Search Results (1,314)

Tea plantations of the Northeastern Himalayan region of India represent major tea-producing landscapes and support a large workforce. Their warm, humid climate, dense vegetation, and intensive processing activities generate diverse bioaerosols, including pollen, fungal spores, bacteria, and organic dust, with potential occupational respiratory health implications. This review synthesizes evidence on the aerobiological characteristics of tea-growing ecosystems and their association with respiratory allergy and other occupational respiratory disorders among tea workers. Literature from India and other major tea-producing regions was critically evaluated, focusing on the diversity, seasonal dynamics, and environmental determinants of airborne pollen and fungal spores, particularly in Assam, Darjeeling, Dooars, Terai, and adjoining Himalayan tea-growing areas. Fungal genera including Cladosporium, Aspergillus, Penicillium, Alternaria, and Curvularia, along with allergenic pollen from grasses, weeds, and surrounding vegetation, frequently constitute important components of the bioaerosol burden. Their abundance varies with temperature, humidity, rainfall, wind, and seasonal vegetation. Processing environments may further increase exposure through respirable tea dust and “tea fluff.” Available evidence from tea-worker studies indicates respiratory symptoms, ventilatory impairment, and allergic or sensitization responses associated with occupational tea-related exposures. However, direct evidence linking specific airborne pollen or fungal taxa detected in tea-growing environments to specific respiratory outcomes in tea workers remains limited. The available literature therefore supports a distinction between direct aerobiological observations, occupational exposure evidence, and clinical evidence, rather than assuming a direct exposure–disease relationship and highlights the need for standardized monitoring, respiratory health surveillance, engineering controls, and evidence-based workplace policies. Full article

Understanding the overwintering patterns of Colletotrichum spp. is important for managing walnut anthracnose. This exploratory study integrated traditional tissue isolation with high-throughput sequencing (HTS) to describe the pathogen’s overwintering distribution across four orchards in Hubei Province. Buds, twigs, fallen leaves, and mummified fruits were sampled in January (late dormancy) and March (pre-budbreak), with five trees pooled into composite samples per tissue–orchard–month combination. Traditional isolation identified buds and fallen leaves as tissues with higher recovery rates, frequently exceeding 70% in March. HTS revealed a more complex community composition, with Ascomycota dominance and Fusarium, Alternaria, and Colletotrichum as co-dominant genera. Notably, the HTS-detected relative abundance of Colletotrichum reached 40.19% in mummified fruits at one orchard; however, because HTS cannot distinguish viable from non-viable organisms, this should be interpreted as a potential DNA signal rather than a confirmed epidemiological reservoir. The two methods showed qualitatively different patterns across tissues, underscoring that traditional isolation detects the culturable fraction whereas HTS captures total DNA, which may include DNA from non-viable or non-culturable sources. These descriptive findings elucidate candidate overwintering niches and temporal differences between January and March, providing a preliminary basis for future hypothesis-driven studies. We suggest that integrated analysis of the culturable and DNA-detected fractions may improve disease risk assessment, pending experimental validation. Full article

Background: Sustainable strategies to control fungal diseases are urgently needed due to the environmental and human health impacts of conventional fungicides and the rise in fungicide resistance. Ferroptosis modulation, an iron-dependent programmed cell death, could represent an alternative strategy for crop protection, although its potential for fungal disease management remains largely unexplored. Methods: The aim of this study was to run preliminary screening assays, identify plant extracts and natural products with requested chemical properties for ferroptosis inhibition, and evaluate their ability to limit Alternaria brassicicola infection. Results: The CAT-based screening of 165 plant extracts led to the identification of several antioxidant-active extracts, including Garcinia amplexicaulis (G. amplexicaulis) (bark, DCM), Garcinia kola (G. kola) (nut, DCM), Magnolia sieboldii (M. sieboldii) (leaf, MeOH) and G. amplexicaulis (leaf, MeOH). The major constituents, δ-amplexichromanol, δ-garcinoic acid, sieboldin and (−)-epicatechin, found in the most active fractions from these extracts displayed CAT activities comparable to those of the synthetic ferroptosis inhibitors ferrostatin-1 and phenoxazine. Among these compounds, δ-amplexichromanol showed detectable in vitro inhibitory activity against A. brassicicola and significantly reduced lesion development in planta, with an efficacy comparable to ferrostatin-1 and phenoxazine. The antifungal activity of G. amplexicaulis (leaf, MeOH) observed in vitro was also confirmed in planta. Conclusions: these findings highlighted δ-amplexichromanol and G. amplexicaulis (leaf, MeOH) as candidates for further investigation and supported the potential of CAT-based antioxidant screening to prioritize plant extracts for subsequent evaluation against A. brassicicola. Full article

