Search Results (1,649)

Rice sheath rot has progressively developed into a growing threat to global rice production, particularly in intensively managed systems conducive to disease development. Therefore, accurate identification of the causal pathogen and the development of sustainable management strategies represent urgent scientific requirements. In this study, we isolated the causal organism of rice sheath rot from infected rice tissues and identified it as Fusarium verticillioides based on multi-locus sequence analysis. Eight endophytic bacterial strains were recovered from healthy rice root systems. Among the isolates, Bacillus velezensis isolate 7-A exhibited the strongest antifungal activity against F. verticillioides. This isolate demonstrated broad-spectrum antifungal activity, with inhibition rates ranging from 54.8% to 71.8%. Phylogenetic analysis based on 16S rRNA and gyrB gene sequences identified it as B. velezensis. Further characterization revealed that B. velezensis 7-A is capable of secreting proteases and synthesizing siderophores. The filtered liquid from sterile fermentation markedly inhibited the growth of mycelium in F. verticillioides and induced marked morphological abnormalities. Liquid LC-MS analysis identified multiple antifungal active substances, including camphor, ginkgolides B, salicin, cinnamic acid, hydroxygenkwanin, stearamide, β-carotene, and others. A pot experiment demonstrated that the fermentation broth of B. velezensis 7-A effectively suppressed the occurrence of rice sheath rot, achieving a relative control efficacy of 61.3%, which is comparable to that of a 10% carbendazim water-dispersible granule (WDG). Additionally, isolate 7-A enhances plant disease resistance by activating the activities of key defense enzymes. These findings provide preliminary insights into its potential application in integrated and sustainable disease management programs. Full article

Trichogramma is an important genus of egg parasitoids, applied against agricultural and forest lepidopteran pests. Known species differ in host specificity, which affects both their efficiency in field and suitability for mass rearing. In 2022, a novel strain of T. dendrolimi was recovered from eggs of the Siberian silk moth Dendrolimus sibiricus in Eastern Siberia. Freshly laid eggs of lepidopteran insects belonging to 17 species were exposed to adult T. dendrolimi. Besides the original host, successful reproduction was observed in the eggs of 13 species belonging to the families of Sphingidae (3 species), Noctuidae (2 species), Pyralidae (1 species), Crambidae (1 species), Erebidae (3 species), Gelechiidae (1 species), Geometridae (2 species), Nolidae (1 species), and Lasiocampidae (3 species). The maximum parasitoid yield of 33 adults per egg was observed in D. sibiricus, followed by Dendrolimus pini (32 adults/egg), Macrothylacia rubi (27 adults/egg), Manduca sexta (26 adults/egg), Orgyia antiqua (4 adults/egg), Pseudoips prasinana (3 adults/egg), Mamestra brassicae, Angerona prunaria, and Chrysorithrum flavomaculata (2 adults/egg), as well as Hydraecia micacea, Ostrinia nubilalis, Galleria mellonella, and Sitotroga cerealella (1 adult/egg). Thirty generations were successfully reproduced in the laboratory using D. sibiricus, M. sexta, M. brassicae, and S. cerealella eggs. The parasitoid remained viable and efficiently attacked eggs of various lepidopteran hosts. The present study extends the knowledge of susceptible hosts of T. dendrolimi. Some of these host species provide high reproduction indices of the parasitoid and could be used for large scale propagation of this biocontrol agent. Full article

Root rot in Lycium barbarum, an economically vital crop, is a critical barrier to its sustainable development in China. To elucidate the underlying micro-ecological mechanisms, this study aimed to characterize and compare the rhizosphere microbial communities of healthy and diseased plants from the Qaidam Basin. We employed PacBio full-length amplicon sequencing to analyze bacterial and fungal populations, complemented by network analysis and in vitro antagonistic assays. The results indicated that while microbial species richness was similar, the community structures of healthy and diseased soils were fundamentally different, suggesting that the disease is primarily driven by microbial dysbiosis rather than species loss. Healthy soil was enriched with beneficial Trichoderma, whereas diseased soil was dominated by the pathogen Fusarium, with an abundance 6.7 times higher than that in healthy soil. Network analysis revealed the healthy fungal community was significantly more stable (modularity index: 0.818) than the diseased network (0.4131), where Fusarium occupied a core hub position. Crucially, Trichoderma strains isolated from healthy soil exhibited strong antagonistic activity against Fusarium, with an average inhibition rate exceeding 75%. This study identifies Fusarium as the key pathogen of Goji root rot and native Trichoderma as a potent biocontrol agent, providing a scientific basis for a sustainable, micro-ecological control strategy. Full article

