Zinc oxide nanoparticles (ZnONPs) as a novel nanofertilizer: Influence on seed yield and antioxidant defense system in soil grown soybean (Glycine max cv. Kowsar)

Eco-friendly fabrication of Zn-based nanoparticles: implications in agricultural advancement and elucidation of toxicity aspects

Zinc (Zn) is a vital micronutrient required for optimal plant growth and soil fertility. Its use in the form of nanoparticles (NPs) has gained significant attention in agricultural applications. Green synthesized Zn-based NPs offer an eco-friendly solution to several conventional problems in agriculture. Several plants, bacteria, fungi and yeast have shown significant potential in fabricating Zn NPs that can provide environmentally friendly solutions in agriculture and the approach is aligned with sustainable agricultural practices, reducing the dependency on harmful agrochemicals. Zn-based NPs act as plant growth promoters, enhance crop yield, promote resilience to abiotic stressors and are efficient crop protection agents. Their role as a smart delivery system, enabling targeted and controlled release of agrochemicals, further signifies their potential use in agriculture. Because agriculture requires repeated applications hence, the toxicological aspects of Zn NPs cannot be ignored. Zn NPs are reported to cause phytotoxicity, including root damage, physiological and biochemical disturbances, and genotoxic effects. Furthermore, exposure to Zn NPs poses risks to soil microbiota, and aquatic and terrestrial organisms potentially impacting the ecosystem. The green synthesis of Zn-based NPs has a promising aspect for advancing sustainable agriculture by reducing agrochemical use and improving crop productivity. Their diverse applications as plant growth promoters, crop protectants and smart delivery systems emphasize their potential. However, the toxicological aspects are essential to ensure the standardization of doses for their safe and effective use. Further research would help address such concerns and help in developing viable and eco-friendly solutions for modern agriculture. © 2025 Society of Chemical Industry.

A comprehensive review on nano-fertilizers: preparation, development, utilization, and prospects for sustainable agriculture in Ethiopia

With their many benefits including better crop yield and nutrient delivery, nano fertilizers are a promising option in the agriculture sector. The production and formulation of nanoparticles with regulated size, shape, and content are required to prepare nano fertilizers. Metals, metal oxides, and polymers are among the materials from which nanoparticles are made using chemical and physical processes. Subsequently, these nanoparticles are mixed into fertilizers to enhance plant absorption and availability of nutrients. Nano-fertilizers have several benefits, including efficient nutrient absorption, reduced nutrient losses, minimized environmental pollution, optimized resource utilization, and controlled release of nutrients for sustained plant nourishment. Studies have demonstrated that by boosting nutrient availability, encouraging root development, and strengthening stress tolerance, nano fertilizers can greatly enhance crop yields. Moreover, it has been discovered that they increase microbial activity and soil fertility, which improves soil health and long-term sustainability. Nano-fertilizers can be applied in different ways, like foliar spraying, seed coating, soil integration, or irrigation systems. They are beneficial in precision agriculture for better nutrient management, soil restoration, and addressing nutrient deficiencies. Furthermore, they potentially lessen the negative environmental effects of traditional fertilization methods. Nevertheless, there are still several issues that need to be resolved before nano fertilizers may be commercialized and widely used. Regulatory frameworks, environmental destiny, potential toxicity of nanoparticles, and cost-effectiveness are some of these challenges. The purpose of this review is to provide readers with a comprehensive understanding of the benefits of nano fertilizers. It will cover topics such as their preparation and characterization, potential side effects, and a diverse range of applications. Additionally, it will present an overview of the importation of chemical fertilizers and explore the prospects of utilizing fertilizers in the Ethiopian context.

Biosynthesized ZnO NPs loaded-electrospun PVA/sodium alginate/glycine nanofibers: synthesis, spinning optimization and antimicrobial activity evaluation

In this work, microalgae-based zinc oxide nanoparticles loaded with electrospun polyvinyl alcohol (PVA)/sodium alginate (SA) nanofibers were fabricated by electro-spinner. PVA/SA fibrous mats were crosslinked by citric acid, which enhanced their thermal stability and swelling behavior. Green-synthesized ZnO NPs were laboratory synthesized and characterized by FTIR, XRD, EDX, SEM, TEM and TGA analyses. Electrospinning of PVA/SA with optimized mixing ratios was further carried out with different ratios of ZnO NPs of (0.25, 0.50 and 0.75%, wt./v) to fabricate SA/PVA/ZnO composite nanofibers. The formula of NF of (SA/PVA/ZnO (0.75%) with different ratios of glycine was used for testing as topical wound dressing as promised biomaterials. Results revealed that NF formula coded AS3.3; composed of (10%PVA/1.5%SA/10%CA/0.75%ZnO/0.5% glycine), in contrast to all the other formulations examined; showed marked reduced percentages of biofilm development of both Gram-positive and Gram-negative bacteria in relation to fungal cells. The relative viable count for Bacillus cereus (98.40 ± 0.51%), Salmonella paratyphi (98.33 ± 0.79%), and Candida albicans (94.29 ± 0.76%) decreased significantly after 36-hour of incubation period with AS3.3 treatment. The obtained findings offered that the prepared composite nanofiber based on ZnO NPs and glycine; could be used as a promising and excellent antimicrobial dressing for inhibiting the microbial growth for the topical wounds healing.

Drought stress mitigation and improved yield in Glycine max through foliar application of zinc oxide nanoparticles

The impact of climate change on agricultural production is apparent due to declining irrigation water availability vis-à-vis rising drought stress, particularly affecting summer crops. Growing evidence suggests that zinc (Zn) supplementation may serve as a potential drought stress management strategy in agriculture. Field studies were conducted using soybean (Glycine max var. Saba) as a model crop to test whether foliar application of zinc oxide nanoparticles (ZnO-NPs) or conventional Zn fertilizer (ZnSO4) would mitigate drought-related water stress and improve soybean yield. Each fertilizer was foliar applied twice at a two-week interval during the flowering stage. Experiments were concurrently conducted under non-drought conditions (70% field capacity) for comparison. Results showed drought significantly reduced relative water content, chlorophyll-a, and chlorophyll-b in untreated control plants by 35.7%, 47.7%, and 41.4%, respectively, compared to non-drought conditions (p < 0.05). Under drought conditions, ZnO-NPs (200 mg Zn/L) led to 33.1% and 20.7% increase in chlorophyll-a and chlorophyll-b levels, respectively, compared to ZnSO4 at 400 mg Zn/L. Likewise, catalase, peroxidase and superoxide dismutase activities increased by 62.6%, 39.5% and 28.5%, respectively, with ZnO-NPs (200 mg Zn/L) under drought compared to non-drought conditions. Proline was significantly increased under drought but was remarkably suppressed (~ 54% lower) with ZnO-NPs (200 mg Zn/L) treatment. More importantly, the highest seed yield was observed with ZnO-NPs (200 mg Zn/L) treatment under drought (39% higher than untreated control) and non-drought (79.4% higher than control) conditions. Overall, the findings suggest that ZnO-NPs could promote seed yield in soybean under drought stress via increased antioxidant activities, increased relative water content, decreased stress-related proline content, and increased photosynthetic pigments. It is recommended that foliar application of 200 mg Zn/L as ZnO-NPs could serve as an effective drought stress management strategy to improve soybean yield.

Microbial biosurfactant-mediated green synthesis of zinc oxide nanoparticles (ZnO NPs) and exploring their role in enhancing chickpea and rice seed germination

Malnutrition is one of the greatest challenges faced by humanity, which may be addressed by improving crop productivity to ensure food security. However, extensive use of synthetic fertilizers can lead to soil fertility degradation. This study highlights the potential of combining nanotechnology with biotechnology to enhance the germination rates of commercially important crop seeds. Bacterial biosurfactant extracted from a newly isolated Klebsiella sp. strain RGUDBI03 was used as a reducing and capping agent for the synthesis of zinc oxide nanoparticles (ZnO NPs) through a simple method. Extensive characterization of ZnO NPs through electron microscopic analysis showed well-dispersed, homogeneous NPs with a size range of 2-10 nm. High-resolution transmission electron microscopy (HR-TEM) images also revealed molecular fringes of 0.26 nm in single crystal ZnO NPs, with approximately 50% of the NPs exhibiting a size range of 2-4 nm. X-ray diffraction (XRD) results of ZnO NPs indicated the presence of (100), (002), (101), (102), (200), and (112) planes, confirming their crystalline nature. The presence of C = C-H, C = C, C-H, and C = C groups in both the bacterial biosurfactant and ZnO NPs, as depicted by Fourier-transform infrared spectroscopy (FTIR) spectra, confirmed the function of the biosurfactant as a reducing and capping agent. The nano-primed chickpea (Cicer arietinum) and rice (Oryza sativa) seeds showed an increase in water uptake rate, 89% and 92% respectively, compared to the control (73% and 44%), leading to an enhanced germination rate of 98% and 76%, compared to their respective controls (80% and 30%) under optimized conditions. Additionally, the nano-primed seeds exhibited higher levels of α-amylase activity in both seeds (0.37 mg/g for chickpea and 2.49 mg/g for rice) compared to the control. Notably, the ZnO NP priming solution exhibited no cytotoxicity on red blood cells and earthworms (Eudrilus eugeniae), indicating their non-cytotoxic and eco-friendly nature for future field trials.

