotropic genes in their genetic improvement coupled with the use of modern agricultural technologies, like robotics and artificial intelligence (AI), will further improve productivity. Such 'organic-GM' crops will offer consumers healthy, agrochemical-free GM produce. We believe these agricultural practices will lead to the beginning of a potentially new chemical-free GM agricultural revolution in the era of Agriculture 4.0 and help meet the targets of the United Nations Sustainable Development Goals (SDGs). Furthermore, given the advancement in the genome editing (GE) toolbox, we ought to develop a new category of 'trait-reversible GM crops' to avert the fears of those who believe in ecological damage by GM crops. Thus, in this article, we advocate farming with no or minimal chemical use by combining chemical-free organic farming with the existing biofortified and multiple stress tolerant GM crops, while focusing on the development of novel 'biofertilizer-responsive GE crops' and 'trait-reversible GE crops' for the future.

Emerging concern of nano-pollution in agro-ecosystem: Flip side of nanotechnology

Nanomaterials (NMs) have proven to be a game-changer in agriculture, showcasing their potential to boost plant growth and safeguarding crops. The agricultural sector has widely adopted NMs, benefiting from their small size, high surface area, and optical properties to augment crop productivity and provide protection against various stressors. This is attributed to their unique characteristics, contributing to their widespread use in agriculture. Human exposure from various components of agro-environmental sectors (soil, crops) NMs residues are likely to upsurge with exposure paths may stimulates bioaccumulation in food chain. With the aim to achieve sustainability, nanotechnology (NTs) do exhibit its potentials in various domains of agriculture also have its flip side too. In this review article we have opted a fusion approach using bibliometric based analysis of global research trend followed by a holistic assessment of pros and cons i.e. toxicological aspect too. Moreover, we have also tried to analyse the current scenario of policy associated with the application of NMs in agro-environment.

Unraveling the mysteries of silver nanoparticles: synthesis, characterization, antimicrobial effects and uptake translocation in plant-a review

MAIN CONCLUSION

The study thoroughly investigates nanosilver production, properties, and interactions, shedding light on its multifaceted applications. It underscores the importance of characterizing nanosilver for predicting its behavior in complex environments. Particularly, it highlights the agricultural and environmental ramifications of nanosilver uptake by plants. Nowadays, silver nanoparticles (AgNPs) are a very adaptable nanomaterial with many uses, particularly in antibacterial treatments and agricultural operations. Clarification of key elements of nanosilver, such as its synthesis and characterization procedures, antibacterial activity, and intricate interactions with plants, particularly those pertaining to uptake and translocation mechanisms, is the aim of this in-depth investigation. Nanosilver synthesis is a multifaceted process that includes a range of methodologies, including chemical, biological, and sustainable approaches that are also environmentally benign. This section provides a critical evaluation of these methods, considering their impacts on repeatability, scalability, and environmental impact. The physicochemical properties of nanosilver were determined by means of characterization procedures. This review highlights the significance of analytical approaches such as spectroscopy, microscopy, and other state-of the-art methods for fully characterizing nanosilver particles. Although grasp of these properties is necessary in order to predict the behavior and potential impacts of nanosilver in complex biological and environmental systems. The second half of this article delves into the intricate interactions that plants have with nanosilver, emphasizing the mechanisms of absorption and translocation. There are significant ramifications for agricultural and environmental problems from the uptake of nanosilver by plants and its subsequent passage through their tissues. In summary, by summarizing the state-of-the-art information in this field, this study offers a comprehensive overview of the production, characterization, antibacterial capabilities, and interactions of nanosilver with plants. This paper contributes to the ongoing conversation in nanotechnology.

Impact of silver nanoparticles on secondary metabolite composition and toxicity in anise (Pimpinella anisum L.) callus culture

BACKGROUND

There are numerous challenges associated with producing desired amounts of secondary metabolites (SMs), which are mostly unique and cannot be chemically synthesized. Many studies indicate that nanoparticles (NPs) can boost the production of SMs. Still, the precise manner in which NPs induce metabolic changes remains unidentified. This study examines the influence of eco-friendly silver NPs (AgNPs) on the chemical makeup and toxicity of Pimpinella anisum L. (anise).

RESULTS

AgNPs were introduced into anise callus cultures at different concentrations (0, 1.0, 5.0, 10, and 20 mg/L). The induced oxidative stress was tracked over intervals of 7, 14, 28, and 35 days. Chemical composition evaluations were carried out on the 35th day. Within the first 14 days, plant stress was evident, though the plant adapted to the stress later on. Notably, the plant showed high tolerance at 1 mg/L and 5 mg/L concentrations despite increased toxicity levels. However, relatively high toxicity levels were identified at 10 and 20 mg/L. The AgNP-induced stress significantly impacted anise SMs, particularly affecting fatty acid content. In the 10 and 20 mg/L AgNP groups, essential metabolites, including palmitic and linoleic acid, showed a significant increase. Polyunsaturated (omega) and monounsaturated fatty acids, vital for the food and pharmaceutical industries, saw substantial growth in the 1 and 5 mg/L AgNP groups. For the first time, vanillyl alcohol and 4-Hydroxybenzoic acid were detected along with various phenolic compounds, such as t-anethole, Salicylic acid, and Thiamazole.

