Positive and negative effects of nanoparticles on agricultural crops

Nanomaterials impact in phytohormone signaling networks of plants-A critical review

Nanotechnology offers a transformative approach to augment plant growth and crop productivity under abiotic and biotic stress conditions. Nanomaterials interact with key phytohormones, triggering the synthesis of stress-associated metabolites, activating antioxidant defense mechanisms, and modulating gene expression networks that regulate diverse physiological, biochemical, and molecular processes within plant systems. This review critically examines the impact of nanoparticles on both conventional and genetically modified crops, focusing on their role in nutrient delivery systems and the modulation of plant cellular machinery. Nanoparticle-induced reactive oxygen species (ROS) generation plays a central role in altering secondary metabolite biosynthesis, highlighting their function as potent elicitors and stimulants in plant systems. The review underscores the significant contribution of nanoparticles in enhancing stress resilience through the modulation of phytohormonal signaling pathways, offering novel insights into their potential for improving crop health and productivity under environmental stressors.

Harnessing the potential of copper-based nanoparticles in mitigating abiotic and biotic stresses in crops

The demand for crops production continues to intensify with the rapid increase in population. Agricultural crops continue to encounter abiotic and biotic stresses, which can substantially hamper their productivity. Numerous strategies have been focused to tackle the abiotic and biotic stress factors in various plants. Nanotechnology has displayed great potential to minimize the phytotoxic impacts of these environmental constraints. Copper (Cu)-based nanoparticles (NPs) have displayed beneficial effects on plant growth and stress tolerance. Cu-based NPs alone or in combination with plant growth hormones or microorganisms have been documented to induce plant tolerance and mitigate abiotic or biotic stresses in different plants. In this review, we have comprehensively discussed the uptake and translocation of Cu-based NPs in plants, and beneficial roles in improving the plant growth and development at various growth stages. Moreover, we have discussed how Cu-based NPs mechanistically modulate the physiological, biochemical, metabolic, cellular, and metabolic functions to enhance plant tolerance against both biotic (viruses, bacterial and fungal diseases, etc.) and abiotic stresses (heavy metals or metalloids, salt, and drought stress, etc.). We elucidated recent advancements, knowledge gaps, and recommendations for future research. This review would help plant and soil scientists to adapt Cu-based novel strategies such as nanofertilizers and nanopesticides to detoxify the abiotic or biotic stresses. These outcomes may contribute to the promotion of healthy food production and food security, thus providing new avenues for sustainable agriculture production.

Nanotechnology in sustainable agriculture: A double-edged sword

Nanotechnology is a rapidly developing discipline that has the potential to transform the way we approach problems in a variety of fields, including agriculture. The use of nanotechnology in sustainable agriculture has gained popularity in recent years. It has various applications in agriculture, such as the development of nanoscale materials and devices to boost agricultural productivity, enhance food quality and safety, improve the efficiency of water and nutrient usage, and reduce environmental pollution. Nanotechnology has proven to be very beneficial in this field, particularly in the development of nanoscale delivery systems for agrochemicals such as pesticides, fertilizers, and growth regulators. These nanoscale delivery technologies offer various benefits over conventional delivery systems, including better penetration and distribution, enhanced efficacy, and lower environmental impact. Encapsulating agrochemicals in nanoscale particles enables direct delivery to the targeted site in the plant, thereby reducing waste and minimizing off-target effects. Plants are fundamental building blocks of all ecosystems and evaluating the interaction between nanoparticles (NPs) and plants is a crucial aspect of risk assessment. This critical review therefore aims to provide an overview of the latest advances regarding the positive and negative effects of nanotechnology in agriculture. It also explores potential future research directions focused on ensuring the safe utilization of NPs in this field, which could lead to sustainable development. © 2024 Society of Chemical Industry.

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.

