Search Results (569)

Fusarium head blight of cereal, caused by fungi of the genus Fusarium spp., reduces yield and accumulates mycotoxins. The increasing resistance of pathogens to synthetic fungicides encourages the search for natural alternatives. This work aims to determine the chemical composition of essential oils (EOs) of caraway, sage, and pine and to evaluate their antifungal activity against Fusarium graminearum and Fusarium culmorum. The composition of EOs was determined by gas chromatography and gas chromatography–mass spectrometry, and activity was assessed by agar dilution to determine mycelial growth inhibition and EC₅₀, with the effect evaluated by two-way ANOVA. Caraway EO, belonging to the carvone chemotype (carvone 57.57%, limonene 35.86%), had the highest antifungal activity (EC₅₀ = 727 ppm), sage EO (cis-thujone 29.59%, camphor 21.74%) had an average activity (EC₅₀ = 1017 ppm), and pine EO, rich in α-pinene and δ-3-carene, had the lowest activity (EC₅₀ > 3000 ppm). The antifungal activity was determined by the compounds’ chemical nature, not by their amount. Low EO concentrations (125–250 ppm) elicited a biphasic response, promoting mycelial growth (zero effect point ≈ 269–295 ppm); therefore, insufficient dosage could increase the risk of mycotoxin contamination. Carvone-rich caraway EO exhibited the highest antifungal activity among the oils tested and is worthy of further investigation as a potential tool for sustainable control of Fusarium head blight in cereals. Full article

Botrytis cinerea, the causal agent of gray mold or Botrytis rot on many vegetable and fruit crops worldwide, is ranked among the main limiting factors for strawberry production, being able to strongly compromise the quality, shelf life, and commercial value of fruit. UV-C is considered an environmentally friendly strategy for postharvest protection for several commodities. In this regard, this research evaluated the performance of short-wavelength UV-C radiation in reducing postharvest Botrytis decay, extending or maintaining the shelf life and quality of strawberry fruit, and detecting possible negative effects. The topic is of growing interest, as it falls within the strategic priorities of so-called “Green Technologies” to pursue a sustainable agriculture and safe food supply by minimizing fungicide use as much as possible. UV-C exposure (at a rate of 1428 J m⁻²) by means of a UV-C lamp (15 W) at a source distance of 25 cm for just 1 min provided significant reductions (from 41 up to almost 80%) depending on the artificial or natural decay pressure of gray mold caused by B. cinerea on strawberry fruit without phytotoxic effects. Analyses performed under both refrigerated and room-temperature storage conditions at different day intervals showed that postharvest UV-C does not significantly affect key chemical parameters, including the ascorbic acid content, total sugars, pH, and titratable acidity of strawberry fruit. Thus, UV-C exposure for a brief time, especially if combined with a low temperature, can be effectively considered for sustainable protection of strawberry fruit at the postharvest stage, providing a theoretical basis for further elucidation of the action modes for this and other targets, and potential large-scale application. Full article

Hevea brasiliensis (Willd. ex A.Juss.) Müll.Arg., the world’s primary source of natural rubber, faces increasing threats from emerging diseases in tropical cultivation regions. During recent field surveys in Yunnan and Hainan provinces of China, previously uncharacterized brown, water-soaked necrotic lesions were observed on tender stems and leaves of rubber trees. This study aimed to identify the causal pathogen, characterize its biological traits, and evaluate candidate fungicides for disease management. The pathogen was isolated via tissue explant methods and identified through morphological observation combined with multigene phylogenetic analyses based on the internal transcribed spacer (ITS) region, large subunit (LSU) ribosomal DNA, and cytochrome c oxidase subunits I and II (coxI and coxII) sequences. Pathogenicity was rigorously confirmed by fulfilling Koch’s postulates on rubber tree seedlings. The isolates produced spherical to ovoid, papillate sporangia, and phylogenetic reconstruction strongly supported clustering them with Phytopythium vexans. The pathogen grew optimally at 16–31 °C, with growth ceasing at 35 °C. Fungicide sensitivity assays revealed that metalaxyl exhibited the strongest inhibitory activity against mycelial growth, with half-maximal effective concentration (EC₅₀) values as low as 0.04 μg/mL. To our knowledge, this is the first report of P. vexans causing foliar and stem necrosis on H. brasiliensis. These findings provide a theoretical foundation for accurate disease diagnosis, epidemiological surveillance, and the development of effective chemical control strategies for rubber plantations. Full article

