Strategies for Enhancing Plant Immunity and Resilience Using Nanomaterials for Sustainable Agriculture.

Research on plant-nanomaterial interactions has greatly advanced over the past decade. One particularly fascinating discovery encompasses the immunomodulatory effects in plants. Due to the low doses needed and the comparatively low toxicity of many nanomaterials, nanoenabled immunomodulation is environmentally and economically promising for agriculture. It may reduce environmental costs associated with excessive use of chemical pesticides and fertilizers, which can lead to soil and water pollution. Furthermore, nanoenabled strategies can enhance plant resilience against various biotic and abiotic stresses, contributing to the sustainability of agricultural ecosystems and the reduction of crop losses due to environmental factors. While nanoparticle immunomodulatory effects are relatively well-known in animals, they are still to be understood in plants. Here, we provide our perspective on the general components of the plant's immune system, including the signaling pathways, networks, and molecules of relevance for plant nanomodulation. We discuss the recent scientific progress in nanoenabled immunomodulation and nanopriming and lay out key avenues to use plant immunomodulation for agriculture. Reactive oxygen species (ROS), the mitogen-activated protein kinase (MAPK) cascade, and the calcium-dependent protein kinase (CDPK or CPK) pathway are of particular interest due to their interconnected function and significance in the response to biotic and abiotic stress. Additionally, we underscore that understanding the plant hormone salicylic acid is vital for nanoenabled applications to induce systemic acquired resistance. It is suggested that a multidisciplinary approach, incorporating environmental impact assessments and focusing on scalability, can expedite the realization of enhanced crop yields through nanotechnology while fostering a healthier environment.

Investigation of the effects and mechanisms of manganese-based NMs on rice growth.

Manganese-based (Mn-based) nanomaterials (NMs) have great potential as alternatives to conventional Mn fertilizers. Yet, its environmental risks and effects on plant growth are not completely well understood. This study investigated the physiological effects of manganese dioxide (MnO2) and manganese tetroxide (Mn3O4) NMs on inter-root exposure (0-500 mg/L) of hydroponically grown rice. The results showed that on inter-root exposure, 50 mg/L Mn-based NMs promoted the uptake of mineral elements and enhanced the enzymatic activities of antioxidant systems (CAT and SOD) in rice, whereas 500 mg/L Mn3O4 NMs disrupted the mineral element homeostasis and led to phytotoxicity. The promotion effect of MnO2 NMs was better, firstly because MnO2 NMs treatment had lower Mn content in the plant than Mn3O4 NMs. In addition, MnO2 NMs are more transported and absorbed in the plant in ionic form, while Mn3O4 NMs exist in granular form. MnO2 NMs and Mn3O4 NMs both can be used as nano-fertilizers to improve the growth of rice by inter-root application, but the doses should be carefully selected.

Unlocking the potential of nanoscale sulfur in sustainable agriculture.

The global population is growing rapidly, which poses a significant challenge to food security. Innovation in agricultural technologies is necessary to achieve sustainable development in agriculture and combat food insecurity. Nanotechnology has emerged as a promising tool in agriculture; compared to conventional agricultural chemicals, demonstrated benefits include increased efficiency of delivery and utilization of both nutrients and pesticides, as well as nanoscale-specific stimulation of stress tolerance pathways. Among the many studied nanomaterials, nano-sulfur has demonstrated superior effects at enhancing plant resilience to pathogens and abiotic stresses, as well as improving plant growth and nutritional quality of edible tissues. A number of published studies have investigated the physiological effects (growth promotion, disease resistance) of single or several sulfur and sulfide compounds on crop species. However, there is no systematic analysis of this literature, including the effects and specific mechanisms of various sulfur forms in agricultural applications. In this review, we will discuss the effects of sulfur (including nano-sulfur) on crop species, the underlying mechanisms of action for their transport and transformation in the soil-plant system, and evaluate their suitability in sustainable agricultural development. Additionally, we discuss the current challenges and knowledge gaps for nanoscale sulfur use in agriculture, and describe future research directions to advance our understanding of the sustainable use of this material at the scale of individual fields.