CONCLUSION

AgNPs can function as an elicitor to efficiently generate essential SMs such as omegas and phenolic compounds in anise callus culture. This study explores the application of AgNPs as plant elicitors in anise SM production, offering invaluable insight into potential uses.

Biocompatible silver nanoparticles as nanopriming mediators for improved rice germination and root growth: A transcriptomic perspective

Silver nanoparticles (AgNPs) have an important role in agriculture since they have several applications that are essential for the enhanced yield of crops. Furthermore, they act as nano-pesticides, delivering a proper dose to the target plants without releasing unwanted pesticides into the environment. Upholding the sustainable nano agriculture, biocompatible silver nanoparticles were synthesised utilising Piper colubrinum Link. leaf extract. Different characterization methods (TEM, EDX and XRD) revealed that AgNPs were successfully formed and coated with phytochemicals that constituted the plant extract. Enhanced root development during the early post-germination phase is crucial for the success of direct seeding in rice cultivation. The effects of AgNPs on the growth of plant roots are poorly understood. In this work, Piper colubrinum mediated AgNPs-primed Oryza sativa L. seeds, at various concentrations (0, 50, 80, 100, and 150 mg/L), exceeded typical hydro-primed controls in terms of germination and seedling growth. Oryza sativa L. treated with AgNPs at a concentration of 80 mg/L enhanced root elongation. Additionally, exposure to AgNPs significantly enhanced the content of chlorophyll. The Kyoto Encyclopedia of Genes and Genomes (KEGG) study revealed that the identified pathways like Aromatic amino acid biosynthesis genes, Fatty acid biosynthesis genes, and Carotenoid biosynthesis genes were the most enriched. Some of the genes associated with root growth and development like glucosyltransferases, Glutathione pathway genes, Calcium-ion binding pathway genes, Peroxidase precursor and Nitrilase-associated protein were up regulated. Overall, AgNPs treatments promoted seed germination, growth, chlorophyll content and gene expression patterns, which might be attributable to the beneficial effects of AgNPs on rice.

Unraveling the impact of nanopollution on plant metabolism and ecosystem dynamics

Nanopollution (NPOs), a burgeoning consequence of the widespread use of nanoparticles (NPs) across diverse industrial and consumer domains, has emerged as a critical environmental issue. While extensive research has scrutinized the repercussions of NPs pollution on ecosystems and human health, scant attention has been directed towards unraveling its implications for plant life. This comprehensive review aims to bridge this gap by delving into the nuanced interplay between NPOs and plant metabolism, encompassing both primary and secondary processes. Our exploration encompasses an in-depth analysis of the intricate mechanisms governing the interaction between plants and NPs. This involves a thorough examination of how physicochemical properties such as size, shape, and surface characteristics influence the uptake and translocation of NPs within plant tissues. The impact of NPOs on primary metabolic processes, including photosynthesis, respiration, nutrient uptake, and water transport. Additionally, this study explored the multifaceted alterations in secondary metabolism, shedding light on the synthesis and modulation of secondary metabolites in response to NPs exposure. In assessing the consequences of NPOs for plant life, we scrutinize the potential implications for plant growth, development, and environmental interactions. The intricate relationships revealed in this review underscore the need for a holistic understanding of the plant-NPs dynamics. As NPs become increasingly prevalent in ecosystems, this investigation establishes a fundamental guide that underscores the importance of additional research to shape sustainable environmental management strategies and address the extensive effects of NPs on the development of plant life and environmental interactions.

Toxicological effects of nanoparticles in plants: Mechanisms involved at morphological, physiological, biochemical and molecular levels

The rapid advancement of nanotechnology has led to unprecedented innovations across diverse industries, including pharmaceuticals, agriculture, cosmetics, electronics, textiles, and food, owing to the unique properties of nanoparticles. The extensive production and unregulated release of synthetic nanoparticles may contribute to nanopollution within the ecosystem. In the agricultural sector, nanotechnology is increasingly utilized to improve plant productivity, enhance resistance to stressors, and reduce the usage of chemicals. However, the uncontrolled discharge of nanoparticles into the natural environment raises concerns regarding possible plant toxicological impacts. The review focuses on the translocation of these particles within the plants, emphasizing their phytotoxicological effects at morphological, physiological, biochemical, and molecular levels. Eventhough the beneficial aspects of these nanoparticles are evident, excessive usage of nanoparticles at higher concentrations may lead to potential adverse effects. The phytotoxicity resulting from excessive amounts of nanoparticles affects seed germination and biomass production, disrupts the photosynthesis system, induces oxidative stress, impacts cell membrane integrity, alters gene expression, causes DNA damage, and leads to epigenetic variations in plants. Nanoparticles are found to directly associate with the cell membrane and cell organelles, leading to the dissolution and release of toxic ions, generation of reactive oxygen species (ROS) and subsequent oxidative stress. The present study signifies and accumulates knowledge regarding the application of nanoparticles in agriculture and illustrates a clear picture of their possible impacts on plants and soil microbes, thereby paving the way for future developments in nano-agrotechnology. The review concludes by addressing current challenges and proposing future directions to comprehend and mitigate the possible biological risks associated with nanoparticles in agriculture.