Fusarium oxysporum f. sp. lycopersici (Fol) is a destructive soil-borne pathogen responsible for major global losses in tomato production, within a context of increasingly constrained fungicide use in intensive farming systems. Sustainable alternatives to chemical fungicides are urgently needed, and microbial secondary metabolites represent a promising source of antifungal compounds. This study explores the antifungal potential of secondary metabolites produced by a natural isolate of Beauveria bassiana (Bb758) previously reported to exhibit strong biocontrol activity against Fol. LC-HRMS metabolomic profiling revealed a chemically diverse metabolite profile dominated by amino acid-derived compounds, peptides and alkaloids. Purification of the crude extract by column chromatography and reverse-phase HPLC yielded beauvericin and several 2,5-diketopiperazines as the main bioactive constituents. These compounds were identified by NMR and LC-HRMS analyses. The antifungal activity of beauvericin (BEA), cyclo(l-Phe-l-Pro) (CFP) and fractions was evaluated against spore germination and germ tube development of Fol. BEA exhibited dose-dependent but limited activity, showing significant inhibition only at high concentrations (100 μg mL⁻¹). In contrast, CFP showed significantly higher antifungal activity than BEA, inhibiting both germination and germ tube formation at concentrations as low as 10 μg mL⁻¹. These results identify CFP as a promising antifungal compound targeting the early infection stages of Fol and highlight fungal-derived diketopiperazines as candidate molecules for sustainable disease management strategies. Full article

Plasmopara viticola, the causal agent of grapevine downy mildew, is one of the most important pathogens affecting vineyards worldwide. In Italy, the 2023 growing season was among the most critical in recent years, with severe downy mildew outbreaks favored by exceptionally conducive climatic conditions. Proper management minimizes yield losses and reduces reliance on synthetic and copper-based fungicides, thereby mitigating risks for the environment and consumer health. Our research aimed to develop an effective and sustainable biological control strategy based on the application of a beneficial microorganism combined with natural compounds, while reducing copper inputs. Over two years, different biological and integrated control strategies were compared with conventional programs based on synthetic anti-downy mildew fungicides. Overall, the results highlighted the importance of: (i) a preventive approach, involving early-season applications targeting primary inoculum and initial infections; and (ii) an integrated strategy, combining different anti-downy mildew formulations with multiple modes of action. Across two years of field trials, the greatest reduction in disease incidence was achieved with integrated control strategies in which the bioformulate YSY^®, based on the beneficial yeast PT22AV, was applied early in the season, in combination with other commercial formulations based on copper and plant extracts. Full article

Rice (Oryza sativa L.) is one of the world’s major staple foods. However, its production is severely constrained by rice blast disease, caused by Magnaporthe oryzae, which leads to substantial yield losses. Conventional management relies on fungicides and chemical treatments; however, these methods raise concerns regarding the development of pathogen resistance and potential environmental impacts. This study evaluated carrageenan from Hypnea musciformis, collected from the coast of Saint Martin (92°19′21.28″ E and 20°37′38.12″ N), located in the Bay of Bengal, Bangladesh, as a natural plant growth promoter as well as a biocontrol agent. Carrageenan was characterized by high sulfate (19–35%) and galactose (12–18%) contents, with FT-IR confirming characteristic κ-carrageenan functional groups. Application of 15% carrageenan significantly increased the germination of seed (27%), seedling vigor (93%), shoot and root lengths (54% and 47%), and biomass compared with untreated controls. Carrageenan markedly suppressed M. oryzae, inhibiting mycelial growth (83%), reducing conidiogenesis and conidial germination, and decreasing lesion length in detached leaves and potted plants. Treated rice seedlings exhibited improved soluble sugars, photosynthetic pigments, proline, phenolic and flavonoid contents, and enhanced antioxidant enzyme activities such as CAT (catalase) and POD (peroxidase), while lowering oxidative stress markers such as H₂O₂ and MDA (malondialdehyde). These results demonstrate that carrageenan from H. musciformis enhances rice growth and elicits defense responses against rice blast, offering a sustainable and environmentally friendly alternative to chemical-based fungicides for integrated M. oryzae management. Full article