The combination of nanotechnology and potassium: applications in agriculture.

Potassium fertilizer is indispensable for ensuring crop production, which in turn supports global food supply and safe farming practices. Potassium resources are primarily located in the Northern Hemisphere, leading to a current shortage of affordable potash and severe soil deficiencies in certain regions of the Southern Hemisphere. There is a shift away from mined salts in favor of locally available potassium resources. Utilizing potassium-rich silicates, for instance, could be a viable option to address this situation. The imperative of enhancing crop productivity and quality necessitates either increasing potassium availability or utilizing potassium more efficiently. Geneticists may find the development of plants that use potassium more effectively to be a valuable pursuit. Nanomaterials are increasingly becoming part of people's professional lives as a novel material category. This technology is gradually finding applications in agriculture to boost crop yields while reducing environmental pollution. This paper reviews the applications of common potassium-containing materials, explores the effects and mechanisms of nano-fertilizers on plants, and offers insights into future applications of nano-potassium fertilizers in agriculture. All in all, the application of nanotechnology in the production and utilization of potassium fertilizers is both necessary and effective. However, there are still many gaps in the current field of nano-potassium fertilizer application that require further research. It is hoped that this review can serve as a valuable reference for researchers working in this field.

Harnessing synergy: Integrating agricultural waste and nanomaterials for enhanced sustainability.

This paper aims to explore the cooperative use of agricultural waste and nanomaterials to improve environmental sustainability. The introduction highlights global environmental challenges and the objectives of integrating the two are highlighted. Valorization of agricultural waste is considered to reduce waste generation, while nanomaterials act as conversion catalysts that help to increase the efficiency of waste conversion and environmental remediation. In addition, synergistic approaches are discussed, including the combination of agricultural waste and nanomaterials, as well as the concept of enhanced resource management. The paper also presents case studies that demonstrate the success of such synergistic applications in pollution control and environmental remediation. Despite the challenges and risks, this approach can provide new ways to create more sustainable and resilient environments through the integration of resources, interdisciplinary cooperation and policy support.

Phosphorus-based nanomaterials as a potential phosphate fertilizer for sustainable agricultural development.

Phosphorus-based nanomaterials (PNMs) have been reported to have substantial promise for promoting plant growth, improving plant tolerance mechanisms, and increasing resistance to pathogenic organisms. Recent scientific investigation has demonstrated that utilizing PNMs can enhance plant physiological growth, photosynthetic pigments, antioxidant system, metabolism, nutrient absorption, rhizosphere secretion, and soil nutrients activation. Previous research on PNMs mostly concentrated on calcium phosphate, zeolite, and chitosan, with little systematic summarization, demanding a thorough evaluation of PNMs' broader uses. In our current review article, we address the knowledge gap by classifying PNMs according to green synthesis methods and the valence state of phosphorus while elucidating the underlying mechanisms through which these PNMs facilitate plant growth. In addition, we also targeted some strategies to improve the bioavailability of PNMs, offering valuable insights for the future design and safe implementation of PNMs in agricultural practices.

Nickel Oxide Nanoparticles Improve Soybean Yield and Enhance Nitrogen Assimilation.