Small molecule, big impacts: Nano-nutrients for sustainable agriculture and food security

Human existence and the long-term viability of society depend on agriculture. Overuse of synthetic fertilizers results in increased contamination of the land, water, and atmosphere as well as financial constraints. In today's modern agriculture, environmentally friendly technology is becoming more and more significant as a substitute for conventional fertilizers and chemical pesticides. Using nanotechnology, agricultural output can be improved in terms of quality, biological support, financial stability, and environmental safety. There is a lot of promise for the sustainable application of nano-fertilizers in crop productivity and soil fertility, with little or no negative environmental effects. In this context, the present review provided an overview of the benefits of using nanofertilizers, its application and types. Mechanistic approach for increasing soil fertility and yield via nanofertilizers also described in detail. We concluded this article to compare the advantages of nanofertilizers over chemicals and nano-chemicals. Nonetheless, additional investigation is required to comprehend the effects and possible hazards of nanomaterials in the food production chain.

Nanomaterials for Plant Disease Diagnosis and Treatment: A Review

Currently, the excessive use of pesticides has generated environmental pollution and harmful effects on human health. The controlled release of active ingredients through the use of nanomaterials (NMs) appears to reduce human exposure and ecosystem alteration. Although the use of NMs can offer an alternative to traditional methods of disease diagnosis and control, it is necessary to review the current approach to the application of these NMs. This review describes the most recent and significant advances in using NMs for diagnosing and treating plant diseases (bacteria, phytopathogenic fungi, viruses, and phytopathogenic nematodes) in cultivated plants. Most studies have focused on reducing, delaying, or eliminating bacteria, fungi, viruses, and nematodes in plants. Both metallic (including metal oxides) and organic nanoparticles (NPs) and composites are widely used in diagnosing and controlling plant diseases due to their biocompatibility and ease of synthesis. Few studies have been carried out with regard to carbon-based NPs due to their toxicity, so future studies should address the development of detection tools, ecological and economic impacts, and human health. The synergistic effect of NMs as fertilizers and pesticides opens new areas of knowledge on the mechanisms of action (plant-pathogen-NMs interaction), the interaction of NMs with nutrients, the effects on plant metabolism, and the traceability of NMs to implement sustainable approaches. More studies are needed involving in vivo models under international regulations to ensure their safety. There is still controversy in the release of NMs into the environment because they could threaten the stability and functioning of biological systems, so research in this area needs to be improved.

Foliar application of selenium and gibberellins reduce cadmium accumulation in soybean by regulating interplay among rhizosphere soil metabolites, bacteria community and cadmium speciation

Both selenium (Se) and gibberellins (GA3) can alleviate cadmium (Cd) toxicity in plants. However, the application of Se and GA3 as foliar spray to against Cd stress on soybean and its related mechanisms have been poorly explored. Herein, this experiment evaluated the effects of Se and GA3 alone and combined application on soybean rhizosphere microenvironment, Cd accumulation and growth of soybean seedlings. The results revealed that both Se and GA3 can effectively decrease the accumulation of Cd in soybean seedlings. Foliar application of Se, GA3 and their combination reduced Cd contents in soybean seedlings respectively by 21.70 %, 27.53 % and 45.07 % when compared with the control treatment, suggest a synergistic effect of Se and GA3 in decreasing Cd accumulation. Se and GA3 also significantly increased diversity and abundance of the metabolites in rhizosphere, which consequently played an important role in shaping rhizosphere bacteria community and improve rhizosphere soil physicochemical properties of Cd contaminated soil, as well as decreased the Cd available forms contents but enhance the immobilized form levels. Overall, this study affords a novel approach on mitigating Cd accumulation in soybean seedlings which is attributed to Se and GA3 regulated interplay among rhizosphere soil metabolites, bacteria community and cadmium speciation.

Copper oxide nanoparticles mitigate cadmium toxicity in rice seedlings through multiple physiological mechanisms

Heavy metal pollution poses a serious threat to crops growth and yield. Recently, nanoparticles (NPs) have emerged as a promising strategy to mitigate the negative effect of heavy metal on crop growth. This study investigated the beneficial effects of copper oxide nanoparticles (CuO NPs) on the morphological and physiological-biochemical traits of rice seedlings (Oryza sativa L.) under cadmium (Cd) stress. The results demonstrated that the application of CuO NPs increased the contents of nutrition elements in shoots and roots as well as photosynthetic pigments, consequently improving the growth of rice seedlings under Cd stress, especially at low level of Cd stress. Meanwhile, CuO NPs obviously decreased the Cd accumulation in the rice seedlings and immobilized Cd in less toxic chemical forms and subcellular compartments. Moreover, CuO NPs modulated the antioxidant system, ameliorating oxidative damage and membrane injury caused by Cd. Multivariate analysis established correlations between physio-biochemical parameters and further revealed the mitigation of Cd damage to rice seedlings by CuO NPs was associated with inhibition Cd accumulation, altering Cd chemical form and subcellular distribution, increasing the contents of mineral nutrients, photosynthetic pigments and secondary metabolites and antioxidant enzyme activities, and reducing oxidative damage. Overall, the present study indicated that CuO NPs could effectively reduce the Cd toxicity to rice seedlings, demonstrating their potential application in agricultural production.

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.

Antibacterial Action of Zn2+ Ions Driven by the In Vivo Formed ZnO Nanoparticles

Antibacterial formulations based on zinc oxide nanoparticles (ZnO NPs) are widely used for antibiotic replacement in veterinary medicine and animal nutrition. However, the undesired environmental impact of ZnO NPs triggers a search for alternative, environmentally safer solutions. Here, we show that Zn2+ in its ionic form is a more eco-friendly antibacterial, and its biocidal action rivals that of ZnO NPs (<100 nm size), with a minimal biocidal concentration being 41(82) μg mL-1 vs 5 μg mL-1 of ZnO NPs, as determined for 103(106) CFU mL-1 E. coli. We demonstrate that the biocidal activity of Zn2+ ions is primarily associated with their uptake by E. coli and spontaneous in vivo transformation into insoluble ZnO nanocomposites at an internal bacterial pH of 7.7. Formed in vivo nanocomposite then damages E. coli membrane and intracellular components from the inside, by forming insoluble biocomposites, whose formation can also trigger ZnO characteristic reactions damaging the cells (e.g., by generation of high-potential reactive oxygen species). Our study defines a special route in which Zn2+ metal ions induce the death of bacterial cells, which might be common to other metal ions capable of forming semiconductor oxides and insoluble hydroxides at a slightly alkaline intracellular pH of some bacteria.

Nano hybrid fertilizers: A review on the state of the art in sustainable agriculture

The advent of Nanohybrid (NH) fertilizers represents a groundbreaking advancement in the pursuit of precision and sustainable agriculture. This review abstract encapsulates the transformative potential of these innovative formulations in addressing key challenges faced by modern farming practices. By incorporating nanotechnology into traditional fertilizer matrices, nanohybrid formulations enable precise control over nutrient release, facilitating optimal nutrient uptake by crops. This enhanced precision not only fosters improved crop yields but also mitigates issues of over-fertilization, aligning with the principles of sustainable agriculture. Furthermore, nanohybrid fertilizers exhibit the promise of minimizing environmental impact. Their controlled release mechanisms significantly reduce nutrient runoff, thereby curbing water pollution and safeguarding ecosystems. This dual benefit of precision nutrient delivery and environmental sustainability positions nanohybrid fertilizers as a crucial tool in the arsenal of precision agriculture practices. The intricate processes of uptake, translocation, and biodistribution of nutrients within plants are examined in the context of nanohybrid fertilizers. The nanoscale features of these formulations play a pivotal role in governing the efficiency of nutrient absorption, internal transport, and distribution within plant tissues. Factors affecting the performance of nanohybrid fertilizers are scrutinized, encompassing aspects such as soil type, crop variety, and environmental conditions. Understanding these variables is crucial for tailoring nanohybrid formulations to specific agricultural contexts, and optimizing their impact on crop productivity and resource efficiency. Environmental considerations are integral to the review, assessing the broader implications of nanohybrid fertilizer application. This review offers a holistic overview of nanohybrid fertilizers in precision and sustainable agriculture. Exploring delivery mechanisms, synthesis methods, uptake dynamics, biodistribution patterns, influencing factors, and environmental implications, it provides a comprehensive understanding of the multifaceted role and implications of nanohybrid fertilizers in advancing modern agricultural practices.

Advancement of metal oxide nanomaterials on agri-food fronts

The application of metal oxide nanomaterials (MOx NMs) in the agrifood industry offers innovative solutions that can facilitate a paradigm shift in a sector that is currently facing challenges in meeting the growing requirements for food production, while safeguarding the environment from the impacts of current agriculture practices. This review comprehensively illustrates recent advancements and applications of MOx for sustainable practices in the food and agricultural industries and environmental preservation. Relevant published data point out that MOx NMs can be tailored for specific properties, enabling advanced design concepts with improved features for various applications in the agrifood industry. Applications include nano-agrochemical formulation, control of food quality through nanosensors, and smart food packaging. Furthermore, recent research suggests MOx's vital role in addressing environmental challenges by removing toxic elements from contaminated soil and water. This mitigates the environmental effects of widespread agrichemical use and creates a more favorable environment for plant growth. The review also discusses potential barriers, particularly regarding MOx toxicity and risk evaluation. Fundamental concerns about possible adverse effects on human health and the environment must be addressed to establish an appropriate regulatory framework for nano metal oxide-based food and agricultural products.

