Chemical and Biological Technologies in Agriculture最新文献

Cadmium (Cd) contamination in agricultural soils poses a significant threat to sustainable food production, necessitating innovative remediation strategies. This study introduces knowledge-based augmented manure (AM), formulated through controlled microbial oxidation of sulfur to generate H⁺ ions for targeted soil acidification, optimizing phosphate (P)-mediated Cd immobilization. A greenhouse experiment was conducted using B. napus in non-spiked and Cd-spiked alkaline soils (0 and 60 mg kg⁻¹ Cd), with two P fertilizer rates (0.5% and 1% DAP) applied in combination with either normal manure (NM) or AM. The amendment rates (P40 and P80) were determined based on an incubation trial to achieve specific soil pH targets (7.5 and 6.5) while preventing over-acidification. Results showed that Cd stress severely impaired plant growth and triggered antioxidant enzyme activity. However, AM + P80 significantly improved plant physiological and agronomic traits, leading to a 90.9% reduction in Cd bioaccumulation, an 83% decrease in the Cd bioconcentration factor, and a 78.8% decline in the Cd harvest index. Additionally, the AM + P80 treatment reduced the health risk index by 83.2%, demonstrating its potential to enhance soil health, suppress Cd uptake, and safeguard food safety. These findings highlight AM as a promising, precision-based soil amendment that regulates pH, optimizes P-Cd interactions, and improves plant resilience in Cd-contaminated calcareous soils.

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Background

Plant viruses cause severe agricultural losses. Conventional pesticides have issues such as residues and resistance, while the delivery efficiency of functional microRNAs in RNA interference strategies is low. This study aimed to evaluate the inhibitory effect of miR168d on potato virus Y in Nicotiana benthamiana and construct a high-efficiency nanodelivery system.

Results

MicroRNA168d significantly reduces the replication and spread of potato virus Y by targeting and inhibiting Heat Shock Protein 90-5. For the nanocomplex with a tetrahedral DNA nanostructure as the carrier and the cationic lipid 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) as the coating—characterization showed that it enhances the vascular transport efficiency, nuclease resistance, and cellular permeability of miR168d. Additionally, this nanocomplex exhibits low toxicity and good biocompatibility toward tobacco suspension cells. After foliar application, the nanocomplex group showed higher accumulation of miR168d in the leaves and stems of N. benthamiana compared with that in the control group. Specifically, the accumulation of mRNA and protein of the PVY coat protein in the nanocomplex group decreased by 64.3% and the corresponding percentage (consistent with the reduction at the protein level), respectively. As a result, the disease resistance of the plants was significantly improved.

Conclusion

This study reveals the antiviral mechanism of the miR168d-HSP90-5 regulatory module, provides a green non-transgenic nanoscale strategy, and is of great significance for agricultural antiviral breeding and sustainable agriculture.

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Background

Gray mold, a highly destructive disease that affects economically significant crops such as tomatoes, has been a subject of considerable research. Biological control via microorganisms is considered safe, effective, and environmentally friendly. Therefore, screening for biocontrol agents against Botrytis cinerea and elucidating their antagonistic mechanisms are essential for the biological management of tomato gray mold.

Results

In this study, Burkholderia plantarii BpMS90, which exhibited a 63.51% inhibition rate against B. cinerea and broad-spectrum antifungal activity against 10 plant pathogenic fungi, was isolated from the roots of Potentilla kleiniana. Biochemical, morphological, and genomic analyses classified BpMS90 as a strain of B. plantarii. Microscopic examination revealed that BpMS90 inhibited B. cinerea hyphae growth and markedly suppressed B. cinerea spore germination. Needle inoculation assays revealed that BpMS90 mitigates tomato fruit gray mold disease symptoms. Transcriptomic analysis and quantitative reverse transcription polymerase chain reaction demonstrated that BpMS90 induces the upregulation of disease resistance-associated genes, such as RPM1, RPS2, and PIK1 within the Avr-mediated defense pathway.

Conclusions

BpMS90 reduces the relative abundance of B. cinerea in postharvest tomato fruit and mitigates rot diseases caused by this fungus during storage by inducing the upregulation of genes involved in Avr-mediated defense pathways. This study is the first to reveal the biocontrol potential of BpMS90, thereby laying a foundation for B. cinerea control strategies and offering valuable insights into the postharvest biological control of fruits.