Zno nanoparticles: improving photosynthesis, shoot development, and phyllosphere microbiome composition in tea plants

BACKGROUND

Nanotechnology holds revolutionary potential in the field of agriculture, with zinc oxide nanoparticles (ZnO NPs) demonstrating advantages in promoting crop growth. Enhanced photosynthetic efficiency is closely linked to improved vigor and superior quality in tea plants, complemented by the beneficial role of phyllosphere microorganisms in maintaining plant health. However, the effects of ZnO NPs on the photosynthesis of tea plants, the sprouting of new shoots, and the community of phyllosphere microorganisms have not been fully investigated.

RESULTS

This study investigated the photosynthetic physiological parameters of tea plants under the influence of ZnO NPs, the content of key photosynthetic enzymes such as RubisCO, chlorophyll content, chlorophyll fluorescence parameters, transcriptomic and extensive targeted metabolomic profiles of leaves and new shoots, mineral element composition in these tissues, and the epiphytic and endophytic microbial communities within the phyllosphere. The results indicated that ZnO NPs could enhance the photosynthesis of tea plants, upregulate the expression of some genes related to photosynthesis, increase the accumulation of photosynthetic products, promote the development of new shoots, and alter the content of various mineral elements in the leaves and new shoots of tea plants. Furthermore, the application of ZnO NPs was observed to favorably influence the microbial community structure within the phyllosphere of tea plants. This shift in microbial community dynamics suggests a potential for ZnO NPs to contribute to plant health and productivity by modulating the phyllosphere microbiome.

CONCLUSION

This study demonstrates that ZnO NPs have a positive impact on the photosynthesis of tea plants, the sprouting of new shoots, and the community of phyllosphere microorganisms, which can improve the growth condition of tea plants. These findings provide new scientific evidence for the application of ZnO NPs in sustainable agricultural development and contribute to advancing research in nanobiotechnology aimed at enhancing crop yield and quality.

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.

Agriculture and environmental management through nanotechnology: Eco-friendly nanomaterial synthesis for soil-plant systems, food safety, and sustainability

Through the advancement of nanotechnology, agricultural and food systems are undergoing strategic enhancements, offering innovative solutions to complex problems. This scholarly essay thoroughly examines nanotechnological innovations and their implications within these critical industries. Traditional practices are undergoing radical transformation as nanomaterials emerge as novel agents in roles traditionally filled by fertilizers, pesticides, and biosensors. Micronutrient management and preservation techniques are further enhanced, indicating a shift towards more nutrient-dense and longevity-oriented food production. Nanoparticles (NPs), with their unique physicochemical properties, such as an extraordinary surface-to-volume ratio, find applications in healthcare, diagnostics, agriculture, and other fields. However, concerns about their potential overuse and bioaccumulation raise unanswered questions about their health effects. Molecule-to-molecule interactions and physicochemical dynamics create pathways through which nanoparticles cause toxicity. The combination of nanotechnology and environmental sustainability principles leads to the examination of green nanoparticle synthesis. The discourse extends to how nanomaterials penetrate biological systems, their applications, toxicological effects, and dissemination routes. Additionally, this examination delves into the ecological consequences of nanomaterial contamination in natural ecosystems. Employing robust risk assessment methodologies, including the risk allocation framework, is recommended to address potential dangers associated with nanotechnology integration. Establishing standardized, universally accepted guidelines for evaluating nanomaterial toxicity and protocols for nano-waste disposal is urged to ensure responsible stewardship of this transformative technology. In conclusion, the article summarizes global trends, persistent challenges, and emerging regulatory strategies shaping nanotechnology in agriculture and food science. Sustained, in-depth research is crucial to fully benefit from nanotechnology prospects for sustainable agriculture and food systems.