Emerging trends to replace pesticides with nanomaterials: Recent experiences and future perspectives for ecofriendly environment

Despite the widespread usage to safeguard crops and manage pests, pesticides have detrimental effects on the environment and human health. The necessity to find sustainable agricultural techniques and meet the growing demand for food production has spurred the quest for pesticide substitutes other than traditional ones. The unique qualities of nanotechnology, including its high surface area-to-volume ratio, controlled release, and better stability, have made it a promising choice for pest management. Over the past ten years, there has been a noticeable growth in the usage of nanomaterials for pest management; however, concerns about their possible effects on the environment and human health have also surfaced. The purpose of this review paper is to give a broad overview of the worldwide trends and environmental effects of using nanomaterials in place of pesticides. The various types of nanomaterials, their characteristics, and their possible application in crop protection are covered. The limits of the current regulatory frameworks for nanomaterials in agriculture are further highlighted in this review. Additionally, it describes how standard testing procedures must be followed to assess the effects of nanomaterials on the environment and human health before their commercialization. In order to establish sustainable and secure nanotechnology-based pest control techniques, the review concludes by highlighting the significance of taking into account the possible hazards and benefits of nanomaterials for pest management and the necessity of an integrated approach. It also emphasizes the importance of more investigation into the behavior and environmental fate of nanomaterials to guarantee their safe and efficient application in agriculture.

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.

Nano-elicitation and hydroponics: a synergism to enhance plant productivity and secondary metabolism

MAIN CONCLUSION

This review has explored the importance of using a synergistic approach of nano-elicitation and hydroponics to improve plant growth and metabolite production. Furthermore, it emphasizes the significance of green nanotechnology and eco-friendly practices while utilizing this approach to promote the development of a sustainable agriculture system. Nano-elicitation stimulates metabolic processes in plants using nanoparticles (NPs) as elicitors. The stimulation of these biochemical processes can enhance plant yield and productivity, along with the production of secondary metabolites. Nanoparticles have garnered the attention of scientific community because of their unique characteristics, such as incredibly small size and large surface-to-volume ratio, which make them effective elicitors. Hydroponic systems, which optimize growing conditions to increase plant production, are typically used to study the effect of elicitors. By integrating these two approaches, the qualitative and quantitative output of plants can be increased while employing minimal resources. As the global demand for high-quality crops and bioactive compounds surges, embracing this synergistic approach alongside sustainable farming practices can pave the way for resilient agricultural systems, ensuring food security and fostering an eco-friendly environment.

Green chemistry routed sugar press mud for (2D) ZnO nanostructure fabrication, mineral fortification, and climate-resilient wheat crop productivity

Nanotechnology appears to be a promising tool to redefine crop nutrition in the coming decades. However, the crucial interactions of nanomaterials with abiotic components of the environment like soil organic matter (SOM) and carbon‒sequestration may hold the key to sustainable crop nutrition, fortification, and climate change. Here, we investigated the use of sugar press mud (PM) mediated ZnO nanosynthesis for soil amendment and nutrient mobilisation under moderately alkaline conditions. The positively charged (+ 7.61 mv) ZnO sheet-like nanoparticles (~ 17 nm) from zinc sulphate at the optimum dose of (75 mg/kg blended with PM (1.4% w/w) were used in reinforcing the soil matrix for wheat growth. The results demonstrated improved agronomic parameters with (~ 24%) and (~ 19%) relative increases in yield and plant Zn content. Also, the soil solution phase interactions of the ZnO nanoparticles with the PM-induced soil colloidal carbon (- 27.9 mv and diameter 0.4864 μm) along with its other components have influenced the soil nutrient dynamics and mineral ecology at large. Interestingly, one such interaction seems to have reversed the known Zn-P interaction from negative to positive. Thus, the study offers a fresh insight into the possible correlations between nutrient interactions and soil carbon sequestration for climate-resilient crop productivity.

Development of amine-functionalized fluorescent silica nanoparticles from coal fly ash as a sustainable source for nanofertilizer

Scaling up the synthesis of fluorescent silica nanoparticles to meet the current demand in diverse applications involves technological limitations. The present study relates to the hydrothermal synthesis of water-soluble, crystalline, blue-emitting amine-functionalized silica nanoparticles from coal fly ash sustainably and economically. This study used tertiary amine (trimethylamine) to prepare amine-functionalized fluorescent silica nanoparticles, enhancing fluorescence quantum yield and nitrogen content for nanofertilizer application. The TEM and FESEM studies show that the silica nanoparticles have a spherical morphology with an average diameter of 4.0 nm. The x-ray photoelectron and Fourier transform infrared spectroscopy studies reveal the presence of the amine group at the surface of silica nanoparticles. The silica nanoparticles exhibit blue fluorescence with an emission maximum of 454 nm at 370 nm excitation and show excitation-dependent emission properties in the aqueous medium. With the perfect spectral overlap between silica nanoparticle emission (donor) and chlorophyll absorption (acceptor), fluorescent silica nanoparticles enhance plant photosynthesis rate by resonance energy transfer. This process accelerates the photosynthesis rate to improve the individual plant's quality and growth. These findings suggested that the fly ash-derived functionalized silica nanoparticles could be employed as nanofertilizers and novel delivery agents.

Foliar co-application of zinc oxide and copper oxide nanoparticles promotes phytochemicals and essential oil production in dragonhead (Dracocephalum moldavica)

Individual nanoparticle application has been documented to promote plant production; however, whether co-application of two nanoparticles (NPs) is more sustainable and significantly promotes plant production is unclear. Herein, foliar co-applications of two NPs or their conventional fertilizer forms on the growth, micronutrient (copper and zinc) enrichment, primary productivity, and essential oil (EO) production in a medicinal annual, dragonhead (Dracocephalum moldavica L.), were investigated. Treatments included 1:1 ratio of zinc oxide nanoparticles (ZnONPs):copper oxide nanoparticles (CuONPs) (40-400 mg/L), and compared with individual NPs, individual zinc suspension (ZnS) and chelated copper (chelated-Cu), and their combination, at equivalent concentrations. Results showed that the highest bioenrichment of Zn and Cu was observed with 80-160 mg/L ZnS+chelated-Cu, 400 mg/L ZnONPs+CuONPs, or ionic combination treatments. A dose-dependent increase in hydrogen peroxide and malondialdehyde was observed with co-treatment of NPs or ions, and oxidative stress responses were higher with NPs or ions co-treatment than individual treatment. With 160 mg/L ZnONPs+CuONPs treatment, total chlorophyll, aboveground biomass, and essential oil production increased significantly compared to control, 160 mg/L CuONPs, and 160 mg/L ZnONPs (227, 157 and 823 %; 58, 79, and 51 %; and 46, 80, and 3 %, respectively). Flavonoid and anthocyanin content also increased significantly (58 and 50 %, respectively) with ZnONPs+CuONPs compared to ZnS+chelated-Cu and were higher than ZnONPs or CuONPs alone by 10 and 25 %, and 37 and 36 %, respectively. More importantly, EO production and quality improved with 160 mg/L ZnONPs+CuONPs treatment compared to control. Taken together, our findings showed that foliar co-treatment of 160 mg/L ZnONPs+CuONPs could significantly improve primary productivity, aboveground biomass, and EO quality and yield in dragonhead grown in semi-arid field conditions; and thus, 160 mg/L ZnONPs+CuONPs is recommended as an optimal foliar co-treatment strategy for promoting sustainable plant production in semi-arid regions where soil nutrients and water are limiting factors inhibiting crop yield.

Seed Priming with Zinc Oxide Nanoparticles to Enhance Crop Tolerance to Environmental Stresses

Drastic climate changes over the years have triggered environmental challenges for wild plants and crops due to fluctuating weather patterns worldwide. This has caused different types of stressors, responsible for a decrease in plant life and biological productivity, with consequent food shortages, especially in areas under threat of desertification. Nanotechnology-based approaches have great potential in mitigating environmental stressors, thus fostering a sustainable agriculture. Zinc oxide nanoparticles (ZnO NPs) have demonstrated to be biostimulants as well as remedies to both environmental and biotic stresses. Their administration in the early sowing stages, i.e., seed priming, proved to be effective in improving germination rate, seedling and plant growth and in ameliorating the indicators of plants' well-being. Seed nano-priming acts through several mechanisms such as enhanced nutrients uptake, improved antioxidant properties, ROS accumulation and lipid peroxidation. The target for seed priming by ZnO NPs is mostly crops of large consumption or staple food, in order to meet the increased needs of a growing population and the net drop of global crop frequency, due to climate changes and soil contaminations. The current review focuses on the most recent low-cost, low-sized ZnO NPs employed for seed nano-priming, to alleviate abiotic and biotic stresses, mitigate the negative effects of improper storage and biostimulate plants' growth and well-being. Taking into account that there is large variability among ZnO NPs and that their chemico-physical properties may play a role in determining the efficacy of nano-priming, for all examined cases, it is reported whether the ZnO NPs are commercial or lab prepared. In the latter cases, the preparation conditions are described, along with structural and morphological characterizations. Under these premises, future perspectives and challenges are discussed in relation to structural properties and the possibility of ZnO NPs engineering.

