Chemical and Biological Technologies in Agriculture最新文献

Background

Sugarcane smut, caused by the fungus Sporisorium scitamineum, is a devastating disease that limits sugarcane production and causes significant yield losses worldwide. This urgent threat highlights the critical need for novel sustainable control strategies. While utilizing beneficial plant-associated microbes shows promise for enhancing disease resistance, the contribution of the sugarcane rhizosphere microbiome in smut resistance remains poorly understood.

Results

In this study, rhizosphere microbial communities of sugarcane cultivars with contrasting resistance to smut were comparatively analyzed using high-throughput amplicon sequencing of the 16S rRNA gene and ITS region. Analysis of microbial co-occurrence networks analysis revealed that the resistant cultivars maintained more complex and stable networks than the susceptible cultivars. The rhizosphere microbiome of smut-resistant cultivars was predominantly enriched in beneficial genera such as Trichoderma, Penicillium, Talaromyces, Psathyrella, and Sphingomonas whereas that of susceptible cultivars contained more Streptomyces and Gibberella. Functional prediction also revealed distinct metabolic functions between the two microbiomes.

Conclusion

These findings demonstrate that network stability and enrichment of antagonistic microbes constitute key determinants of rhizosphere-mediated smut resistance. Our study provides critical insights for developing microbiome-driven breeding strategies and biological control measures against this economically important disease.

Graphic abstract

Background

Selenium (Se) deficiency affects a significant portion of the global population, making biofortification of staple crops essential for public health. While selenium nanoparticles (SeNPs) show promise for biofortification due to their low toxicity and high bioavailability, their application is limited by poor colloidal stability. This study explores the potential of Phellinus igniarius polysaccharide-stabilized SeNPs (SHP–SeNPs) to enhance rice growth and selenium biofortification (Se biofortification), focusing on their underlying molecular mechanisms.

Results

SHP–SeNPs demonstrated excellent colloidal stability and significantly improved rice physiological parameters. A foliar application of 45 mg/L SHP–SeNPs increased chlorophyll content, soluble sugars, and soluble proteins, surpassing the effects of unmodified selenium nanoparticles (SeNPs) and SHP alone. Field trials confirmed that SHP–SeNPs boosted rice grain yield and achieved Se biofortification, with polished rice containing 0.228 mg/kg Se, primarily as bioavailable selenomethionine. Metabolomics analysis revealed that SHP–SeNPs activated metabolic pathways such as the TCA cycle and sugar metabolism, upregulating 16 core metabolites including flavonoids, terpenoids, and glycerophospholipids, which contributed to the observed growth promotion.

Conclusions

SHP–SeNPs enhance rice growth, biofortification, and overall metabolic activity through a synergistic effect between SHP and SeNPs. The results highlight the potential of SHP–SeNPs as a stable and effective agent for Se biofortification in rice. This work provides valuable insights into the metabolic reprogramming of plants induced byfunctionalized nanoparticles and lays the foundation for developing intelligent nano-fertilizers to improve crop nutrition.

Graphical Abstract

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.

Graphical abstract

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.

Graphical abstract

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.

Graphical abstract

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.

Graphical abstract

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.

Graphical abstract

As a functional extract of green agricultural resources, anthocyanins possess significant potential as a source of intelligent packaging materials. A novel intelligent indicator film was developed by combining Vitis amurensis anthocyanins (VAA) with soy protein isolate (SPI) and chitosan (CS). The incorporation of anthocyanins enhanced both the mechanical and barrier properties of the films. Furthermore, the optimized concentration VAA had a beneficial effect on crystalline structure and could provide VAA/SPI/CS film with excellent DPPH scavenging ability. Packaging fresh fish with the film significantly improved quality parameters. Additionally, as the pH changes, the films exhibited noticeable color changes, transitioning from fuchsia to dark green. These findings suggest that VAA/SPI/CS intelligent indicator films can effectively monitor fish freshness in real-time through color changes, precisely because fish spoilage can cause color changes in the film.

Graphical abstract