Chemical and Biological Technologies in Agriculture最新文献

Background

Plant-derived substances have long been valued as eco-friendly pesticides, with pyrethrum flowers recognized for their insecticidal properties since the nineteenth century. Over time, pyrethrum extracts became widely adopted as a natural, effective, and relatively safe green pesticide. However, the high production costs of these natural compounds prompted the development of synthetic pyrethroids, such as cypermethrin, which dominate the market today. While these synthetic alternatives offer effectiveness in pest control, they also present environmental concerns, such as pest resistance and toxicity to aquatic organisms. This has led some countries to continue using natural pyrethrins, resulting in large amounts of pyrethrum residue waste.

Results

In response to the need for sustainable solutions, we focused on repurposing these residues by isolating and evaluating 11 pyrethroid-related compounds. Among them, pyrethrindreg II, first isolated from natural sources, exhibited the highest insecticidal activity. Morphological observation and molecular docking revealed that pyrethrindreg II acts as a promising voltage-gated sodium channel (VGSC) inhibitor. The quantification of esterase-β, esterase-α, and GST concentrations explains the biochemical responses of pyrethrindreg II in Armigeres subalbatus. Density functional theory (DFT) calculations provide insight into its relatively weaker activity compared to the positive control, cypermethrin.

Conclusions

Pyrethrindreg II exhibited significantly lower toxicity, indicating its potential as a safer, greener alternative to synthetic pyrethroids.

Graphical Abstract

Background

The influence of various environmental factors on the formation of different morphological forms of soil organic matter has been extensively studied, but there is still uncertainty about how time spent in solution affects the evolution and possible transformation of the morphological structures of soil humic substances.

Methods

The transmission electron microscopy (TEM) with negative contrast staining by uranyl acetate was used to study morphological differences between soil humic acids (HAs) and their individual electrophoretic fractions before and after 150 days of incubation in the same solution under constant environmental conditions.

Results

For the first time, it was found that during 150 days of incubation in constant environmental conditions, soil humic samples can aggregate by two fundamentally different ways, forming vesicle-like or ribbon-flat/sheet-like supramolecular morphological structures.

Conclusions

The types of morphological supramolecular structures observed using TEM were found to be related to different chemical compositions and physical–chemical properties of soil humic substances. These data could be relevant to better understanding the overall makeup of soil HAs, their structural organization, and various ecological and biogeochemical functions.

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Objectives

This study explores Russelia equisetiformis as a sustainable source for the green synthesis of antifungal nanomaterials. In response to increasing phytopathogenic fungi and environmental issues, it focuses on the fabrication of manganese nanoparticles (MnONPs), nitrogen-doped carbon dots (N-CDs), and their nanocomposite (MnO NPs@N-CDs) using R. equisetiformis extract.

Methods

The synthesized nanomaterials were characterized by UV–Vis spectrophotometry, FTIR, DLS, TEM, and EDX to confirm nanoparticle formation. Their antifungal effectiveness was evaluated against Sclerotinia sclerotiorum, Fusarium equiseti, and Fusarium venenatum. Additionally, bioactive metabolites were identified via LC–QTOF-MS, and their antifungal activity, pharmacokinetic profiles, and toxicity levels were assessed through computational tools.

Results

Nanomaterials produced from R. equisetiformis extract significantly reduced fungal growth, highlighting their potential as eco-friendly solutions for plant disease control. Most metabolites exhibited favorable safety profiles with minimal predicted cardiotoxicity and mutagenicity, indicating their promise as safe fungicides.

Conclusion

R. equisetiformis provides compounds with effective antifungal activity and low toxicity, offering a promising, environmentally friendly alternative to conventional chemical fungicides for sustainable plant disease management. Further research is essential to expand their application in agriculture.

Graphical Abstract

Entomopathogenic nematodes (EPNs) belonging to the genera Heterorhabditis and Steinernema are mutualistically associated with bacteria in the genera Photorhabdus and Xenorhabdus. The complexes of EPNs and their bacterial symbionts infect and kill a wide range of soil-dwelling insects that are harmful to crops. Given this advantage, these complexes have been primarily developed as a biocontrol agent to replace chemical pesticides on crops when society calls for healthy agriculture. This review examined recent advances in mutualistic bacteria of EPNs, secondary metabolites, and the mechanisms underpinning the interactions between mutualistic bacteria and insect hosts, as well as their potential application as a biocontrol agent. Based on this, new insights were provided to address the current issues that restrict the exploration of such biological agents, informing future research and guiding the development of biocontrol strategies for sustainable agriculture.