Nickel (Ni) is a trace element beneficial for plant growth and development and could improve crop yield by stimulating urea decomposition and nitrogen-fixing enzyme activity. A full life cycle study was conducted to compare the long-term effects of soil-applied NiO nanoparticles (n-NiO), NiO bulk (b-NiO), and NiSO4 at 10-200 mg kg-1 on plant growth and nutritional content of soybean. n-NiO at 50 mg kg-1 significantly promoted the seed yield by 39%. Only 50 mg kg-1 n-NiO promoted total fatty acid content and starch content by 28 and 19%, respectively. The increased yield and nutrition could be attributed to the regulatory effects of n-NiO, including photosynthesis, mineral homeostasis, phytohormone, and nitrogen metabolism. Furthermore, n-NiO maintained a Ni2+ supply for more extended periods than NiSO4, reducing potential phytotoxicity concerns. Single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS) for the first time confirmed that the majority of the Ni in seeds is in ionic form, with only 28-34% as n-NiO. These findings deepen our understanding of the potential of nanoscale and non-nanoscale Ni to accumulate and translocate in soybean, as well as the long-term fate of these materials in agricultural soils as a strategy for nanoenabled agriculture.

Iron-based nanomaterials reduce cadmium toxicity in rice (Oryza sativa L.) by modulating phytohormones, phytochelatin, cadmium transport genes and iron plaque formation.

Rice is known to accumulate cadmium (Cd) in its grains, causing a severe threat to billions of people worldwide. The possible phytotoxicity and mechanism of 50-200 mg/L hydroxyapatite NPs (nHA), iron oxide NPs (nFe2O3) or nano zero valent iron (nZVI) co-exposed with Cd (100 µM) in rice seedlings were investigated. Three types of nanoparticles significantly reduced the bioaccumulation of Cd in rice shoots by 16-63%, with nZVI showing the greatest effect, followed by nHA and nFe2O3. A decrease in Cd content in the roots was observed only in the nZVI treatment, with values ranging from 8 to 19%. Correspondingly, nZVI showed the best results in promoting plant growth, increasing rice plant height, shoot and root biomass by 13%, 29% and 42%. In vitro studies showed that nZVI reduced the content of Cd in the solution by 20-52% through adsorption, which might have contributed to the immobilization of Cd in root. Importantly, the nZVI treatment resulted in 267% more iron plaques on the root surface, which acted as a barrier to hinder the entry of Cd. Moreover, all three nanoparticles significantly reduced the oxidative stress induced by Cd by regulating phytohormones, phytochelatin, inorganic homeostasis and the expression of genes associated with Cd uptake and transport. Overall, this study elucidates for the first time the multiple complementing mechanisms for some nanoparticles to reduce Cd uptake and transport in rice and provides theoretical basis for applying nanoparticles for reducing Cd accumulation in edible plants.

Effects of two Mn-based nanomaterials on soybean antioxidant system and mineral element homeostasis.

Since less attention has been paid to the physiological effects of manganese-based nanomaterials (Mn-based NMs) on plants, it is necessary to explore the application of Mn-based NMs in improving crop yield and the concentration range of Mn-based NMs that produce toxicity. The results showed that soil application of 100 mg/kg manganese oxide (MnO2) and manganese tetroxide (Mn3O4) NMs could increase the shoot height of soybean by 51.8% and 31.8%, respectively, compared with the control. In addition, 100 mg/kg MnO2 NMs increased catalase (CAT) activity in roots by 62.2%, and 50 mg/kg Mn3O4 NMs increased CAT activity in roots by 200%, thereby increasing the stress resistance of soybean. However, at the highest concentration of 500 mg/kg, Mn-based NMs increased the Mn content in soybean extremely so that the absorption of mineral elements such as potassium, phosphorus, and calcium in the root was inhibited. This research lays the foundation for the safe application of Mn-based NMs in agriculture, benefiting the development of nanotechnology and agriculture globally.

Application and mechanisms of metal-based nanoparticles in the control of bacterial and fungal crop diseases.

Nanotechnology is a young branch of the discipline generated by nanomaterials. Its development has greatly contributed to technological progress and product innovation in the field of agriculture. The antimicrobial properties of nanoparticles (NPs) can be used to develop nanopesticides for plant protection. Plant diseases caused by bacterial and fungal infestations are the main types of crop diseases. Once infected, they will seriously threaten crop growth, reduce yield and quality, and affect food safety, posing a health risk to humans. We reviewed the application of metal-based nanoparticles in inhibiting plant pathogenic bacteria and fungi, and discuss the antibacterial mechanisms of metal-based nanoparticles from two aspects: the direct interaction between nanoparticles and pathogens, and the indirect effects of inducing plant resilience to disease. © 2022 Society of Chemical Industry.

