Search Results (530)

This review explores the innovative approaches in the development of next-generation biopesticides, focusing on molecular and microbial strategies for effective control of fungal plant pathogens. As agricultural practices increasingly seek sustainable solutions to combat plant diseases, biopesticides have emerged as a promising alternative to chemical pesticides, offering reduced environmental impact and enhanced safety for non-target organisms. The review begins by outlining the critical role of fungal pathogens in global agriculture, emphasizing the need for novel control methods that can mitigate their detrimental effects on crop yields. Key molecular strategies discussed include the use of genetic engineering to enhance the efficacy of biopesticides, the application of RNA interference (RNAi) techniques to target specific fungal genes, and the development of bioactive compounds derived from natural sources. Additionally, this review highlights the potential of microbial agents, such as beneficial bacteria and fungi, in establishing biocontrol mechanisms that promote plant health and resilience. Through a comprehensive review of recent studies and advancements in the field, this manuscript illustrates how integrating molecular and microbial strategies can lead to the development of effective biopesticides tailored to combat specific fungal threats. The implications of these strategies for sustainable agriculture are discussed, alongside the challenges and future directions for research and implementation. Ultimately, this review aims to provide a thorough understanding of the transformative potential of next-generation biopesticides in the fight against fungal plant pathogens, contributing to the broader goal of sustainable food production. Full article

The Orthoflavivirus genus includes a variety of human-pathogenic, mosquito-borne flaviviruses (MBFs) including dengue, Zika, and West Nile viruses, which pose significant global public health threats. Insect-specific flaviviruses (ISFs) are another group within the genus that exclusively replicate in mosquitoes and are incapable of infecting vertebrates. ISFs have recently attracted growing research interest due to their potential applications in vaccine development. In addition, multiple studies have demonstrated that prior infection with ISFs such as Palm Creek virus and Binjari virus can suppress subsequent infection with human-pathogenic MBFs. This phenomenon, known as superinfection exclusion (SIE), opens the avenue for the potential applications of ISFs in MBF transmission control. This prompted a growing number of studies into ISFs and their interactions with MBFs in mosquito hosts. In this review, we provide an overview on ISFs, with a particular emphasis on the capacity of different ISFs to cause SIE, the current insights into the mechanisms of this phenomenon, and the potential use of ISFs in the SIE-based biocontrol strategies. Full article

Bacillus velezensis strain G2T39 is an endophytic bacterium previously isolated from Crotalaria retusa L., with evidenced biocontrol activity against Fusarium oxysporum f. sp. Cubense and Fusarium graminearum. In this study, it was shown that this strain also exhibited biocontrol activity against Colletotrichum gloeosporioides and Fusarium oxysporum f. sp. Vasinfectum, two important crop pathogens in tropical zones. Comprehensive phylogenetic and genomic analyses were performed to further characterize this strain. The genome of B. velezensis G2T39 consists of a single circular chromosome of 4,040,830 base pairs, with an average guanine–cytosine (GC) content of 46.35%. Both whole-genome-based phylogeny and average nucleotide identity (ANI) confirmed its identity as B. velezensis, being closely related to biocontrol and plant growth promotion Gram-positive model strains such as B. velezensis FZB42. Whole-genome annotation revealed 216 carbohydrate-active enzymes and 14 gene clusters responsible for secondary metabolite production, including surfactin, macrolactin, bacillaene, fengycin, bacillibactin, bacilysin, and difficidin. Genes involved in plant defense mechanisms were also identified. Additionally, G2T39 genome harbors multiple plant growth-promoting traits, such as genes associated with nitrogen metabolism (nifU, nifS, nifB, fixB, glnK) and a putative phosphate metabolism system (phyC, pst glpQA, ugpB, ugpC). Additional genes linked to biofilm formation, zinc solubilization, stress tolerance, siderophore production and regulation, nitrate reduction, riboflavin and nicotinamide synthesis, lactate metabolism, and homeostasis of potassium and magnesium were also identified. These findings highlight the genetic basis underlying the biocontrol capacity and plant growth-promoting properties of B. velezensis G2T39 and support its potential application as a sustainable bioinoculant in agriculture. Full article