Antimicrobial resistance represents a major global health challenge, highlighting the urgent need for alternative bioactive compounds from natural sources. This study investigated the phytochemical composition and antimicrobial potential of saponin-enriched extracts from the trunk bark of Argania spinosa (L.) Skeels, collected from two contrasting Algerian regions: the coastal area of Stidia (ES) and the Saharan region of Tindouf (ET). Extraction yields were comparable (approximately 12.6%). UHPLC-MS analysis revealed distinct phytochemical profiles, with ES enriched in oleanane-type saponins and flavonoids, whereas ET showed a higher abundance of bayogenin-type derivatives. Key compounds included arganine C, E, and J, as well as catechin and quercetin. Antimicrobial activity was evaluated using agar well diffusion and broth microdilution assays against clinically relevant microorganisms, including the reference strains Staphylococcus aureus and Listeria innocua, together with Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Proteus mirabilis, and Candida albicans. Both extracts exhibited broad-spectrum antimicrobial activity, although ES consistently showed lower Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal, Fungicidal Concentration (MBC)/(MFC) values than ET. MIC values ranged from 25 to 50 mg/mL for ES and from 50 to 100 mg/mL for ET. Synergistic interactions were observed between ES and gentamicin against S. aureus and between both extracts and kanamycin against K. pneumoniae. Membrane permeability assays demonstrated that both extracts increased bacterial membrane permeability, with ET producing a stronger permeabilizing effect. Atomic force microscopy of ES-treated cells revealed marked alterations in bacterial surface morphology, while molecular docking supported strong interactions of mi-saponin B and arganine derivatives with key bacterial targets. Collectively, these findings highlight the potential of A. spinosa bark saponins as natural antimicrobial agents and promising antibiotic adjuvants against multidrug-resistant pathogens. Full article

This study aimed to identify the volatile organic compounds (VOCs) present in the essential oil (EO) of Schinus lentiscifolia and to evaluate the effect of chitosan coatings (1%) enriched with EO of S. lentiscifolia (1000, 2000, and 4000 mg L⁻¹) on the control of Penicillium sp. and on the quality of ‘Fuji’ apples. The EO was extracted from S. lentiscifolia collected in the municipality of Lages, Santa Catarina State, Brazil, in March, May, and November 2022. The antifungal activity of S. lentiscifolia EO against Penicillium sp. was evaluated in vitro. Apples were stored under refrigerated conditions (0 ± 0.5 °C; 90 ± 5% RH) for 30 days and subsequently under ambient conditions (23 ± 3 °C; 70 ± 5% RH) for 5 days. A total of 14 VOCs were identified in the EO of S. lentiscifolia, with the monoterpenes β-pinene (34.68%) and α-pinene (30.61%) as the major compounds, followed by γ-terpinene (10.13%), camphene (9.66%), and o-cymene (7.14%). The application of chitosan coating with S. lentiscifolia EO (2000 mg L⁻¹) reduced the severity of blue mold in ‘Fuji’ apples by 88.1% during refrigerated storage and by 69.2% under ambient conditions. Ethylene production by the apples was also reduced when treated with chitosan and EO. No influence of the treatments was observed on fruit quality attributes. The postharvest application of chitosan coatings combined with S. lentiscifolia EO reduces disease caused by Penicillium sp. in ‘Fuji’ apples without affecting fruit quality. Full article

The use of natural products as alternatives to synthetic fungicides has gained increasing importance in crop protection. Among these, clove (Syzygium aromaticum) and its active compound, eugenol, are well known for their antifungal properties. However, it remains unclear whether the antifungal activity of clove is primarily driven by its major constituent, eugenol, or whether the whole essential oil exhibits greater or synergistic efficacy. Addressing this question is crucial for optimizing their application as biofungicidal agents; The chemical composition of clove essential oil was characterized using gas chromatography–flame ionization detection (GC-FID) and gas chromatography–mass spectrometry(GC-MS). The antifungal activity of the essential oil and pure eugenol (300 µg/mL) was evaluated in vitro against Botryotinia fuckeliana, Rhizoctonia solani, and Verticillium dahliae on potato dextrose agar (PDA). Mycelial growth inhibition was quantified, and data were analyzed using two-way analysis of variance (ANOVA) followed by Tukey’s honestly significant difference (HSD) test (α = 0.05); Eugenol exhibited higher antifungal activity than the essential oil across all tested species. V. dahliae was completely inhibited (100%) by eugenol, while the essential oil showed lower efficacy. Despite the high eugenol content (87.3%) in the oil, its reduced activity suggests that minor constituents may modulate overall antifungal performance. These findings demonstrate that eugenol is more effective than clove essential oil as an antifungal agent. This highlights that the biological activity of clove is largely driven by its major active component, providing key insights for the development of more efficient biofungicidal strategies. Full article

