Chemical and Biological Technologies in Agriculture最新文献

Background

Fermentation, a fundamental process in the production of cigar tobacco leaves, substantially influences the improvement of tobacco leaf quality. The initial water content is a crucial factor that regulates the fermentation process. This research systematically analyzed the dynamics of volatile aroma components, microbial community structure, and differential metabolites during the fermentation of cigar tobacco under three initial water content conditions (H1, H2, and H3).

Results

For three different initial water contents of cigar tobacco leaves, GC–MS analysis examined changes in key aroma compounds during the fermentation; Metagenomic analysis revealed differences in the microbial community composition of tobacco leaves, identifying characteristic microorganisms at the species level. Correlation analysis further elucidated the relationship between these characteristic microorganisms and flavor compounds; Untargeted metabolomics identified differential metabolites and their corresponding metabolic pathways during fermentation.

Conclusion

The research findings provide theoretical guidance for further optimizing the fermentation process and enhancing the quality of cigar tobacco leaves.

Graphical Abstract

Background

Composting converts organic residues into a stable amendment rich in nutrients and beneficial microorganisms, improving soil structure and fertility. Bacillus species are common plant-associated microbes that mobilise nutrients, produce phytohormone and protect plant against pathogens. Compost is vital to sustainable agriculture, but are often slow-acting and insufficiently effective under intensive farming conditions. Its partial substitution with mineral fertilisers and reduce practices to maintain soil organic matter, drives soil degradation and biodiversity loss. Integrating compost with biochar and plant growth-promoting rhizobacteria (PGPR) can improve its performance. This study tested the combined effects of compost, biochar and Bacillus siamensis MTA1-3 on plant growth and rhizosphere microbial communities at three doses (1.0%, 1.5%, 3.0%) in a ryegrass (Lolium multiflorum) microcosm experiment to identify the most effective formulation and evaluate its impacts on soil microbial structure and potential functions.

Results

The triple combination at 1.5% significantly increased plant growth compared to compost + biochar and control treatments. In the first cycle, fresh biomass was 14.83 ± 1.30 g vs. 12.45 ± 0.84 g (compost + biochar) and 7.93 ± 0.58 g (control); dry biomass was 1.89 ± 0.18 g vs. 1.57 ± 0.15 g and 0.97 ± 0.09 g, respectively. In the second cycle, fresh biomass was 12.68 ± 0.70 g vs. 12.03 ± 0.86 g (compost + biochar) and 6.70 ± 0.95 g (control); dry biomass was 1.55 ± 0.13 g vs. 0.89 ± 0.13 g. In addition, Bacillus abundance increased in the rhizosphere under the 1.5% treatment (8.79%) compared with control (1.70%), whereas in the bulk soil the change was minor (2.73%). Predictive functional profiling showed higher relative abundance of groups involve in nitrogen cycle under the 1.5% treatment.

Conclusions

The triple treatment induces beneficial, yet non-permanent, changes in the rhizosphere microbiome, improving the potential functionality of the soil without altering the bulk microbial community. This approach enhances both plant growth and soil biodiversity, providing a promising sustainable strategy to improve nutrient availability and promote soil biodiversity in intensive agricultural systems.

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Background

Rice blast disease, caused by Magnaporthe oryzae (M. oryzae), poses a major threat to global rice production annually. The Pi1 gene is a key determinant of resistance to this pathogen. However, the proteomic responses of rice to M. oryzae infection in both Pi1-containing and Pi1-deficient backgrounds remain poorly understood.

Results

This study investigated Pi1-mediated protein responses in rice using quantitative proteomics to compare the susceptible line MeiB and its Pi1-introgression line 96B. Comparative analysis of 4-day post-infection samples versus untreated controls identified 121 differentially expressed proteins (DEPs) in 96B and 126 in MeiB. Functional classification showed that DEPs related to cellular processes, metabolic processesprocesses, and responses to stimuli were significantly enriched in Gene Ontology (GO) analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed enrichment in metabolic pathways, secondary metabolite biosynthesis, and phenylpropanoid biosynthesis in both lines. Notably, Pi1 modulated proteins associated with apoptosis and purine metabolism during M. oryzae infection in 96B. Network analysis revealed 44 DEPs, including the pathogenesis-related protein PR10a, forming protein–protein interaction networks in 96B, compared to only 22 DEPs in MeiB.