Fungal endophytes are important components of plant-associated fungal communities and have considerable potential for agricultural and biotechnological applications. This study evaluated basil leaf agar (BLA), formulated using dried basil leaves as a nutrient source, as an alternative culture medium for the isolation of endophytic fungi from Ocimum basilicum. Endophytic fungi were isolated using BLA and potato dextrose agar (PDA) and identified based on morphological characteristics and internal transcribed spacer (ITS) rDNA sequence analysis. Eight fungal species, Alternaria alternata NZ01, Cladosporium halotolerans NZ02, Curvularia lunata NZ03, Diaporthe stewartii NZ04, Epicoccum sorghinum NZ05, Penicillium chrysogenum NZ06, Phyllosticta capitalensis NZ07, and Quambalaria cyanescens NZ08, were identified on BLA, whereas six species were recovered on PDA from the same tissue, with D. stewartii NZ04 and P. capitalensis NZ07 not detected on PDA. The two species D. stewartii NZ04, and P. capitalensis NZ07 that were exclusively detected on BLA were selected for further evaluation. These isolates showed higher radial growth on modified supplemented PDA (MSPDA) than on standard PDA, indicating that optimization of Mn and P availability and reduction of Na content improved the growth-supporting capacity of PDA. Overall, BLA demonstrated potential as a low-cost, natural, basil-based medium for the selective isolation and cultivation of endophytic fungi associated with O. basilicum, while MSPDA provided an improved medium for subsequent cultivation of selected basil endophytic fungi. Full article

The aim of this study was to evaluate the co-occurrence and to assess the dietary health risk of multiple mycotoxins in fruit-based purées intended for infant consumption, combining targeted quantification and dietary exposure assessment with high-resolution suspect screening. Forty samples with varying apple content were randomly collected from Italian (n = 20) and Spanish markets (n = 20). A fit-for-purpose ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the simultaneous determination of patulin (PAT) and three Alternaria toxins, including alternariol (AOH), alternariol monomethyl ether (AME), and tentoxin (TEN), providing satisfactory sensitivity, accuracy and precision. Targeted analysis revealed frequent co-occurrence of PAT, AOH, and AME, whereas TEN was not detected. Dietary exposure assessment indicated that PAT posed negligible health risks, whereas AOH and AME exceeded their respective Thresholds of Toxicological Concern (TTCs) across all evaluated population groups, indicating Alternaria toxins as the main contributors to dietary risk. High-resolution mass spectrometry (HRMS) suspect screening expanded the mycotoxin profile through the identification of tenuazonic acid, the tentative identification of altenusin and aflatoxin G2, and the annotation of 2,3-dihydroxybenzoic acid, a potential interferent in PAT determination. Overall, the proposed workflow provides a comprehensive strategy for mycotoxin monitoring in infant fruit purées and supports enhanced surveillance of emerging Alternaria toxins. Full article

