ACS agricultural science & technology最新文献

Plant infiltration techniques, particularly agroinfiltration, have transformed plant science and biotechnology by enabling transient gene expression for genetic engineering of plants or genomic studies. Recently, the use of infiltration has expanded to introduce nanomaterials and polymers in plants to enable nonnative functionalities. Despite its wide use, the impact of the infiltration process per se on plant physiology needs to be better understood. This study investigates the effect of syringe infiltration, a commonly employed technique in plants, using a typical infiltration buffer solution. Noninvasive and real-time monitoring methods, including high-resolution thermal imaging and a porometer/fluorometer, were used to study the physiological responses and stress levels of the infiltrated plants. Our results revealed localized cell damage at the infiltration site due to syringe compression, but the overall cell viability and tissue integrity were largely unaffected. Thermography showed a temporary temperature increase of the leaves and stomatal conductance alterations postinfiltration, with leaf recovery in 3–6 days. Additionally, fluorescence measurements indicated a 6% decrease in maximum quantum efficiency (F_v/F_m) and a 34% decrease in photosystem II (ΦPSII) quantum yield, persisting for 5 days after infiltration, suggesting sustained photosystem efficiency changes. Our work highlights the need to consider the effect of infiltration when performing biological studies and aims to facilitate the optimization of protocols commonly used in plant science and biotechnology.

Plant protoplasts are very useful in plant biotechnology, molecular biology, and cell biology. However, an efficient method for protoplast production remains a challenge for many economically important dicotyledonous vegetables, including lettuce (Lactuca sativa L.). Herein, a protocol was optimized for efficient protoplast production from various tissues (leaf and shoot apex) of different lettuce subtypes (romaine, loose-leaf, and semiheading lettuces) by optimizing the major factors affecting protoplast yielding. The optimized protocol yields protoplasts up to 2.0 × 10⁷/g (fresh weight, FW) with viability more than 85%, which is 3–10 times higher than those previously reported. This optimized protocol was also found to be applicable to other dicotyledonous plants (bok choy (Brassica parachinensis), celery cabbage (Brassica pekinensis), and Arabidopsis thaliana) for efficient protoplast production from leaves and shoot apexes. Moreover, an optimized poly(ethylene glycol)-mediated transient expression system (TES), using lettuce shoot apex protoplasts generated via the aforementioned protocol, exhibited high transfection efficiency exceeding 80%. This was further evidenced by the elevated expression levels and subcellular localization of four representative plasma membrane transporters: AAP2, ABCG22, ALMT10, and OATP. In conclusion, the optimized protoplast production protocol along with TES developed in this study will be useful tools for the functional analyses of genes in lettuce and other important dicotyledonous vegetables.

Quantifying dermal and inhalation exposure to nanopesticides is essential for risk assessment and management. This study investigated the potential dermal and inhalation exposures characteristics of applying nanopesticides in wheat fields and assessed the associated occupational health risks for workers exposed to nanopesticides. The mean recoveries of the established analytical methods ranged from 70% to 104%, the relative standard deviations ranged from 1.6 to 11.2%, and the limits of quantification were 1 μg/kg. The total dermal (and inhalation) exposures were as follows: 6153.192 ± 2006.998 μg (0.001 ± 0.001 μg), 3337.832 ± 464.828 μg (<0.001 μg), 5117.742 ± 1174.357 μg (0.003 ± 0.002 μg), and 4351.127 ± 527.835 μg (0.001 μg) when spraying different tebuconazole formulations including suspension concentrate, nanoemulsion, nanocapsules, and microcapsules, respectively. The exposure of spraying nanopesticides was generally not significantly different from that of conventional pesticide formulations. The thighs exhibited the highest exposure among workers during operation, so protective measures for the operator’s legs should be strengthened. The operator is recommended to wear long clothes and pants and prefer back-to-wind moving backward for spraying operations to minimize exposure. All risk quotients were less than 1, indicating that the occupational health risks associated with spraying tebuconazole nanopesticides and conventional formulations under poor, moderate, and better protection precautions remain acceptable. The findings of this study provide valuable insights for the safe use and risk management of nanopesticides.

