Chemical and Biological Technologies in Agriculture最新文献

Ammonia (NH₃ ) and nitrous oxide (N₂O) emitted from the pig slurry (PS)-applied soil lead not only to the risk of environmental pollution, but also to the loss of plant nutritional nitrogen (N). This study aimed to compare the effectiveness of zeolite and rice husk biochar (RHB) in mitigating the N losses via NH₃ and N₂O emissions from PS-amended soils, and N use efficiency (NUE) for vegetative growth of oilseed rape (Brassica napus L.). Both zeolite and RHB application significantly reduced NH₃ and N₂O emissions from the PS-applied soil and improved the NUE for the vegetative growth. When compared the effectiveness of two materials, RHB application has more positive effectiveness in soil pH buffering, urease activity, organic acid content and NH₄⁺ content in soil throughout the experimental period, resulting in a higher mitigation of NH₃ and N₂O emissions as well as NUE for dry matter (DM) and crude protein (CP) production. The enhanced NH₄⁺ content in soil closely related to the reduction of NH₃ and N₂O emissions, and with improved NUE for DM and CP production. A superior performance of RHB relative to zeolite is attributed mainly to a stronger capacity of NH₄⁺ adsorption by higher oxygen-containing functional groups on its surface, and in part to the supply of bioavailable carbon derived from RHB leading to an increase in urease activity and soil organic acid content. Therefore, RHB can be considered a more promising amendment than zeolite for simultaneously mitigating gaseous N losses and enhancing NUE in oilseed rape cultivation.

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Background

Hydrogen peroxide and hypochlorous acid are reactive oxygen species that naturally occur in biological systems; the oxidation products of biological molecules, such as carotenoids, formed by these oxidants are found in foods and living organisms. This study aims to identify these metabolite products and propose the degradation mechanism based on the identified product structures and the obtained kinetic data. To protect carotenes from oxidation and improve their use as food additives and pharmaceuticals, carrot carotenoids were encapsulated in a chitosan-TPP copolymer.

Results

The results revealed that the main carotene oxidation product from H₂O₂ and HOCl was apo-13-carotenone-5,6-epoxide; LC–MS/MS also detected additional products for the first time. The kinetics study indicated that oxidation follows first-order kinetics in carotene and second-order kinetics in H2O2, with epoxidation of the ring double bonds and cleavage of the 13-double bond forming the major product, while cleavage of the single bond C10’–C11 resulted in the minor product, β-apo-12ʹ-carotenone-5,6-epoxide; proposed mechanisms were outlined. To protect carotenoids from oxidation, a chitosan-TPP complex was prepared and characterized. While free carotene stability decreased to 63% after 120 min and 34% after 30 min under H₂O₂ and HOCl treatments, respectively, the complex remained stable at over 94% for 300 min. Additionally, the complex did not reduce the antioxidant activity of carotene against hydroxyl radicals but slightly lowered its reducing power. Carotene release followed first-order kinetics with an 88.33% recovery over nine days, mainly controlled by diffusion.

Conclusion

Producing apo-13-carotenone-5,6-epoxide as a major product in carotene oxidation by both oxidants suggests that it may serve as a potential biomarker. Other new products were identified that require further study to examine their activities. The prepared chitosan-TPP complex effectively stabilizes carotenes against both ROS while retaining most of their original antioxidant activities, indicating its potential applications in the pharmaceutical and food industries.

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Forestry pests pose serious ecological challenges, yet their biological value remains underexplored. This study aimed to convert the destructive longhorn beetle Glenea cantor (G. cantor) into biomass carbon dots (GC-CDs) with both antibacterial and wound healing properties. GC-CDs were synthesized by a simple microwave-assisted method and characterized by techniques such as transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The particles were quasi-spherical with an average size of 1.02 nm and displayed excellent water solubility. In vitro assays confirmed the low cytotoxicity and hemolysis rates of GC-CDs, while in vivo evaluations showed no systemic toxicity. GC-CDs inhibited Escherichia coli growth and enhanced cell migration and wound closure in scratch assays, Transwell tests, and mouse wound models. These results demonstrate that GC-CDs possess dual antibacterial and wound healing activities, offering a sustainable strategy for transforming forestry pests into valuable biomedical resources.