Fungi associated with coffee leaf lesions provide a diverse target panel for evaluating fungicide sensitivity and microbial antagonism. This study evaluated the antagonistic spectrum of mangrove-derived Streptomyces sp. CD103 and fungicide sensitivity in selected lesion-associated fungi. Of 49 isolates recovered from symptomatic Coffea arabica leaves in Wanning, Hainan, 39 induced necrosis following wound inoculation. These isolates were assigned to eight genera based on internal transcribed spacer (ITS) sequence comparisons and phylogenetic placement; Colletotrichum accounted for 64.1% of the necrosis-inducing isolates. Six fungicides were tested against seven isolates spanning four genera. Sensitivity varied among isolates and compounds; concentrations causing 50% inhibition of mycelial growth (EC₅₀) for thiophanate-methyl ranged from 0.57 to 22.53 µg mL⁻¹. Among 45 mangrove-derived actinomycetes screened against Colletotrichum gloeosporioides CCG3, CD103 showed the highest mean inhibition (99.21 ± 0.40%). In subsequent dual-culture assays, CD103 completely inhibited 19 of the 21 selected lesion-associated isolates spanning eight genera and all six reference plant pathogens. The two exceptions, a Fusarium isolate and an Alternaria isolate, showed 85.04% and 97.10% inhibition, respectively. These findings identify CD103 as a broad-spectrum in vitro antagonist against the tested fungi and warrant further evaluation of its disease-suppressive potential on coffee plants. Full article

This study evaluated the ability of filamentous fungi to biosynthesize silver nanoparticles (AgNPs). The nitrate reductase activity of the selected fungi, considered a key enzyme involved in AgNP biosynthesis, was assessed as a selection criterion. AgNPs were mycosynthesized using Fusarium equiseti AM-0197, F. cerealis AM-0206, F. oxysporum AM-0192, Alternaria scrophulariae AM-0187, and Aspergillus sp. (1-HSF-08 and 3-HSF-02) isolates. The synthesized AgNPs were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Zeta potential analysis. In all cases, spherical AgNPs were obtained, with maximum absorption peaks ranging from 400 to 420 nm. XRD analysis demonstrated a face-centered cubic crystalline structure, whereas Zeta potential measurements revealed a negative surface charge. FTIR analysis indicated the presence of organic functional groups on the nanoparticle surface acting as capping agents. The antibacterial activity of the synthesized nanomaterials was evaluated against reference strains of Escherichia coli and Staphylococcus aureus, two major foodborne pathogens, using the disk diffusion method. Inhibition zones ranged from 11.3 to 13.6 mm for E. coli ATCC 25922 and from 9.3 to 15.0 mm for S. aureus ATCC 43300. The minimum inhibitory concentration (MIC) determined by microdilution was 37.5 ppm for all AgNPs tested against E. coli, whereas MIC values against S. aureus ranged from 18.7 to 75 ppm depending on the nanoparticle evaluated. These findings demonstrate the effectiveness of mycosynthesized AgNPs as next-generation antibacterial agents for the in vitro control of foodborne bacterial pathogens. Full article

The present study aimed to evaluate the biocontrol and plant growth-promoting potential of putative nitrogen-fixing bacterial strains isolated from the soils of Northern Kazakhstan against major cereal crop phytopathogens and during the early stages of plant development. Phytopathogenic fungi, Fusarium proliferatum and Alternaria alternata, were isolated from infected cereal tissues and seeds using conventional mycological techniques. The antagonistic activity of the bacterial strains was assessed using a dual-culture assay. A total of 26 bacterial isolates were screened for antagonistic activity and plant growth-promoting effects. Several isolates exhibited pronounced inhibitory activity against both pathogens by suppressing fungal mycelial growth. The plant growth-promoting potential of bacterial culture filtrates was evaluated under in vitro conditions using buckwheat (Fagopyrum esculentum Moench) varieties ‘Shortandinskaya 6’ and ‘Shortandinskaya Krupnozernaya’. Germination energy, laboratory germination, shoot length, and root length were recorded during seedling development. The tested bacterial culture filtrates showed a stimulatory effect on seedling growth, with the most pronounced response observed in root elongation, indicating their positive influence on rhizogenesis. The obtained results demonstrate that Agrobacterium pusense st.51S, Ensifer fredii st.59S, and Oricola cellulosilytica st.70S exhibited strong antagonistic activity against Fusarium proliferatum, whereas O. cellulosilytica st.70S, Streptomyces virginiae st.11S, and Ensifer meliloti st.56S effectively inhibited the growth of Alternaria alternata. In addition, E. meliloti st.56S, Priestia megaterium st.35S, Rhizobium giardinii st.2S, and Ensifer sp. st.91S significantly promoted buckwheat seed germination and seedling growth. The most pronounced growth-promoting effect was observed for E. meliloti st.56S, which increased shoot and root length of ‘Shortandinskaya 6’ by 31.4% and 23.8%, respectively, compared with the control. These strains represent promising candidates for the development of microbial bioformulations aimed at improving seed quality, enhancing early plant development, and promoting sustainable crop production under the dry steppe conditions of Northern Kazakhstan. Full article