Conclusions

The key findings include the specific regulation of biotic stress-related proteins such as Gnk2-homologous domain-containing protein and AT-hook motif nuclear-localized protein in 96B; apoptosis and purine metabolism pathways being unique to DEPs from 96B; and the presence of pathogenesis-related protein 10a and stress-responsive proteins (e.g., Bet_v_1 domain-containing and Gnk2-homologous domain-containing proteins) in the 96B interaction network. Therefore, these results suggest that Pi1 contributes to rice blast resistance by modulating apoptosis/purine metabolism pathways and protein–protein interaction networks.

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Background

Drought has been recognized as a major threat to crop yields. Protein hydrolysates, a group of plant biostimulants, appear to be a promising eco-friendly strategy for enhancing plant tolerance to various environmental stresses. The current study aimed to evaluate the effects of a novel protein hydrolysates derived from pig blood (PP) on growth performances of tomato and its underlying mechanisms under drought stress.

Results

The results showed that PEG-induced drought stress significantly increased the levels of hydrogen peroxide (H₂O₂), superoxide (O₂·⁻), and malondialdehyde (MDA), resulting in the obvious reduction of plant height, stem diameter, and shoot or root fresh weight. Exogenous PP stimulated the rapid accumulation of total phenolic, flavonoids, and individual phenolic compounds in tomato plants by regulating the relative expression of genes involved in phenolic biosynthesis, including phenylalanine ammonia-lyase (PAL), cinnamic acid 4-hydroxylase (C4H), 4-coumarate-CoA ligase (4CL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase(F3H), and flavonol synthase (FLS). Meanwhile, PP application also significantly reduced the content of H₂O₂, O₂·⁻, and MDA, and improved the antioxidant capacity and growth performances of tomato plants under drought stress. However, exogenous phenolic biosynthesis inhibitors, 2-aminoindan-2-phosphonic acid (AIP), significantly decreased the contents of total phenolic and flavonoids, which partially abolished the positive impacts of PP in reducing ROS accumulation, oxidative damage and increasing drought tolerance under drought stress. In addition, PP treatment also simultaneously enhanced the enzyme activities of superoxide (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and total antioxidant activity of tomatoes under drought stress.

Conclusions

In conclusion, PP application might be a useful method in reducing ROS accumulation and oxidative damage by regulating the accumulation of phenolic compounds and activities of antioxidant enzymes, thus enhancing the drought tolerance of tomato.

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Metisa plana Walker (Lepidoptera: Psychidae) is a major defoliator in oil palm plantations. The continuous application of Bacillus thuringiensis (Bt) bioinsecticide has raised concerns about its declining efficacy. In this study, we report the first comparative transcriptomic profiling of M. plana populations exhibiting reduced susceptibility to Bt Cry toxin. Bioassays using the leaf-dip method revealed a 5.44-fold increase in LC₅₀ values between populations, indicating early signs of reduced susceptibility. De novo transcriptome assembly generated 114,860 unigenes and 261,955 transcripts. Differential expression analysis identified 4507 significantly regulated unigenes, including those encoding key Cry toxin receptors such as cadherin, aminopeptidase-N, alkaline phosphatase, and ABC transporters. Notably, three cadherin unigenes were downregulated in the reduced-susceptibility group, suggesting altered receptor expression may contribute to Bt response variation. Selected unigenes were validated via qRT-PCR. This study provides novel insights into the molecular response of M. plana to Bt Cry toxin exposure and offers a foundation for future functional validation and resistance management strategies.

Graphical Abstract

Background

Powdery mildew is a fungal disease threatening major global crops such as tobacco, rice, and grapes. Pathogens cause severe yield losses by disrupting photosynthesis and inducing premature plant senescence. Traditional chemical fungicides face challenges of drug resistance, environmental pollution, and health risks, urgently requiring low-toxic and sustainable alternatives. This study aims to identify novel sesquiterpenoids against powdery mildew from the high-trichome sun-cured tobacco variety (Huize Liuye) and elucidate their antifungal mechanisms.