Slugs pose a significant threat to agriculture, causing substantial crop damage and economic losses. Traditional molluscicides harm nontarget organisms and endanger ecosystems. Environmentally friendly molluscicides that ensure safety for humans and animals and promote sustainable agriculture are urgently needed. This study is the first to explore the fumigant toxicity, contact toxicity, and repellent effects of four monoterpenoids (geraniol, citral, geranyl nitrile, and citronellal) against Philomycus bilineatus. Compared to metaldehyde, monoterpenoids exhibited stronger contact toxicity, leading to rapid slug elimination (within 4 h), while metaldehyde caused death in slugs over a longer period of 48 h. Among the monoterpenoids, citral has weaker contact toxicity compared with the other three compounds, and geranyl nitrile (GN) and citronellal have stronger fumigant toxicity than the other two compounds. In terms of repellence and antifeeding effects, citral has the weakest toxicity. GN and citronellal stand out with excellent molluscidal activity (LC₅₀ values of 0.10 and 0.14 g/L, respectively). The computational results based on the density functional theory (DFT) indicate that appropriate energy gaps, electrophilicity indices, and molecular softness correlate with the high molluscidal activity of monoterpenoids. From the computational results of this study, GN and citronellal, which have a moderate energy gap (approximately 0.200 eV), show the best effectiveness in controlling the slugs. In addition, unlike metaldehydes, which have a long half-life and limited biodegradability, these monoterpenoids have low toxicity and are easily degradable in the environment, making them more environmentally friendly. These findings underscore the potential of monoterpenoid compounds as eco-friendly alternatives for managing slugs in agriculture and gardens, thereby reducing reliance on traditional chemical pesticides.

A significant portion of the global population lacks access to a balanced diet, leading to widespread micronutrient deficiencies. Selenium (Se) deficiency affects approximately 1 billion people worldwide, and agronomic biofortification of food crops using inorganic Se fertilizers or Se nanoparticles (SeNPs) has emerged as a potential solution. However, to ensure food safety, it is critical to assess whether nonbioavailable or toxic Se species are formed when SeNPs are introduced into plants. In this study, pot experiments with rice plants (Oryza sativa L.) were conducted to evaluate the effects of foliar applications of selenite (Se(IV)) and SeNPs on Se uptake, translocation, and speciation. Plant growth, chemical, and biochemical parameters were evaluated. Selenium accumulation and speciation were determined using inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography coupled with ICP-MS (HPLC-ICP-MS). The results demonstrated that SeNP treatment did not adversely affect plant growth, grain yield, and oxidative stress or significantly increase the inorganic Se content in rice grains. From a nutritional perspective, grains biofortified with SeNPs had the potential to meet 100% of the recommended daily Se intake. Meanwhile, Se(IV) was more efficient for grain biofortification but increased the concentration of inorganic Se in rice grains by 141% compared to the control group. Regardless of the Se species applied, rice fertilization increased the proportion of selenomethionine while it reduced selenocysteine in grains. The treatment with SeNPs did not compromise the nutritional quality of rice grains but increased As content from 175 to 210 μg kg^–1, which remains below the maximum allowable limit of 350 μg kg^–1 for husked rice. The foliar application of SeNPs enables the production of Se-enriched rice with Se levels controlled within a safe range for human consumption and without significantly altering inorganic Se concentrations. This approach offers a viable strategy for addressing Se deficiency through biofortified rice.

Bacterial blight is a plant disease that severely threatens the yield and quality of rice. Copper agents are a kind of efficient pesticide to protect plants from bacterial diseases. Due to the hydrophobicity of rice leaves, the deposition of pesticides on these leaves is not always satisfactory. In this study, copper nanoparticles (Cu₂O and CuS) were formulated into oil dispersions (OD) using renewable vegetable oil as solvent, and the potential strategies for enhancing the efficiency of pesticide delivery and increasing deposition of droplets on the surface of hydrophobic leaves were investigated. The OD of Cu₂O (Cu₂O-OD) was superior to those of wettable powder and suspension concentrate in terms of wetting and spreading performance. The contact angle of droplets was reduced by over 40°, while the retention amount was increased by 1.38–2.65 times, and droplet bouncing and splashing were significantly inhibited. The microbial growth curve test indicated that the bioactivity of Cu₂O-OD increased 2.5 times. In the safety test, Cu₂O-OD and CuS-OD were found to be safer than zinc thiazole (an effective bactericide registered for the management of rice bacterial blight). Copper nanoparticles were appropriate to be formulated into OD; both Cu₂O-OD and CuS-OD have the advantages of low contact angle, high adhesion, and retention on hydrophobic leaves, which make up for the limitations of Cu₂O and CuS themselves and have broad application prospects.

