Bio-Synthesized Nanoparticles in Developing Plant Abiotic Stress Resilience: A New Boon for Sustainable Approach

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.

Biosynthesis of TiO2 nano particles by using Rosemary (Rosmarinus officinalis) leaf extracts and its application for crystal dye degradation under sunlight

Titanium dioxide (TiO2) nanoparticles were prepared through Rosmarinus-officinalis leaf extracts at 90 and 200°C. In this research, the degradations of methylene blues by using TiO2 nanoparticles Sun light radiations were studied. The synthesized materials were characterized using XRDs, UV-Vis, PL, SEM, TEM, EDS and XPS. The results displayed that bio-synthesis temperatures intrude the shapes and sizes of TiO2 nanoparticles. For TiO2-90, micrographs show separable crystalline with irregular morphologies and agglomerate cubic particles. For the other TiO2-200 sample, SEM and TEM micro-imaging shows crumbly agglomerated cubic structures. The XRD shows that the intense peaks observed at angles of 25.37°, 37.19°, 47.81° and 53.89° confirming a highly crystalline oriented as (004), (200), and (105) planes respectively. The optical properties of TiO2 nanoparticles synthesized were conveyed by PL and UV-Vis. The energy band gap calculated was 3.0 eV for both samples; that indicates heating temperature didn't influence the band gap of the samples. The elemental composition Ti and O2 is shown by EDS and XPS. Photo-catalytic experiments discovered that TiO2-90 nanoparticles were well-organized in photo-degradations of MB, likened to TiO2-200. The great activities of TiO2-90 were because of better physicochemical characteristics associated with TiO2-200 effectively degrading MB under photo-light. Photo-degradations of dye under sunlight as plentifully obtainable energy sources by TiO2, synthesized by simpler techniques, can be hopeful to grow an eco-friendly and economical process.

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

Introduction

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

Methods

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

Results

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

Discussion

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

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.

Recent advancements in sustainable synthesis of zinc oxide nanoparticles using various plant extracts for environmental remediation

The sustainable synthesis of zinc oxide nanoparticles (ZnO-NPs) using plant extracts has gained significant attention in recent years due to its eco-friendly nature and potential applications in numerous fields. This synthetic approach reduces the reliance on non-renewable resources and eliminates the need for hazardous chemicals, minimizing environmental pollution and human health risks. These ZnO-NPs can be used in environmental remediation applications, such as wastewater treatment or soil remediation, effectively removing pollutants and improving overall ecosystem health. These NPs possess a high surface area and band gap of 3.2 eV, can produce both OH° (hydroxide) and O2-° (superoxide) radicals for the generation of holes (h+) and electrons (e-), resulting in oxidation and reduction of the pollutants in their valence band (VB) and conduction band (CB) resulting in degradation of dyes (95-100% degradation of MB, MO, and RhB dyes), reduction and removal of heavy metal ions (Cu2+, Pb2+, Cr6+, etc.), degradation of pharmaceutical compounds (paracetamol, urea, fluoroquinolone (ciprofloxacin)) using photocatalysis. Here, we review an overview of various plant extracts used for the green synthesis of ZnO NPs and their potential applications in environmental remediation including photocatalysis, adsorption, and heavy metal remediation. This review summarizes the most recent studies and further research perspectives to explore their applications in various fields.

Morpho-physiological growth performance and anti-oxidative capabilities of Acacia jacquemontii and Acacia nilotica upon exposure to Co3O4 Nbs in lead-contaminated soil

Immense crowd of heavy metal in cultivated land is evolving as a global concern as a result of boosted level of soil toxicity. Amongst various metals, Lead (Pb) contamination has become alarming for plant and human heath through ingesting of polluted soils and food crops. To counterfeit this, a nanotechnological neutralizer effective in form of soiling of cobalt oxide Co3O4 Nbs to Acacia jacquemontii and Acacia nilotica with various meditations as 25, 50, 75 and 100 ppm). A Substantial result was observed on growth of plants but premium results were got by applications of cobalt oxide Nbs at 75 ppm. By this means, enhanced root length (39%), fresh weight (32%), shoot length (58%), as well as dry weight (28%) in selected Acacia species compared to control. Chlrophy contents in A. jacquemontii were estimated to be 0.23, 2.73 and 3.19 mg/L with treated with different concentrations of cobalt Nbs while in A. nilotica, the contents were 0.51, 2.93 and 3.12 mg/L respectively on same concentration. The atomic absorption (AAS), antioxidant activity and defendable positive comeback by using Co3O4 Nbs. Hence, the greenly synthesized Co3O4 Nbs counter acts lead toxicity to override and preserving the growth of plant. Such nanotechnological kits can consequently enhance the alternative system to stunned toxicity for distinguish the yield demand end to end with the progress of agronomic management approaches.

