Search Results (646)

Chitosan-based silver nanoparticles (Ch-AgNPs) are emerging as promising antimicrobial materials with potential applications in crop protection. This study evaluated the formulation-dependent antimicrobial activity and plant compatibility of Ch-AgNPs synthesized from chitosan extracted via different routes from shrimp shells. Antibacterial activity was assessed against representative Gram-negative and Gram-positive model bacteria (Escherichia coli and Staphylococcus aureus), as well as phytopathogenic bacteria (Xanthomonas campestris, Pseudomonas syringae), using disk diffusion assays. Antifungal activity was evaluated against Fusarium graminearum in vitro and in a controlled growth chamber. All formulations exhibited concentration-dependent antibacterial activity, with L10 and L20 formulations derived from optimized lactic acid-based extraction routes and DP4 derived from an inorganic deproteinization-based extraction route showing the highest efficacy at 1.0 mg/mL. Strong antifungal activity was observed, particularly for L10 and DP4, achieving mycelial growth inhibition of 92% and 84%, respectively, at 1.0 mg/mL. Seed germination and seedling growth assays confirmed that all formulations were non-phytotoxic at 1.0 mg/mL, with L10 and DP4 significantly enhancing germination parameters and early plant growth. Under controlled conditions, these formulations also reduced the incidence and severity of crown and root rot in spring wheat caused by F. graminearum. These findings demonstrate that optimized Ch-AgNP formulations combine antimicrobial activity with plant compatibility, highlighting their potential for crop protection, pending further environmental safety and agronomic validation under field conditions. Full article

Fusarium graminearum infection of maize induces complex transcriptional reprogramming, yet existing differential-expression and local graph convolutional approaches struggle to capture long-range and multi-scale regulatory dependencies. We propose DC-FusionGNN, a dual-channel fusion graph neural network for key resistance-gene identification. Based on the transcriptome dataset GSE174508, we first construct a comprehensive gene interaction network by integrating a WGCNA co-expression network with a STRING-based interaction network. The left channel combines structure-aware propagation with a Transformer-based global self-attention mechanism to model long-range cross-module dependencies, while the right channel couples GraphSAGE with a GCN to capture local topology and neighborhood heterogeneity. Embeddings from the two channels are concatenated to form a unified gene representation, trained via self-supervised link prediction. Compared with baseline graph neural networks, DC-FusionGNN achieves competitive and overall improved performance across multiple metrics, and robustness and independent cross-species (rice, GSE39635) experiments further confirm its stability and generalization ability. GO and KEGG enrichment analyses show that the top-ranked candidate genes are significantly enriched in plant defense responses, hormone signaling, and secondary metabolism, supporting the biological relevance of the model’s predictions. Full article

Maize ear rot, primarily caused by Fusarium verticillioides (Fusarium ear rot, FER) and Fusarium graminearum (Gibberella ear rot, GER), is a devastating disease that causes significant yield losses and mycotoxin contamination. Breeding resistant varieties is the most effective control strategy, but this requires the identification of stable genetic loci for resistance. In this study, we employed bulked segregant analysis (BSA) on two F₂ mapping populations to identify quantitative trait loci (QTLs) conferring resistance to FER and GER. We identified five and eleven QTLs for FER and GER, respectively. Notably, chromosome 4 was identified as a major hotspot for resistance to both diseases, and there was a co-localization of the FER QTL (qFER4.05) and GER QTL (qGER4.05-1) within a 58.58–71.34 Mb interval on bin 4.05, suggesting a potential locus for broad-spectrum resistance. Within this overlapping region, we identified 18 high-confidence candidate genes, including genes encoding leucine-rich repeat receptor-like kinases (LRR-RLKs), remorin, cytochrome P450 monooxygenases, and wall-associated receptor kinase-like (WAKL) protein, all with established roles in plant defense. These findings advance the understanding of the genetic architecture of ear rot resistance and provide critical resources for marker-assisted breeding to develop maize hybrids with durable resistance to both FER and GER. Full article