Warm Temperature Increments Strengthen the Crosstalk between Roots and Soil in the Rhizosphere of Soybean Seedlings

The plant rhizosphere underlies the crosstalk between plant and soil and has a crucial role in plant growth and development under various environments. We examined the effect of temperature rise on the rhizosphere environment of soybean roots to clarify the rhizosphere crosstalk between roots and soil in response to warm temperature rises in a global warming background. The in situ results of root enzyme activity revealed that soybean roots secrete β-glucosidase, and enzyme spectrum imaging demonstrated different enzymatic activities under different temperature environments. The soil enzyme kinetics results showed that soil enzymatic activity increased with increasing temperature, and soybean rhizosphere soil enzymatic activity was higher than that of non-rhizosphere soil. Rhizosphere soil and non-rhizosphere soil showed that the dominant bacterial phylum in soybean rhizosphere soil was Acidobacteria, and the dominant bacterial genus was JG30-KF-AS9. Compared with non-rhizosphere soil, rhizosphere soil was more nutrient-rich, and root secretions provided abundant carbon sources and other nutrients for soil microorganisms in the rhizosphere. Rhizosphere microorganisms affect plant growth by influencing the decomposition of soil organic carbon. The organic carbon content of rhizosphere soil was higher than that of non-rhizosphere soil under high temperatures.

Efficacy of zinc-based nanoparticles in alleviating the abiotic stress in plants: current knowledge and future perspectives

Due to sessile, plants are unable to avoid unfavorable environmental conditions which leads to inducing serious negative effects on plant growth, crop yield, and food safety. Instead, various approaches were employed to mitigate the phytotoxicity of these emerging contaminants from the soil-plant system. However, recent studies based on the exogenous application of ZnO NPs approve of their important positive potential for alleviating abiotic stress-induced phytotoxicity leads to ensuring global food security. In this review, we have comprehensively discussed the promising role of ZnO NPs as alone or in synergistic interactions with other plant growth regulators (PGRs) in the mitigation of various abiotic stresses, i.e., heavy metals (HMs), drought, salinity, cold and high temperatures from different crops. ZnO NPs have stress-alleviating effects by regulating various functionalities by improving plant growth and development. ZnO NPs are reported to improve plant growth by stimulating diverse alterations at morphological, physiological, biochemical, and ultrastructural levels under abiotic stress factors. We have explained the recent advances and pointed out research gaps in studies conducted in earlier years with future recommendations. Thus, in this review, we have also addressed the opportunities and challenges together with aims to uplift future studies toward effective applications of ZnO NPs in stress management.

Development and Evaluation of Zinc and Iron Nanoparticles Functionalized with Plant Growth-Promoting Rhizobacteria (PGPR) and Microalgae for Their Application as Bio-Nanofertilizers

Micronutrient deficiencies are widespread and growing global concerns. Nanoscale nutrients present higher absorption rates and improved nutrient availability and nutrient use efficiency. Co-application of nanofertilizers (NFs) with biological agents or organic compounds increases NF biocompatibility, stability, and efficacy. This study aimed to develop and evaluate zinc and iron bio-nanofertilizers formulated with plant growth-promoting rhizobacteria (PGPR) and microalgae. Nanoparticles (NPs) were synthesized with the co-precipitation method and functionalized with Pseudomonas species and Spirulina platensis preparation. NPs were characterized and evaluated on seed germination, soil microbial growth, and early plant response under seedbed conditions. NPs corresponded to zinc oxide (ZnO; 77 nm) and maghemite (γ-Fe2O3; 68 nm). Functionalized nanoparticles showed larger sizes, around 145-233 nm. The seedling vigor index of tomato and maize was significantly increased (32.9-46.1%) by bacteria-functionalized ZnO- and γ-Fe2O3-NPs at 75 ppm. NFs at 250 and 75 ppm significantly increased bacterial growth. NFs also improved early plant growth by increasing plant height (14-44%), leaf diameter (22-47%), and fresh weight (46-119%) in broccoli and radish, which were mainly influenced by bacteria capped ZnO- and γ-Fe2O3-NPs at 250 ppm. Beneficial effects on plant growth can be attributed to the synergistic interaction of the biological components and the zinc and iron NPs in the bio-nanofertilizers.

Zinc Oxide Nanoparticles Affect Early Seedlings' Growth and Polar Metabolite Profiles of Pea (Pisum sativum L.) and Wheat (Triticum aestivum L.)

The growing interest in the use of zinc oxide nanoparticles (ZnO NPs) in agriculture creates a risk of soil contamination with ZnO NPs, which can lead to phytotoxic effects on germinating seeds and seedlings. In the present study, the susceptibility of germinating seeds/seedlings of pea and wheat to ZnO NPs of various sizes (≤50 and ≤100 nm) applied at concentrations in the range of 100-1000 mg/L was compared. Changes in metabolic profiles in seedlings were analyzed by GC and GC-MS methods. The size-dependent harmful effect of ZnO NPs on the seedling's growth was revealed. The more toxic ZnO NPs (50 nm) at the lowest concentration (100 mg/L) caused a 2-fold decrease in the length of the wheat roots. In peas, the root elongation was slowed down by 20-30% only at 1000 mg/L ZnO NPs. The metabolic response to ZnO NPs, common for all tested cultivars of pea and wheat, was a significant increase in sucrose (in roots and shoots) and GABA (in roots). In pea seedlings, an increased content of metabolites involved in the aspartate-glutamate pathway and the TCA cycle (citrate, malate) was found, while in wheat, the content of total amino acids (in all tissues) and malate (in roots) decreased. Moreover, a decrease in products of starch hydrolysis (maltose and glucose) in wheat endosperm indicates the disturbances in starch mobilization.

Modification of Tomato Photosystem II Photochemistry with Engineered Zinc Oxide Nanorods

We recently proposed the use of engineered irregularly shaped zinc oxide nanoparticles (ZnO NPs) coated with oleylamine (OAm), as photosynthetic biostimulants, to enhance crop yield. In the current research, we tested newly engineered rod-shaped ZnO nanorods (NRs) coated with oleylamine (ZnO@OAm NRs) regarding their in vivo behavior related to photosynthetic function and reactive oxygen species (ROS) generation in tomato (Lycopersicon esculentum Mill.) plants. ZnO@OAm NRs were produced via solvothermal synthesis. Their physicochemical assessment revealed a crystallite size of 15 nm, an organic coating of 8.7% w/w, a hydrodynamic diameter of 122 nm, and a ζ-potential of -4.8 mV. The chlorophyll content of tomato leaflets after a foliar spray with 15 mg L-1 ZnO@OAm NRs presented a hormetic response, with an increased content 30 min after the spray, which dropped to control levels 90 min after the spray. Simultaneously, 90 min after the spray, the efficiency of the oxygen-evolving complex (OEC) decreased significantly (p < 0.05) compared to control values, with a concomitant increase in ROS generation, a decrease in the maximum efficiency of PSII photochemistry (Fv/Fm), a decrease in the electron transport rate (ETR), and a decrease in the effective quantum yield of PSII photochemistry (ΦPSII), indicating reduced PSII efficiency. The decreased ETR and ΦPSII were due to the reduced efficiency of PSII reaction centers (Fv'/Fm'). There were no alterations in the excess excitation energy at PSII or the fraction of open PSII reaction centers (qp). We discovered that rod-shaped ZnO@OAm NRs reduced PSII photochemistry, in contrast to irregularly shaped ZnO@OAm NPs, which enhanced PSII efficiency. Thus, the shape and organic coating of the nanoparticles play a critical role in the mechanism of their action and their impact on crop yield when they are used in agriculture.

Zinc oxide nanoparticles mitigated the arsenic induced oxidative stress through modulation of physio-biochemical aspects and nutritional ions homeostasis in rice (Oryza sativa L.)

Zinc oxide nanoparticles (nZn) have emerged as vital agents in combating arsenic (As) stress in plants. However, their role in mitigation of As induced oxidative stress is less studied. Therefore, this study aimed to assess the comparative role of nZn and ZnO in alleviating As toxicity in rice genotype "9311". The results of this study revealed that nZn demonstrated superior efficacy compared to ZnO in mitigating As toxicity. This superiority can be attributed to the unique size and structure of nZn, which enhances its ability to alleviate As toxicity. Exposure to As at a concentration of 25 μM L-1 led to significant reductions in shoot length, root length, shoot dry weight, and root dry weight by 39%, 51%, 30%, and 46%, respectively, while the accumulation of essential nutrients such as magnesium (Mg), potassium (K), iron (Fe), manganese (Mn), and zinc (Zn) decreased by 25%-47% compared to the control plants. Additionally, As exposure resulted in stomatal closure and structural damage to vital cellular components such as grana thylakoids (GT), starch granules (SG), and the nucleolus. However, the application of nZn at a concentration of 30 mg L-1 exhibited significant alleviation of As toxicity, resulting in a reduction of As accumulation by 54% in shoots and 62% in roots of rice seedlings. Furthermore, nZn demonstrated the ability to scavenge reactive oxygen species (ROS) like hydrogen peroxide (H2O2) and superoxide anion (O2.-), while significantly promoted the gas exchange parameters, chlorophyll content (SPAD value), fluorescence efficiency (Fv/m) and antioxidant enzyme activities under As-induced stress. These findings highlight the potential of nZn in mitigating the adverse impacts of As contamination in rice plants. However, further research is necessary to fully comprehend the underlying mechanisms responsible for the protective effects of nZn and to determine the optimal conditions for their application in real-world agricultural settings.