Interplay of higher plants with lithium pollution: Global trends, meta-analysis, and perspectives.

Lithium (Li) is gaining attention due to rapid rise in modern industries but their ultimate fingerprints on plants are not well established. Herein, we executed a meta-analysis of the existing recent literature investigating the impact of Li sources and levels on plant species under different growth conditions to understand the existing state of knowledge. Toxic effects of Li exposure in plants varies as a function of medium and interestingly, more negative responses are reported in hydroponic media as compared to soil and foliar application. Additionally, toxic effects of Li vary with Li source materials and LiCl more negatively affected plant development parameters such as plant germination (n = 48) and root biomass (n = 57) and recorded highly uptake in plants (n = 78), while LiNO3 has more negative effects on shoot biomass. The Li at <50 mg L-1 concentrations significantly influenced the plant physiological indicators including plant germination and root biomass, while 50-500 mg L-1 Li concentration influence the biochemical parameters. The dose-response relationship (EC50) ranges regarding the exposure medium of Li sources in plant species were observed 24.6-196.7 ppm respectively. The uptake potential of Li is dose-dependent and their translocation/bioaccumulation remains unknown. Future work should include full life cycle studies of the crops to elucidate the bioaccumulation of Li in edible tissues and to investigate possible trophic transfer of Li.

Effect of Silica-Based Nanomaterials on Seed Germination and Seedling Growth of Rice (Oryza sativa L.).

The application of nanomaterials (NMs) in agriculture has become a global concern in recent years. However, studies on their effects on plants are still limited. Here, we conducted a seed germination experiment for 5 days and a hydroponics experiment for 14 days to study the effects of silicon dioxide NMs(nSiO2) and silicon carbide NMs(nSiC) (0,10, 50, 200 mg/L) on rice (Oryza sativa L.). Bulk SiO2 (bSiO2) and sodium silicate (Na2SiO3) were used as controls. The results showed that nSiO2 and nSiC increased the shoot length (11-37%, 6-25%) and root length (17-87%, 59-207%) of germinating seeds, respectively, compared with the control. Similarly, inter-root exposure to nSiO2, bSiO2, and nSiC improved the activity of aboveground catalase (10-55%, 31-34%, and 13-51%) and increased the content of trace elements magnesium, copper, and zinc, thus promoting the photosynthesis of rice. However, Na2SiO3 at a concentration of 200 mg/L reduced the aboveground and root biomass of rice by 27-51% and 4-17%, respectively. This may be because excess silicon not only inhibited the activity of root antioxidant enzymes but also disrupted the balance of mineral elements. This finding provides a new basis for the effect of silica-based NMs promotion on seed germination and rice growth.

Engineered Nanomaterials for Improving the Nutritional Quality of Agricultural Products: A Review.

To ensure food safety, the current agricultural development has put forward requirements for improving nutritional quality and reducing the harmful accumulation of agricultural chemicals. Nano-enabled sustainable agriculture and food security have been increasingly explored as a new research frontier. Nano-fertilizers show the potential to be more efficient than traditional fertilizers, reducing the amount used while ensuring plant uptake, supplying the inorganic nutrients needed by plants, and improving the process by which plants produce organic nutrients. Other agricultural uses of nanotechnology affect crop productivity and nutrient quality in addition to nano-fertilizers. This article will review the research progress of using nanomaterials to improve nutritional quality in recent years and point out the focus of future research.

Aldolase A promotes cell proliferation and cisplatin resistance via the EGFR pathway in gastric cancer.