The low utilization rate of pesticide leads to the pollution of soil and environment, which ultimately endangers human health. In this study, TiO₂ nanoparticles were synthesized and loaded with fluopyram (Flu) on halloysite (Ha) via sol–gel methods which was named Flu@THa. Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the structure of all samples, and then the performances of zeta potential, fungistatic ability, antileaching behavior, and biosafety were tested. The results showed that anatase-phase TiO₂ was synthesized on halloysite with a particle size of ∼10 nm. Under neutral conditions (pH 7), the cumulative rate of pesticide release from Flu@THa was three times higher than that under acidic and alkaline conditions in 24 h. Flu@THa was evenly distributed in the soil and slowed the loss of pesticides. In addition, Flu@THa can promote germination and growth of peanut seeds and had good biocompatibility with low toxicity to zebrafish. This study is expected to be able to provide implications for environmentally friendly nanopesticides.

Plant nematode disease management is still a difficult problem in agricultural production. To develop novel green nematicides, pyridazine compounds with nematicidal activities against Ditylenchus destructor (D. destructor), Bursaphelenchus xylophilus (B. xylophilus), Aphelenchoides besseyi (A. besseyi), and Meloidogyne incognita (M. incognita) were discovered. The LC₅₀ values of compound C2 were 7.1 and 3.4 mg/L against D. destructor and A. besseyi, respectively. Compound C2 not only caused an adverse oxidative stress response of nematodes, resulting in intestinal damage, but also significantly inhibited egg hatching of D. destructor. Compound C2 may lead to decreased cellular tolerance and antioxidant function of D. destructor by significantly downregulating the differential gene of the heat shock 70 kDa protein, thereby accelerating the cell litter process and ultimately leading to the death of the nematode. Compound C2 can serve as a potential novel nematicide worthy of further study in the future.

The application of nanoparticles (NPs) in agriculture has increased remarkably in recent years as a promising strategy for sustainable crop protection. Strategies involving the foliar use of NPs can significantly improve plant resistance to soilborne fungal diseases. NPs have been shown to be transported from leaves to roots, with potential release to the rhizosphere, although the precise mechanisms for reduced infection and damage from soilborne pathogens are complex, likely varying with disease system, nanoparticle type, and growth conditions. In this study, we investigated 100 ppm of CuO NPs of different sizes [sCuO NPs, 20–50 nm and lCuO NPs, 100 nm], along with 200 ppm of CuSO₄, for potential ability to inhibit Fusarium graminearum PH-1 in an in vitro leaf bioassay, as well as an in vivo assay on wheat leaves. Three days after treatment, the Cu salt and NPs (20–50 nm) both restricted fungal growth on wheat leaves in vitro. Laser scanning confocal microscopic observations revealed that the CuO NPs (20–50 nm) inhibited F. graminearum growth by direct effects on the hyphae, spores, and conidial spore germination. Reactive oxygen species (ROS) were significantly (p ≤ 0.05) increased by 214.84 and 191.55 J/cm² in the hyphae and conidia when treated with CuO NPs (20–50 nm), respectively; intracellular ROS content also increased with the treatment of the CuO NPs (100 nm), although inhibition on the conidial spore germination was limited. CuO NPs also compressed the membrane, which was different than the CuO ions-induced ROS caused cell membrane damage and apoptosis. We observed the smaller NP size (20–50 nm) had greater toxicity than the larger size (100 nm). The study demonstrates that size-dependent CuO NPs offer a promising approach for sustainable crop protection, with multiple mechanisms of pathogen control that may provide greater versatility than conventional CuO products. These findings have important implications for developing more effective and environmentally sustainable strategies to combat fungal diseases in agricultural systems, particularly for managing Fusarium head blight in wheat production.

In recent years, pesticides have been overapplied to prevent and control cucumber diseases, and high pesticide residues on cucumbers have become a growing concern. Therefore, the establishment of a rapid and reliable method for the detection of pesticide residues is particularly required to ensure the health of humans and livestock. This study optimized the determination method of pesticide residues in cucumber using a QuEchERS pretreatment combined with an ultrahigh performance liquid chromatography-tandem mass spectrometry. The optimized method achieved a spike recovery rate of 79.1–103.3% for the kasugamycin, oxine-copper, dimethomorph, and pyraclostrobin in cucumber, and the limit of quantification was 0.01 mg/kg. The optimized method was used to detect there residues in 12 regions. The dissipation half-lives of oxine-copper, dimethomorph, and pyraclostrobin were 1.64–2.19, 1.15, and 1.20–1.27 days, respectively. The final residue levels of these pesticides were all below the maximum residue limit. The dietary risk assessment showed that the daily intake of kasugamycin, oxine-copper, dimethomorph, and pyraclostrobin accounted for 0.7, 35.7, 23.7, and 20.5% of the daily allowable intake, respectively, which were all within acceptable ranges. This indicates that under the ecological conditions in China, these pesticides are safe under good agricultural practices. This study provides guidance for the comprehensive evaluation and scientific use of fungicide residues in the cultivation of vegetables cash crops such as cucumber.