Nano-Biofertilizer Formulations for Agriculture: A Systematic Review on Recent Advances and Prospective Applications

In the twenty-first century, nanotechnology has emerged as a potentially game-changing innovation. Essential minerals are mostly unavailable in modern cropping systems without the application of synthetic fertilizers, which have a serious negative impact on the ecosystem. This review focuses on the coupling of nanoparticles with biofertilizers to function as nano-biofertilizers (NBFs), which may ensure world food security in the face of the rising population. The inoculation of plants with NBFs improves plant development and resistance to stress. Metallic nanoparticles as well as organic components comprising polysaccharide and chitosan may be encapsulated, utilizing microbe-based green synthesis to make NBFs, which circumvents the limitations of conventional chemical fertilizers. The application of NBFs is just getting started, and shows more promise than other approaches for changing conventional farming into high-tech "smart" farming. This study used bibliographic analysis using Web of Science to find relevant papers on "nano biofertilizers", "plants", and "agriculture". These subjects have received a lot of attention in the literature, as shown by the co-citation patterns of these publications. The novel use of nanotechnology in agriculture is explored in this research work, which makes use of the unique characteristics of nanoscale materials to address urgent concerns including nutrient delivery, crop protection, and sustainable farming methods. This study attempts to fill in some of the gaps in our knowledge by discussing the formulation, fabrication, and characterization of NBFs, as well as elucidating the mechanisms by which NBFs interact with plants and how this benefits the ability of the plant to withstand biotic and abiotic stress brought about by climate change. This review also addresses recent developments and future directions in farming using NBF formulations in the field.

Nano-zinc and plant growth-promoting bacteria is a sustainable alternative for improving productivity and agronomic biofortification of common bean

Background and aims

Nano-zinc (Zn) fertilizer is an easily adaptable and environmentally safe alternative option that can effectively improve growth, yield and biofortification of common bean. Plant growth-promoting bacteria (PGPBs) could promote plant growth and nutrients availability in sustainable manner. Therefore, this study aimed to investigate the influence of foliar nano-Zn application in association with seed co-inoculations of PGPBs on growth, yield, biofortification and Zn use efficiencies in common bean cultivation. Two field experiments were performed with seven co-inoculations of PGPBs and three foliar nano-Zn doses applied 50% at R5 and 50% at R8 stages of common bean to determine plant height, shoot dry matter, grain yield, Zn concentration and uptake in shoot and grains, Zn partitioning index, daily Zn intake and Zn use efficiencies for agronomic biofortification.

Results

The combined foliar nano-Zn application and co-inoculation of R. tropici + B. subtilis enhance grain yield, leaf chlorophyll index, total protein content, grain Zn concentration and uptake, daily Zn intake, Zn use efficiency, applied Zn recovery and Zn utilization efficiency in common beans in 2019 and 2020 cropping seasons. Foliar nano-Zn application at a dose of 1.5 kg ha−1 increased plant height, shoot dry matter, shoot Zn uptake, Zn partitioning and agro-physiological efficiency under co-inoculation with R. tropici + B. subtilis in both cropping years.

Conclusions

The treatments with foliar nano-Zn application at a dose of 1.5 ha−1 and co-inoculation with R. tropici + B. subtilis improved performance, chlorophyll index, protein content, grain yield, and Zn efficiencies that can lead to better biofortification of common bean in tropical savannah. Therefore, it is recommended that applying nano-Zn via foliar along with co-inoculation of PGPBs could be the better option for productivity and biofortification of common bean.

Graphical Abstract

Nanopriming Action of Microwave-Assisted Biofunctionalized ZnO Nanoparticles to Enhance the Growth under Moisture Stress in Vigna radiata

Bare and stabilized zinc oxide nanoparticles (ZnO NPs) were prepared by a microwave-assisted method and used as a priming agent to improve the morphological, physiological, and biochemical quality of Vigna radiata. The priming action was made under normal and moisture stress conditions. A microwave reactor of 850 watts power was used to heat 30 mL of a nanocolloidal solution at 140 °C for 20 min. The stable spherical ZnO NPs at 50.4 mV with 28.2 nm particle size were generated and capped with different biomolecules, cysteine and PVA, to get biostabilized ZnO NPs at 48.8 and 108.5 nm with ζ potentials of -56.2 and -52.0 mV, respectively, holding distinct morphology. The nanopriming effect was studied in V. radiata seeds for bare ZnO and capped ZnO NPs under normal and moisture stress environments. Cysteine-capped ZnO NPs at 250 ppm showed improved germination (90 and 76%), radicle growth (7.6 and 3.6 cm), seedling Vigor (3064 and 1816), dry matter production (145.06 and 96.92 mg/25 seedlings), and hydrolytic (α-amylase and protease) and antioxidant (peroxidase and superoxide dismutase) enzyme activity under normal and moisture stress conditions. The improved priming action of cysteine-capped ZnO NPs is due to increased cell elongation and cell division in the radicle. The uptake and translocation of ZnO NPs in the V. radiata root are evidenced by the presence of an 11.4 ppm zinc level, which was also supported by EDAX and FITC labeling results.

Formulation of Zinc oxide/Gum acacia nanocomposite as a novel slow-release fertilizer for enhancing Zn uptake and growth performance of Spinacia oleracea L

Zinc (Zn) deficiency has caused nutritional disorders in 17% of the world's population; thus, producing Zn-enriched plants as a dietary source is necessary. Recently, nanofertilizers have gained much attention as a substitute for conventional fertilizers; however, soil application of polymer-coated Zn-based nanofertilizer has not been explored much. The present study depicts the green synthesis of ZnO nanoparticles using Melia azedarach L. leaf extract, whose phytoconstituents have reducing abilities. The synthesized nanoparticles were combined with gum acacia (GA) to form a ZnOGA nanocomposite. The structural and morphological properties of ZnOGA were studied using XRD, FTIR, FESEM, and EDX. A pot experiment study was carried out with Spinacia oleracea L. at various doses (3, 5, and 10 mg/kg) of the synthesized ZnOGA to evaluate its effectiveness as a slow-release fertilizer and was compared with a commercial Zn fertilizer. The plant growth studies revealed a significant increase in the phyto-morphological traits of the plants fertilized with ZnOGA compared to commercial fertilizer. The plants also displayed significantly higher contents of protein (17-47%), phenols (25-60%), proline (82-94%), total soluble sugar (20-31%), DPPH activity (70-72%), and Zn uptake (91-106%). The doses of ZnOGA played an imperative role in determining the growth and productivity of the plant. Soil column studies showed that ZnOGA reduces Zn leaching by 52% compared to commercial Zn fertilizer. This study signifies the potential of ZnOGA to be applied as an eco-friendly and sustainable substitute for conventional Zn fertilizer minimizing Zn losses and Zn deficiency-related health problems in human populations.

Fe-Mn nanocomposites doped graphene quantum dots alleviate salt stress of Triticum aestivum through osmolyte accumulation and antioxidant defense

An investigation was carried out to evaluate the effect of graphene quantum dots (GQD) and its nanocomposites on germination, growth, biochemical, histological, and major ROS detoxifying antioxidant enzyme activities involved in salinity stress tolerance of wheat. Seedlings were grown on nutrient-free sand and treatment solutions were applied through solid matrix priming and by foliar spray. Control seedlings under salinity stress exhibited a reduction in photosynthetic pigment, sugar content, growth, increased electrolyte leakage, and lipid peroxidation, whereas iron-manganese nanocomposites doped GQD (FM_GQD) treated seedlings were well adapted and performed better compared to control. Enzymatic antioxidants like catalase, peroxidase, glutathione reductase and NADPH oxidase were noted to increase by 40.5, 103.2, 130.19, and 141.23% respectively by application of FM_GQD. Histological evidence confirmed a lower extent of lipid peroxidation and safeguarding the plasma membrane integrity through osmolyte accumulation and redox homeostasis. All of these interactive phenomena lead to an increment in wheat seedling growth by 28.06% through FM_GQD application. These findings highlight that micronutrient like iron, manganese doped GQD can be a promising nano-fertilizer for plant growth and this article will serve as a reference as it is the very first report regarding the ameliorative role of GQD in salt stress mitigation.

Addressing global food insecurity: Soil-applied zinc oxide nanoparticles promote yield attributes and seed nutrient quality in Glycine max L

Consumed globally, oilseeds serve as a major source of proteins and oils in human and animal nutrition, supporting global food security. Zinc (Zn) is an essential micronutrient critical for oil and protein synthesis in plants. In this study, we synthesized three distinct sized zinc oxide nanoparticles (nZnO: 38 nm = S [small], 59 nm = M [medium], and > 500 nm = L [large], and assessed the potential effects of varied particle sizes and concentrations (0, 50, 100, 200, and 500 mg/kg-soil) on seed yield attributes, nutrient quality and oil and protein yield in soybean (Glycine max L.) grown for a full lifecycle of 120 days, and compared with soluble Zn²⁺ ions (ZnCl₂) and water-only controls. We observed particle size- and concentration-dependent influence of nZnO on photosynthetic pigments, pod formation, potassium and phosphorus accumulation in seed, and protein and oil yields. Overall, soybean showed significant stimulatory responses to nZnO-S for most of the parameters tested compared to nZnO-M, nZnO-L, and Zn²⁺ ions treatments up to 200 mg/kg, suggesting the potential for small size nZnO to improve seed quality and production in soybean. At 500 mg/kg, however, for all endpoints (except for carotenoids and seed formation) toxicity was observed with all Zn compounds. Further, TEM analysis of seed ultrastructure indicated potential alterations in seed oil bodies and protein storage vacuoles at a toxic concentration (500 mg/kg) of nZnO-S compared to control. These findings suggest 200 mg/kg as an optimal dose for the smallest size nZnO-S (38 nm) to significantly improve seed yield, nutrient quality, and oil and protein yield, paving a path for addressing global food insecurity using small sized nZnO as a novel nano-fertilizer to promote crop yield and nutrient quality, in soil-grown soybean.