Fusarium head blight (FHB), caused by Fusarium graminearum, is a devastating wheat disease leading to significant yield loss and mycotoxin contamination. This study elucidated the biocontrol mechanism of Bacillus velezensis 20507 fermentation broth against FHB during wheat infection. The broth exhibited strong, time-dependent antifungal activity in vitro, with optimal growth suppression (inhibition rates up to 75%) achieved using broth fermented for 3–7 days. In planta experiments confirmed its efficacy in alleviating disease symptoms. Employing a dual RNA-seq strategy, we analyzed the tripartite interaction between the biocontrol agent, pathogen, and wheat host. Transcriptomic analysis revealed that the broth directly suppressed the pathogen, causing 1510 differentially expressed genes (DEGs, predominantly down-regulated) and disrupting pathways related to carbohydrate metabolism and cell wall integrity. In wheat, the fermentation broth of B. velezensis 20507 counteracted F. graminearum infection by reprogramming the host transcriptome. KEGG analysis during co-inoculation showed that the broth up-regulated defense-related pathways involved in energy, hormone signaling, and cellular maintenance, while down-regulating primary metabolic pathways, indicating a resource reallocation strategy. Furthermore, transcriptomic analysis revealed that the broth alone primed the wheat defense system, and this primed state significantly enhanced the defense response upon pathogen challenge. Untargeted metabolomics identified key antimicrobial compounds, including lipopeptides and the macrolide Macrolactin A. Bioassay-guided fractionation isolated two active fractions (Fr A and Fr B) with potent antifungal activity. This integrated multi-omics study demonstrates that B. velezensis 20507 combats FHB through a coordinated dual mechanism: direct inhibition of the fungus via specific metabolites like Macrolactin A, and simultaneous reprogramming of the host defense and metabolic landscape. These findings provide a scientific foundation for developing this strain as an effective biocontrol agent. Full article

The BONZAI/BON (copine) gene family encodes evolutionarily conserved proteins that modulate the balance between plant defense responses and growth. However, comprehensive identification and functional exploration of BON members have remained largely lacking in wheat. In this study, we identified 10 Triticum aestivum BON (TaBON) members, which are unevenly distributed across seven wheat chromosomes. Phylogenetic analysis clustered these TaBON proteins into two distinct groups. Gene structure and conserved motif analyses revealed high evolutionary conservation within the TaBON family. Cis-acting element analysis revealed that the promoter regions of TaBON genes are enriched with elements responsive to hormones, abiotic stress, and biotic defense signals. Expression profiling further demonstrated distinct transcriptional patterns of TaBON genes in response to infections by Puccinia striiformis f. sp. tritici (stripe rust), Blumeria graminis f. sp. tritici (powdery mildew), Fusarium graminearum, and Zymoseptoria tritici. Overall, this study presents a comprehensive analysis of the TaBON members and provides valuable molecular information for understanding its role in disease resistance. Full article

The increasing demand for sustainable plant protection products has intensified interest in microbial biocontrol agents (BCAs). This study aimed to evaluate the antifungal activity of selected Streptomyces, Bacillus, and Trichoderma asperellum strains against phytopathogenic fungi and to assess their potential as BCAs under in vitro conditions. The antifungal activity of ten Streptomyces strains was first evaluated against Botrytis cinerea, Colletotrichum salicis, Fusarium oxysporum, and F. graminearum using a dual-culture assay. All isolates exhibited antifungal activity, with Streptomyces venezuelae MSCL 350 showing the strongest inhibition. In addition, the antifungal activity of T. asperellum MSCL 309 and three Bacillus strains was assessed against twelve Fusarium spp. isolates obtained from oats. T. asperellum demonstrated broad-spectrum inhibition, with growth inhibition ranging from 44.6% to 78.4%, primarily due to soluble metabolites, while volatile compounds showed no significant effect. Among the other tested Bacillus strains, only Bacillus subtilis MSCL 1441 exhibited antifungal activity, inhibiting all tested isolates. These results demonstrate strong strain-dependent antifungal activity and highlight T. asperellum MSCL 309, S. venezuelae MSCL 350, and B. subtilis MSCL 1441 as promising candidates for the development of environmentally friendly biocontrol agents. Full article