Plant-nano interactions: A new insight of nano-phytotoxicity

Whether nanoparticles (NPs) are boon or bane for society has been a centre of in-depth debate and key consideration in recent times. Exclusive physicochemical properties like small size, large surface area-to-volume ratio, robust catalytic activity, immense surface energy, magnetism and superior biocompatibility make NPs obligatory in many scientific, biomedical and industrial ventures. Nano-enabled products are newer entrants in the present era. To attenuate environmental stress and maximize crop yields, scientists are tempted to introduce NPs as augmented supplements in agriculture. The feasible approaches for NPs delivery are irrigation, foliar spraying or seed priming. Internalization of excessive NPs to plants endorses negative implications at higher trophic levels via biomagnification. The characteristics of NPs (dimensions, type, solubility, surface charge), applied concentration and duration of exposure are prime factors conferring nanotoxicity in plants. Several reports approved NPs persuaded toxicity can precisely mimic abiotic stress effects. The signature effects of nanotoxicity include poor root outgrowth, biomass reduction, oxidative stress evolution, lipid peroxidation, biomolecular damage, perturbed antioxidants, genotoxicity and nutrient imbalance in plants. NPs stress impels mitogen-activated protein kinase signaling cascade and urges stress responsive defence gene expression to counteract stress in plants. Exogenous supplementation of nitric oxide (NO), arbuscular mycorrhizal fungus (AMF), phytohormones, and melatonin (ME) is novel strategy to circumvent nanotoxicity. Briefly, this review appraises plants' physio-biochemical responses and adaptation scenarios to endure NPs stress. As NPs stress represents large-scale contaminants, advanced research is indispensable to avert indiscriminate NPs usage for synchronizing nano-security in multinational markets.

Suppression of Root Rot Fungal Diseases in Common Beans (Phaseolus vulgaris L.) through the Application of Biologically Synthesized Silver Nanoparticles

The biosynthesis of silver nanoparticles (AgNPs) using plant extracts has become a safe replacement for conventional chemical synthesis methods to fight plant pathogens. In this study, the antifungal activity of biosynthesized AgNPs was evaluated both in vitro and under greenhouse conditions against root rot fungi of common beans (Phaseolus vulgaris L.), including Macrophomina phaseolina, Pythium graminicola, Rhizoctonia solani, and Sclerotium rolfsii. Among the eleven biosynthesized AgNPs, those synthesized using Alhagi graecorum plant extract displayed the highest efficacy in suppressing those fungi. The findings showed that using AgNPs made with A. graecorum at a concentration of 100 μg/mL greatly slowed down the growth of mycelium for R. solani, P. graminicola, S. rolfsii, and M. phaseolina by 92.60%, 94.44%, 75.93%, and 79.63%, respectively. Additionally, the minimum inhibitory concentration (75 μg/mL) of AgNPs synthesized by A. graecorum was very effective against all of these fungi, lowering the pre-emergence damping-off, post-emergence damping-off, and disease percent and severity in vitro and greenhouse conditions. Additionally, the treatment with AgNPs led to increased root length, shoot length, fresh weight, dry weight, and vigor index of bean seedlings compared to the control group. The synthesis of nanoparticles using A. graecorum was confirmed using various physicochemical techniques, including UV spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) analysis. Collectively, the findings of this study highlight the potential of AgNPs as an effective and environmentally sustainable approach for controlling root rot fungi in beans.

Root-Applied Cerium Oxide Nanoparticles and Their Specific Effects on Plants: A Review

With the pronounced increase in nanotechnology, it is likely that biological systems will be exposed to excess nanoparticles (NPs). Cerium oxide nanoparticles (CeO2 NPs) are among the most abundantly produced nanomaterials in the world. Their widespread use raises fundamental questions related to the accumulation in the environment and further interactions with living organisms, especially plants. NPs present in either soil or soilless environments are absorbed by the plant root systems and further transported to the aboveground parts. After entering the cytoplasm, NPs interact with chloroplast, nucleus, and other structures responsible for metabolic processes at the cellular level. In recent years, several studies have shown the impact of nanoceria on plant growth and metabolic processes. Research performed on different plants has shown a dual role for CeO2 NPs. The observed effects can be positive or negative and strongly depend on the plant species, characterization, and concentrations of NPs. This review describes the impact of root-applied CeO2 NPs on plant growth, photosynthesis, metal homeostasis, and parameters of induced oxidative stress.