Human and environmental impacts of nanoparticles: a scoping review of the current literature

Use of nanoparticles have established benefits in a wide range of applications, however, the effects of exposure to nanoparticles on health and the environmental risks associated with the production and use of nanoparticles are less well-established. The present study addresses this gap in knowledge by examining, through a scoping review of the current literature, the effects of nanoparticles on human health and the environment. We searched relevant databases including Medline, Web of Science, ScienceDirect, Scopus, CINAHL, Embase, and SAGE journals, as well as Google, Google Scholar, and grey literature from June 2021 to July 2021. After removing duplicate articles, the title and abstracts of 1495 articles were first screened followed by the full-texts of 249 studies, and this resulted in the inclusion of 117 studies in the presented review.In this contribution we conclude that while nanoparticles offer distinct benefits in a range of applications, they pose significant threats to humans and the environment. Using several biological models and biomarkers, the included studies revealed the toxic effects of nanoparticles (mainly zinc oxide, silicon dioxide, titanium dioxide, silver, and carbon nanotubes) to include cell death, production of oxidative stress, DNA damage, apoptosis, and induction of inflammatory responses. Most of the included studies (65.81%) investigated inorganic-based nanoparticles. In terms of biomarkers, most studies (76.9%) used immortalised cell lines, whiles 18.8% used primary cells as the biomarker for assessing human health effect of nanoparticles. Biomarkers that were used for assessing environmental impact of nanoparticles included soil samples and soybean seeds, zebrafish larvae, fish, and Daphnia magna neonates.From the studies included in this work the United States recorded the highest number of publications (n = 30, 25.64%), followed by China, India, and Saudi Arabia recording the same number of publications (n = 8 each), with 95.75% of the studies published from the year 2009. The majority of the included studies (93.16%) assessed impact of nanoparticles on human health, and 95.7% used experimental study design. This shows a clear gap exists in examining the impact of nanoparticles on the environment.

Differential response of nano zinc sulphate with other conventional sources of Zn in mitigating salinity stress in rice grown on saline-sodic soil

Salinization causes the degradation of the soil and threatening the global food security but the application of essential micronutrients like zinc (Zn), improve the plant growth by stabilizing the plant cell and root development. Keeping in view the above-mentioned scenario, an experiment was conducted to compare the efficiency of conventional Zn fertilizers like zinc sulphate (ZnSO₄), zinc ethylene diamine tetra acetic acid (Zn-EDTA) and advance nano Zn fertilizers such as zinc sulphate nanoparticles (ZnSO₄NPs), and zinc oxide nanoparticles (ZnONPs) (applied at the rate of 5 and 10 mg/kg) in saline-sodic soil. Results revealed that the maximum plant height (67%), spike length (72%), root length (162%), number of tillers (71%), paddy weight (100%), shoot dry weight (158%), and root dry weight (119%) was found in ZnSO₄NPs applied at the rate of 10 mg/kg (ZnSO₄NPs-10) as compared to salt-affected control (SAC). Similarly, the plants physiological attributes like chlorophyll contents (91%), photosynthesis rate (113%), transpiration rate (106%), stomatal conductance (56%) and internal CO₂ (11%) were increased by the application of ZnSO₄NPs-10, as compared to SAC. The maximum Zn concentration in root (153%), shoot (205%) and paddy (167%) found in ZnSO₄NPs-10, as compared to control. In the body of rice plants, other nutrients like phosphorus and potassium were also increased by the application of ZnSO₄NPs-10 and soil chemical attributes such as sodium and sodium adsorption ratio were decreased. The current experiment concluded that the application of ZnSO₄NPs at the rate of 10 mg/kg in salt-affected paddy soil increased the growth, physiology, up take of essential nutrients and yield of rice by balancing the cationic ratio under salt stress.

Effect of Green Synthesized ZnO-NPs on Growth, Antioxidant System Response and Bioactive Compound Accumulation in Echinops macrochaetus, a Potential Medicinal Plant, and Assessment of Genome Size (2C DNA Content)

Echinops macrochaetus is a medicinal plant that can be used to cure various diseases. In the present study, plant-mediated zinc oxide nanoparticles (ZnO-NPs) were synthesized using an aqueous leaf extract of the medicinal plant Heliotropium bacciferum and characterized using various techniques. E. macrochaetus was collected from the wild and identified using the internal transcribed spacer sequence of nrDNA (ITS-nrDNA), which showed the closeness to its related genus in a phylogenetic tree. The effect of synthesized biogenic ZnO-NPs was studied on E. macrochaetus in a growth chamber for growth, bioactive compound enhancement and antioxidant system response. The irrigation of plants at a low concentration of ZnO-NPs (T1 = 10 mg/L) induced more growth in terms of biomass, chlorophyll content (273.11 µg/g FW) and carotenoid content (135.61 µg/g FW) than the control and other treatments (T2-20 mg/L and T3-40 mg/L). However, the application of a high concentration of ZnO-NPs (20 and 40 mg/L) increased the level of antioxidant enzymes (SOD, APX and GR), total crude and soluble protein, proline and TBARS contents. The accumulations of the compounds quercetin-3-β-D-glucoside, luteolin 7-rutinoside and p-coumaric acid were greater in the leaf compared to the shoot and root. A minor variation was observed in genome size in treated plants as compared to the control group. Overall, this study revealed the stimulatory effect of phytomediated ZnO-NPs, which act as bio-stimulants/nano-fertilizers as revealed by more biomass and the higher production of phytochemical compounds in different parts of the E. macrochaetus.

Foliar enrichment of copper oxide nanoparticles promotes biomass, photosynthetic pigments, and commercially valuable secondary metabolites and essential oils in dragonhead (Dracocephalum moldavica L.) under semi-arid conditions

High alkaline and low organic carbon hinder micronutrients, such as copper (Cu), bioavailability in (semi-) arid soils, affecting plant nutrient quality and productivity. This study aimed at investigating the potential beneficial effects of foliar Cu oxide nanoparticles (CuONPs) and conventional chelated-Cu applications (0-400 mg Cu/L) on the biomass, physiological biomarkers of plant productivity and oxidative stress, Cu bioaugmentation, and essential oils and secondary metabolites in dragonhead (Dracocephalum moldavica [L.]) grown in Cu-limited alkaline soil in semi-arid condition. Employing a randomized complete block design with three replicates, two different sources of Cu (CuONPs and chelated-Cu), and a wide range of Cu concentrations (0, 40, 80, 160, and 400 mg Cu/L), plants were foliarly treated at day-60 and day-74. At day-120, plants were harvested at the end of the flowering stage. Results showed shoot Cu bioaccumulation, flavonoids and anthocyanin increased in a dose-dependent manner for both Cu compounds, but the beneficial effects were significantly higher with CuONPs compared to chelated-Cu treatments. Further, shoot biomass (23 %), photosynthetic pigments (chlorophyll-a and chlorophyll-b; 77 and 123 %, respectively), and essential oil content and yield (70 and 104 %, respectively) increased significantly with foliar application of 80 mg/L CuONPs compared to equivalent concentration of chelated-Cu, suggesting an optimal threshold beyond which toxicity was observed. Likewise, commercially important secondary metabolites' yield (such as geranyl acetate, geranial, neral, and geraniol) was higher with 80 mg/L CuONPs compared to 160 mg/L chelated-Cu (2.3, 0.5, 2.5, and 7.1 %, respectively). TEM analyses of leaf ultrastructure revealed altered cellular organelles for both compounds at 400 mg/L, corroborating the results of oxidative stress response (malondialdehyde and H2O2). In conclusion, these findings indicate significantly higher efficacy of CuONPs, with an optimal threshold of 80 mg/L, in promoting essential oil and bioactive compound yield in dragonhead and may pave a path for the use of nano-Cu as a sustainable fertilizer promoting agricultural production in semi-arid soils that are micronutrient Cu deficient.

Transformation of zinc oxide nanoparticles in the presence of aluminum oxide with pre-sorbed phosphorus ligands

Naturally occurring oxides could react with zinc oxide (ZnO) nanoparticles (NPs) and then change its transformation and toxicity to ecological receptors. The reaction may be affected by a variety of environmental factors, yet the relevant processes and mechanisms are limitedly investigated. Natural prevalent ligands, as an important factor, can sorb on natural oxide minerals and change its surface property, finally affecting ZnO NP transformation. This study investigated the interactions of ZnO NPs with phosphorus ligands (i.e., phytate and orthophosphate) pre-sorbed γ-alumina (γ-Al₂O₃) via batch experiments and multi-technique analyses. A limited amount of aqueous Zn²⁺ is observed when the concentration of ZnO NPs is relatively low (<64.8 mg L^-1) in the presence of phytate pre-sorbed γ-Al₂O₃. Solid Zn(II) species includes binary/ternary surface Zn(II) complexes on γ-Al₂O₃ with minor amounts of zinc phytate precipitates. As the concentration of ZnO NPs increases, surface Zn(II) complexes gradually transform into zinc phytate and Zn-Al layered double hydroxide (Zn-Al LDH) precipitates. The quantitative analysis indicates that, as the concentration of ZnO NPs increases from 32.4 to 388.8 mg L^-1, the proportion of Zn(II) species as binary/ternary surface complexes decreases from 81.9 to 30.2%; and the proportion as zinc phytate and Zn-Al LDH increases from 17.9 to 27.6% and 0 to 43.8%, respectively. The pre-sorption of orthophosphate can also inhibit ZnO NP transformation into Zn-Al LDH precipitates on γ-Al₂O₃. This study suggests that natural ligands pre-existed on natural oxide minerals could greatly influence the solubility, stability, transformation, and fate of easily dissoluble metal oxides (e.g., ZnO) in the environments.