Debaryomyces hansenii, a yeast that plays an important role in several agri-food processes, is increasingly being investigated as a biological protection factor against fruit and grain pathogens because of its ability to inhibit the growth of unwanted microorganisms. Biological plant protection can be used as an alternative to pesticides, which cannot be used in organic farming. The mechanism of action associated with the biocontrol capacity of D. hansenii against Fusarium graminearum, the agent of Fusarium head blight in wheat, and its involvement in induced plant defense were studied in Triticum turgidum ssp. durum on the mRNA level. A total of 3432 differentially expressed genes (DEGs) of T. turgidum ssp. durum were identified by using RNA-Seq analysis in a sample primed with D. hansenii before pathogen application in comparison to a non-protected sample. Upregulated DEGs encode the proteins involved in cell wall biosynthesis and their modification, photosynthesis, secondary metabolism, and cytoskeleton organization. Among the DEGs, candidate transcription factors as well as protein kinases involved in the signal transduction activated by D. hansenii were also shown. Priming durum wheat seedlings with D. hansenii leads to enhancing the cell wall structure, which increases plant resistance to fungal infection. Full article

This study aimed to isolate and characterize native Trichoderma species from soils with low anthropogenic activity in the central Peruvian rainforest and evaluate their antagonistic mechanisms against Botrytis cinerea, the causal agent of gray mold and a model polyphagous pathogen. Twenty Trichoderma isolates were evaluated using inhibition assays, a quantitative assessment of mycoparasitism, and endophytic colonization tests in Capsicum baccatum. Ten isolates with promising antifungal activity were identified at the molecular level, revealing T. azadirachtae and T. anisohamatum as the first reports for Peru. Several strains showed a remarkable capacity for root colonization, and in vitro antagonistic activity reached maximum values of approximately 65%. These findings highlight the functional and phylogenetic diversity of Trichoderma strains from Peruvian rainforest soils and support their potential as sustainable biocontrol agents against B. cinerea. Full article

Background/Objectives: Fungi produce a diverse array of metabolites, including various volatile organic compounds (VOCs) with known physiological functions and other biological activities. These metabolites hold significant potential for medical and industrial applications. Within the fungal domain, Penicillium species represent a particularly important group. Methods: This study characterized the VOC profiles of four Penicillium expansum strains (R11, R19, R21, and R27) and one Penicillium polonicum strain (RS1) using the solid-phase microextraction–gas chromatography–mass spectrometry technique. Results: The analysis revealed that the only compound in common among the five strains of Penicillium was phenyl ethanol. The high toxicity of P. polonicum RS1 to Drosophila larvae correlated with its diverse and abundant alkene production. Specifically, alkenes constituted 31.28% of its total VOCs, followed by alcohols at 29.13%. GC-MS analyses detected 22, 17, 22, and 18 specific VOCs from R11, R19, R21, and R27, respectively. Overall, alkenes dominated the R11 profile (17.03%), alcohols were most abundant in R19 (28.82%), and R21 showed the highest combined release of alcohols (23.2%) and alkenes (11.7%), while R27 produced a moderate abundance of alcohols (9.16%) and alkenes (4.19%). Among the P. expansum strains, R11, R21, and R27 exhibited substantially higher toxicity than R19 strain in our previous assessment; these findings are consistent with their respective VOC profiles. Conclusions: The distinct VOC compositions across Penicillium strains significantly influence their biological characteristics and ecological functions. These findings provide a basis for follow-up research into the mechanisms of fungal volatile-mediated toxicity and support the development of biocontrol strategies. Full article