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Background

Saline-alkali stress severely impacts global crop productivity, while basic leucine zipper (bZIP) transcription factors (TFs) are known regulators of abiotic stress responses, the specific mechanisms of StbZIP1 in potato saline-alkaline tolerance remains unclear.

Methods

We cloned StbZIP1 from tetraploid potato ‘Favorita’, analyzed its sequence characteristics, and generated overexpression lines. StbZIP1-overexpressing (OE) and wild-type (WT) plants were subjected to saline-alkaline stress (NaCl: NaHCO₃ = 1:1) to assess physiological and molecular responses.

Results

StbZIP1 encodes a 16.61 kDa protein with conserved bZIP domains. Secondary structure prediction revealed that the protein comprises 55.48% α-helix and 44.52% random coil, consistent with the structural characteristics of typical bZIP family features. Physicochemical characterization revealed StbZIP1 was a highly hydrophilic protein (GRAVY index: −0.882) with no transmembrane region, and it harbors 27 predicted phosphorylation sites. Subcellular localization analysis using GFP-tagged StbZIP1 via confocal microscopy confirmed its exclusive nuclear localization, classifying it as a nuclear-targeted transcription factor. Under saline-alkaline stress, WT plants displayed severe wilting and complete desiccation of lower leaves, whereas StbZIP1-OE plants exhibited delayed wilting, no death and retained greener apical leaves. Quantitative analysis revealed that StbZIP1-OE plants showed a 33%–50% increase in chlorophyll content compared to WT (p < 0.01). Notably, StbZIP1-OE plants exhibited a more pronounced increase in Pro content (28% ~ 46%) higher than WT, while their MDA content was significantly reduced compared to WT. Furthermore, the activities of antioxidant enzymes (SOD, POD, and APX) were markedly elevated in StbZIP1-OE plants, showing increases of 81% ~ 100%, 81% ~ 104%, and 20% ~ 43%, respectively, relative to WT. Analysis of stress-related gene expression showed that after 12 d of saline-alkaline stress, the OE plants exhibited significantly increased expression of all six genes (StNCED, StRD29B, StABI5, StP5CS, StSOD, and StCAT) compared with WT (p < 0.05).

Conclusions

StbZIP1 positively regulates saline-alkaline tolerance by enhancing antioxidant capacity, providing a reference for the further cultivation of new stress-resistant potatoes.

Graphical Abstract

The detection of melamine in milk has consistently been a crucial issue in food safety. Near-infrared spectroscopy is widely used for rapid, non-destructive quantitative analysis and adulteration detection in dairy products, as evidenced by its application in detecting components, such as moisture, fat, and protein, and identifying adulterants, such as water and starch. Despite advancements in qualitative and quantitative models using near-infrared spectroscopy for melamine detection in milk, such as those employing discriminant analysis and partial least squares methods, the technique still faces challenges due to its inherent low sensitivity and high detection limits. This paper proposes a novel method for the detection of melamine in milk based on surface-enhanced near-infrared absorption (SENIRA) spectroscopy with gold nanoparticles. Gold nanospheres were successfully fabricated as substrates for enhancing near-infrared spectroscopy signals, leveraging their unique quantum confinement effects and interactions with light. Utilizing a wavelength range of 900 ~ 1700 nm and various chemometric methods, the concentration of melamine in milk, ranging from 0.0001 to 0.1 mg/mL, was quantified. The modelling effects were found to be favourable, with a calibration correlation coefficient (R_c²) of 0.9853, a prediction correlation coefficient (R_p²) of 0.9837, and a root mean square error of calibration (RMSEC) of 0.0059, the root mean square error of prediction (RMSEP) was 0.0066, the relative prediction deviation (RPD) was 5.3940, and the average recovery rate was calculated to be 117%. The combination of a high correlation coefficient a low prediction error, a high RPD value, and acceptable recovery rates suggests that the established model is robust and has competent predictive performance. Furthermore, experiments have demonstrated the feasibility of using SENIRA in conjunction with chemometrics for the determination of melamine content in milk, a process that aligns with the successful application of HPLC and NIR spectroscopy techniques as detailed in recent studies.