Nanomaterials in agriculture for plant health and food safety: a comprehensive review on the current state of agro-nanoscience

In the modern epoch, nanotechnology took forward the agriculture and food industry with new tools that promise to increase food production sustainably. It also anticipated that it would become a driving economic force shortly. Nanotechnology has the potential to reduce agricultural inputs, enrich the soil by absorbing nutrients, manage plant diseases, and detect diseases. The aim of the present review is to cover the potential aspects of nanoscience and its trend-setting appliances in modern agriculture and food production. This review focuses on the impact of various nanomaterials on plant health to improve agricultural production and its cooperative approach to food production. Nanotechnology has great potential compared to conventional approaches. The appealing path of nanotrends in the farming sector raises hopes and illuminates the route of innovative technologies to overcome various diseases in plants with an enhanced yield to meet the growing global population's need for food security.

Recent Advances in Nano-Enabled Seed Treatment Strategies for Sustainable Agriculture: Challenges, Risk Assessment, and Future Perspectives

Agro seeds are vulnerable to environmental stressors, adversely affecting seed vigor, crop growth, and crop productivity. Different agrochemical-based seed treatments enhance seed germination, but they can also cause damage to the environment; therefore, sustainable technologies such as nano-based agrochemicals are urgently needed. Nanoagrochemicals can reduce the dose-dependent toxicity of seed treatment, thereby improving seed viability and ensuring the controlled release of nanoagrochemical active ingredients However, the applications of nanoagrochemicals to plants in the field raise concerns about nanomaterial safety, exposure levels, and toxicological implications to the environment and human health. In the present comprehensive review, the development, scope, challenges, and risk assessments of nanoagrochemicals on seed treatment are discussed. Moreover, the implementation obstacles for nanoagrochemicals use in seed treatments, their commercialization potential, and the need for policy regulations to assess possible risks are also discussed. Based on our knowledge, this is the first time that we have presented legendary literature to readers in order to help them gain a deeper understanding of upcoming nanotechnologies that may enable the development of future generation seed treatment agrochemical formulations, their scope, and potential risks associated with seed treatment.

Noval bio-organic fertilizer containing Arthrobacter sp. DNS10 alleviates atrazine-induced growth inhibition on soybean by improving atrazine removal and nitrogen accumulation

Herbicide atrazine restricts nutrient accumulation and thus inhibits the growth of sensitive crops. The application of organic fertilizer is a common measure that contributes to modulating abiotic tolerance of crops and providing nutrients, but its advantages in combination with atrazine degrading microorganisms as bio-organic fertilizer to alleviate atrazine stress on sensitive crops and the associated mechanisms are unknown. We investigated the beneficial effects of organic and bio-organic fertilizer (named DNBF10) containing Arthrobacter sp. DNS10 applications on growth, leaf nitrogen accumulation, root surface structure and root physiological properties of soybean seedlings exposed to 20 mg kg^-1 atrazine in soil. Compared with organic fertilizer, bio-organic fertilizer DNBF10 exhibited more reduction in soil atrazine residue and plant atrazine accumulation, as well as alleviation in atrazine-induced root oxidative stress and damaged cells of soybean roots. Transcriptome analysis revealed that DNBF10 application enhanced nitrogen utilization by improving the expression of genes involved in nitrogen metabolism in soybean leaves. Besides, genes expression of cytochrome P450 and ABC transporters involved in atrazine detoxification and transport in soybean leaves were also down-regulated by DNBF10 to diminish phytotoxicity of atrazine to soybean seedlings. These results illustrate the molecular mechanism by which the application of DNBF10 alleviates soybean seedlings growth under atrazine stress, providing a step forward for mitigate the atrazine induced inhibition on soybean seedlings growth through decreasing atrazine residues as well as enhancing damaged root repair and nitrogen accumulation.

Impact on Some Soil Physical and Chemical Properties Caused by Metal and Metallic Oxide Engineered Nanoparticles: A Review

In recent years, the release of metal and metallic oxide engineered nanoparticles (ENPs) into the environment has generated an increase in their accumulation in agricultural soils, which is a serious risk to the ecosystem and soil health. Here, we show the impact of ENPs on the physical and chemical properties of soils. A literature search was performed in the Scopus database using the keywords ENPs, plus soil physical properties or soil chemical properties, and elements availability. In general, we found that the presence of metal and metallic oxide ENPs in soils can increase hydraulic conductivity and soil porosity and reduce the distance between soil particles, as well as causing a variation in pH, cation exchange capacity (CEC), electrical conductivity (EC), redox potential (Eh), and soil organic matter (SOM) content. Furthermore, ENPs or the metal cations released from them in soils can interact with nutrients like phosphorus (P) forming complexes or precipitates, decreasing their bioavailability in the soil solution. The results depend on the soil properties and the doses, exposure duration, concentrations, and type of ENPs. Therefore, we suggest that particular attention should be paid to every kind of metal and metallic oxide ENPs deposited into the soil.

Metabolomics as a Tool to Understand Nano-Plant Interactions: The Case Study of Metal-Based Nanoparticles

Metabolomics is a powerful tool in diverse research areas, enabling an understanding of the response of organisms, such as plants, to external factors, their resistance and tolerance mechanisms against stressors, the biochemical changes and signals during plant development, and the role of specialized metabolites. Despite its advantages, metabolomics is still underused in areas such as nano-plant interactions. Nanoparticles (NPs) are all around us and have a great potential to improve and revolutionize the agri-food sector and modernize agriculture. They can drive precision and sustainability in agriculture as they can act as fertilizers, improve plant performance, protect or defend, mitigate environmental stresses, and/or remediate soil contaminants. Given their high applicability, an in-depth understanding of NPs' impact on plants and their mechanistic action is crucial. Being aware that, in nano-plant interaction work, metabolomics is much less addressed than physiology, and that it is lacking a comprehensive review focusing on metabolomics, this review gathers the information available concerning the metabolomic tools used in studies focused on NP-plant interactions, highlighting the impact of metal-based NPs on plant metabolome, metabolite reconfiguration, and the reprogramming of metabolic pathways.

Novel oxymagnesite/green rust nanohybrids for selective removal and slow release of phosphate in water

The new paradigm in wastewater treatment demands to change traditional pollutants removal into resource recovery, especially for non-renewable P resources, effectively recovering phosphate from wastewater and reutilizing it as a nutrient is crucial to P sustainable utilization and P-related pollution control. The nanomaterial-based adsorption technology for P recovery from wastewater is becoming a research hotspot due to its high efficiency and selectivity. Herein, to recover aqueous phosphate, we developed novel oxymagnesite/green rust (OMGR) nanohybrids by a one-pot hydrothermal method. Green rust nanoparticles dispersed on the highly reactive oxymagnesite (MgO2MgCO₃) nanosheets could achieve efficient recovery and reuse of P. The volume ratio of water to ethylene glycol played an important role in the preparation of OMGR. The OMGR possessed an excellent selectivity of phosphate removal in the presence of multi-anions and wide pH adaptability in 4.0-10.0. The formation of MgP nanocrystals and the inner-sphere FeOP complexes via ligand exchange contributed to the selective removal of P by OMGR, and the removal capacity reached 141 mg P^.g^-1. The process of phosphate removal by OMGR was spontaneously endothermic and controlled by the intraparticle and boundary layer diffusion. Most importantly, the high bioavailable P (127 mg^.g^-1) of P-loaded OMGR had a persistent release behavior regulated by dissolution and diffusion, indicating that the P-loaded OMGR can act as a slow-release P-fertilizer. The findings provide a green and eco-friendly approach to realizing P resource recovery and reuse for phosphate-containing wastewaters.