Potential cellular targets of platinum in the freshwater microalgae Chlamydomonas reinhardtii and Nitzschia palea revealed by transcriptomics

Platinum group element levels have increased in natural aquatic environments in the last few decades, in particular as a consequence of the use of automobile catalytic converters on a global scale. Concentrations of Pt over tens of μg L-1 have been observed in rivers and effluents. This raises questions regarding its possible impacts on aquatic ecosystems, as Pt natural background concentrations are extremely low to undetectable. Primary producers, such as microalgae, are of great ecological importance, as they are at the base of the food web. The purpose of this work was to better understand the impact of Pt on a cellular level for freshwater unicellular algae. Two species with different characteristics, a green alga C. reinhardtii and a diatom N. palea, were studied. The bioaccumulation of Pt as well as its effect on growth were quantified. Moreover, the induction or repression factors of 16 specific genes were determined and allowed for the determination of possible intracellular effects and pathways of Pt. Both species seemed to be experiencing copper deficiency as suggested by inductions of genes linked to copper transporters. This is an indication that Pt might be internalized through the Cu(I) metabolic pathway. Moreover, Pt could possibly be excreted using an efflux pump. Other highlights include a concentration-dependent negative impact of Pt on mitochondrial metabolism for C. reinhardtii which is not observed for N. palea. These findings allowed for a better understanding of some of the possible impacts of Pt on freshwater primary producers, and also lay the foundations for the investigation of pathways for Pt entry at the base of the aquatic food web.

Silver nanoparticles in plant health: Physiological response to phytotoxicity and oxidative stress

Silver nanoparticles (AgNPs) have gained significant attention in various fields due to their unique properties, but their release into the environment has raised concerns about their environmental and biological impacts. Silver nanoparticles can enter plants following their exposure to roots or via stomata following foliar exposure. Upon penetrating the plant cells, AgNPs interact with cellular components and alter physiological and biochemical processes. One of the key concerns associated with plant exposure to AgNPs is the potential of these materials to induce oxidative stress. Silver nanoparticles can also suppress plant growth and development by disrupting essential plant physiological processes, such as photosynthesis, nutrient uptake, water transport, and hormonal regulation. In crop plants, these disruptions may, in turn, affect the productivity and quality of the harvested components and therefore represent a potential threat to agricultural productivity and ecosystem stability. Understanding the phytotoxic effects of AgNPs is crucial for assessing their environmental implications and guiding the development of safe nanomaterials. By delving into the phytotoxic effects of AgNPs, this review contributes to the existing knowledge regarding their environmental risks and promotes the advancement of sustainable nanotechnological practices.

Attenuation of photosynthesis in nanosilver-treated Arabidopsis thaliana is inherently linked to the particulate nature of silver

Silver nanoparticles (AgNPs) are known to affect the physiology and morphology of plants in various ways, but the exact mechanism by which they interact with plant cells remains to be elucidated. An unresolved question of silver nanotoxicology is whether the interaction is triggered by the physical features of the particles, or by silver ions leached from their surface. In this study, we germinated and grew Arabidopsis thaliana seedlings in synthetic medium supplemented with sub-morbid concentrations (4 μg/mL) of AgNPs and silver nitrate (AgNO3). This treatment led to in planta accumulation of 106 μg/g and 97 μg/g of silver in the AgNO3- and AgNP-exposed seedlings, respectively. Despite the statistically indistinguishable silver accumulation, RNA sequencing data demonstrated distinct changes in the transcriptome of the AgNP-exposed, but not in the AgNO3-exposed plants. AgNP exposure induced changes in the expression of genes involved in immune response, cell wall organization, photosynthesis and cellular defense against reactive oxygen species. AgNO3 exposure, on the other hand, caused the differential expression of only two genes, neither of which belonged to any AgNP-enriched gene ontology categories. Moreover, AgNP exposure led to a 39% reduction (p < 0.001) in total chlorophyll concentration relative to untreated plants which was associated with a 56.9% and 56.2% drop (p < 0.05) in carbon assimilation rate at ambient and saturating light, respectively. Stomatal conductance was not significantly affected by AgNP exposure, and limitations to carbon assimilation, as determined through analysis of light and carbon dioxide (A/Ci) curves, were attributed to rates of electron transport, maximum carboxylation rates and triose phosphate use. AgNO3-exposure, on the other hand, did not lead to significant reduction either in chlorophyll concentration or in carbon assimilation rate. Given these data, we propose that the impact of AgNPs cannot be simply attributed to the presence of the metal in plants, but is innate to the particulate nature of nanosilver.