Alternaria alternata, a major postharvest pathogen of grapes and goji berries, causes black spot disease and produces Alternaria toxins that threaten food safety and human health. Carbon quantum dots (CQDs) are emerging promising nanophotosensitizers for photodynamic antimicrobial therapy (PDT), yet their efficacy against A. alternata remains unclear. This study systematically investigated the antifungal effect of CDs-PDT against A. alternata and revealed the possible mechanisms at cellular and physiological-biochemical levels. The inhibitory effect of CDs-PDT against A. alternata exhibited a clear concentration-dependent characteristic, achieving a 100% inhibition rate at 48 h; meanwhile, mycelial dry and fresh weights were reduced by 98.4% and 94.7%, respectively. The possible inhibitory mechanism of CDs-PDT against A. alternata was revealed that it damages cell wall and membrane integrity, evidenced by scanning electron microscope (SEM) observation, propidium iodide (PI) staining, increased malondialdehyde (MDA) content, and altered lactate dehydrogenase (LDH) and alkaline phosphatase (AKP) activities. Intracellular reactive oxygen species (ROS) accumulation was confirmed via 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA), 3,3′-diaminobenzidine (DAB), and nitroblue tetrazolium (NBT) staining, accompanied by initial upregulation followed by collapse of antioxidant defenses, such as superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), glutathione (GSH). CDs-PDT further impaired energy metabolism, reflected by decreased adenosine triphosphate (ATP) and acetyl-CoA content. Additionally, CDs-PDT can also increase A. alternata’s sensitivity to exogenous stress. These results indicate that CDs-PDT is an effective strategy for controlling A. alternata diseases and provide mechanistic insights into future nanophotosensitizer-based antifungal research in postharvest grape and goji berries management. Full article

Winter oilseed rape (Brassica napus L.) production is constrained by a complex of fungal pathogens, including Alternaria alternata, A. brassicicola, Botrytis cinerea, Phoma lingam and Sclerotinia sclerotiorum, which are conventionally managed with synthetic fungicides such as prothioconazole. This study evaluated the biocontrol and biostimulant potential of two plant extracts (garlic, Allium sativum; Jerusalem artichoke, Helianthus tuberosus) and two bacterial fermentation supernatants (Enterobacter sp. and Paenibacillus sp.) against these pathogens under in vitro, greenhouse and field conditions (2022–2024, two locations: Winna Góra and Rzeszów, Poland). In vitro, the Paenibacillus sp. supernatant showed the broadest and strongest activity, with inhibition of mycelial growth comparable to prothioconazole for several pathogens, particularly A. brassicicola and B. cinerea. Garlic extract was most effective against S. sclerotiorum and B. cinerea, with efficacy increasing with concentration and reaching complete inhibition at 10%; because each concentration was analysed in a separate one-way model, this concentration trend is reported descriptively and was not formally tested as a product × concentration interaction. Jerusalem artichoke extract was consistently the most effective agent against P. lingam (88–92% inhibition, largely independent of concentration), while Enterobacter sp. showed a comparatively narrow spectrum, with no measurable activity against B. cinerea and only negligible activity against S. sclerotiorum (≤6% inhibition at all tested concentrations). In the greenhouse, all four bioproducts significantly stimulated seedling growth, with fresh shoot weight increases exceeding 100% relative to the untreated control; fresh root weight showed a similar but non-significant trend. Under field conditions, garlic extract and Paenibacillus sp. gave the most consistent statistically significant and, in several site-years, fungicide-comparable control of Phoma stem canker (Phoma lingam) and Alternaria black spot (Alternaria spp.), occasionally matching the fungicide Protikon 250 EC; on the other hand, Enterobacter sp. was more variable and Jerusalem artichoke extract intermediate. Seed yield was increased over the untreated control at Rzeszów in both seasons, with the exception of Enterobacter sp. in 2023/2024, but not at Winna Góra, and thousand-seed weight was unaffected by treatment. Full article

