Liupeng Yang

Global agriculture and food security are under serious threat from abiotic stresses, including salinity, drought, heavy metals, and extreme temperatures. While industrial development has driven progress, it has also intensified environmental challenges and contributed to declining crop productivity. Tackling these issues demands innovative and sustainable solutions. Nanotechnology has emerged as an effective approach to enhance stress tolerance, improve nutrient use efficiency, and increase crop yield and quality. This review critically examines the expanding role of nanoparticles (NPs) in mitigating abiotic stresses and promoting sustainable agricultural systems. While several studies have investigated the use of NPs in stress mitigation, ongoing research continues to reveal novel mechanisms and applications, highlighting the untapped potential of nanotechnology in plant science. The review discusses the impact of abiotic stress on plant growth and physiology, followed by a detailed analysis of the mechanisms through which NPs confer stress tolerance. Particular attention is given to the interaction of NPs with phytohormones and other growth regulators, as well as their role in the remediation of contaminated soils. Furthermore, the review highlights the dual role of NPs in stress alleviation and environmental remediation, while also considering emerging concerns about their potential ecological and toxicological impacts. Emphasis is placed on the need for risk assessments and effective management strategies. The review also identifies key knowledge gaps and methodological limitations, offering recommendations to guide future research in this emerging field.

Brassinosteroids (BRs) play an essential role in regulating plant metabolic pathways that influence growth, development, and stress responses. However, their role in alleviating cobalt (Co) stress has not been extensively studied. This research aimed to assess the impact of exogenous BRs (0.1 µM) on maize subjected to Co stress (300 µM) in a hydroponic experiment. The results indicated that BR supplementation significantly decreased the accumulation of H₂O₂ by 17.79 and 16.66%, O₂^•− by 28.5 and 21.48%, and MDA by 37.5 and 37.9% in shoot and root, respectively, as compared to Co stress alone. Additionally, BRs enhanced endogenous levels of BRs (31.16%) and growth hormones (IAA 50.8%, JA 57.8%, GA 52.5%), and reduced Co contents by 26.3% in roots and 36.1% in shoots. BRs enhanced antioxidant enzyme activity both in the shoot and root, leading to reduced ROS levels as confirmed by laser scanning confocal microscopy. Furthermore, BRs increased phenols, flavonoids, and soluble sugars, and elevated total protein content. Observations from transmission electron microscopy indicated reduced ultrastructural damage in plants treated with BRs under Co stress. Taken together, this study highlights the role of BRs in alleviating Co stress in maize, demonstrating their efficiency in enhancing stress tolerance by modulating hormone levels and key metabolic processes.

BACKGROUND: Downy mildew, a devastating disease of cucurbitaceous crops caused by Pseudoperonospora cubensis. Although a variety of fungicides are used to control downy mildew, choosing an effective product can be challenging. Environmental stimulus‐responsive pesticide delivery systems have great potential to improve the effectiveness of disease and pest control and reduce the impact on environmentally beneficial organisms.RESULTS: In this work, a disulfide bond (SS)‐modified and chitosan oligosaccharide (COS)‐capped hollow mesoporous silica (HMS) pesticide delivery system was synthesized using a hard template method for the control of downy mildew in cucurbit crops. The synthesized nanoparticles were loaded with dimethomorph (DMM), denoted as DMM@HMS‐SS‐COS, and the developmental toxicity of these nanoparticles to zebrafish embryos were evaluated. The results showed that the prepared DMM@HMS‐SS‐COS exhibited excellent dual response properties to pH and glutathione (GSH), with an encapsulation rate of up to 24.36%. DMM@HMS‐SS‐COS has good ultraviolet (UV) radiation stability and adhesion properties. Compared with dimethomorph suspension concentrate (SC), DMM@HMS‐SS‐COS was more effective against downy mildew for up to 21 days. Toxicity tests showed that DMM@HMS‐SS‐COS significantly reduced the effect of DMM on the hatching rate and survival rate of zebrafish embryos.CONCLUSIONS: This work not only demonstrates that DMM@HMS‐SS‐COS could be used as a nanodelivery system for intelligent control of downy mildew but also emphasizes the necessity of increasing the acute toxicity of nanoformulations to non‐target organisms in environmental risk assessment. © 2022 Society of Chemical Industry.