Biospectroscopic fingerprinting phytotoxicity towards environmental monitoring for food security and contaminated site remediation

Human activities have resulted in severe environmental pollution since the industrial revolution. Phytotoxicity-based environmental monitoring is well known due to its sedentary nature, abundance, and sensitivity to environmental changes, which are essential preconditions to avoiding potential environmental and ecological risks. However, conventional morphological and physiological methods for phytotoxicity assessment mainly focus on descriptive determination rather than mechanism analysis and face challenges of labour and time-consumption, lack of standardized protocol and difficulties in data interpretation. Molecular-based tests could reveal the toxicity mechanisms but fail in real-time and in-situ monitoring because of their endpoint manner and destructive operation in collecting cellular components. Herein, we systematically propose and lay out a biospectroscopic tool (e.g., infrared and Raman spectroscopy) coupled with multivariate data analysis as a relatively non-destructive and high-throughput approach to quantitatively measure phytotoxicity levels and qualitatively profile phytotoxicity mechanisms by classifying spectral fingerprints of biomolecules in plant tissues in response to environmental stresses. With established databases and multivariate analysis, this biospectroscopic fingerprinting approach allows ultrafast, in situ and on-site diagnosis of phytotoxicity. Overall, the proposed protocol and validation of biospectroscopic fingerprinting phytotoxicity can distinguish the representative biomarkers and interrogate the relevant mechanisms to quantify the stresses of interest, e.g., environmental pollutants. This state-of-the-art concept and design broaden the knowledge of phytotoxicity assessment, advance novel implementations of phytotoxicity assay, and offer vast potential for long-term field phytotoxicity monitoring trials in situ.

The impact of various forms of silver nanoparticles on the rhizosphere of wheat (Triticum aestivum L.) - Shifts in microbiome structure and predicted microbial metabolic functions

The study investigated the effects of different silver nanoparticles (AgNPs) on the soil microbiome and wheat growth. For comparison purposes, a commercial fungicide and silver nitrate (AgNO3) were used. The results revealed three distinct groups of nanoparticles based on their impacts. Small-size AgNPs (10 nm) with a negative charge, as well as fungicide had limited effects on the microbiome, similar to the no-treatment control. Bigger in size (30-60 nm) and a negative charge AgNPs showed the most beneficial effects on soil microbiota shifts. These AgNPs increased the abundance of bacteria with beneficial traits such as nitrogen-fixing, urease, protease, and lignin degradation bacteria. The third type of AgNPs had a positive charge of nanostructure and influenced specific microbial populations, increasing the abundance of anaerobic and autotrophic groups of microorganisms, which could be assessed as a harmful shift for plants growth promotions and was similar to the AgNO3 treatment. Overall, the study emphasized the potential of AgNPs in agriculture not only as biocidal. The conducted study proved that AgNPs with bigger size/negative charge, used in low concentration can have a surprisingly stimulating effect on the positive characteristics of the rhizosphere microbiome. Moreover, the surface charge of AgNPs is a significant factor affecting microbial activity of wheat rhizosphere soil, which in this treatment is significantly similar to the AgNO3 treatment.

Recent advances in nano-fertilizers: synthesis, crop yield impact, and economic analysis

The escalating global demand for food production has predominantly relied on the extensive application of conventional fertilizers (CFs). However, the increased use of CFs has raised concerns regarding environmental risks, including soil and water contamination, especially within cereal-based cropping systems. In response, the agricultural sector has witnessed the emergence of healthier alternatives by utilizing nanotechnology and nano-fertilizers (NFs). These innovative NFs harness the remarkable properties of nanoparticles, ranging in size from 1 to 100 nm, such as nanoclays and zeolites, to enhance nutrient utilization efficiency. Unlike their conventional counterparts, NFs offer many advantages, including variable solubility, consistent and effective performance, controlled release mechanisms, enhanced targeted activity, reduced eco-toxicity, and straightforward and safe delivery and disposal methods. By facilitating rapid and complete plant absorption, NFs effectively conserve nutrients that would otherwise go to waste, mitigating potential environmental harm. Moreover, their superior formulations enable more efficient promotion of sustainable crop growth and production than conventional fertilizers. This review comprehensively examines the global utilization of NFs, emphasizing their immense potential in maintaining environmentally friendly crop output while ensuring agricultural sustainability.

Harmonization Risks and Rewards: Nano-QSAR for Agricultural Nanomaterials

This comprehensive review explores the emerging landscape of Nano-QSAR (quantitative structure-activity relationship) for assessing the risk and potency of nanomaterials in agricultural settings. The paper begins with an introduction to Nano-QSAR, providing background and rationale, and explicitly states the hypotheses guiding the review. The study navigates through various dimensions of nanomaterial applications in agriculture, encompassing their diverse properties, types, and associated challenges. Delving into the principles of QSAR in nanotoxicology, this article elucidates its application in evaluating the safety of nanomaterials, while addressing the unique limitations posed by these materials. The narrative then transitions to the progression of Nano-QSAR in the context of agricultural nanomaterials, exemplified by insightful case studies that highlight both the strengths and the limitations inherent in this methodology. Emerging prospects and hurdles tied to Nano-QSAR in agriculture are rigorously examined, casting light on important pathways forward, existing constraints, and avenues for research enhancement. Culminating in a synthesis of key insights, the review underscores the significance of Nano-QSAR in shaping the future of nanoenabled agriculture. It provides strategic guidance to steer forthcoming research endeavors in this dynamic field.