To determine Fusarium species and their pathogenicity in maize-production areas of the Tepebaşı, Odunpazarı, Alpu, and Seyitgazi districts of Eskişehir province, Türkiye, 180 samples were collected from 45 fields during survey studies conducted in 2023–2024. A total of 110 Fusarium isolates were obtained from the collected plant samples. The isolates were identified as F. verticillioides, F. culmorum, F. proliferatum, F. graminearum, F. sambucinum, F. acuminatum, F. chlamydosporum, and F. equiseti. The most common species was F. verticillioides, while the most virulent species was F. graminearum, with a disease severity of 96.67%. The effects of different doses of soil-applied herbicides containing the active ingredients Isoxaflutole + Thiencarbazone-methyl + Cyprosulfamide, Dimethenamid-P + Saflufenacil, and S-Metolachlor + Terbuthylazine on F. graminearum were evaluated under both in vitro and in vivo conditions. Under in vitro conditions, the highest inhibition rate (57.23%) was observed in the double-dose application of the herbicide containing S-Metolachlor + Terbuthylazine. This was followed by the upper and recommended doses of the same herbicide with inhibition rates of 47.16% and 39.46%, respectively. For the other herbicides, inhibition rates increased with increasing herbicide dose. In field trials, the highest suppression of the pathogen was also observed with the herbicide containing S-Metolachlor + Terbuthylazine. While the recommended dose showed a 38.6% effect against the pathogen, the upper dose resulted in a 45.31% effect. This study suggests that herbicide applications may be associated with improved plant growth, likely due to reduced pathogen pressure and decreased weed competition. The findings highlight the complex interactions between soil-applied herbicides, soil-borne pathogens, and host plants, and provide insights into the development of integrated disease management strategies in maize-production systems. Full article

Plant fungal diseases, such as apple tree canker caused by Valsa mali, have caused severe losses in agricultural production. Traditional chemical fungicides induce drug resistance in pathogens and cause environmental pollution. Therefore, it is of substantial importance to screen efficient and environmentally friendly bacterial strains as potential biocontrol agents. The tea rhizosphere harbors abundant microbial resources, and previous research has identified microorganisms with antifungal activity existing in this environment. Therefore, in this study, we isolated antagonistic bacteria with broad-spectrum biocontrol potential from tea rhizosphere soil. In this study, a strain with strong antagonistic activity against V. mali was isolated from tea rhizosphere soil. Based on morphological characteristics, 16S rRNA gene sequencing, and whole-genome analysis, the isolated strain was identified as Bacillus velezensis and designated as LW-66. This strain demonstrated broad-spectrum antifungal activity against various plant pathogenic fungi, including Valsa mali, Fusarium graminearum, Bipolaris sorokinianum, Alternaria solani, and Exserohilum turcicum. The active extract of B. velezensis maintained strong stability across a wide range of temperatures (25–90 °C) and pH values (2–8), with stability decreasing only when the temperature reached 100 °C or pH ≥ 10. In a preventive assay using detached apple branches inoculated with V. mali, the control efficacy of LW-66 against apple tree canker reached more than 90%. Additionally, in a therapeutic assay using V. mali-infected potted apple seedlings, the LW-66 bone-glue bacterial agent achieved a survival rate of up to 90%. Whole-genome analysis revealed that the genome of LW-66 contains 13 predicted secondary metabolite biosynthetic gene clusters, seven of which showed high homology (≥92% similarity) with known antimicrobial gene clusters, including surfactin, bacillaene, macrolactin H, fengycin, difficidin, bacillibactin, and bacilysin. These gene clusters may be connected to the broad-spectrum antifungal activity of B. velezensis, as well as its ability to disrupt hyphal morphology. The volatile organic compounds produced by LW-66 inhibited V. mali growth by 91.70%. Collectively, these findings demonstrate that B. velezensis LW-66 has a wide antimicrobial range and strong antagonistic effects against multiple plant pathogenic fungi. Therefore, B. velezensis shows promise as a biocontrol agent for managing fungal diseases in plants, providing a basis for developing LW-66-derived biocontrol products aimed at controlling diseases such as apple tree canker. Full article