Continuous monoculture of Panax notoginseng leads to severe replant disease, yet the mechanisms by which root exudates mediate rhizosphere microbiome assembly and pathogen enrichment remain poorly understood. Here, we demonstrate that long-term root exudate accumulation acts as an ecological filter, driving the fungal community toward a phylogenetically impoverished, pathogen-dominated state. Specifically, exudates enriched the soil-borne pathogen Fusarium while reducing the abundance of potentially antagonistic fungi. In contrast, bacterial communities exhibited higher resilience, with exudates selectively enriching oligotrophic taxa such as Terrimonas and MND1, but suppressing nitrifying bacteria (e.g., Nitrospira) and plant-growth-promoting rhizobacteria (PGPR). Microbial functional profiling revealed a shift in nitrogen cycling, characterized by suppressed nitrification and enhanced nitrate reduction. Crucially, co-occurrence network analysis identified bacterial taxa strongly negatively correlated with Fusarium, providing a synthetic community blueprint for biocontrol strategies. Our study establishes a mechanistic link between root exudate accumulation and negative plant–soil feedback in monoculture systems, highlighting microbiome reprogramming as a key driver of replant disease. These insights offer novel avenues for manipulating rhizosphere microbiomes to sustain crop productivity in intensive agricultural systems. Full article

Anthracnose caused by Colletotrichum graminicola (Ces.) G.W.Wils is a significant disease of maize (Zea mays) worldwide. To obtain an efficient biocontrol strain and elucidate its mechanisms, 103 bacterial isolates were obtained from soil samples collected in the Tianshan Mountains, Xinjiang, China. Among these, Bacillus atrophaeus F4’s fermentation broth had the highest efficacy in controlling maize anthracnose, reaching 79.78%. To further investigate biocontrol mechanisms of F4 strain, its complete genome was sequenced, assembled, and annotated. Lipopeptides extracted from the fermentation broth of F4 were found to strongly inhibit the growth of hyphae and the germination of conidia in the pathogen. Microscopic and biochemical analyses indicated that the lipopeptide extract inhibited chitin synthesis and disrupted the integrity of the cell wall and membrane, thereby exerting antifungal effects. Further MALDI-TOF MS analysis identified antimicrobial compounds, including surfactin, iturin, and fengycin B, in the lipopeptide extract. Furthermore, plate antagonistic test showed that F4 strain exhibited broad-spectrum antagonistic activity against multiple plant pathogenic fungi. F4 strain also displayed motility, biofilm-forming capacity, and the ability to produce extracellular enzymes such as proteases and amylases, which are associated with biocontrol activity. These findings suggest the significant potential of B. atrophaeus F4 as a biocontrol agent against maize anthracnose. Full article

Burkholderia is a metabolically versatile genus of Gram-negative bacteria that inhabits niches ranging from soil and water to plants and clinical environments. This review provides an integrated examination of Burkholderia species, focusing on their dual roles as both pathogens and beneficial microorganisms. Key pathogenic species, such as members of the Burkholderia cepacia complex and the Burkholderia pseudomallei group, pose significant threats to human, animal, and plant health due to their intrinsic antibiotic resistance and diverse virulence factors. Conversely, several environmental and plant-associated Burkholderia species promote plant growth, enhance nutrient uptake, and serve as biocontrol agents, supporting sustainable agriculture. We synthesize current knowledge across taxonomy, genomics, pathogenicity, beneficial interactions, and secondary metabolite biosynthesis—including the prolific production of antibiotics, toxins, and volatile organic compounds with pharmaceutical and agricultural potential. Advances in high-throughput genomics are revealing substantial genetic diversity, genome plasticity, and mechanisms underlying both pathogenicity and beneficial traits. Clarifying this dual nature and identifying strategies to mitigate risks will guide the safe and effective exploitation of Burkholderia in medicine, agriculture, and biotechnology. Full article