Zinc Oxide Nanoparticles Alleviate Salt Stress in Cotton (Gossypium hirsutum L.) by Adjusting Na+/K+ Ratio and Antioxidative Ability

Soil salinization poses a threat to the sustainability of agricultural production and has become a global issue. Cotton is an important cash crop and plays an important role in economic development. Salt stress has been harming the yield and quality of many crops, including cotton, for many years. In recent years, soil salinization has been increasing. It is crucial to study the mechanism of cotton salt tolerance and explore diversified materials and methods to alleviate the salt stress of cotton for the development of the cotton industry. Nanoparticles (NPs) are an effective means to alleviate salt stress. In this study, zinc oxide NPs (ZnO NPs) were sprayed on cotton leaves with the aim of investigating the intrinsic mechanism of NPs to alleviate salt stress in cotton. The results show that the foliar spraying of ZnO NPs significantly alleviated the negative effects of salt stress on hydroponic cotton seedlings, including the improvement of above-ground and root dry and fresh weight, leaf area, seedling height, and stem diameter. In addition, ZnO NPs can significantly improve the salt-induced oxidative stress by reducing the levels of MDA, H2O2, and O2- and increasing the activities of major antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Furthermore, RNA-seq showed that the foliar spraying of ZnO NPs could induce the expressions of CNGC, NHX2, AHA3, HAK17, and other genes, and reduce the expression of SKOR, combined with the CBL-CIPK pathway, which alleviated the toxic effect of excessive Na+ and reduced the loss of excessive K+ so that the Na+/K+ ratio was stabilized. In summary, our results indicate that the foliar application of ZnO NPs can alleviate high salt stress in cotton by adjusting the Na+/K+ ratio and regulating antioxidative ability. This provides a new strategy for alleviating the salt stress of cotton and other crops, which is conducive to the development of agriculture.

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.

Silicon nanoparticles alleviate cadmium toxicity in rice (Oryza sativa L.) by modulating the nutritional profile and triggering stress-responsive genetic mechanisms

This study investigated the physiological and molecular responses of rice genotype '9311' to Cd stress and the mitigating effects of silicon oxide nanoparticles (SiO NPs). Cd exposure severely hindered plant growth, chlorophyll content, photosynthesis, and Cd accumulation. However, SiO NPs supplementation, particularly the SiONP100 treatment, significantly alleviated Cd-induced toxicity, mitigating the adverse effects on plant growth while maintaining chlorophyll content and photosynthetic attributes. The SiONP100 treatment also reduced Cd accumulation, indicating a preference for Si uptake in genotype 9311. Complex interactions among Cd, Si, Mg, Ca, and K were uncovered, with fluctuations in MDA and H2O2 contents. Distinct morphological changes in stomatal aperture and mesophyll cell structures were observed, including changes in starch granules, grana thylakoids, and osmophilic plastoglobuli. Moreover, following SiONP100 supplementation, genotype 9311 increased peroxidase, superoxide dismutase, and catalase activities by 56%, 44%, and 53% in shoots and 62%, 49%, and 65% in roots, respectively, indicating a robust defense mechanism against Cd stress. Notably, OsNramp5, OsHMA3, OsSOD-Cu/Zn, OsCATA, OsCATB, and OsAPX1 showed significant expression after SiO NPs treatment, suggesting potential Cd translocation within rice tissues. Overall, SiO NPs supplementation holds promise for enhancing Cd tolerance in rice plants while maintaining essential physiological functions.

Eco-Efficient Systems Based on Nanocarriers for the Controlled Release of Fertilizers and Pesticides: Toward Smart Agriculture

The excessive application of pesticides and fertilizers has generated losses in biological diversity, environmental pollution, and harmful effects on human health. Under this context, nanotechnology constitutes an innovative tool to alleviate these problems. Notably, applying nanocarriers as controlled release systems (CRSs) for agrochemicals can overcome the limitations of conventional products. A CRS for agrochemicals is an eco-friendly strategy for the ecosystem and human health. Nanopesticides based on synthetic and natural polymers, nanoemulsions, lipid nanoparticles, and nanofibers reduce phytopathogens and plant diseases. Nanoproducts designed with an environmentally responsive, controlled release offer great potential to create formulations that respond to specific environmental stimuli. The formulation of nanofertilizers is focused on enhancing the action of nutrients and growth stimulators, which show an improved nutrient release with site-specific action using nanohydroxyapatite, nanoclays, chitosan nanoparticles, mesoporous silica nanoparticles, and amorphous calcium phosphate. However, despite the noticeable results for nanopesticides and nanofertilizers, research still needs to be improved. Here, we review the relevant antecedents in this topic and discuss limitations and future challenges.