Results

Sequential chemical extraction, chromatographic purification, and spectroscopic identification (NMR and HR-ESI–MS) led to the isolation and identification of seven novel (1–7) and four known (8–11) aromatic sesquiterpenes. Compounds 5 and 6 represent the first examples of sesquiterpenes containing a 4-methylfuran-2-yl moiety, while compound 7 is a rare sesquiterpene featuring a benzo[c]azepin-1-one skeleton. Antifungal assays revealed that compound 7 (250 μg/mL) exhibited the highest inhibitory activity against Golovinomyces cichoracearum with an inhibition rate of 86.2% ± 5.6, surpassing the positive control carbendazim (inhibition rate: 83.5% ± 6.0, 250 μg/mL). Analyses using microscopy and scanning electron microscopy (SEM) demonstrated that compound 7 disrupts conidial morphology and inhibits hyphal development. Transcriptomic and metabolomic studies further indicated that compound 7 may enhance induced immunity in tobacco by either directly acting as an inducer or indirectly by promoting the rupture of G. cichoracearum and the release of its pathogen-associated molecular patterns (PAMPs), thereby affecting various plant defense pathways, including salicylic acid (SA), jasmonic acid (JA), and abscisic acid (ABA) mediated plant hormone signaling, the MAPK signaling pathway, and the biosynthetic pathways of antifungal secondary metabolites. Molecular docking confirmed strong interactions between compound 7 and tubulin proteins, which also supported its efficacy. Additionally, compound 7 also showed activity against Podosphaera pannosa in rose.

Conclusion

This study establishes Huize Liuye tobacco as a valuable resource for natural sesquiterpene-based antifungal agents, with compound 7 demonstrating exceptional potential as an efficient fungicide due to its unique chemical structure, high antifungal activity, and broad-spectrum efficacy. The findings provide a theoretical basis for utilizing tobacco byproducts, such as trichomes, as renewable sources for biopesticide development, thereby underscoring the ecological value of high-trichome crops in sustainable agriculture as substitutes for synthetic chemicals.

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Background

Environmental variations exert substantial influences on gene expression, growth, development, and product quality in field crops. However, the mechanisms underlying how environmental factors regulate tobacco growth, development, and post-curing quality under field conditions remain poorly understood, primarily owing to the complexity of the field environment.

Results

Our study demonstrates that precipitation serves as a predominant environmental driver that governs rhizosphere microbiome assembly, which subsequently modulates host carbon and nitrogen metabolic pathways, thereby determining nicotine accumulation and leaf irritability. We conducted an integrated multi-omics study across two representative tobacco growing regions (i.e., Chuxiong and Jianshui) in Yunnan, China, which exhibit distinct geographical and climatic conditions. Results revealed precipitation as a critical regulator of nicotine accumulation, with higher precipitation promoting nicotine biosynthesis and lower precipitation favoring sugar compound accumulation. The most pronounced difference between the two regions was the irritancy of cured tobacco leaves in the cultivar Yun87, which positively correlated with total nitrogen content. Crucially, rhizosphere microorganisms, along with climatic and soil abiotic factors (e.g., pH and available mineral elements), modulated nitrogen-containing compounds, including nicotine accumulation, by regulating carbon, nitrogen transport and utilization cycles, suggesting genetic-level interactions within the tobacco plant.

Conclusions

Our integrated multi-omics approach reveals a complex cross-kingdom network, providing a mechanistic understanding of how environmental cues are transduced into crop quality traits through the rhizosphere microbiome. This study offers insights in guiding targeted agricultural practices and future research on sustainable production of higher-quality tobacco.

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Background

The integration of mineral fertilizers with biostimulants offers a valuable solution to improve nutrient use efficiency and reduce environmental impact, especially considering the increasing prices of synthetic fertilizers and of the growing ecological concerns. This work explores the valorisation of low-value materials, derived from the organic fraction of municipal solid waste (OFMSW), to produce potential biostimulants.

Results

OFMSW was processed using different treatments and extraction methods to obtain several products containing humic-like substances. Three of these extracts, selected through germination tests, were evaluated for their biostimulant effects on rocket (Eruca sativa Mill.) plants grown under soilless conditions. All treatments resulted efficient in enhancing leaf and root development and significantly increasing nitrogen acquisition and assimilation by the plant. The biostimulant mechanism of the humic-like materials was investigated under both high and low nitrogen conditions, not only considering biomass production and nitrogen uptake, but also evaluating nitrate content in the leaves, activity of enzymes involved in N assimilation, and total antioxidant activity.