Liquid chromatography–mass spectrometry analysis of Pseudomonas chlororaphis subsp. phenazini S1Bt23 extracts detected phenazine-1-carboxylic acid (PCA) and 2-hydroxyphenazine (2-OH-PHZ) as the main phenazine derivatives. We investigated their relative contributions to the antagonistic activity of strain S1Bt23 against Pythium arrhenomanes, a root rot pathogen of corn. CRISPR-Cas9 knockouts were carried out on the phzF gene, required for PCA synthesis, and the phzO gene, which is involved in converting PCA to 2-OH-PHZ. Deletion of the phzF gene abrogated the production of PCA and 2-OH-PHZ, and the ΔphzF mutant lost the antagonism against Pythium arrhenomanes. In contrast, deletion of the phzO gene created a 2-OH-PHZ-negative mutant with intact antagonistic ability. Concordantly, S1Bt23 wild type and the ΔphzO mutant, but not the ΔphzF mutant, significantly bioprotected corn seeds of a susceptible inbred variety, CO441, from P. arrhenomanes. At equimolar amounts of 75 nM, synthetic PCA inhibited Pythium growth, whereas 2-OH-PHZ did not. This highlights the critical contribution of PCA to the biocontrol activity of strain S1Bt23 against P. arrhenomanes. Unexpectedly, deletion of phzO did not result in additional PCA accumulation. This suggests that the conversion of PCA to 2-OH-PHZ by S1Bt23 is a potential protective mechanism against the overproduction of lethal cellular doses. This study paves the way for bioengineering strain S1Bt23 into a more effective biopesticide. Full article

Zearalenone (ZEN) poses serious risks to human and animal health. Compared with physical and chemical methods, microbial transformation offers a safer and more sustainable strategy for ZEN detoxification. The yeast Hannaella zeae, isolated from the Qinghai–Tibet Plateau, showed the highest ZEN removal efficiency among 11 strains, achieving an 85.87% transformation rate within 36 h. Optimal conditions for ZEN transformation were determined by varying culture time, temperature, and pH. The products were putatively identified as zearalenone-14-β-D-glucopyranoside (C₂₄H₃₂O₁₀) and zearalenone-16-β-D-glucopyranoside (C₂₄H₃₂O₁₀) by UHPLC-Q-Orbitrap-HRMS. The safety of the mixed culture medium extract was further evaluated using a Caenorhabditis elegans model, showing significantly lower toxicity than untreated ZEN. H. zeae maintained high transformation efficiency under low temperature (57.48%) and acidic stress (47.10%), supported by active antioxidant enzymes (SOD, CAT, APX, GPx) and stress metabolites (trehalose, proline). Overall, this study identifies H. zeae as a promising, stress-tolerant biocontrol agent and elucidates its glycosylation-based detoxification mechanism, providing a foundation for future application in real food and feed systems. Full article

Cyst nematodes are persistent soilborne pests that severely impact crop productivity worldwide. Their protective cysts enable long-term survival and host diverse fungal communities that remain largely unexplored as potential sources of biological control agents. In this study, we isolated culturable fungi from cysts of Globodera, Heterodera, and Punctodera, as well as from soils collected across Swiss potato fields between 2018 and 2024. Sequencing identified 78 fungal operational taxonomic units (OTUs), predominantly belonging to Ascomycota (73%), mainly Sordariomycetes (59%) and Eurotiomycetes (8%), with additional representatives from Mortierellomycota and Basidiomycota. Fusarium was the most abundant genus, followed by Clonostachys, Chaetomium, and Pochonia, while 28% of isolates remained unclassified, indicating potentially novel taxa. Selected fungi, including Orbilia brochopaga CH-02, Clonostachys rosea CH-04 and CH-15, and Pochonia chlamydosporia CH-51, significantly reduced motility, infection and root galling of Meloidogyne incognita in vitro and in planta. Notably, CH-02 reduced root galling by 63%, highlighting its strong mechanical and antagonistic activity. These results demonstrate that cyst nematodes harbor a rich and functionally diverse fungal community with substantial biocontrol potential, providing a foundation for developing sustainable and environmentally friendly alternatives to chemical nematicides in crop protection. Full article