Comparative bioaccumulation, translocation, and phytotoxicity of metal oxide nanoparticles and metal ions in soil-crop system

Exposure of the soil environment to metal nanoparticles (MNPs) has been extensive because of their indiscriminate use and the disposal of MNP products in various applications. In MNP-amended soil, various crops can absorb the nanoparticles, and accumulation of the MNPs in farm products has potential risks for bioconcentration in humans and livestock. Here, we evaluated the comparative bioaccumulation, translocation, and phytotoxicity of MNPs (ZnO and CuO NPs) and metal ions (Zn(NO3)2 and Cu(NO3)2) in four different crops, namely lettuce, radish, bok choy, and tomato. We carried out pot experiments to evaluate the phytotoxicity in the crops from the presence of MNPs and metal ions. Phytotoxicity from different treatments differed depending on the plant species, and metal types. In addition, exposure to Zn and Cu showed positive dose-dependent effects on their bioaccumulation in each crop. However, there were no significant differences in metal bioaccumulation depending on whether the crops were exposed to MNPs or metal ions. By calculating the bioconcentration factor (BCF) and translocation factor (TF), we were able to estimate the biological uptake and translocation abilities of MNPs and metal ions for each crop. It was found that lettuce and radish had greater BCFs than bok choy and tomato, while bok choy and tomato had higher TFs. Also, the uptake and translocation of Zn were better than those of Cu. However, the values for BCF and TF for each crop showed no significant differences between MNP and metal ion exposure. A micro X-ray fluorescence (μ-XRF) spectrometer analysis demonstrated that only Zn elements appeared in the primary veins and edges of all leaves and the storage root of radish. Our study aims to estimate bioaccumulation, translocation, and the implied potential risks from MNPs accumulated in different plant species.

Nanotechnology for sustainable agro-food systems: The need and role of nanoparticles in protecting plants and improving crop productivity

The rapid population growth and environmental challenges in agriculture need innovative and sustainable solutions to meet the growing need for food worldwide. Recent nanotechnological advances found its broad applicability in agriculture's protection and post-harvesting. Engineered nanomaterials play a vital role in plant regulation, seed germination, and genetic manipulation. Their size, surface morphology, properties, and composition were designed for controlled release and enhanced properties in agriculture and the food industry. Nanoparticles can potentially be applied for the targeted and controlled delivery of fertilizers, pesticides, herbicides, plant growth regulators, etc. This help to eliminate the use of chemical-based pesticides and their water solubility, protect agrochemicals from breakdown and degradation, improve soil health, and naturally control crop pathogens, weeds, and insects, ultimately leading to enhanced crop growth and production capacity in the food industry. They can be effectively utilized for nano-encapsulation, seed germination, genetic manipulation, etc., for protecting plants and improving crop productivity, safe and improved food quality, and monitoring climate conditions. Nanoparticles played a crucial role in the uptake and translocation processes, genetically modifying the crops, high seed germination, and productivity. In this article, we have reviewed some important applications of nanoparticles for sustainable agro-food systems. The need and role of nanotechnology concerning challenges and problems faced by agriculture and the food industry are critically discussed, along with the limitations and future prospects of nanoparticles.

Phyto-interactive impact of green synthesized iron oxide nanoparticles and Rhizobium pusense on morpho-physiological and yield components of greengram

The iron oxide nanoparticles (IONPs) prepared by green synthesis method using Syzigium cumini leaf extract was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The XRD confirmed the crystalline structure of green synthesized NPs measuring around 33 nm while SEM revealed its nearly spherical shape. Rhizobium species recovered from greengram nodules, identified by 16s rRNA gene sequencing as Rhizobium pusense produced 30% more exopolysaccharides (EPS) in basal medium treated with 1000 μg IONPs/ml. Compositional variation in EPS was observed by Fourier-transform infrared spectroscopy (FTIR). There was no reduction in rhizobial viability and no damage to bacterial membrane was observed under SEM and confocal laser scanning microscopy (CLSM), respectively. Effects of IONPs and R. pusense, used alone and in combination on the growth and development of greengram plants varied considerably. Plants grown with IONPs and R. pusence, used alone and in combination, showed a significant increase in seed germination rate, length and dry biomass of plant organs and seed components compared to controls. The IONPs in the presence of rhizobial strain further increased seed germination, plant growth, seed protein and pigments. Greater protein content (442 mg/g) was observed in seeds at 250 mg/kg of IONPs compared to control. Plants raised with mixture of IONPs plus R. pusense had maximum chlorophyll content (39.2 mg/g FW) while proline content decreased by 53% relative to controls. This study confirms that the green synthesis of IONPs from S. cumini leaf possess useful plant growth promoting effects and could be developed as a nano-biofertilizer for optimizing legume production.

The behavior, transport, and positive regulation mechanism of ZnO nanoparticles in a plant-soil-microbe environment

ZnO nanoparticles (ZnO NPs) have been widely used in several fields, and they have the potential to be a novel fertilizer to promote plant growth. For the effective use of ZnO NPs, it is necessary to understand their influence mechanisms and key interactions with the soil physical and biological environment. In this review, we summarize the fate and transport of ZnO NPs applied via soil treatment or foliar spray in plant-soil systems and discuss their positive regulation mechanisms in plants and microbes. The latest research shows that the formation, bioavailability, and location of ZnO NPs experience complicated changes during the transport in soil-plant systems and that this depends on many factors. ZnO NPs can improve plant photosynthesis, nutrient element uptake, enzyme activity, and the related gene expression as well as modulate carbon/nitrogen metabolism, secondary metabolites, and the antioxidant systems in plants. Several microbial groups related to plant growth, disease biocontrol, and nutrient cycling in soil can be altered with ZnO NP treatment. In this work, we present a systematic comparison between ZnO NP fertilizer and conventional zinc salt fertilizer. We also fill several knowledge gaps in current studies with the hope of providing guidance for future research.

Fighting Obesity-Related Micronutrient Deficiencies through Biofortification of Agri-Food Crops with Sustainable Fertilization Practices

Obesity is a critical medical condition worldwide that is increasingly involved with nutritional derangements associated with micronutrient deficiencies, including iron, zinc, calcium, magnesium, selenium, and vitamins A, C, D, and E. Nutritional deficiencies in obesity are mainly caused by poor-quality diets, higher nutrient requirements, alterations in micronutrient metabolism, and invasive obesity treatments. The current conventional agricultural system is designed for intensive food production, focusing on food quantity rather than food quality, consuming excessive agricultural inputs, and producing nutrient-deficient foods, thus generating severe health and environmental problems; agricultural food products may worsen obesity-related malnutrition. Therefore, modern agriculture is adopting new biofortification technologies to combat micronutrient deficiencies and improve agricultural productivity and sustainability. Biofertilization and nanofertilization practices are increasingly used due to their efficiency, safety, and reduced environmental impact. Biofertilizers are preparations of PGP-microorganisms that promote plant growth by influencing plant metabolism and improving the nutrient uptake, and nanofertilizers consist of synthesized nanoparticles with unique physicochemical properties that are capable of increasing plant nutrition and enriching agricultural products. This review presents the current micronutrient deficiencies associated with obesity, the modern unsustainable agri-food system contributing to obesity progression, and the development of bio- and nanofertilizers capable of biofortifying agri-food crops with micronutrients commonly deficient in patients with obesity.

Potential of enhancing anti-obesogenic agriceuticals by applying sustainable fertilizers during plant cultivation

Overweight and obesity are two of the world's biggest health problems. They are associated with excessive fat accumulation resulting from an imbalance between energy consumed and energy expended. Conventional therapies for obesity commonly include synthetic drugs and surgical procedures that can lead to serious side effects. Therefore, developing effective, safe, and readily available new treatments to prevent and treat obesity is highly relevant. Many plant extracts have shown anti-obesogenic potential. These plant extracts are composed of different agriceuticals such as fibers, phenolic acids, flavonoids, anthocyanins, alkaloids, lignans, and proteins that can manage obesity by suppressing appetite, inhibiting digestive enzymes, reducing adipogenesis and lipogenesis, promoting lipolysis and thermogenesis, modulating gut microbiota and suppressing obesity-induced inflammation. These anti-obesogenic agriceuticals can be enhanced in plants during their cultivation by applying sustainable fertilization strategies, improving their capacity to fight the obesity pandemic. Biofertilization and nanofertilization are considered efficient, eco-friendly, and cost-effective strategies to enhance plant growth and development and increase the content of nutrients and bioactive compounds, representing an alternative to overproducing the anti-obesogenic agriceuticals of interest. However, further research is required to study the impact of anti-obesogenic plant species grown using these agricultural practices. This review presents the current scenario of overweight and obesity; recent research work describing different plant species with significant effects against obesity; and several reports exhibiting the potential of the biofertilization and nanofertilization practices to enhance the concentrations of bioactive molecules of anti-obesogenic plant species.

Zinc- and magnesium-doped hydroxyapatite-urea nanohybrids enhance wheat growth and nitrogen uptake

The ongoing and unrestrained application of nitrogen fertilizer to agricultural lands has been directly linked to climate change and reductions in biodiversity. The agricultural sector needs a technological upgrade to adopt sustainable methods for maintaining high yield. We report synthesis of zinc and magnesium doped and undoped hydroxyapatite nanoparticles, and their urea nanohybrids, to sustainably deliver nitrogen to wheat. The urea nanohybrids loaded with up to 42% nitrogen were used as a new source of nitrogen and compared with a conventional urea-based fertilizer for efficient and sufficient nitrogen delivery to pot-grown wheat. Doping with zinc and magnesium manipulated the hydroxyapatite crystallinity for smaller size and higher nitrogen loading capacity. Interestingly, 50% and 25% doses of urea nanohybrids significantly boosted the wheat growth and yield compared with 100% doses of urea fertilizer. In addition, the nutritional elements uptake and grain protein and phospholipid levels were significantly enhanced in wheat treated with nanohybrids. These results demonstrate the potential of the multi-nutrient complexes, the zinc and magnesium doped and undoped hydroxyapatite-urea nanoparticles, as nitrogen delivery agents that reduce nitrogen inputs by at least 50% while maintaining wheat plant growth and nitrogen uptake to the same level as full-dose urea treatments.