In agroecosystems, bacterial antagonism is an alternative to agrochemicals, which are a threat to the environment and global health. From this perspective, a collection of environmental bacterial isolates was tested for their potential as antagonists against the phytopathogenic bacterium Xanthomonas vesicatoria, which is one of the etiological agents of bacterial spot in tomato and pepper. The isolates with the greatest in vitro antagonistic activity were selected for ex vivo assays using tomato plant leaves and further characterized for their capacity to produce hydrolytic enzymes. The results revealed promising prospects for an antagonism-based X. vesicatoria biocontrol against bacterial spot disease, thus favouring more sustainable agricultural production. Full article

This study investigates the range of secondary metabolites with antifungal activity produced by bacterial strains that have been previously characterised as antagonistic strains to phytopathogenic fungi. The properties of ten strains were analyzed in silico through functional genomic analysis and in vitro by mass spectrometry. The research has demonstrated that Bacillus and Paenibacillus strains possess diverse gene clusters for biosynthesis of secondary metabolites, including peptides and polyketides. Mass spectrometry analysis confirmed the synthesis of key antimicrobial peptides, such as surfactin, fengycin, macrolactin, and fusaricidin, which are associated with antifungal activity. These strains have been observed to exhibit robust antagonism against phytopathogenic fungi—the diameter of the inhibition zones for the presented strains was at least 20 mm. This feature highlights their potential as biocontrol agents. The presence of numerous uncharacterized gene clusters suggests the possibility of discovering previously undescribed bioactive compounds. Full article

Bacterial diseases cause significant economic losses and pose a major challenge to global crop yields. These diseases reduce yields and affect food security, particularly for small-scale farmers in developing regions. Post-harvest losses also contribute to resource waste, soil degradation, and deforestation. Conventional management strategies, such as synthetic fungicides and antimicrobials, raise concerns about environmental sustainability, human health, and pathogen resistance. Bacteriophages—viruses that selectively infect bacterial pathogens—offer a highly specific and eco-friendly alternative for disease management both post-harvest and pre-harvest, reducing the need for chemical pesticides throughout the plant lifecycle. This review examines bacteriophage biology, advantages over traditional treatments, and challenges to their application. Phages effectively target pathogens such as Pectobacterium, Xanthomonas, Xylella, Clavibacter, and Dickeya, while preserving beneficial microorganisms. Key challenges include bacterial resistance, regulatory hurdles, and phage stability under environmental conditions. Advances in phage genomics, bioengineering, and formulation have enhanced viability and efficacy, supporting phages as promising biocontrol agents. Integrating phage therapy with other eco-friendly strategies may improve effectiveness further. Future research should focus on optimizing production, refining regulations, and large-scale field studies to ensure practical feasibility. Addressing these issues will help bacteriophages contribute significantly to sustainable plant disease management and global food security. Full article

Trichoderma aggressivum f. aggressivum is a major pathogen responsible for the green mould disease in Agaricus bisporus, causing significant yield losses. This study evaluated the effects of native bacterial strains as biocontrol agents against T. aggressivum f. aggressivum in the cultivation of Agaricus bisporus. Bacterial strains were collected from mushroom caps and screened for plant growth-promoting traits, including siderophore production, phosphate solubilisation, indole-3-acetic acid synthesis, chitinolytic, and proteolytic activities. In vitro antagonism assays identified Pseudomonas chlororaphis (Pl 4/2), Bacillus wiedmannii (Pl 6/1), and Bacillus cereus (Pl 5/2) as the most promising candidates. In vivo assays under controlled compost conditions revealed that Pl 5/2 significantly enhanced mycelial growth in A. bisporus. Field trials have confirmed its strong biocontrol potential, with disease severity reductions comparable to the fungicide Prochloraz. Furthermore, Pl 5/2 markedly increased the mushroom yield and the improved cap number and weight in A. bisporus. These results demonstrate the dual functionality of B. cereus Pl 5/2 in suppressing green mould and promoting yield, supporting its potential integration into sustainable, chemical-free mushroom production systems. Full article

Grifola frondosa is a rare fungus valued for its nutritional and medicinal properties; however, its bacterial spot disease has been largely overlooked. Thus, this study systematically investigated, isolated, and identified the pathogen and evaluated control strategies for bacterial spot disease affecting G. frondosa cultivation in Qingyuan County, Zhejiang Province. Through integrated morphological, physiological and biochemical analysis, and multi-locus phylogenetic analyses (16S rRNA, gyrB), Priestia aryabhattai was identified as the causal pathogen. This pathogen exhibited host specificity, infecting only G. frondosa and Pleurotus ostreatus, inducing primordial growth arrest and causing spots on the stipe of mature fruiting bodies. Control assessments revealed significant antimicrobial efficacy for four chemical agents, benziothiazolinone, copper sulfate, ethylicin and tetramycin, three plant extracts, garlic, leek and onion, and two biocontrol strains, Chlorophyllum molybdites and Aspergillus fumigatus. Scanning electron microscopy (SEM) demonstrated that these treatments caused ultrastructural damage to the pathogen’s cells, including membrane shrinkage, depression, and perforation. These findings establish key pathogenic characteristics and provide a scientific foundation for integrated disease management, supporting sustainable G. frondosa cultivation. Full article