BACKGROUND: Gastric cancer is the third leading cause of cancer-related mortality worldwide, and the 5-year survival rate remains poor, globally. Overexpression of Aldolase A (ALDOA) has been linked to tumor cell proliferation and metastasis in numerous cancer types, including pancreatic, colorectal, hepatocellular carcinoma, and lung cancer. Although the significance of ALDOA as a potential biomarker in GC prognosis has been reported, its potential role and possible mechanism of ALDOA in GC cell sensitivity to chemotherapy remains to be elucidated. METHODS: The GEPIA platform and clinical samples were used to investigate ALDOA expression in GC tumors and neighboring normal tissues. The CCK8 and colony formation tests were used to examine whether ALDOA increased GC cell proliferation and decreased resistance to the chemotherapy drug cisplatin. Furthermore, the underlying molecular mechanisms were elucidated. RESULTS: Overexpression of ADOLA was seen in GC tumors and GC cells. Prognostic markers, i.e., invasion depth, tumor size, and metastasis of lymph node were all negatively impacted by ADOLA overexpression. Following ADOLA knockdown, in vitro proliferation of AGS cells was decreased and drug resistance was reduced. Conversely, ADOLA overexpression exhibited an inverse effect in MKN45 cells. ALDOA knockdown dramatically slowed the development of GC tumors in in vivo experiments. Mechanistically, ADOLA regulated the activity of epidermal growth factor receptor (EGFR), its downstream molecue the extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (AKT) signaling pathway in GC cells. Moreover, in the absence of EGFR, ALDOA overexpression had no effect on GC cell growth. CONCLUSION: In the EGFR signaling pathway, ADOLA boosted the proliferation and cisplatin resistance of GC cells, making it a viable GC therapeutic target.

Engineered Zn-based nano-pesticides as an opportunity for treatment of phytopathogens in agriculture.

People's desire for food has never slowed, despite the deterioration of the global agricultural environment and the threat to food security. People rely on agrochemicals to ensure normal crop growth and to relieve the existing demand pressure. Phytopathogens have acquired resistance to traditional pesticides as a result of pesticdes' abuse. Compared with traditional formulations, nano-pesticides have superior antimicrobial performance and are environmentally friendly. Zn-based nanoparticles (NPs) have shown their potential as strong antipathogen activity. However, their full potential has not been demonstrated yet. Here, we analyzed the prerequisites for the use of Zn-based NPs as nano-pesticides in agriculture including both intrinsic properties of the materials and environmental conditions. We also summarized the mechanisms of Zn-based NPs against phytopathogens including direct and indirect strategies to alleviate plant disease stress. Finally, the current challenges and future directions are highlighted to advance our understanding of this field and guide future studies.

Green synthesis of metal-based nanoparticles for sustainable agriculture.

The large-scale use of conventional pesticides and fertilizers has put tremendous pressure on agriculture and the environment. In recent years, nanoparticles (NPs) have become the focus of many fields due to their cost-effectiveness, environmental friendliness and high performance, especially in sustainable agriculture. Traditional NPs manufacturing methods are energy-intensive and harmful to environment. In contrast, synthesizing metal-based NPs using plants is similar to chemical synthesis, except the biological extracts replace the chemical reducing agent. This not only greatly reduces the used of traditional chemicals, but also produces NPs that are more economical, efficient, less toxic, and less polluting. Therefore, green synthesized metal nanoparticles (GS-MNPs) are widely used in agriculture to improve yields and quality. This review provides a comprehensive and detailed discussion of GS-MNPs for agriculture, highlights the importance of green synthesis, compares the performance of conventional NPs with GS-MNPs, and highlights the advantages of GS-MNPs in agriculture. The wide applications of these GS-MNPs in agriculture, including plant growth promotion, plant disease control, and heavy metal stress mitigation under various exposure pathways, are summarized. Finally, the shortcomings and prospects of GS-MNPs in agricultural applications are highlighted to provide guidance to nanotechnology for sustainable agriculture.