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Background

Selenium (Se) deficiency poses significant health risks to human populations globally, necessitating effective biofortification strategies. Amaranth (Amaranthus retroflexus), a nutrient-dense vegetable with demonstrated capacity for Se accumulation in seleniferous soils, represents a promising biofortification vehicle. Critically, arbuscular mycorrhizal fungi (AMF) enhance rhizospheric Se mobilization, yet their synergistic effects on plant energy metabolism remain unexplored.

Results

This pot study investigated the influence of exogenous selenium (Se) treatment on energy metabolism in amaranth colonized by the arbuscular mycorrhizal fungus Glomus mosseae. Using LC–MS/MS-based targeted metabolomics with OPLS-DA and KEGG analysis, we identified 14 differentially expressed metabolites (8 up-/6 down-regulated) in Se-exposed plants. These metabolites mapped to glycolysis, TCA cycle, pentose phosphate pathway, electron transport chain, and amino acid/pyruvate metabolism. Activity assays of key enzymes, including PGI, SDH, G6PDH, 6PGDH, and CCO, revealed potential multi-pathway perturbations in energy metabolism under Se treatment.

Conclusions

Based on these results, it can be concluded that selenium addition significantly affected amaranth energy metabolism.

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Background

As a valuable agricultural product derived primarily from cultivated toads, toad venom has been widely used for its significant antitumor properties in pharmacological formulations. However, the structural and biological characteristics of its major constituents, polysaccharides, remain poorly understood, limiting the development of innovative antitumor drugs.

Results

In this study, an extracellular acidic homogeneous polysaccharide (TvPs3-2, average molecular mass: 3.43 × 10² kDa) is isolated from toad venom. Compositional analysis by 1-phenyl-3-methyl-5-pyrazolone (PMP) pre-column derivatization high-performance liquid chromatography (PMP-HPLC) reveals that TvPs3-2 consists of mannose (Man), glucuronic acid (GlcA), glucose (Glc), galactose (Gal), arabinose (Ara), and fucose (Fuc) in a molar ratio of 9.30:26.52:17.26:2.20:8.40:36.31. Comprehensive structural characterization through methylation analysis combined with extensive nuclear magnetic resonance (NMR) spectroscopy indicates a possible backbone: → 4)-β-D-GlcAp-(1 → 3,6)-β-D-Galp-(1 → 3)-α-L-Fucp-(1 → 4)-α-D-Manp-(1 → 2)-β-D-Glcp-(1 → 2,4)-α-D-Glcp-(1 → 4)-β-D-Glcp-(1 → 2)-α-L-Fucp-(1 → 4)-β-D-GlcAp-(1 → , with multiple branched segments. Morphologically, TvPs3-2 exhibits interconnected bulges, undulating surfaces, and square/rhombic crystals while maintaining a triple-helix conformation. Additionally, TvPs3-2 exhibits good antioxidant activity, particularly against 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS, half maximal inhibitory concentration (IC₅₀) = 0.36 mg/mL), alongside moderate 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging effects. Furthermore, TvPs3-2 demonstrates notable antiproliferative effects on lung (A549), liver (SK-Hep1), and colon (HCT116 and HT-29) cancer cell lines, with the highest efficacy against SK-Hep1 hepatoma cells (IC₅₀ = 1.6 mg/mL), mediated by apoptosis induction, migration inhibition, and modulation of metabolic/oxidative stress pathways, while it demonstrates relatively low inhibitory activity against healthy H9C2(2-1) cells.

Conclusions

This study comprehensively characterizes a novel acidic polysaccharide (TvPs3-2) from toad venom with remarkable antioxidant and antitumor activities, providing a molecular basis for its future application in anticancer drug development.