Phytopathogenic fungi cause major agricultural losses worldwide. Their control relies largely on synthetic fungicides, which raise concerns related to environmental impact, resistance development, and human health. Botanical extracts represent a promising, sustainable alternative, and members of the Brassicaceae family are recognized as rich sources of antifungal metabolites. In this study, the antifungal activity of ethanol extracts from Brassica napus and Capsella bursa-pastoris was evaluated against Botrytis cinerea, Colletotrichum acutatum, and Fusarium oxysporum, which are major phytopathogens widely recognized for causing significant diseases in diverse commercial crops worldwide. Antifungal effects on mycelial radial growth and conidial production were assessed in vitro using the amended culture medium assay. Extracts were chemically characterized by LC-DAD-ESI-MS, and a single-Y orthogonal partial least squares (OPLS) analysis was applied to integrate chemical and bioactivity data to identify metabolites associated with antifungal activity. Test botanical extracts showed organ- and pathogen-dependent antifungal activity. B. napus was more active, as seeds reduced B. cinerea growth, and roots strongly suppressed conidiation and inhibited F. oxysporum. In contrast, C. bursa-pastoris was less effective, with only the flower and fruit extracts causing modest reductions in F. oxysporum, while the other extracts were largely inactive. Fourteen metabolites were tentatively identified based on UV-Vis and mass spectral data. Among them, one flavanol and two indole-containing compounds were statistically correlated with antifungal activity, were subsequently isolated, and were structurally confirmed by NMR spectroscopy. These compounds (1–3) exhibited reasonable antifungal activity (IC₅₀ < 40 µM). The integrative covariate-based metabolic profiling approach proved operative for identifying bioactive constituents in the test botanical extracts, supporting the potential of Brassicaceae-derived extracts and their metabolites as natural antifungal agents. Full article

Phytophthora species are among the most destructive plant pathogens worldwide, causing severe losses in agricultural, forest, and natural ecosystems. In recent years, the management of Phytophthora diseases has increasingly shifted toward eco-sustainable strategies, with growing interest in plant-derived extracts, particularly essential oils, as low-risk alternatives to synthetic fungicides. In this study, a structured review was combined with new in vitro assays to assess the antifungal activity of essential oils from Thymus vulgaris (TV-EO) and T. serpyllum (TS-EO) against P. cinnamomi, P. drechsleri, P. cactorum, P. citrophthora, P. nicotianae, P. palmivora, and P. infestans. Literature searches were conducted in April 2025 using the Web of Science and Scopus databases, following PRISMA guidelines, with the search term “Thymus” or “Thyme” and “Phytophthora”. Twenty studies included in the review demonstrated that the activity of Thymus essential oils against Phytophthora species was highly variable and shaped by chemotype, Thymus species, pathogen, and experimental setup. Additional in vitro assays further confirmed a clear dose-dependent inhibitory effect for both TV-EO and TS-EO. TS-EO consistently exhibited stronger activity than TV-EO, likely reflecting its carvacrol-rich chemotype, while thymol-based TV-EO showed lower but still significant inhibition depending on the pathogen species. Overall, these results highlight the potential of Thymus essential oils as eco-friendly tools for the management of Phytophthora diseases. However, the strong dependence on chemotype, pathogen species, and assay conditions underscores the need for standardized testing, detailed chemical characterization, and in vivo validation. Full article

Background: Plant essential oils are extensively utilized for their antimicrobial properties; however, the specific antifungal mechanisms of certain compounds are not well characterized. Geraniol, a naturally occurring monoterpene alcohol approved for use in foods, demonstrates potential efficacy against spoilage fungi, yet detailed mechanistic insights are lacking. Methods: In this study, we determined the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of geraniol against P. polonicum. We assessed the underlying mechanisms by evaluating membrane integrity, intracellular leakage, reactive oxygen species (ROS), antioxidant enzymes (superoxide dismutase [SOD], peroxidase [POD], catalase [CAT]), malondialdehyde (MDA) levels, ATP content, and ATPase activity. Inoculated yam slices were exposed to geraniol vapor, and we monitored sensory, physicochemical, enzymatic, and microbial parameters. Results: Geraniol exhibited a minimum inhibitory concentration/minimum fungicidal concentration (MIC/MFC) of 0.3 mL/L. It disrupted cellular membranes, induced leakage, generated ROS, and caused lipid peroxidation, leading to elevated levels of malondialdehyde (MDA). Additionally, geraniol activated antioxidant enzymes and impaired energy metabolism. Fumigation with geraniol dose-dependently delayed the deterioration of yam, reduced weight loss, preserved texture and color, inhibited polyphenol oxidase (PPO) and POD activities, enhanced CAT and SOD activities, lowered MDA levels, and suppressed bacterial growth. Conclusions: Geraniol inhibits P. polonicum through multiple mechanisms, including membrane disruption, oxidative stress, and interference with energy metabolism, thereby effectively preserving the quality of fresh-cut yam and demonstrating potential as a natural preservative. Full article