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Background

Astragalus L. (Fabaceae), a genus rich in bioactive triterpene saponins like astragalosides (ASTs), is recognized for its diverse biological activities. The present study aimed to quantify ASTs I, II, and IV in root extracts of fifteen Iranian Astragalus species. The acetylcholinesterase inhibitory activity of root extracts from astragaloside-rich species was also evaluated, and their neuroprotective effects were estimated using molecular docking analysis. Additionally, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity in root and aerial parts of species were evaluated.

Results

A. michauxianus and A. gossypinus yielded the highest ASTs I and IV content (2.49 ± 0.03 and 6.27 ± 0.89 mg/g DW, respectively), among Astragalus species examined in this study. TPC and TFC of roots were higher than that of aerial parts for all species, and the highest TPC and TFC were obtained for A. verus (12.12 ± 1.05 mg GAE/g DW) and A. floccosus (115.48 ± 1.54 mg RUE /g DW), respectively. Furthermore, the aerial parts extracts of A. remotijugus and A. aduncus showed the best free radical scavenging ability with the lowest IC₅₀ values (28.83 ± 0.64 and 28.86 ± 0.64 μg/mL, respectively), while for A. gossypinus and A. floccosus, the best scavenging ability (IC₅₀) was displayed in root extracts (23.32 ± 0.79 and 23.45 ± 0.74 μg/mL, respectively). The highest AChE inhibitory activity was exhibited by A. aduncus with the lowest IC₅₀ (200 ± 14.02 µg/ mL), followed by A. gossypinus and A. michauxianus. Moreover, molecular docking studies revealed that astragaloside I exhibits the strongest binding affinity to AChE (− 7.610 kcal/mol), forming multiple stabilizing interactions within the active site, suggesting its superior inhibitory potential compared to astragalosides II and IV.

Conclusions

These findings highlight the potential of selected Astragalus species as valuable resources for pharmaceutical applications and provide a foundation for future breeding programs aimed at maximizing ASTs production.

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Background

Alfalfa (Medicago sativa L.) is one of the most important forage crop in northern China, suffers from low-temperature (LT) stress, which significantly impairs its yield. While selenium (Se) supplementation has been reported to enhance abiotic stress tolerance in plants, the underlying molecular mechanisms in alfalfa remain poorly understood. This study aims to explore how Se mediates LT tolerance in alfalfa through transcriptomic analysis.

Results

Selenium significantly increased total Se in both shoots and roots, enhanced root-to-shoot translocation, and under low temperature (LT) shifted Se speciation toward organic forms at the higher dose. Meanwhile, 0.4 mg kg⁻¹ Se was sufficient to restore Pn, Gs, Ci, and Tr, reduce MDA, and elevate SOD, POD, APX, GR, GSH, and ASA, indicating improved photosynthetic performance and antioxidant status. Co-expression network analysis identified modules tightly associated with these traits: in the photosynthetic module, MS.gene064837 and MS.gene051360 were positively correlated with Gs, whereas MS.gene061853 and MS.gene037454 were positively correlated with Ci and Tr but negatively with Gs, suggesting coordination between carbon assimilation and stomatal control. In the antioxidant module, MS.gene036174 correlated positively with GSH and MDA and negatively with GSSG, while MS.gene064490 showed negative correlations with Pro, SS, GSSG, SOD, and POD. qRT-PCR of six targets corroborated the RNA-seq trends. Collectively, these results indicate that moderate soil Se (0.4 mg·kg⁻¹) supplementation enhances LT tolerance in alfalfa by concurrently optimizing photosynthetic regulation and antioxidant defense, with MS.gene064837, MS.gene051360, MS.gene036174, and MS.gene064490 emerging as candidate regulators whose specific functions require further validation.

Conclusions

This study reveals that selenium enhances LT tolerance in alfalfa by promoting Se conversion into its organic form, optimizing redox homeostasis, and activating key genes associated with photosynthesis and antioxidant defense. These findings provide valuable insights into Se-mediated cold tolerance mechanisms, offering a foundation for Se-based strategies in improving the resilience of forage crops to cold stress.

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Background

This study was based on the identification of drought-resistant wheat varieties from trials to assess drought levels accurately in wheat and respond promptly to the impact of drought stress on grain yield. Hyperspectral remote sensing data and canopy temperature parameters for different wheat varieties were obtained, and classification models for drought resistance were constructed using various machine learning algorithms.