Alleviated lead toxicity in rice plant by co-augmented action of genome doubling and TiO2 nanoparticles on gene expression, cytological and physiological changes

Lead is a very toxic and futile heavy metal for rice plants because of its injurious effects on plant growth and metabolic processes. Polyploidy or whole genome doubling increases the ability of plants to withstand biotic and abiotic stress. Considering the beneficial effects of nanoparticles and tetraploid rice, this research was conducted to examine the effectiveness of tetraploid and titanium dioxide nanoparticles (TiO2 NPs) in mitigating the toxic effects of lead. A diploid (E22-2x) and it's tetraploid (T-42) rice line were treated with Pb (200 μM) and TiO2 NPs (15 mg L-1). Lead toxicity dramatically reduced shoot length (16 % and 4 %) and root length (17 % and 9 %), biological yield (55 % and 36 %), and photosynthetic activity, as evidenced by lower levels of chlorophyll a and b (30 % and 9 %) in E-22 and T-42 rice cultivars compared to the control rice plants, respectively. Furthermore, lead toxicity amplified the levels of reactive oxygen species (ROS), such as malondialdehyde and H2O2, while decreasing activities of all antioxidant enzymes, such as superoxidase, peroxidase, and glutathione predominately in the diploid cultivar. Transmission electron microscopy and semi-thin section observations revealed that Pb-treated cells in E22-2x had more cell abnormalities than T-42, such as irregularly shaped mitochondria, cell wall, and reduced root cell size. Polyploidy and TiO2 reduced Pb uptake in rice cultivars and expression levels of metal transporter genes such as OsHMA9 and OsNRAMP5. According to the findings, genome doubling alleviates Pb toxicity by reducing Pb accumulation, ROS, and cell damage. Tetraploid rice can withstand the toxic effect of Pb better than diploid rice, and TiO2 NPs can alleviate the toxic impact of Pb. Our study findings act as a roadmap for future research endeavours, directing the focus toward risk management and assessing long-term impacts to balance environmental sustainability and agricultural growth.

Nanoparticle elicitation: A promising strategy to modulate the production of bioactive compounds in hairy roots

Hairy root culture is one of the promising biotechnological tools to obtain the stable and sustainable production of specialized metabolites from plants under controlled environment conditions. Various strategies have been adopted to enhance the accumulation of bioactive compounds in hairy roots yet their utilization at the commercial scale is restricted to only a few products. Recently, nanotechnology has been emerged as an active technique that has revolutionized the many sectors in an advantageous way. Elicitation using nanoparticles has been recognized as an effective strategy for enhancing the bioactive compounds of interest in plants. Nanoparticles elicit the activity of defense-related compounds through activation of the specific transcription factors involved in specialized metabolites production. This review discusses the recent progress in using nanoparticles to enhance specialized metabolite biosynthesis using hairy root culture system and the significant achievements in this area of research. Biotic and abiotic elicitors to improve the production of bioactive compounds in hairy roots, different types of nanoparticles as eliciting agents, their properties as dependent on shape, most widely used nanoparticles in plant hairy root systems are described in detail. Further challenges involved in application of nanoparticles, their toxicity in plant cells and risks associated to human health are also envisaged. No doubt, nanoparticle elicitation is a remarkable approach to obtain phytochemicals from hairy roots to be utilized in various sectors including food, medicines, cosmetics or agriculture but it is quite essential to understand the inter-relationships between the nanoparticles and the plant systems in terms of specifics such as type, dosage and time of exposure as well as other important parameters.

Impact of nanopollution on plant growth, photosynthesis, toxicity, and metabolism in the agricultural sector: An updated review

Nanotechnology provides distinct benefits to numerous industrial and commercial fields, and has developed into a discipline of intense interest to researchers. Nanoparticles (NPs) have risen to prominence in modern agriculture due to their use in agrochemicals, nanofertilizers, and nanoremediation. However, their potential negative impacts on soil and water ecosystems, as well as plant growth and physiology, have caused concern for researchers and policymakers. Concerns have been expressed regarding the ecological consequences and toxicity effects associated with nanoparticles as a result of their increased production and usage. Moreover, the accumulation of nanoparticles in the environment poses a risk, not only because of the possibility of plant damage but also because nanoparticles may infiltrate the food chain. In this review, we have documented the beneficial and detrimental effects of NPs on seed germination, shoot and root growth, plant biomass, and nutrient assimilation. Nanoparticles exert toxic effects by inducing ROS generation and stimulating cytotoxic and genotoxic effects, thereby leading to cell death in several plant species. We have provided possible mechanisms by which nanoparticles induce toxicity in plants. In addition to the toxic effects of NPs, we highlighted the importance of nanomaterials in the agricultural sector. Thus, understanding the structure, size, and concentration of nanoparticles that will improve plant growth or induce plant cell death is essential. This updated review reveals the multifaceted connection between nanoparticles, soil and water pollution, and plant biology in the context of agriculture.