Peptaibols, predominantly secreted by Trichoderma species, are a class of linear peptides composed of five to twenty amino acid residues, synthesized non-ribosomally and enriched with α-amino isobutyric acid. These unique peptides appear to be highly effective in mediating the interactions between Trichoderma and plant pathogenic fungi. In this study, Ultra-Performance Liquid Chromatography–Quadrupole Time-Of-Flight Mass Spectrometry/Mass Spectrometry (UPLC-QTOF-MS/MS) technology was used to detect peptaibols profiles of Trichoderma strains during their interactions with the pathogen Fusarium graminearum. MS investigations of crude extracts derived from in vitro confrontations of Trichoderma atroviride T23 and its genetically modified counterparts, dual-culture assays of Mlae1, Mvel1, OElae1, and OEvel1 with F. graminearum were performed to shed light on the regulatory role of the velvet complex composed of LAE1&VEL1 in the synthesis of peptaibols during the microbial interaction. These results revealed intriguing variations in the total peptaibols produced during the interactions, as well as some differences in the specific peptaibol profiles between the confrontation and control tests. The overexpression strains, OElae1 and OEvel1, distinguished themselves by their proficiency in inducing long-residue peptaibols synthesis, attaining an impressive biocontrol index of up to 76%. The crude extracts containing peptaibols of OElae1 and OEvel1 demonstrated a capability to enhance cell membrane permeability and decrease DON toxin production in F. graminearum, and the crude extracts of OElae1 strains exhibited more effectiveness in reducing DON toxin production. In conclusion, the interaction with F. graminearum significantly impacted the peptaibol production in the examined Trichoderma strain, emphasizing the intricate interplay and reciprocal influence of genetic factors and environmental stimuli. Full article

Ceylon cinnamon (Cinnamomum verum J. Presl) bark essential oil (CBO) represents a promising source of natural bioactive compounds for biological plant protection. For the first time, the antibacterial and antifungal activity of CBO was systematically evaluated against a curated panel of phytopathogenic strains (IOR collection), revealing broad-spectrum efficacy across both bacteria and filamentous pathogens. This study evaluated its chemical composition, antimicrobial activity against phytopathogens, effects on bacterial metabolic activity, and its ability to induce plant defence responses. CBO was dominated by cinnamaldehyde, linalool, and eucalyptol. The oil exhibited strong antibacterial activity against Dickeya dadantii, Pectobacterium carotovorum, Pseudomonas syringae, and Xanthomonas hortorum as well as antifungal activity against Fusarium graminearum, F. culmorum, Rhizoctonia solani and Phytophthora cinnamomi. Metabolic assays revealed a marked reduction in bacterial metabolic activity, indicating that CBO disrupts physiological processes and inhibits growth. In planta experiments showed that foliar application of CBO stimulated PAL activity in wheat leaves without visible phytotoxic symptoms. These findings demonstrate a multifunctional mode of action of CBO, combining direct antimicrobial effects with the elicitation of plant defence responses, and support its potential application in sustainable crop protection. Full article

Fusarium head blight (FHB), caused by Fusarium graminearum, is a fungal disease that severely affects wheat. The mycotoxins it produces, such as deoxynivalenol (DON), pose serious risks to human and animal health. In this study, a biocontrol strain, LYH8, was isolated from local sources in Jingzhou, Hubei Province. Plate confrontation assays demonstrated that LYH8 effectively inhibited the mycelial growth of F. graminearum, with an inhibition rate of 43%, and induced morphological abnormalities such as hyphal swelling and shrinkage. Based on 16S rRNA and gyrB gene sequencing and phylogenetic analysis, LYH8 was identified as Bacillus velezensis. In vivo experiments showed that disease severity in wheat coleoptiles and spikes was significantly reduced by treatment with LYH8 by 75–85%, and the accumulation of DON and its deoxynivalenol-3-glucoside (D3G) in grains was decreased by 20–22%. Further transcriptome analysis revealed that it affects pathogen growth by regulating amino acid biosynthesis, ribosomal biosynthesis, carbon metabolism pathways, and the catalytic activities of related genes. In summary, LYH8 significantly controlled FHB through multiple mechanisms, including inhibiting mycelial growth, reducing infection, and blocking toxin synthesis, demonstrating strong biocontrol potential. Full article

Mycotoxin contamination of grains during storage and transportation represents a significant threat to global food security. Conventional detection methods exhibit limitations in terms of real-time monitoring. This study presents a compact smart gas sensing system for mycotoxins, facilitating non-destructive testing of corn infected with fungi by analyzing the volatile organic compounds (VOCs) emitted during fungal growth. It also facilitates the precise quantitative detection of Aflatoxin B₁ (AFB₁). Additionally, a dual-branch convolutional neural network (DB-CNN) model has been developed to conduct an in-depth analysis of the temporal and spatial characteristics of VOCs signals. The system achieves 100% accuracy in identifying grains (corn, peanuts, wheat, and rice) infected with Fusarium graminearum and Aspergillus flavus by extracting the characteristic fingerprint spectra of fungal VOCs. In the quantitative analysis, the DB-CNN exhibits good performance (RMSE = 1.0292 μg/kg, R² = 0.9994). In addition, the designed detection system supports wireless transmission and can be connected to a smartphone for data transfer, thereby facilitating data storage and remote monitoring. The entire detection process is completed within 4 min. This study provides an innovative technical foundation for dynamic real-time monitoring of fungal contamination in the food supply chain, contributing to early warning systems and quality control measures. Full article