Enterohemorrhagic Escherichia coli (EHEC) forms persistent biofilms on meat processing surfaces, posing a significant cross-contamination risk. This study assessed the antagonistic capacity of lactic acid bacteria (LAB) against EHEC under meat-processing-like conditions. Three LAB strains were tested in planktonic co-culture with EHEC at 12 °C, all displaying bactericidal activity. In biofilm assays on stainless steel, LAB reduced EHEC biofilms without affecting their own viability. LAB cell-free supernatants further inhibited EHEC biofilms by 2.6–3.5 log CFU/cm², highlighting the role of secreted antagonistic compounds. Among the tested strains, Pediococcus pentosaceus CRL 2145 showed the strongest effect and was selected for deeper analysis. Fluorescence microscopy confirmed EHEC cell death within mixed biofilms. Proteomic profiling of CRL 2145 under mixed-biofilm conditions revealed 162 differentially expressed proteins, with 156 upregulated. These proteins were mainly associated with metabolism, transcription, translation, and stress response pathways, suggesting a multifactorial inhibitory mechanism involving metabolic dominance, physical competition, and secretion of antagonistic molecules. Overall, this study deepens our understanding of the molecular and physiological aspects of LAB–EHEC interaction. P. pentosaceus CRL 2145 emerges as a promising biocontrol agent that could be applied, alone or with its supernatants, to meat processing surfaces to improve food safety. Proteomic data: ProteomeXchange PXD067300. Full article

miR-71 has been determined to enhance the efficacy of biological control agents against termites. However, it is not clear how miR-71 functions in enhancing the termite control. In this study, we tested the effects of termite miR-71 on the transcriptional and translational profiles of termites via the commercial product miR-71 agomir, and meanwhile developed a cost-effective method using T7 RNA polymerase to synthesize a miR-71 mimic, comparing the effects of the T7-synthesized miR-71 mimic versus the commercial miR-71 agomir on the gene expressions and infection mortality of termites. Comparative bioassays demonstrated that both miR-71 mimic and agomir significantly increased fungus-induced termite mortality with equivalent bioactivity. Mechanistically, transcriptomic and proteomic analyses revealed that commercial miR-71 agomir modulated the expression of defense-related genes, such as hexamerin-1, neuroligin-4, and probable chitinase-10. Meanwhile, RT-qPCR confirmed that T7-synthesized miR-71 mimic induced similar expression changes in the same target genes. Additionally, the dsRNA-mediated silencing of hexamerin-1, neuroligin-4, and probable chitinase-10 made termites more vulnerable to the fungus, respectively. Our study establishes in vitro-transcribed miRNA mimics as potent and cost-effective tools for studying ‘miRNA–mRNA’ interaction, and meanwhile lays the foundation for the microbe-mediated expression of small-RNA mimics in enhancing termite biocontrol. Full article

The promising biocontrol agent Brevibacillus brevis is a broadly dispersed bacterium exhibiting significant antibacterial properties against plant diseases. This study conducted a comprehensive comparative genomic analysis of 25 B. brevis strains to examine their taxonomic classification, genetic diversity, and biocontrol potential. The genome sizes, excluding strain NEB573, varied from 5.95 to 6.73 Mb, with GC content between 47.0% and 47.5%. Notably, strain NEB573 exhibited distinct genomic characteristics based on Average Nucleotide Identity (ANI), digital DNA-DNA hybridisation (dDDH), and phylogenetic analyses, suggesting it may represent a novel Brevibacillus species pending additional phenotypic confirmation. The remaining 24 strains were grouped into six phylogenetic clades. The pan-genome study demonstrated significant genomic flexibility, demonstrating an open architecture with 2855 core gene families (33.08%) and 1699 distinct genes. Functional annotations indicated that unique genes were enriched in tasks related to DNA repair and environmental adaptation, while core genes predominantly participated in amino acid metabolism and transcription. The examination of biosynthetic gene clusters (BGCs) identified multiple antimicrobial compounds, such as gramicidin and tyrocidine, which have been reported to exhibit both antibacterial and antifungal activities, thereby underscoring the broad-spectrum biocontrol potential of B. brevis. These findings endorse the application of biocontrol in sustainable plant disease management and offer novel perspectives on its genetic basis in B. brevis. Future investigations of its metabolic repertoire may unveil novel agro-biotechnological applications. Full article