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The red imported fire ant, Solenopsis invicta Buren, 1972, is a significant invasive pest threatening public health, agriculture, and biodiversity. Our previous study revealed that d-(+)-Camphor and 1,8-cineole, the dominant constituents of Artemisia subg. Seriphidium exhibits promising fumigant activity against S. invicta. However, their rapid volatility limits their broader application, requiring innovative formulations for sustained release and environmental compatibility. To address this issue, we developed a slow-release tablet formulation that offers an eco-friendly solution for S. invicta management, reducing environmental impact and promoting sustainability. The tablet ensures controlled release with uniform volatilization, while individual constituents exhibit rapid volatilization. The morphological analysis of the fumigant tablet revealed a rough surface and granulation characteristics that facilitate uniform volatilization. The XRD and TGA analyses confirmed the crystalline structure and thermal stability of the formulation. Stability studies using GC–MS demonstrated minimal degradation over 12 months of storage in an air-tight container, with slight losses of 3.5% d-(+)-Camphor and 2.40% 1,8-cineole. FTIR analysis confirmed the presence of characteristic peaks for both d-(+)-camphor and 1,8-cineole, validating their incorporation in the fumigant tablet. The toxicity evaluation indicated the tablet has significant efficacy against workers and alates, with LC₅₀ values ranging from 0.71 to 17.35 mg/L. The tablet achieved 100% mortality against workers at 0.22 g/L in 120 min, while alates required 0.29 g/L and 300 min in a substrate-free fumigation container. Furthermore, under laboratory-simulated field conditions using single ant mounds, the tablet achieved 100% mortality of all life stages of S. invicta at a concentration of 2.5 g/kg soil after 96 h. Our study highlights the potential of bioactive phytochemicals in sustainable pest management, paving the way for eco-friendly solutions. The findings will significantly contribute to developing a novel fumigant tablet effective against S. invicta, with potential applications extending to various stored grain pests, thereby fostering a more environmentally conscious approach to sustainable pest control.

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With the widespread application of high-resolution low-altitude remote sensing technology in agricultural monitoring, fine semantic segmentation of crop plots has become a hot research topic. However, due to the high similarity of land features in large-scale agricultural scenes and the presence of complex situations such as blurred land boundaries, achieving accurate semantic segmentation still faces significant challenges. In response to the above issues, this study proposes a hybrid architecture that combines Convolutional Neural Networks and Transformers, aiming to improve the segmentation accuracy of crop plots in complex scenes, especially in handling areas with fuzzy boundaries and similar features. This method innovatively constructs a global local attention mechanism (GPM-Attention), which generates adaptive attention regions through multi-scale convolution operations, significantly enhancing the model's ability to capture global contextual information. This mechanism not only effectively improves the overall segmentation performance, but also significantly reduces computational redundancy and model complexity by optimizing the computation path. In addition, this study constructed a lightweight edge enhancement module (EEI) as an encoder, which not only expands the local receptive field but also enhances the recognition ability of fine-grained features, effectively solving the problem of crop plot edge blurring. To further optimize the feature fusion effect, this study designed a Feature Adaptive Fusion Module (FAM), which efficiently integrates the multi-level features generated by CNN and Transformer encoders, significantly reducing the semantic information loss of small target features. The experimental results demonstrate that the proposed method achieves a significant performance improvement on the publicly available barley remote sensing dataset, attaining a mean Intersection over Union (mIoU) of 80.39%, which represents an 11.33% increase over state-of-the-art approaches. In addition, the method achieves a 14.2% improvement in F1-score, further confirming its effectiveness. Compared to existing techniques, this study presents a more favorable trade-off among segmentation accuracy, computational efficiency, and model complexity, thereby offering reliable technical support for the practical deployment of low-altitude remote sensing imagery in agricultural monitoring applications.

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Background

Vitamin E, particularly α-tocopherol (α-TOC), is a chloroplast-synthesized antioxidant that plays a crucial role in protecting photosynthetic membranes from oxidative damage caused by environmental stressors. Its biosynthesis involves several key enzymes: hydroxyphenylpyruvate dioxygenase (HPPD), homogentisate phytyltransferase (HPT), tocopherol cyclase (VTE1), tocopherol methyltransferase (VTE4), and phytolkinase (VTE5). However, the expression patterns and functional roles of genes involved in α-TOC biosynthesis under pesticide stress remain poorly characterized.

Results

In this study, we identified 10 α-TOC biosynthesis genes, including 2 HPPD, 1 HPT, 2 VTE1, 1 VTE4, and 4 VTE5 genes, in rice (Oryza sativa) genome using transcriptome datasets from plants treated with anilofos and α-TOC to explore their properties under pesticide stress. Phylogenetic analysis classified the α-TOC biosynthesis gene family into five subfamilies across rice, Arabidopsis (Arabidopsis thaliana), soybean (Glycine max), wheat (Triticum aestivum), and maize (Zea mays). Chromosomal localization revealed that segmental duplications contributed to the expansion of this gene family in rice, with 10 genes distributed across 7 of its 12 chromosomes. In addition, 10 rice genes involved in α-TOC biosynthesis exhibited collinearity with corresponding genes in Arabidopsis, soybean, wheat, and maize. In silico subcellular localization prediction suggested that the proteins encoded by these 10 genes localize to multiple cellular compartments, including the nucleus, cytoplasm, mitochondria, plasma membrane, and endoplasmic reticulum. OsHPPD, OsHPT, OsVTE1, OsVTE4, and OsVTE5 possess diverse gene structures, cis-regulatory elements, motifs, and conserved domains, suggesting their diverse functions in response to biotic and abiotic stresses. RT-qPCR analysis confirmed that a subset of these genes was preferentially expressed under pesticide exposure. Notably, combined treatment with 250 mg/L α-TOC and 0.04 mg/L anilofos upregulated the expression of all 10 genes by 1.64–3.75-fold in roots and by 2.66–5.34-fold in shoots compared with anilofos-only treatment. Protein–protein interaction analysis further supported the involvement of these 10 rice α-TOC biosynthesis proteins in anilofos metabolism.