Aspergillus fungi are a source of low-molecular compounds of various structures possessing biological activities. We investigated the secondary metabolite profile of the soil fungus A. calidoustus VKM F-4916. The strain was found to synthesize new metabolites attributed to furoisocoumarins, which we named asperisocoumarin J and K, and a known siderophore desferritriacetylfusigen. The structure of asperisocoumarin J and K were determined by mass spectrometry and NMR spectroscopy. Asperisocoumarins J, K and desferritriacetylfusigen possessed a phytotoxicity, inhibiting the lettuce root growth. Sow thistle leaf and wheat leaf cuttings were sensitive to the action of asperisocoumarin J and K at a concentration of 5 mg/mL. Analysis of the structures of furoisocoumarins (asperisocoumarins J and K) using the online resource Pesti-DGI-Net showed that compounds had the physico-chemical properties favorable for pesticide development, in particular, fungicides and herbicides. An in-depth study of the phytotoxic properties of furoisocoumarins and their natural analogs is of interest in the context of the search for new herbicide compounds. Full article

Botrytis cinerea is a major phytopathogen responsible for significant postharvest losses in plant-derived foods. The increasing resistance to synthetic fungicides has driven the search for sustainable alternatives, including enzyme-based biofungicides. In this study, the proteolytic fraction P1G10 from Vasconcellea pubescens latex was encapsulated in an alginate–chitosan (ALG-CS) matrix to improve its stability and antifungal performance. The encapsulated formulation (ALG-CS-P1G10) retained ~95% enzymatic activity after 8 h under stress conditions (37 °C, 1350 lux), compared with 67% for the free enzyme. In vitro assays demonstrated a dose-dependent inhibition of B. cinerea growth, with an IC₅₀ value of ~11 mg/mL determined using a logistic model. At this concentration, the formulation reduced fungal adhesion by more than 80% and increased sensitivity to cell wall-disrupting agents (Congo Red and Calcofluor White), pointing to alterations in cell wall integrity. Importantly, the encapsulated system provided a more stable and sustained antifungal effect, consistent with a controlled-release mechanism. These results demonstrate that coupling enzyme stabilization with controlled release can improve the functional performance of protease-based antifungal systems, offering a promising strategy for the development of biofungicides in postharvest applications. Full article

Plant hormones and their synthetic analogueues offer sustainable alternatives for crop protection, yet the direct antifungal activity of strigolactone (SL) and its analogues against necrotrophic pathogens remain largely unexplored. Here, we screened eight phytohormones and related analogues for treatments of Botrytis cinerea and identified the SL analogue rac-GR24 (racemic GR24) as a concentration-dependent growth inhibitor active at low micromolar concentrations. Given the stereochemical complexity of SLs and their analogues, we evaluated multiple enantiopure isomers and found that ent-5DS and GR24^ent-5DS, which differ in configuration from natural SLs, exhibited the strongest inhibitory activity. This stereospecific response was further validated using another filamentous fungus, Sclerotinia sclerotiorum, which displayed an identical susceptibility profile. Combinatorial treatments with enantiopure isomers and double-concentration rac-GR24 revealed that the antifungal effect of the racemate is primarily attributable to the GR24^ent-5DS enantiomer, whereas the opposite enantiomer GR24^5DS is almost inactive. Collectively, our findings uncover a stereospecific response in fungal pathogens, demonstrating that B. cinerea and S. sclerotiorum respond to exogenous SL analogues in a chirally selective manner. This work establishes a stereochemically defined framework for developing enantioselective fungicidal agents with potential applications in sustainable agriculture. Full article