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

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

Nanoparticles regulate redox metabolism in plants during abiotic stress within hormetic boundaries

Abiotic stress management remains under scrutiny because of the unpredictable nature of climate, which undergoes abrupt alterations. Population pressure, loss of cultivable lands, environmental pollution and other anthropogenic disturbances add to the problem and grossly hinder ongoing management strategies. This has driven increasing effort to find better performing, eco-friendly and reliable alternatives that can contribute to sustainable agricultural practices to manage abiotic stress. Nanotechnology and its implementation in agriculture have emerged as a promising option to cater to the problem of abiotic stress. Induction of reactive oxygen species (ROS) is an inevitable phenomenon linked to stress. Nanoparticles (NPs) perform dual actions in regulating ROS biology. The bidirectional roles of NPs in modulating ROS generation and/or ROS detoxification is tightly coupled within the hormetic boundaries. Nonetheless, how these NPs control the ROS metabolism within hormetic limits demands extensive investigation. This review focuses on the details of ROS metabolism under normal versus stressed conditions. It shall elaborate on the types, modes and process of uptake and translocation of NPs. The molecular dissection of the role of NPs in controlling transcriptomic expressions and modulating molecular crosstalks with other growth regulators, ions, reactive nitrogen species and other signalling molecules shall also be detailed. Throughout, this review aims to summarise the potential roles and regulation of NPs and consider how they can be used for green synthesis within a sustainable agricultural industry.

Salinity stress and nanoparticles: Insights into antioxidative enzymatic resistance, signaling, and defense mechanisms

Salinized land is slowly spreading across the world. Reduced crop yields and quality due to salt stress threaten the ability to feed a growing population. We discussed the mechanisms behind nano-enabled antioxidant enzyme-mediated plant tolerance, such as maintaining reactive oxygen species (ROS) homeostasis, enhancing the capacity of plants to retain K+ and eliminate Na+, increasing the production of nitric oxide, involving signaling pathways, and lowering lipoxygenase activities to lessen oxidative damage to membranes. Frequently used techniques were highlighted like protecting cells from oxidative stress and keeping balance in ionic state. Salt tolerance in plants enabled by nanotechnology is also discussed, along with the potential role of physiobiochemical and molecular mechanisms. As a whole, the goal of this review is meant to aid researchers in fields as diverse as plant science and nanoscience in better-comprehending potential with novel solutions to addressing salinity issues for sustainable agriculture.

Multifactorial role of nanoparticles in alleviating environmental stresses for sustainable crop production and protection

In the era of dire environmental fluctuations, plants undergo several stressors during their life span, which severely impact their development and overall growth in negative aspects. Abiotic stress factors, especially moisture stress i.e shortage (drought) or excess (flooding), salinity, temperature divergence (i.e. heat and cold stress), heavy metal toxicity, etc. create osmotic and ionic imbalance inside the plant cells, which ultimately lead to devastating crop yield, sometimes crop failure. Apart from the array of abiotic stresses, various biotic stress caused by pathogens, insects, and nematodes also affect production. Therefore, to combat these major challenges in order to increase production, several novel strategies have been adapted, among which the use of nanoparticles (NPs) i.e. nanotechnology is becoming an emerging tool in various facets of the current agriculture system, nowadays. This present review will elaborately depict the deployment and mechanisms of different NPs to withstand these biotic and abiotic stresses, along with a brief overview and indication of the future research works to be oriented based on the steps provided for future research in advance NPs application through the sustainable way.