Bioinspired silver nanoparticle-based nanocomposites for effective control of plant pathogens: A review

Plant pathogens, including bacteria, fungi, and viruses, pose significant challenges to the farming community due to their extensive diversity, the rapidly evolving phenomenon of multi-drug resistance (MDR), and the limited availability of effective control measures. Amid mounting global pressure, particularly from the World Health Organization, to limit the use of antibiotics in agriculture and livestock management, there is increasing consideration of engineered nanomaterials (ENMs) as promising alternatives for antimicrobial applications. Studies focusing on the application of ENMs in the fight against MDR pathogens are receiving increasing attention, driven by significant losses in agriculture and critical knowledge gaps in this crucial field. In this review, we explore the potential contributions of silver nanoparticles (AgNPs) and their nanocomposites in combating plant diseases, within the emerging interdisciplinary arena of nano-phytopathology. AgNPs and their nanocomposites are increasingly acknowledged as promising countermeasures against plant pathogens, owing to their unique physicochemical characteristics and inherent antimicrobial properties. This review explores recent advancements in engineered nanocomposites, highlights their diverse mechanisms for pathogen control, and draws attention to their potential in antibacterial, antifungal, and antiviral applications. In the discussion, we briefly address three crucial dimensions of combating plant pathogens: green synthesis approaches, toxicity-environmental concerns, and factors influencing antimicrobial efficacy. Finally, we outline recent advancements, existing challenges, and prospects in scholarly research to facilitate the integration of nanotechnology across interdisciplinary fields for more effective treatment and prevention of plant diseases.

Transport of Nanoparticles into Plants and Their Detection Methods

Nanoparticle transport into plants is an evolving field of research with diverse applications in agriculture and biotechnology. This article provides an overview of the challenges and prospects associated with the transport of nanoparticles in plants, focusing on delivery methods and the detection of nanoparticles within plant tissues. Passive and assisted delivery methods, including the use of roots and leaves as introduction sites, are discussed, along with their respective advantages and limitations. The barriers encountered in nanoparticle delivery to plants are highlighted, emphasizing the need for innovative approaches (e.g., the stem as a new recognition site) to optimize transport efficiency. In recent years, research efforts have intensified, leading to an evendeeper understanding of the intricate mechanisms governing the interaction of nanomaterials with plant tissues and cells. Investigations into the uptake pathways and translocation mechanisms within plants have revealed nuanced responses to different types of nanoparticles. Additionally, this article delves into the importance of detection methods for studying nanoparticle localization and quantification within plant tissues. Various techniques are presented as valuable tools for comprehensively understanding nanoparticle-plant interactions. The reliance on multiple detection methods for data validation is emphasized to enhance the reliability of the research findings. The future outlooks of this field are explored, including the potential use of alternative introduction sites, such as stems, and the continued development of nanoparticle formulations that improve adhesion and penetration. By addressing these challenges and fostering multidisciplinary research, the field of nanoparticle transport in plants is poised to make significant contributions to sustainable agriculture and environmental management.

Influence of surface modification and size of lanthanide-doped upconverting nanoparticles on wheat seedlings

In recent years, nanotechnology has found widespread applications in environmental monitoring, medical applications, plant fertilisers, cosmetics and others. Therefore, it is important to study nanomaterials' influence and subsequent risks to the environment and organisms (from production to disposal). Therefore, in the present study, the toxic effects of two surface modifications (poly (ethylene glycol)-neridronate, PEG-Ner and poly (acrylic acid), PAA) in comparison to unmodified, 26 nm- and 52 nm-sized core@shell lanthanide-doped upconverting nanoparticles (UCNPs, NaYF4:Yb3+,Er3+@NaYF4) were analysed. Wheat seedlings (Triticum aestivum L.) were chosen as a model organism since this species is one of the most widely cultivated crops. The influence of UCNPs (at concentrations of 0, 10, 50, and 100 μg/mL) on germination percentage, germination rate and growth was studied based on morphological parameters such as root number, root and hypocotyl length, and root and hypocotyl mass. In addition, an assay based on Evans blue staining was conducted to analyse damaged cell membranes and cell death. The type, size and concentration of UCNPs influenced the growth but not the germination of wheat. 52-nm-sized ligand-free UCNPs and the 26-nm-sized UCNPs/PAA decreased plant growth. Moreover, the ligand-free 26-nm-sized UCNPs interacted with the root cell membranes of seedlings. No significant changes were observable regarding viability (tetrazolium chloride reduction assay), oxidative stress and electrolyte leakage from root cells in plants incubated with ligand-free 26-nm-sized UCNPs. Overall, we have shown that the ligand-free UCNPs (of both sizes) had the strongest toxic effect; PAA-modified UCNPs were toxic only at smaller sizes and PEG-Ner-modified UCNPs had no toxic impact. Therefore, PEG-Ner was identified as the safest surface compound among the UCNPs investigated in the study, which may neutralise the harmful effects of nanoparticles on plants.