Graphical Abstract

Xanthomonas oryzae pv. oryzae (Xoo), the causative agent of bacterial leaf blight (BLB) in rice, poses significant threats to global crop productivity. To develop eco-friendly alternatives to chemical pesticides, this study synthesized zinc (Zn) and silver (Ag) nanoparticles (NPs) using Citrus maxima and Citrus sinensis extracts. NPs were characterized via UV–vis spectroscopy (peaks at 349 nm and 441 nm), FT-IR (identifying capping agents), and electron microscopy (spherical NPs, 8–56 nm). Antimicrobial assays revealed potent activity against Xoo, with Ag Nps exhibiting larger inhibition zones (31.32 mm) than ZnO NPs (19.31 mm). In vivo trials demonstrated infection reductions of 63.39% (Ag Nps) and 52.76% (Zn NPs), comparable to conventional pesticides. NPs enhanced superoxide dismutase (SOD) and peroxidase (POD) activities, thereby reducing ROS accumulation. Soil analysis indicated treatment-specific heavy metal dynamics: Zn NPs elevated Zn and Al levels. Microbial communities shifted under NP exposure; Flavisolibacter, Sphingomonas, and Candidatus Koribacter abundances varied significantly, distinguishing NP treatments from pesticides. Metabolomic profiling highlighted Ag Nps -induced upregulation of fatty acid and monoterpenoid biosynthesis pathways, suggesting targeted metabolic responses. While both NPs effectively suppressed BLB, Ag Nps showed superior antimicrobial performance, whereas Zn NPs influenced soil nutrient profiles. These findings underscore the potential of green-synthesized NPs as sustainable alternatives for BLB management, balancing disease control with minimal adverse effects on plant physiology and soil ecosystems. Further research is warranted to optimize NP dosages and assess long-term impacts on soil health.

Graphical Abstract

Background

Quinoline, an important nitrogen-containing heterocycle, is frequently found in both natural and synthetic compounds. Numerous quinoline derivatives have been developed as commercial pharmaceuticals and pesticides. Due to quinoline derivatives having exhibited various bioactivities, this research aims to investigate novel quinolin-8-amine derivatives as potential antifungal agents. Elucidating the structure–activity relationships (SAR) provides insights to facilitate the discovery of new agrochemicals.

Results

A series of quinolin-8-amine derivatives were designed, synthesized, and structurally characterized by nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectroscopy (HRMS). Single-crystal X-ray diffraction analysis confirmed the molecular architecture of compound 3n (4-chloro-N-(4-fluorophenyl)-2,3-dimethylquinolin-8-amine). Biological evaluation revealed several synthesized derivatives exhibited fungicidal activity against ten phytopathogenic fungi. Structural analysis of compound 3n revealed two distinct intermolecular hydrogen-bonding motifs: N–H···Cl and C–H···Cl interactions. Hirshfeld surface analysis identified H···H (37.0%) and C···H (12.2%) contacts as the major intermolecular interactions, while energy framework calculations revealed their respective contributions to crystal packing stability. Computational investigations including energy framework analysis, and density functional theory (DFT) calculations consistently emphasized the critical role of the quinoline scaffold in the antifungal activity.

Conclusions

This study provides an improved understanding of the SAR of quinoline-based fungicides, which is valuable for synthesizing novel quinoline derivatives and discovering more potent quinoline-based fungicides.

Graphical Abstract

Sinorhizobium sp. enhances plant vitality and stress resilience and improves soil structure. Underscoring their significance as agriculturally important bioagents for increased agricultural productivity requires understanding their taxonomic and functional relationships and the genetic foundations and pathways that drive plant growth-promoting traits. Genome sequencing, comparative genomics, functional annotation, and hybrid genome assemblies can achieve these. Comparative genomic analyses revealed a close relationship between the studied strains and Sinorhizobium meliloti and Sinorhizobium kummerowiae, which was further supported by phylogenomic, ANI, AAI, and dDDH analyses. Gene family cluster analysis identified 5999 gene families in the FRNB45 strain, 6116 in the FRNB101 strain, and 5996 in the FRNB126 strain. Functional genomic analysis identified several biosynthetic gene clusters (BGCs) related to secondary metabolite production, including polyketides, non-ribosomal peptides (NRPs), and siderophores, highlighting the metabolic versatility of these strains. KEGG pathway analysis confirmed the presence of nitrogen fixation and phosphate solubilization pathways, genes associated with the synthesis of indole-3-acetic acid (IAA), and siderophores. These findings support the potential application of FRNB45, FRNB101, and FRNB126 as plant growth-promoting rhizobacteria (PGPR), particularly suited for diverse climatic conditions and high-altitude ecosystems. However, further experimental validation is required to confirm their efficacy and consistency under field conditions.

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