The emergence of multidrug-resistant (MDR) Proteus mirabilis poses a significant threat in porcine farming and public health, highlighting the need for alternative biocontrol agents. This study aimed to isolate and characterize a lytic bacteriophage with therapeutic potential against MDR P. mirabilis. Using the clinical MDR P. mirabilis strain Pm 07 as host, a bacteriophage, vB_Pmc_P-07 (P-07), was successfully isolated from fecal and sewage samples via an enrichment protocol. Phage P-07 forms plaques surrounded by a distinct translucent “halo,” suggesting the production of depolymerase. It achieved high titers of up to 1.40 × 10⁸ PFU/mL and exhibited a narrow host range, high stability across a broad range of temperatures (40–60 °C) and pH (4–12), as well as considerable anti-biofilm activity. An optimal multiplicity of infection (MOI) of 0.001 was determined. Whole-genome sequencing revealed a linear double-stranded DNA genome of 58,582 bp with a GC content of 46.91%, encoding 63 open reading frames. Crucially, no virulence or antibiotic resistance genes were detected, supporting its safety profile. Phylogenetic analysis classified P-07 within the Casjensviridae family, closely related to phages PM87 and pPM01. These findings indicate that phage P-07 is a novel, safe, and effective lytic phage with strong potential as a biocontrol agent against biofilm-forming MDR P. mirabilis in swine. Full article

The increase in the world population and consequent rise in food demand have led to the extensive use of chemical pesticides, causing environmental and health concerns. In response, biological control methods, particularly those involving microbial agents, have emerged as sustainable alternatives within integrated pest management. This study highlights the potential of Lysinibacillus fusiformis as a biocontrol agent against the dipteran Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), a pest responsible for damaging soft-skinned fruits. Experimental treatments using vegetative cells, spores, and secondary metabolites of L. fusiformis on D. suzukii larvae demonstrated significant larvicidal effects, accompanied by observable changes in gut morphology under microscopy. Moreover, preliminary immunological assays showed the interference of this bacterium with the host immune system. All the results indicate the suitability of L. fusiformis for its possible integration into sustainable agricultural practices, although additional research is required to understand its applicability in the field. Full article

Longya Lily (Lilium brownii var. viridulum) bulb rot, a devastating soil-borne disease caused by Fusarium oxysporum f. sp. lilii (Fol L1-1), severely compromises yield and quality of this economically significant crop. In this study, strain R12 was isolated from the rhizosphere soil of asymptomatic Longya lily plants and identified as Bacillus velezensis. The strain significantly disrupted the spore germination and hyphal morphology of Fol L1-1. In pot experiments, R12 not only effectively suppressed disease development but also promoted plant growth, a trait potentially linked to its indole-3-acetic acid (IAA) production capacity. Genomic analysis revealed a 4,015,523 bp circular chromosome (46.42% GC content) harboring gene clusters for the synthesis of diverse secondary metabolites, including surfactin, fengycin, difficidin, and bacillibactin. These findings highlight the potential of B. velezensis R12 as a biocontrol agent and provide insights into its mechanisms for suppressing phytopathogens and promoting plant growth. Full article

Ten phyllospheric yeast strains were studied for their potential as biocontrol agents against fruit spoilage mould. The efficacy of these yeasts against Botrytis cinerea and Fusarium fujikuroi was assessed using dual-culture, mouth-to-mouth, radial growth inhibition and post-harvest fruit assays. Additionally, their capacity for producing hydrolytic enzymes was examined. Results from the ten yeasts revealed dual culture antagonism ranging from 41% to 63% against B. cinerea and 23% to 48% against F. fujikuroi, along with radial inhibition ranging from 70% to 100% and 47% to 100%, respectively. Additionally, in vitro inhibition through the production of volatile organic compounds (VOCs) varied from 2% to 46% against B. cinerea and 6% to 64% against F. fujikuroi. Overall, Aureobasidium melanogenum J7, Suhomyces pyralidae Y1117, Dekkera anomala V38, and Rhodotorula diarenensis J43 emerged as the best-performing biocontrol yeasts. Volatile organic compounds produced by the four yeasts were also identified and included in fruit bioassays using pears and tomatoes. Various VOCs, including 1-butanol, 3-methylbutanol, and butyric acid, were linked to the antagonistic properties of the selected yeasts. Lastly, the four chosen yeast strains significantly mitigated post-harvest spoilage caused by B. cinerea and F. fujikuroi in pear and tomato fruits, with D. anomala V38 exhibiting the greatest inhibitory activity. These findings underscore a potential sustainable and efficient approach to reducing mould-induced post-harvest spoilage while reducing reliance on synthetic fungicides. Full article