Green Synthesis of Silver Nanoparticles and their Potential Applications in Mitigating Cancer

In recent years, the field of nanotechnology has brought about significant advancements that have transformed the landscape of disease diagnosis, prevention, and treatment, particularly in the realm of medical science. Among the various approaches to nanoparticle synthesis, the green synthesis method has garnered increasing attention. Silver nanoparticles (AgNPs) have emerged as particularly noteworthy nanomaterials within the spectrum of metallic nanoparticles employed for biomedical applications. AgNPs possess several key attributes that make them highly valuable in the biomedical field. They are biocompatible, cost-effective, and environmentally friendly, rendering them suitable for various bioengineering and biomedical applications. Notably, AgNPs have found a prominent role in the domain of cancer diagnosis. Research investigations have provided evidence of AgNPs' anticancer activity, which involves mechanisms such as DNA damage, cell cycle arrest, induction of apoptosis, and the regulation of specific cytokine genes. The synthesis of AgNPs primarily involves the reduction of silver ions by reducing agents. Interestingly, natural products and living organisms have proven to be effective sources for the generation of precursor materials used in AgNP synthesis. This comprehensive review aims to summarize the key aspects of AgNPs, including their characterization, properties, and recent advancements in the field of biogenic AgNP synthesis. Furthermore, the review highlights the potential applications of these nanoparticles in combating cancer.

Investigating the ecological implications of nanomaterials: Unveiling plants' notable responses to nano-pollution

The rapid advancement of nanotechnology has led to unprecedented innovations; however, it is crucial to analyze its environmental impacts carefully. This review thoroughly examines the complex relationship between plants and nanomaterials, highlighting their significant impact on ecological sustainability and ecosystem well-being. This study investigated the response of plants to nano-pollution stress, revealing the complex regulation of defense-related genes and proteins, and highlighting the sophisticated defense mechanisms in nature. Phytohormones play a crucial role in the complex molecular communication network that regulates plant responses to exposure to nanomaterials. The interaction between plants and nano-pollution influences plants' complex defense strategies. This reveals the interconnectedness of systems of nature. Nevertheless, these findings have implications beyond the plant domain. The incorporation of hyperaccumulator plants into pollution mitigation strategies has the potential to create more environmentally sustainable urban landscapes and improve overall environmental resilience. By utilizing these exceptional plants, we can create a future in which cities serve as centers of both innovation and ecological balance. Further investigation is necessary to explore the long-term presence of nanoparticles in the environment, their ability to induce genetic changes in plants over multiple generations, and their overall impact on ecosystems. In conclusion, this review summarizes significant scientific discoveries with broad implications beyond the confines of laboratories. This highlights the importance of understanding the interactions between plants and nanomaterials within the wider scope of environmental health. By considering these insights, we initiated a path towards the responsible utilization of nanomaterials, environmentally friendly management of pollution, and interdisciplinary exploration. We have the responsibility to balance scientific advancement and environmental preservation to create a sustainable future that combines nature's wisdom with human innovation.

Changes of microbiome in response to supplements with silver nanoparticles in cotton rhizosphere

The current study focuses on analyzing the effects of supplements containing silver nanoparticles (AgNPs) on plant growth and rhizospheric bacterial communities. Specifically, the impact of AgNP supplements was assessed on both plant growth promoting traits and bacterial communities in the soil. To do this, a screening process was conducted to select bacteria capable of synthesizing AgNPs through extracellular biosynthesis. UV-Visible spectrophotometer, Fourier transform infrared, X-ray diffraction, scanning electron microscope, and field emission scanning electron microscopy all confirmed, produced AgNPs is in agglomerates form. The resulting AgNPs were introduced into soil along with various supplements and their effects were evaluated after 10 days using next generation sequencing (Illumina-16S rDNA V3-V4 region dependent) to analyze changes in bacterial communities. Seed germination, root-shoot biomass and chlorophyll content were used to assess the growth of the cotton plant, whereas the bacterial ability to promote growth was evaluated by measuring its culturable diversity including traits like phosphate solubilization and indole acetic acid production. The variance in Bray-Curtis β diversity among six selected combinations including control depends largely on the type of added supplements contributing to 95%-97% of it. Moreover, seed germination improves greatly between 63% and 100% at a concentration range of 1.4 to 2.8 mg/L with different types of supplements. Based on the results obtained through this study, it is evident that using AgNPs along with fructose could be an effective tool for promoting Gossypium hirsutum growth and enhancing plant growth traits like profiling rhizospheric bacteria. The results that have been obtained endorse the idea of boosting the growth of rhizospheric bacteria in a natural way when AgNPs are present. Using these supplements in fields that have been contaminated will lead to a better understanding of how ecological succession occurs among rhizospheric bacteria, and what effect it has on the growth of plants.