Potato production is severely threatened by the oomycete Phytophthora infestans, the fungus Alternaria solani, and the bacterium Ralstonia solanacearum; however, strategies capable of simultaneously managing these three pathogen classes remain relatively scarce. In this study, we designed a series of signal peptide (SP)-fused recombinant constructs containing four functional modules with distinct antimicrobial and immune-inducing properties: GAFP1-2×FYVE, an oomycete-inhibiting antimicrobial protein; BbAFP1-ErBD, a fungal-suppressive protein fragment; the pathogen-associated molecular pattern (PAMP) csp22 derived from R. solanacearum, which elicits effective anti-bacterial immunity; and the microbe-associated molecular pattern (MAMP) PpEli2 identified from Pythium periplocum, which triggers broad-spectrum plant defense responses. Through systematic evaluation of six module order rearrangements, we identified SP-cBG as the optimal multi-domain combination. Further optimization via the introduction of a rigid alpha-helical linker (HL4) yielded SP-cBG-HL4, which tended to show superior resistance against all three pathogens, as reflected in smaller lesion diameters and decreased bacterial titers. qRT-PCR analyses revealed that SP-cBG-HL4 significantly upregulated PTI (CYP71D20, PTI5), SA (PR1, PR2), and JA/ET (PR3, PR4) defense marker genes. Collectively, these findings show that modular domain assembly combined with linker-mediated modular combinatorial optimization represents a powerful engineering strategy for achieving broad-spectrum disease resistance, offering a promising approach to simultaneously control oomycete, fungal, and bacterial pathogens of plants. Full article

Marigold (Tagetes spp.), a widely cultivated popular ornamental plant that is highly susceptible to fungal diseases, particularly leaf spot and stem wilt, which can substantially reduce its ornamental and economic value. This study aimed to identify the causal pathogens responsible for these diseases and evaluate the efficacy of selected antifungal agents against them. The causal agent of leaf spot was identified as Alternaria alternata, whereas stem wilt was caused by the Fusarium solani species complex (FSSC), based on Koch’s postulates, morphological characterization, and molecular identification. The antifungal activities of five commercially available fungicides were subsequently evaluated against both pathogens. The results showed that isomycete fluridine suspension (40%), metalaxyl–oxametrin suspension (32%), eugenol liquid (0.3%), pyrazolesterin methyl thiobacillin suspension (41%), and pyrazolesterin tebuconazole suspension (30%) demonstrated varying degrees of inhibitory activity. The EC50 values for A. alternata ranged from 10.588 to 49.604 mg/L, while those against FSSC ranged from 12.273 to 27.921 mg/L. These findings provide insights into the potency of these fungicides and offer a scientific basis for developing integrated disease management strategies for marigold cultivation, although further research is required to validate and evaluate their long-term efficacy and environmental safety. Full article

Tropical pumpkin (Cucurbita spp.) is an underutilized, nutrient-dense vegetable crop with potential to enhance food and nutrition security and generate household income among farming communities. In Uganda, farmers primarily obtain pumpkin seed through informal seed systems, including farmer-produced and -managed sources where seed quality is largely undocumented. This study evaluated the quality of pumpkin seeds collected from 16 selected districts in Uganda and provides the first baseline assessment of tropical pumpkin seed quality within farmer-produced and farmer-managed systems. Seed quality in this study was defined as the ability of seeds to germinate, exhibit high vigor, and remain free of fungal growth. Pumpkin seeds were assessed at 0, 3, and 6 months of storage under conditions representative of local seed traders (25 ± 5 °C; 60 ± 5% RH). Seed-associated fungi recovered on PDA containing streptomycin sulfate after 14 days of incubation were identified morphologically. Seed purity ranged widely (43.8–99.5%), indicating substantial variability among seed sources. Seed germination varied among districts, with most seeds showing improved germination after storage, whereas seed vigor declined with storage duration. Five putatively seedborne fungal genera, Fusarium, Aspergillus, Colletotrichum, Alternaria, and Rhizopus spp., were identified. The findings demonstrate substantial heterogeneity in farmer-produced and -managed seed, which is a predominant seed source in Uganda. Full article