Stripe rust (Puccinia striiformis) and Fusarium head blight (FHB; caused by Fusarium graminearum) are fungal diseases that endanger wheat productivity; however, by pyramiding disease-resistant genes, the long-term resistance of wheat can be strengthened. In this study, a multi-parent pyramiding hybrid population was constructed using marker-assisted selection (MAS). After multiple generations of breeding, 168 F₆ lines were obtained. By combining molecular marker genotyping, field resistance identification, and agronomic trait evaluation, 19 lines with excellent agronomic traits were selected, which not only showed high resistance to stripe rust but also carried Fhb1 genes, some of which have the potential to be developed into new germplasms and offer important genetic resources for the breeding of wheat with long-lasting and broad-spectrum resistance. Full article

Brachypodium distachyon has become a widely studied model plant due to its small genome, ease of cultivation under controlled conditions, and value for synteny and molecular studies. Regarding disease, Fusarium is one of the main fungal genera infecting cereal crops, F. cerealis, F. graminearum, F. poae, and F. pseudograminearum being isolated frequently from several agricultural regions. Therefore, the present study aimed to evaluate three pathosystems, combining three hosts (B. distachyon, barley, and wheat) with four Fusarium species to confirm the use of B. distachyon in Fusarium–crop system models. Three controlled experiments were performed to assess the impact on seeds, roots, and spikes. Variables such as germination inhibition, McKinney’s index, percentage of necrosis, area under the disease progress curve, disease incidence, disease severity, and grain weight were measured. Regarding Fusarium species, the results confirm that F. pseudograminearum could be more aggressive on roots, while F. graminearum affects spikes more severely. In contrast, F. cerealis and F. poae are generally moderate to weak pathogens with irregular behaviour depending on the plant species or genotype. No clear varietal resistance pattern emerged except for wheat genotypes with a known resistance/susceptibility QTL. The present study highlights the importance of using multiple experiments for accurate phenotype characterisation, as relying on a single technique is insufficient. In conclusion, the results presented in the manuscript provide valuable insights into Fusarium spp.–B. distachyon interactions and resistance selection based on seed, root, and spike assessments. Moreover, this work confirmed the use of Brachypodium as a model plant for Fusarium–plant interaction studies. Full article

Fusarium head blight (FHB), caused by Fusarium graminearum, severely threatens wheat production in China’s Huang-Huai region. In order to clarify the resistance status of F. graminearum to pydiflumetofen in Henan Province, the mycelial growth rate method was used to assess the sensitivity of 345 strains isolated from 15 Henan cities during 2021–2024. The EC₅₀ of F. graminearum isolates to pydiflumetofen was determined to be 0.016–3.981 μg/mL, with a right-skewed unimodal pattern, and the Shapiro–Wilk test confirmed a non-normal distribution (W = 0.4936, p < 0.05). Significantly higher mean EC₅₀ values were observed in 2024 relative to 2021–2023, and resistant isolates were predominantly distributed in southwestern Henan Province. Fitness assays conducted in the absence of fungicide showed that most pydiflumetofen-resistant isolates exhibited similar mycelial growth, conidiation, pathogenicity, and deoxynivalenol (DON) production compared with sensitive isolates, suggesting no obvious fitness costs associated with pydiflumetofen resistance. Spearman rank correlation analysis demonstrated positive cross-resistance between pydiflumetofen and fluxapyroxad, but no cross-resistance to prothioconazole, phenamacril, or pyraclostrobin. Resistant strains had mutations in the FgsdhC2 (C89S, A93V) and FgsdhD (A21T, S30F) subunits of succinate dehydrogenase (SDH). Low-frequency pydiflumetofen resistance in F. graminearum from Henan Province highlights that pydiflumetofen should be applied alternately or in combination with fungicides showing no cross-resistance to delay the development of resistance. Full article