Conclusions

These findings indicate that α-TOC biosynthesis genes respond effectively to anilofos-induced stress, likely facilitating α-TOC production and potentially regulating pesticide degradation.

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Arbuscular mycorrhizal (AM) fungi have demonstrated the capacity to increase active ingredient concentrations in industrial plants such as Polygonum cuspidatum, whereas it is still uncertain whether this effect is mediated by AM-facilitated nutritional absorption like phosphorus (P). In this study, a microsystem was utilized to deliver extra P to the hyphal chamber, thereby examining the impacts of hyphal P absorption on plant growth, P acquisition, phosphatase concentration, bioactive compound concentrations, and the expression of resveratrol-related genes in P. cuspidatum. The supplementation of P led to significant increases in Funneliformis mosseae colonization rates in roots and hyphal lengths in soil. AM inoculation significantly improved plant height (34.3–84.7%) and root biomass (10.9–27.8%), particularly when P was supplied to the hyphal chamber. Compared with the uninoculated treatment, AM inoculation also distinctly elevated leaf and root P levels by 110.9–252.2% and 33.0–179.5%, respectively, aligning with an increase in soil acid, neutral, and alkaline phosphatase concentrations. Roots served as the primary site for resveratrol biosynthesis. Inoculation with F. mosseae increased bioactive compound concentrations in both leaves and roots to varying degrees, with the observed increase being greater when hyphae could pass through a 37 μm mesh (permitting hyphal access) into the P-supplemented hyphal chamber, as opposed to a 0.45 μm mesh (restricting hyphal access). Supplying extra P to the hyphal chamber further amplified the promoting effect on root aloe-emodin (23.1%), chrysophanol (28.5%), physcion (14.8%), polydatin (14.7%), and resveratrol (14.4%) concentrations, as well as on leaf chrysophanol (138.0%), physcion (224.5%), and polydatin (113.7%) in AM plants, accompanied by the up-regulated expression of PcCHS1, PcCHS2, PcCRS1, and PcRS genes. In summary, mycorrhizal extraradical hyphal nutrient absorption, especially P, has emerged as a critical mechanism in modulating both plant growth and bioactive compound production in P. cuspidatum.

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The cell wall (CW) serves as a protective barrier against toxic metals, with extensins (EXTs), proline (Pro), and hydroxyproline-rich glycoproteins playing key roles. These components regulate CW synthesis and assembly and can cross-link with pectin (Pec) to reinforce the CW structure. In this study, we investigated how exogenous proline [Pro_(exo)] promotes cross-linking between EXTs and Pec in CW to mitigate hexavalent chromium [Cr(VI)] stress in rice plants. Our physio-biochemical analyses revealed that Pro_(exo) significantly modulated the relative growth rate and root phenotype of the rice seedlings under Cr(VI) stress. It also influenced the synthesis of CW components, altered the structure and composition of CW macromolecules, and enhanced Cr sequestration by CWs. Real-time quantitative PCR analysis demonstrated that Pro_(exo) regulates the expression of OsSULTR1;2, thereby affecting Cr translocation between the roots and shoots of rice seedlings. This regulation alleviated the inhibitory effects of Cr(VI) stress on growth. In addition, Pro_(exo) stimulated the expression of several EXT, proline hydroxylases, and hydroxyproline O-arabinosyltransferase genes, promoting the formation of EXT–Pec cross-links. Furthermore, Pro_(exo) activated genes involved in CW signaling pathways, enhancing the CW response to Cr(VI) stress signals, and effectively triggering adaptive strategies in rice plants. Overall, our findings provide a preliminary understanding of the molecular mechanisms by which Pro_(exo) mediates EXT–Pec cross-linking, thereby influencing the CW structure, function, and signal transduction processes.

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