Biosynthesized Ag nanoparticles on urea-based periodic mesoporous organosilica enhance galegine content in Galega

The biological approach for synthesizing nanoparticles (NPs) using plant extracts is an efficient alternative to conventional physicochemical methods. Galegine, isolated from Galega (Galega officinalis L.), has anti-diabetic properties. In the present study, silver nanoparticles (AgNPs) loaded onto urea-based periodic mesoporous organosilica (AgNPs/Ur-PMO) were bio-synthesized using G. officinalis leaf extract. The synthesized NPs were characterized and confirmed via analysis methods. Different concentrations of biosynthesized AgNPs/Ur-PMO nanoparticles (0, 1, 5, 10, and 20 mg L^-1) were used as elicitors in cell suspension culture (CSC) of G. officinalis. The callus cells from hypocotyl explants were treated at their logarithmic growth phase (8^th d) and were collected at time intervals of 24, 72, 120, and 168 h. The viability and growth of cells were reduced (by 17% and 35%, respectively) at higher concentrations and longer treatments of AgNPs/Ur-PMO; however, the contents of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) were increased (1.23 and 3.01 fold, respectively in comparison with the control average). The highest total phenolic (2.43 mg g^-1 dry weight) and flavonoid (2.22 mg g^-1 dry weight) contents were obtained 168 h after treatment with 10 mg L^-1 AgNPs/Ur-PMO. An increasing tendency in the antioxidant enzyme activities was also observed in all the elicitor concentrations. Treatment with AgNPs/Ur-PMO (in particular 5 mg L^-1 for 120 h) significantly enhanced the galegine content (up to 17.42 mg g^-1) about 1.80 fold compared with the control. The results suggest that AgNPs/Ur-PMO can be used as an effective elicitor for enhancing galegine production in the CSC of G. officinalis. KEY POINTS: • The green biosynthesis of AgNPs/Ur-PMO was done using G. officinalis leaf extract • Its toxicity as an elicitor increased with increasing concentration and treatment time • AgNPs/Ur-PMO significantly increased the antioxidant capacity and galegine content.

Genetic Diversity Analysis of Banana Cultivars (Musa sp.) in Saudi Arabia Based on AFLP Marker

Banana plantation has been introduced recently to a temperate zone in the southeastern parts of Saudi Arabia (Fifa, Dhamadh, and Beesh, located in Jazan province). The introduced banana cultivars were of a clear origin without a recorded genetic background. In the current study, the genetic variability and structure of five common banana cultivars (i.e., Red, America, Indian, French, and Baladi) were analyzed using the fluorescently labeled AFLP technique. Nine different primer pairs combinations yielded 1468 loci with 88.96% polymorphism. Among all locations, high expected heterozygosity under the Hardy–Weinberg assumption was found (0.249 ± 0.003), where Dhamadh was the highest, followed by Fifa and Beesh, respectively. Based on the PCoA and Structure analysis, the samples were not clustered by location but in pairs in accordance with the cultivar’s names. However, the Red banana cultivar was found to be a hybrid between the American and Indian cultivars. Based on ΦST, 162 molecular markers (i.e., loci under selection) were detected among cultivars. Identifying those loci using NGS techniques can reveal the genetic bases and molecular mechanisms involved in the domestication and selection indicators among banana cultivars.