Atmospheric bacteria and fungi are key components of urban bioaerosols, and their community structures are closely related to urban air quality, bioaerosol concentration, and environmental driving factors. However, the temporal dynamics and environmental drivers of bacterial and fungal community structures remain poorly characterized in megacities such as Shanghai, China. From November 2024 to November 2025, we conducted a year-long, cross-seasonal bioaerosol sampling and high-throughput DNA sequencing campaign to investigate the seasonal and diel variations, environmental covariation, and meteorological responses of atmospheric bacteria and fungi in Shanghai. The results show that seasonal transitions cannot significantly alter the α-diversity of bacterial or fungal communities, but significantly shift their community compositions, exhibiting a stronger differentiation for fungi than bacteria (PERMANOVA R² = 0.133 vs. 0.054, p = 0.001). At the diel scale, bacterial communities exhibit weak diurnal variation, whereas fungal communities display significantly higher nocturnal Chao1 richness and Shannon diversity, along with distinct compositional separation. Cladosporium and Alternaria are enriched during the day, while saprotrophic basidiomycetes such as Irpex and Trametes are more abundant at night. Fungal composition covaries most strongly with meteorological gradients governed by boundary layer height, clear-sky surface downward solar radiation, temperature, relative humidity, atmospheric pressure and visibility, whereas bacterial–environment associations are weaker. The Relative Exposure-Relevant Proportion (RERP), dominated by Cladosporium and Alternaria, is higher during daytime and negatively associated with relative humidity (β = −0.23, q = 0.001). During a strong cold-air event, bacterial communities shifted rapidly following immediate air mass replacement and high wind shear before stabilizing, whereas fungal communities underwent a more gradual and cumulative turnover. The RERP also elevated during this event, accompanied by a greater contribution from Talaromyces. These findings reveal contrasting dynamics between airborne bacteria and fungi under both background and transient synoptic disturbances, providing crucial observational insights for bioaerosol modeling and risk prediction in urban environments. Full article

Potato (Solanum tuberosum L.), the third most important food crop worldwide, is constrained by phytopathogens, environmental stress, and heavy agrochemical use. Potato micropropagation is a biotechnological strategy for producing genetically uniform, pathogen-free plantlets. However, the acclimatization phase remains a major bottleneck in micropropagation, often resulting in poor survival and stunted growth. In this context, plant growth-promoting bacteria (PGPB) represent a sustainable strategy to improve plantlet establishment and reduce reliance on synthetic inputs. This study evaluated the biofertilization and biocontrol potential of three Douro vineyard-associated bacterial strains, Bacillus velezensis Nb1, Burkholderia pyrrocinia Gs3, and Streptomyces sp. 42s5, identified using 16S rRNA and gyrB sequence analysis. In dual-culture assays, the isolates showed antagonistic activity against Fusarium oxysporum, F. solani, Botrytis cinerea, and Alternaria alternata. All strains also exhibited key plant growth-promoting traits, including indole-3-acetic acid and siderophore production, and phosphate solubilization. The isolates were tested individually and in consortia on micropropagated potato plantlets during acclimatization under greenhouse conditions. Eight treatments (six replicates each), including a non-inoculated control, were evaluated. The results indicated that inoculations significantly improved vegetative growth and yield-related parameters. Notably, the Gs3 + 42s5 combination produced the highest shoot biomass, while the three-strain consortium achieved the greatest total tuber weight (36.91 g/plant) compared to the control (7.75 g/plant). These findings highlight the potential of these native PGPB, particularly when applied in multi-strain combinations, to enhance acclimatization efficiency and support sustainable potato production by reducing dependence on chemical inputs and promoting eco-friendly agricultural practices. Full article