Conclusions

The results confirm the potential of waste-derived humic-like products to improve plant growth and nutrient use efficiency, supporting their use as effective, sustainable biostimulants in line with circular economy principles.

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Background

Tobacco is a vital economic crop, and its cultivation is severely threatened by black shank disease, caused by Phytophthora nicotianae (P. nicotianae). Actin depolymerizing factor (ADF) proteins are key regulators of actin dynamics and play crucial roles in plant growth, intracellular transport, and stress responses. Although the ADF gene family has been extensively studied in various plant species, characterization in tobacco remains limited, particularly regarding its role in disease resistance.

Results

In this study, 24 NtADF genes were identified in the tobacco genome. Phylogenetic analysis classified them into six groups, with structural and motif compositions supporting functional conservation within groups. Evolutionary analysis revealed that whole-genome duplication (WGD) or segmental duplication (SDR) was the primary drivers of NtADFs duplication, with strong purification selection. Promoter analysis identified numerous stress- and hormone-related cis-elements, and the regulatory network predictions indicated potential interactions with transcription factors (e.g., ERF, MYB, WRKY) and microRNAs (miRNAs). Expression profiling demonstrated tissue-specific patterns and differential responses to abiotic and biotic stresses. Notably, functional characterization demonstrated that NtADF22 played a critical role in conferring resistance to black shank disease.

Conclusions

This study provides comprehensive insights into the NtADF gene family, highlighting its important roles in plant development and stress responses. These findings offer both theoretical and practical significance for molecular breeding and genetic improvement of tobacco.

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Background

Resveratrol (RSV) is a natural polyphenol with potent antimicrobial and anticancer activities. However, its biomedical applications are limited by its poor solubility, instability, and lack of targeted delivery systems. Smart carriers are needed to enhance RSV efficacy, selectivity, and safety.

Method

An innovative magnetic molecularly imprinted polymer (MMIP-RSV) for the selective binding of resveratrol was prepared by embedding Fe₃O₄ nanoparticles into a chitosan–poly(cyclodextrin-citrate) polymer matrix. The polymer was characterized by FT-IR, UV–Vis, TEM, and zeta potential analysis, and Adsorption capacity, kinetics, selectivity, and reusability were assessed. Antimicrobial efficacy was assessed via MIC and MBC against five multidrug-resistant strains, and anticancer activity was evaluated on Caco-2 and MCF-7 cells, with HFB-4 fibroblasts as normal controls.

Results

The MMIP-RSV platform enabled both extraction and nanoformulation of resveratrol in a single step. MMIP-RSV achieved a high adsorption capacity (129.6 ± 1.2 mg/g), a 6.6-fold improvement, with qRSV = 25.6 ± 0.90 µg/mg, IF = 2.88, selectivity factor αRSV = 2.81, indicating 125% enhanced target selectivity. Reusability tests showed >97% capacity retention over five cycles, declining to 82.8% after six cycles. Antimicrobial activity: MMIP-RSV significantly enhanced RSV potency with MIC reductions of ~77% against MRSA (Methicillin-resistant Staphylococcus aureus), Enterococcus faecalis, and Salmonella Typhi . The inhibition zones were 26.0 ± 1.15 mm for S. aureus and 27.0 ± 0.58 mm for E. faecalis, compared to gentamicin (1mg /mL), outperforming free RSV. Gram-negative bacteria exhibited moderate improvement. Anticancer activity: MMIP-RSV selectively inhibited Caco-2 cells (IC₅₀ = 26 µg/mL RSV-equivalent), demonstrating enhanced cytotoxic efficacy compared to free RSV. While free RSV maintained >80% viability in normal HFB-4 fibroblasts even at 1000 µg/mL, MMIP-RSV exhibited a higher selectivity index (6.07 vs. 1.04 for free RSV), although some reduction in fibroblast viability was observed at high total formulation concentrations.

Conclusion

This study successfully developed a novel, eco-friendly MMIP (magnetic molecularly imprinted polymer) via a simple one-pot synthesis for the highly selective extraction and delivery of resveratrol. The remarkable binding capacity, selectivity, and enhanced therapeutic efficacy demonstrated in this study position the MMIP-RSV system as a robust and sustainable strategy with significant potential for applications in targeted drug delivery, nutraceutical purification, and advanced biomedical therapies.

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