Nanotechnology - A new frontier of nano-farming in agricultural and food production and its development

The potential of nanotechnology for the development of sustainable agriculture has been promising. The initiatives to meet the rising food needs of the rapidly growing world population are mainly powered by sustainable agriculture. Nanoparticles are used in agriculture due to their distinct physicochemical characteristics. The interaction of nanomaterials with soil components is strongly determined in terms of soil quality and plant growth. Numerous research has been carried out to investigate how nanoparticles affect the growth and development of plants. Nanotechnology has been applied to improve the quality and reduce post-harvest loss of agricultural products by extending their shelf life, particularly for fruits and vegetables. This review assesses the latest literature on nanotechnology, which is used as a nano-biofertilizer as seen in the agricultural field for high productivity and better growth of plants, an important source of balanced nutrition for the crop, seed germination, and quality enrichment. Additionally, post-harvest food processing and packaging can benefit greatly from the use of nanotechnology to cut down on food waste and contamination. It also critically discusses the mechanisms involved in nanoparticle absorption and translocation within the plants and the synthesis of green nanoparticles.

Bacillus subtilis Synthesized Iron Oxide Nanoparticles (Fe3O4 NPs) Induced Metabolic and Anti-Oxidative Response in Rice (Oryza sativa L.) under Arsenic Stress

Nanoparticle (NP) application is most effective in decreasing metalloid toxicity. The current study aimed to evaluate the effect of Bacillus subtiles synthesized iron oxide nanoparticles (Fe₃O₄ NPs) against arsenic (As) stress on rice (Oryza sativa L.) seedlings. Different concentrations of As (5, 10 and 15 ppm) and Bacillus subtilis synthesized Fe₃O₄ NPs solution (5, 10 and 15 ppm) alone and in combination were applied to rice seedlings. The results showed that As at 15 ppm significantly decreased the growth of rice, which was increased by the low level of As. Results indicated that B. subtilis synthesized Fe₃O₄ NP-treated plants showed maximum chlorophyll land protein content as compared with arsenic treatment alone. The antioxidant enzymes such as SOD, POD, CAT, MDA and APX and stress modulators (Glycine betain and proline) also showed decreased content in plants as compared with As stress. Subsequently, Bacillus subtilis synthesized Fe₃O₄ NPs reduced the stress associated parameters due to limited passage of arsenic inside the plant. Furthermore, reduction in H₂O₂ and MDA content confirmed that the addition of Bacillus subtilis synthesized Fe₃O₄ NPs under As stress protected rice seedlings against arsenic toxicity, hence enhanced growth was notice and it had beneficial effects on the plant. Results highlighted that Fe₃O₄ NPs protect rice seedlings against arsenic stress by reducing As accumulation, act as a nano adsorbent and restricting arsenic uptake in rice plants. Hence, our study confirms the significance of Bacillus subtilis synthesized Fe₃O₄ NPs in alleviating As toxicity in rice plants.

Phytotoxic effect of sub-3-nm crystalline ceria nanoparticles on the hydroponic growth of Daikon radish microgreens

Cerium oxide nanoparticles (ceria NPs) have been widely used in many industrial applications. They have been proposed as a potential remedy for reducing oxidative stress in biological systems. General concerns over the toxicity of engineered ceria NPs have led to studies of their phytotoxicity in plants. Most of these plant growth studies were conducted in soil using grain crops and commercial ceria NPs of sizes from 6 nm to 100's nm. In this paper, we report our evaluation of the phytotoxicity and uptake of sub-3-nm crystalline ceria NPs by exposing Daikon radish (Raphanus sativus var. longipinnatus) microgreens to these NPs with environmentally relevant concentrations under hydroponic growth conditions. Aqueous suspensions of different concentrations of these ceria NPs (0.1 ppm, 1 ppm, and 10 ppm) were applied to these microgreens for the last 7 days of the 12-day growth period. Our results revealed the uptake of cerium by plant roots and the translocation of cerium to the stems and the cotyledons (seed leaves). The accumulation of cerium was found to be maximum at the roots, followed by the cotyledons and the stems of the plants. Even at the lowest concentration (0.1 ppm) of the sub-3-nm ceria NPs, the accumulation of cerium at the roots significantly stunted the root growth. However, these NP treatments did not show significant changes to the distributions of macro-minerals (Mg, K, and Ca) and micro-minerals (Zn and Cu) in the microgreens at the end of the 12-day growth period. The phytotoxic effect of sub-3-nm crystalline ceria nanoparticles on the hydroponic growth of Daikon radish microgreens was studied. The cerium uptake by the plant and its effect on the bioavailability of major macro-minerals and micro-minerals within the plant were examined.