In this study, the safety and risk of pyraclostrobin as an indoor fungicide against banana anthracnose were evaluated for the first time. The dissipation and distribution of pyraclostrobin for 14 days in banana peel and pulp were determined and studied by HPLC after simple, rapid pre-treatment at different indoor temperatures. The mean recovery was 83.46 ~ 95.67%, and the relative standard deviation was 4.01 ~ 10.99%. Results showed that the half-lives of pyraclostrobin in peel and pulp were 8.1 days (25°C), 12.4 days (12°C) and 12.8 days (25°C), 16.1 days (12°C). During the whole storage period of banana after application of pesticide, the residue of banana pulp was lower than the maximum residue level established in China. The potential risk of pyraclostrobin exposure through the dietary intake of bananas to different populations was also studied. According to the results of dietary risk assessment, the residual level of pyraclostrobin was within the acceptable range of chronic and acute dietary risk in different populations in China at 150 mg/kg. Our results show that pyraclostrobin as a fungicide in the indoor control of banana anthracnose has high safety and low risk, and can provide a reference for the safe and reasonable use of pyraclostrobin as an indoor fungicide and risk assessment.

A comprehensive green worker ants control method that can be used to replace traditional chemical synthetic insecticides. In this study, the leaves and stems of Gelsemium elegans were extracted with water as the solvent, and the bioactivity of G. elegans against worker ants was determined by the “water tube” method. The bioassay results of insecticidal activity showed that when the time was extended to the 10th day, the mortality of worker ants treated with G. elegans extract reached 55.00% (1/20 leaf extract), 46.67% (1/20 stem extract) and 45.00% (1 mg/kg koumine). And the behavioral impact test results showed that the aggregation rate was reduced to 56.67% (1/100 leaf extract), 60.00% (1/100 stem extract) and 60.00% (0.5 mg/kg koumine); the climbing rate was reduced to 60.00 % (1/100 leaf extract), 58.33% (1/100 stem extract) and 58.33% (0.5 mg/kg koumine). The effect on the walking ability of worker ants is obvious. The walking rate drops to 1.53cm/s (1/100 leaf extract), 1.60cm/s (1/100 stem extract) and 1.47cm/s (0.5 mg/kg koumine). Therefore, we conclude that the water extract of G. elegans can be used for long-term continuous control of worker ants, which can be used to replace traditional chemical synthetic insecticides.

Traditional pesticide formulations show poor utilization and environmental safety due to their low foliage adhesion and large auxiliaries. In this study, a novel and environment-friendly indoxacarb formulation was prepared to improve the pesticide’s utilization rate, target control characteristics and ecological security. Indoxacarb-loaded waterborne polyurethane–sodium alginate (PU/SA) nanoemulsions with film forming properties, alkaline responsive release, high effectiveness against Spodoptera litura, and reduced acute contact toxicity for nontarget organisms were successfully prepared. The colloidal properties, swelling and release behaviors, leaf adhesion, degradation dynamics and bioactivity assay of the indoxacarb-loaded PU/SA nanoemulsions were determined. Results showed that the obtained indoxacarb-loaded microcapsule particulates were approximately 57 nm in diameter, electronegative −45.9 mV, and uniformly dispersed in the nanoemulsions. The dried latex films of PU/SA in the alkaline environment revealed better responsive swelling and release characteristics than those in acidic and neutral conditions. Compared with a commercial emulsifiable concentrate, the indoxacarb-loaded PU/SA nanoemulsions were useful for the targeted control of S. litura, which have alkaline gut and showed reduced acute contact toxicity to Harmonia axyridia. Furthermore, the PU/SA formulation had better foliage adhesion and indicated the property of controlled-release and a persistent effect.

BACKGROUND: Nilaparvata lugens (Stal) nymphs and adults aggregate and feed on leaf sheaths at the base of rice plants. It is difficult to apply traditional spray treatments directly onto the plant stems due to the blocking agent produced by leaves. Further, spiders and mirids, the natural enemies of N. lugens (Stal), are directly exposed to the chemicals during spraying. Sulfoxaflor‐loaded natural polysaccharide microspheres with good performance were developed and tested in rice fields. The absorption, distribution, and dissipation of sulfoxaflor in rice plants, soil, and water were examined.RESULTS: Sulfoxaflor‐loaded natural polysaccharide microspheres were prepared through physical embedding and ionic crosslinking, using citronellol as an oil phase to provide floatation. The sustained release of sulfoxaflor was achieved through swelling and dissolution, indicating that these structures could effectively control pesticide release. Field experiments showed that these microspheres were able to float in water and gather around the stem of rice plants and that their insecticidal effect was remarkably improved compared to that achieved using the suspension concentrate. Results also showed that the residual content of stems following treatment with sulfoxaflor‐loaded natural polysaccharide microspheres reached 0.331 mg kg^–1, but was reduced in other parts of the plant.CONCLUSION: In the present study, sulfoxaflor‐loaded natural polysaccharide microspheres with optimized properties were successfully prepared. These microspheres produced a better control effect on N. lugens (Stal) compared to the use of the sulfoxaflor suspension concentrate. Their application may help promote the scientific control of target pests in rice fields. © 2020 Society of Chemical Industry