Titanium dioxide nanoparticles potentially regulate the mechanism(s) for photosynthetic attributes, genotoxicity, antioxidants defense machinery, and phytochelatins synthesis in relation to hexavalent chromium toxicity in Helianthus annuus L

Chromium (VI) is one of the hazardous heavy metal, heavily discharged into the soil and severely hampers the plants yield. The TiO₂ NPs was selected due to its potential to alleviate the heavy metals toxicity. This manuscript unravels the mechanisms for Cr(VI) induced toxicity and how foliar application of TiO₂ NP_S potentially ameliorate the toxicity by regulating the photosynthetic attributes, DNA damage, antioxidants defense machinery, and phytochelatins synthesis in Helianthus annuus L. Plants were exposed to Cr(VI) concentrations [0, 15, 30, and 60 mg Cr(VI) kg^-1 of soil], and TiO₂ NP_S (15 mg L^-1, 25 nm size₎ were foliar sprayed thrice to the plants at three days interval. The maximum accumulation of total chromium was recorded in root (12.53 µg g^-1 DW) followed by shoot (5.67 µg g^-1 DW) at 60 mg Cr(VI) treatment. The presence and localization of TiO₂ NPs inside the plant leaf cells were confirmed by TEM-EDS analysis. The results revealed that Cr(VI) exposure had a dose-dependent inhibitory effects on photosynthetic attributes, structure of guard and epidermal cells, photosynthetic pigments; inducing impacts on H₂O₂ and MDA productions, DNA damage, AsA-GSH cycle, and most importantly on PC₂, and PC₃ synthesis which is rarely reported. However, TiO₂ NPs exposure minimized Cr(VI) induced toxicity through reduction of total chromium accumulation, H₂O₂ and MDA productions, thereby reducing DNA damage reported first time under combined treatment of Cr(VI)+ TiO₂ NPs as evidenced through comet assay. It also positively regulate the photosynthetic pigments, AsA-GSH cycle, and modulates PC₂ and PC₃ synthesis which have crucial impacts on ROS quenching and Cr(VI) detoxification, respectively, and in turn, minimizes Cr(VI) toxicity in H. annuus L. Besides, this study strengthens the less acknowledged report that Cr(VI) is an inducer of PCs synthesis and also confirms that TiO₂ NPs potentially counteract Cr(VI) toxicity.

Transcriptome reveals the exposure effects of CeO2 nanoparticles on pakchoi (Brassica chinensis L.) photosynthesis

In this study, soil-grown pakchoi after 2 weeks seedling cultivation were exposed to CeO₂ nanoparticles (CeO₂ NPs) at 0.7, 7, 70, and 350 mg kg^-1 for 30 days. Results showed that chlorophyll content and photosynthetic assimilation rate were decreased significantly under all treatments with the largest decrease of 34.16% (0.7 mg kg^-1 CeO₂ NPs), however, sub-stomatal CO₂ was increased dramatically under low dose of CeO₂ NPs (0.7 mg kg^-1). There were 4576, 3548, 2787, and 2514 genes up/down regulated significantly by 0.7, 7, 70, and 350 mg kg^-1 CeO₂ NPs, respectively, and 767 genes affected under all treatments. In addition, 0.7 mg kg^-1 CeO₂ NPs up-regulated 10 chlorophyll synthesis genes, 20 photosynthesis genes, and 10 carbon fixation enzyme genes; while 350 mg kg^-1 CeO₂ NPs down-regulated 5 photosynthesis genes and 28 auxin-activated genes. Among the key genes of photosynthesis, Ferredoxin-NADP reductase (PetH) was upregulated in 0.7, 7 and 70 mg kg^-1 treatments, while Photosystem II lipoprotein (Psb27) was downregulated under 7, 70 and 350 mg kg^-1 treatments. Top 20 metabolic pathways affected by CeO₂ NPs including plant hormone, amino acids, and glutathione, and carbon metabolism These results provide information about utilizing CeO₂ NPs more safely and effectively in the future.