Fate, bioaccumulation and toxicity of engineered nanomaterials in plants: Current challenges and future prospects

The main focus of this review is to discuss the current advancement in nano-metallic caused phytotoxicity on living organisms and current challenges in crops. Nanostructured materials provide new tools in agriculture to boost sustainable food production, but the main concern is that large-scale production and release of nanomaterials (NMs) into the ecosystem is a rising threat to the surrounding environment that is an urgent challenge to be addressed. The usage of NMs directly influences the transport pathways within plants, which directly relates to their stimulatory/ inhibitory effects. Because of the unregulated nanoparticles (NMs) exposure to soil, they are adsorbed at the root surface, followed by uptake and inter/intracellular mobility within the plant tissue, while the aerial exposure is taken up by foliage, mostly through cuticles, hydathodes, stigma, stomata, and trichomes, but the actual mode of NMs absorption into plants is still unclear. NMs-plant interactions may have stimulatory or inhibitory effects throughout their life cycle depending on their composition, size, concentration, and plant species. Although many publications on NMs interactions with plants have been reported, the knowledge on their uptake, translocation, and bioaccumulation is still a question to be addressed by the scientific community. One of the critical aspects that must be discovered and understood is detecting NMs in soil and the uptake mechanism in plants. Therefore, the nanopollution in plants has yet to be completely understood regarding its impact on plant health, making it yet another artificial environmental influence of unknown long-term consequences. The present review summarizes the uptake, translocation, and bioaccumulation of NMs in plants, focusing on their inhibitory effects and mechanisms involved within plants.

A Review on Nanopesticides for Plant Protection Synthesized Using the Supramolecular Chemistry of Layered Hydroxide Hosts

The rapid growth in the human population has triggered increased demand for food supply, and in turn has prompted a higher amount of agrochemical usage to meet the gaps between food production and consumption. The problem with conventional agro-nanochemicals is the reduced effectiveness of the active ingredient in reaching the target, along with leaching, evaporation, etc., which ultimately affect the environment and life, including humans. Fortunately, nanotechnology platforms offer a new life for conventional pesticides, which improves bioavailability through different kinetics, mechanisms and pathways on their target organisms, thus enabling them to suitably bypass biological and other unwanted resistances and therefore increase their efficacy. This review is intended to serve the scientific community for research, development and innovation (RDI) purposes, by providing an overview on the current status of the host-guest supramolecular chemistry of nanopesticides, focusing on only the two-dimensional (2D), brucite-like inorganic layered hydroxides, layered hydroxide salts and layered double hydroxides as the functional nanocarriers or as the hosts in smart nanodelivery systems of pesticides for plant protection. Zinc layered hydroxides and zinc/aluminum-layered double hydroxides were found to be the most popular choices of hosts, presumably due to their relative ease to prepare and cheap cost. Other hosts including Mg/Al-, Co/Cr-, Mg/Fe-, Mg/Al/Fe-, Zn/Cr- and Zn/Cu-LDHs were also used. This review also covers various pesticides which were used as the guest active agents using supramolecular host-guest chemistry to combat various pests for plant protection. This looks towards a new generation of agrochemicals, "agro-nanochemicals", which are more effective, and friendly to life, humans and the environment.