Results

As the growth period progresses, the spectral reflectance in the near-infrared band first increases but then decreases in the following pattern: flowering > heading > booting > jointing > filling. The effective temperature range of the canopy temperature histogram for different drought-resistant varieties also gradually increased with growth stage, and during each growth stage, the temperature variation in strongly drought-resistant varieties was the smallest compared with that in extremely weak drought-resistant varieties. Vegetation indices can represent the differences in drought resistance among wheat varieties; under drought stress, as drought resistance decreases, the canopy temperature parameters increase. There are certain correlations between the vegetation index (VI), canopy temperature parameter (TP), and the drought index for wheat yield. Furthermore, among the classification models based on the VI, TP, and VI + TP, the random forest (RF) model has the highest accuracy rate. Among them, the accuracy rates of the random forest model for VI + TP are 89.47% for overall accuracy (OA) and 0.85 for Kappa, which are higher than those of VI (OA = 69.57%, Kappa = 0.57) and TP (OA = 76.19%, Kappa = 0.66). In the optimal classification model VI + TP-RF, TP contributes the most to the RF classification algorithm based on multisource data fusion.

Conclusions

This study confirms the feasibility of using multimodal data fusion for classifying drought-resistant wheat varieties and provides a new reference method for further clear evaluation of wheat drought grade.

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Phosphorus (P) recovery from waste byproducts is essential for nutrient recovery, yet its bioavailability in inorganic and organic waste remains a challenge. This study investigates the phosphate solubilization potential of Bacillus megaterium and Pseudomonas putida, both individually and in a dual-consortia system, on sewage sludge ash (SSA), fish meal (FM), and their mixture. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) analyses were conducted to assess biochemical transformations and microstructural modifications post-solubilization. Kinetic modeling using the Hill equation demonstrated distinct solubilization patterns, where P. putida excelled in acid-mediated phosphate release from SSA, while B. megaterium exhibited strong enzymatic mineralization of organic phosphorus in FM. The consortium treatment displayed intermediate effects, balancing acid production and enzymatic degradation but without exceeding the highest-performing single strain. Principal Component Analysis (PCA) and statistical modeling confirmed that pH shifts, redox potential, and enzymatic activity were key drivers of microbial-mediated phosphate solubilization. The results suggest that targeted microbial inoculation based on waste type can optimize phosphorus recovery and improve the potential of nutrient recovery.

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Background

Hunan Province, a major rice-producing region in China, faces severe cadmium (Cd) contamination in rice grains. Cd, a heavy toxic metal, accumulates in rice through the soil–rice system, posing health risks via the food chain. Effective management relies on identifying pollution sources to guide targeted control and reduction strategies.

Results

Through the data collected over the past 5 years across four different regions, a multiple linear regression model was established to explore the effects of those factors influencing Cd accumulation in rice tissues, including the input fluxes of soil Cd, atmospheric deposition Cd (DICd), irrigation water Cd (IRCd), and fertilizer Cd (CFCd). Atmospheric deposition was identified as a major source of Cd input, with a higher annual average input flux than irrigation water and fertilizers. In the industrial and mining zone Zhuzhou, atmospheric deposition accounted for 96.42% of the total Cd input. In the regions with an increasing level of atmospheric deposition, Cd exhibited higher soil Cd concentrations but lower pH. Total soil Cd (TCd) concentrations demonstrated a significant positive correlation with both soil available Cd (ACd) concentrations and DICd. Additionally, TCd and DICd were determined to be the critical factors affecting the accumulation of Cd in rice tissues.

Conclusions

As indicated by the results, the spatial variation in rice Cd accumulation resulted from various sources of Cd input, highlighting the necessity to closely monitor Cd input fluxes across various regions. This study provides a benchmark for understanding the impact of atmospheric deposition on Cd accumulation in rice grains.

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Background

The antimicrobial peptide WMR-4, a myxinidin-derived sequence with Aib and D-amino acid substitutions, showed enhanced stability and strong antifungal activity against Fusarium oxysporum in vitro.

Results

Biophysical studies indicated a lytic mechanism via deep membrane insertion and leakage. However, free WMR-4 failed to block fungal penetration through cellulose barriers, revealing limits in complex systems. To overcome this, we developed supramolecular nanofibers functionalized with WMR-4 and the cell-penetrating peptide gH625. These nanofibers inhibited germ tube formation, partially reduced cellulose membrane penetration, and provided enhanced protection in biological contexts. Specifically, nanofibers limited opportunistic saprophytic colonization in apple tissues lacking epidermal barriers while preserving tissue integrity in intact tomato models, demonstrating barrier-specific therapeutic protection. SEM and AFM confirmed stable nanoscale coatings integrated into plant epidermal layers.

Conclusions

These results highlight WMR-4 as a potent antifungal candidate and demonstrate the potential of AMP-functionalized supramolecular nanostructures for agricultural applications.

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