Bioinspired Cobalt Oxide Nanoball Synthesis, Characterization, and Their Potential as Metal Stress Absorbants

Massive accumulation of heavy metals in agricultural land as a result of enhanced levels of toxicity in the soil is an emerging global concern. Among various metals, zinc contamination has severe effects on plant and human health through the food chain. To remove such toxicity, a nanotechnological neutralizer, cobalt oxide nanoballs (Co₃O₄ Nbs) were synthesized by using the extract of Cordia myxa. The Co₃O₄ Nbs were well characterized via UV-vis spectrophotometry, scanning electron microscopy, and X-ray diffraction techniques. Green-synthesized Co₃O₄ Nbs were exposed over Acacia jacquemontii and Acacia nilotica at different concentrations (25, 50, 75, and 100 ppm). Highly significant results were observed for plant growth by the application of Co₃O₄ Nbs at 100 ppm, thereby increasing the root length (35%), shoot length (48%), fresh weight (44%), and dry weight (40%) of the Acacia species with respect to the control. Furthermore, physiological parameters including chlorophyll contents, relative water contents, and osmolyte contents like proline and sugar showed a prominent increase. The antioxidant activity and atomic absorption supported and justified the positive response to using Co₃O₄ Nbs that mitigated the heavy-metal zinc stress by improving the plant growth. Hence, the biocompatible Co₃O₄ Nbs counteract the zinc toxicity for governing and maintaining plant growth. Such nanotechnological tools can therefore step up the cropping system and overcome toxicity to meet the productivity demand along with the development of agricultural management strategies.

The comparative effects of manganese nanoparticles and their counterparts (bulk and ionic) in Artemisia annua plants via seed priming and foliar application

The world has experienced an unprecedented boom in nanotechnology. Nanoparticles (NPs) are likely to act as biostimulants in various plants due to having high surface/volume value. However, understanding the actual effect of NPs is essential to discriminate them from other counterparts in terms of being applicable, safe and cost-effective. This study aimed to assay the impact of manganese(III) oxide (Mn₂O₃)-NPs via seed-priming (SP) and a combination of SP and foliar application (SP+F) on Artemisia. annua performance at several times intervals and comparison with other available manganese (Mn) forms. Our findings indicate that SP with MnSO₄ and Mn₂O₃-NPs stimulates the processes that occur prior to germination and thus reduces the time for radicle emergence. In both applications (i.e., SP and +F), none of the Mn treatments did show adverse phytotoxic on A. annua growth at morpho-physio and biochemical levels except for Mn₂O_3, which delayed germination and further plant growth, subsequently. Besides, from physio-biochemical data, it can be inferred that the general mechanism mode of action of Mn is mainly attributed to induce the photosynthetic processes, stimulate the superoxide dismutase (SOD) activity, and up-regulation of proline and phenolic compounds. Therefore, our results showed that both enzymatic and non-enzymatic antioxidants could be influenced by the application of Mn treatments in a type-dependent manner. In general, this study revealed that Mn₂O₃-NPs at the tested condition could be used as biostimulants to improve germination, seedling development and further plant growth. However, they are not as effective as MnSO₄ treatments. Nonetheless, these findings can be used to consider and develop Mn₂O₃-NPs priming in future studies to improve seed germination and seedling quality in plants.

Role of Nanoparticles in Enhancing Crop Tolerance to Abiotic Stress: A Comprehensive Review

Plants are subjected to a wide range of abiotic stresses, such as heat, cold, drought, salinity, flooding, and heavy metals. Generally, abiotic stresses have adverse impacts on plant growth and development which affects agricultural productivity, causing food security problems, and resulting in economic losses. To reduce the negative effects of environmental stress on crop plants, novel technologies, such as nanotechnology, have emerged. Implementing nanotechnology in modern agriculture can also help improve the efficiency of water usage, prevent plant diseases, ensure food security, reduce environmental pollution, and enhance sustainability. In this regard, nanoparticles (NPs) can help combat nutrient deficiencies, promote stress tolerance, and improve the yield and quality of crops. This can be achieved by stimulating the activity of certain enzymes, increasing the contents (e.g., chlorophyll) and efficiency of photosynthesis, and controlling plant pathogens. The use of nanoscale agrochemicals, including nanopesticides, nanoherbicides, and nanofertilizers, has recently acquired increasing interest as potential plant-enhancing technologies. This review acknowledges the positive impacts of NPs in sustainable agriculture, and highlights their adverse effects on the environment, health, and food chain. Here, the role and scope of NPs as a practical tool to enhance yield and mitigate the detrimental effects of abiotic stresses in crops are described. The future perspective of nanoparticles in agriculture has also been discussed.