The rapid spread of the invasive blue crab (Callinectes sapidus) in Mediterranean coastal ecosystems poses ecological and socio-economic challenges, highlighting the need to explore natural control mechanisms. We conducted controlled aquarium experiments to assess the functional size preference and feeding rates of two native Mediterranean predators: the common octopus (Octopus vulgaris) and the loggerhead sea turtle (Caretta caretta). Two sets of trials were performed: (1) size preference experiments, in which individual predators were simultaneously offered crabs of varying sizes; and (2) ad libitum feeding experiments to estimate daily consumption rates. Octopuses consumed only the soft tissues biomass (STB, ~54% of total crab biomass), reaching maximum intake rates of 454 ± 71 gWW·d⁻¹ in adult individuals. Sea turtles ingested whole crabs, including the exoskeleton, with total consumption rates up to 815 ± 592 gWW·d⁻¹ of total biomass (TB) in adults. Subadult octopuses exhibited shorter handling times for small crabs, although neither predator showed a statistically significant size preference. Our findings indicate that both predators can consume substantial amounts of blue crab biomass, but O. vulgaris—due to its higher feeding efficiency and ecological abundance—might play a more prominent role as a natural biocontrol agent. These results provide valuable insights for integrated management strategies aimed at mitigating the ecological impact of C. sapidus in the Mediterranean. Full article

The rhizosphere is a dynamic microenvironment where plants interact with diverse native microbial communities that significantly influence growth, health, and resilience. Among plant-growth-promoting rhizobacteria, Bacillus subtilis stands out as a multifunctional species with exceptional ability to colonize plant roots, form robust biofilm, and confer protection against diseases. Its resilience as a spore-former, genetic ability to produce active compounds such as antibiotics, and phytohormones make it a valuable species for agriculture and forest sustainability. This review reveals the molecular and physiological mechanisms underlying B. subtilis interactions with plants, focusing on biofilm formation, root colonization, biocontrol and disease suppression, and promotion of plant growth. We further examine its role in root colonization, which triggers extensive reprogramming of plant gene expression, thereby integrating growth promotion with enhanced immune competence through a network that regulates plant-beneficial traits. Its genomic regulation supports colonization, stress tolerance, and immune support, while synergistic interactions with other microbes highlight its adaptability. As a versatile bio-fertilizer and biocontrol agent, further study of its strain-specific traits and rhizosphere interactions is key to maximizing its role in sustainable agriculture and forest control under environmental changes. Full article

Root-knot nematodes (RKNs), Meloidogyne spp., are the most economically important plant parasites with a worldwide distribution and a very wide host spectrum. The use of rhizobacteria for biocontrol has seen a marked increase in recent years, with particular emphasis on members of the Bacillaceae family in Brazil. This work reports on five years of experience using Bacillus-based products as nematicides, including both commercial and experimental formulations. Trials on cotton (200–300 mL/100 kg of seeds) against M. incognita race 3 produced inconsistent results: one trial achieved approximately 50% control, while another showed no significant effect. In soybean, Bacillus-based biological products (200–300 mL/100 kg) were able to reduce the final population of M. javanica and M. incognita by an average of approximately 30%, although in some cases, no effect was observed. The use of different doses of a product containing the RTI 545 strain (B. thuringiensis) resulted in control efficiencies of approximately 60–80% at a dose of 500 mL/100 kg, when applied as a seed treatment in soybean. This dose is too high to employ in field conditions. In tomato crop, strain S2538 of Priestia aryabhattai and strain RTI 545 (150 mL/100 kg) reduced the final population of M. incognita by 45–50%, confirming the results obtained in previous trials. Additionally, microscopic observations of Bacillus spp. against Meloidogyne spp. in soybean were made during histopathological studies. The bacteria were found to colonize root tissues early, including the cortex and vascular cylinder, probably producing chemical compounds and later disrupting giant cells. This microscopic observation suggests a mechanism aligned with induced resistance. Currently, biological products must be used in integrated management, such as resistant varieties, crop rotation, and other agronomic practices that aim to balance the physical, chemical and biological conditions of soils. Full article