Risks Assessment Associated with Different Sources of Metals in Abandoned Soil of Zhuxianzhuang Coal Mine, Huaibei Coalfield (Anhui, China).

In this paper, the 36 topsoil (0-10 cm) samples were collected and the contents of Cr, Mn, Co, Ni, Cu, Zn, As, Cd and Pb were analyzed. The results indicated that the contents of Cu and As in all samples exceeded the soil background values of Anhui province, while the Co and Pb contents were lower than the background values. Geo-statistics and positive matrix factorization were applied to identify the sources of soil heavy metals, which were nature factor (15.7%), industrial activities (21.2%), coal mine (50.9%) and traffic emission (12.2%), respectively. The calculation results of health risk model based on positive matrix factorization model showed that coal mine activities accounted for the largest proportion of total source contribution, followed by industrial activities. In addition, compared with adults, the trend of health risk of children from four sources in three lands were same as adults, but their health risk was higher than adults.

LATS1 exerts tumor suppressor functions via targeting Gli1 in colorectal cancer.

Background: The Hippo pathway's primary kinase component, large tumor suppressor 1 (LATS1), has been hypothesized as a tumor suppressor in a variety of cancers. LATS1's biological effects on colorectal cancer (CRC) are yet to be determined. Methods: The analysis of LATS1 mRNA expression in CRC was conducted using public databases from the Gene Expressing Profiling Interactive Analysis database (GEPIA). Investigation for the expression of LATS1 protein in 102 CRC tumor tissues and 57 normal tissues was performed using immunohistochemistry (IHC) analysis. In vitro genetic manipulation was used to explore the potential role and mechanism of LATS1 in the regulation of proliferation and migration of CRC cells. Results: LATS1 was found to be considerably downregulated in CRC tissues, with much lower levels in individuals with bigger tumors of size (≥5 cm), deeper invasion (T3-4), positive lymph node metastasis (LNM), and advanced tumor-node-metastasis (TNM) stage (III-IV). As exhibited by clinical data analysis, LATS1 loss was significantly associated with TNM and LNM staging in CRC patients. Furthermore, our in vitro investigations revealed that LATS1 depletion increased CRC cell proliferation and migration in HCT116 cells, whereas overexpressing LATS1 had the opposite effect in SW620 cells. LATS1 suppressed the expression of glioma-associated oncogene-1 (Gli1), and LATS1's tumor-suppressive actions in CRC are dependent on Gli1. Moreover, LATS1 could modulate Yes-associated protein 1 (YAP1) expression and mTOR activation in CRC cells. Conclusion: Our findings identify the LATS1 as a unique Gli1 regulator in CRC cell migration and proliferation, and suggest that LATS1 may serve as a potential therapeutic target for CRC.

PtCo-excavated rhombic dodecahedral nanocrystals for efficient electrocatalysis.

Platinum (Pt)-based catalysts have shown excellent catalytic performance in many fields, particularly for the oxygen reduction reaction (ORR) and direct oxidation of small fuel molecules. Further development of Pt-based electrocatalysts relies on the morphology design of Pt-based alloy nanocrystals (NCs) with highly accessible and active surface sites to optimize Pt atomic utilization. In this work, we reported PtCo-excavated rhombic dodecahedral (ERD) NCs consisting of the self-assembly of 24 ultrathin nanosheets synthesized by a simple wet chemical method. The morphology can be regulated from convex to excavated polyhedra by controlling the amount of formaldehyde and the molar ratio of the Co/Pt precursor. The as-prepared PtCo ERD NCs/C catalyst exhibits excellent ORR performance, which has about 12 times higher specific activity and 6 times higher mass activity than the commercial Pt/C catalyst. It also displays good electrocatalytic ability towards methanol oxidation, in which the specific activity and mass activity are about 6 times higher and 2 times higher than the commercial Pt/C, respectively. Their enhanced activity is attributed to the excavated structure and alloy feature.