Search Results (630)

In the present study, 70 representative strains of potato dry-rot pathogen fungi were collected and isolated from three potato-growing areas in Northern Shanxi Province to determine their distribution and composition. The aim was to determine their distribution and composition by investigating their genetic structure through morphological characterization and phylogenetic tree construction using three DNA fragments (TEF1, RPB1, and RPB2). The results showed that potato dry rot disease in Northern Shanxi Province, is caused by five pathogenic species: Fusarium sambucinum, F. solani, F.oxysporum, F. acuminatum, and F. dimerum, among which F. sambucinum is the dominant species, accounting for 87.14% of all the strains, and distributed primarily in various potato-growing areas in the region. This study is the first to show that F. dimerum is a component of the pathogenic complex causing potato dry rot and is distributed primarily in the basin and hilly regions with relative frequencies of 3.45% and 13.04%, respectively. Fusarium acuminatum is distributed only in the plateau regions with a relative frequency of 5.56%. Full article

Certain essential oils (EOs) from aromatic plants have shown potent antifungal effects. In this work, an in vitro study was conducted to examine the antifungal effect of EOs obtained from Greek flora aromatic plants that belong to the Lamiaceae family on two phytopathogenic fungi. Specifically, Satureja horvatii ssp. macrophylla, Coridothymus capitatus, and Origanum vulgare ssp. hirtum were tested against Alternaria sp., which causes tomato black spot, and Fusarium sp., which causes potato tuber dry rot during storage. The antifungal activity of the EOs was assessed using fumigant assays, and their chemical composition was analyzed using gas chromatography–mass spectrometry (GC–MS). After 8 days of incubation at 26 ± 1 °C, the EOs of O. vulgare ssp. hirtum and C. capitatus completely inhibited mycelial growth at 2 µL plate⁻¹ in the case of Fusarium sp. and at 3 µL plate⁻¹ in the case of Alternaria sp. S. horvatii ssp. macrophylla completely inhibited the mycelial growth of Fusarium sp. at 3 µL plate⁻¹ and that of Alternaria sp. at 4 µL plate⁻¹. All the essential oils used in the experiments were rich in carvacrol (41.4–70.0%), while thymol levels ranged from 0% to 18.9%. This fumigant effect could be further evaluated for the fruits’ postharvest protection from phytopathogenic fungi during storage. Full article

Essential oils (EOs) from oregano (Origanum vulgare), rosemary (Salvia rosmarinus), clove (Syzygium aromaticum), thyme (Thymus vulgaris), cinnamon (Cinnamomum verum), and basil (Ocimum basilicum) possess antifungal properties. This study aimed to evaluate their ability to inhibit the growth of fungi isolated from the rot of banana peel (Musa paradisiaca) to control or reduce fungal growth in bananas. The methodology involved preparing dilutions of EOs and inoculating them onto Potato Dextrose Agar (PDA) medium amended with chloramphenicol to prevent bacterial contamination. Fungal species, including Trichoderma spp., Aspergillus spp., Penicillium spp., and Fusarium spp., were isolated, purified, and characterized macroscopically and microscopically. Their growth was assessed ex vivo and the inhibition percentage was measured in vitro. The ex vivo analysis revealed that the severity of fungal infection, ranked from highest to lowest, was as follows: Penicillium spp., Trichoderma spp., Fusarium spp., and Aspergillus spp. The results showed that rosemary and basil oils did not inhibit fungal growth, whereas clove oil, cinnamon, and oregano were effective against the four tested fungi at 800, 400, and 200 ppm, respectively. These findings suggest that certain EOs, including clove, cinnamon, and oregano, have strong antifungal potential and could serve as eco-friendly alternatives to synthetic fungicides in banana postharvest disease management. Full article

Fusarium proliferatum is the causative agent of rice spikelet rot disease, which can produce a group of toxic secondary metabolites, especially fumonisins. Velvet complex is a master regulator governing the development processes and secondary metabolism in filamentous fungi. In this study, we investigated the biological functions of velvet members FpVeA and FpVelB in F. proliferatum. Compared with the wild-type Fp9 strain, deletion of FpveA or FpvelB genes resulted in retarded hyphal growth but promoted conidiation. Disruption mutants exhibited decreased conidial trehalose contents and enhanced sensitivity to H₂O₂ stress, as well as inducing expression of photoreceptors. Notably, inactivation of FpveA or FpvelB led to a reduction in production of fumonisin B1 (FB1), coinciding with downregulation of fumonisin biosynthetic genes. Furthermore, the absence of FpveA or FpvelB displayed attenuated virulence toward rice spikelets, accompanied by fewer invasive hyphae and a failure of penetration ability. Taken together, these results demonstrated that FpVeA and FpVelB play crucial roles in the asexual development, oxidative stress, toxin synthesis and pathogenicity of F. proliferatum. Full article

Fungal pathogens represent a major constraint to global agricultural productivity, causing a wide range of plant diseases that severely affect staple crops such as cereals, legumes, and vegetables. These infections result in substantial yield losses, deterioration of grain and produce quality, and significant economic impacts across the entire agri-food sector. Among phytopathogens, fungi are considered the most destructive, causing a wide range of diseases such as powdery mildew, rusts, fusarium head blight, smut, leaf spot, rots, late blight, and other fungal pathogens. Traditional plant protection methods do not always provide long-term effectiveness and environmental safety, which requires the introduction of innovative approaches to creating sustainable varieties. CRISPR-Cas technology opens up new opportunities for targeted genome editing, allowing the modification or silencing of susceptibility genes and thus increasing plant resistance to fungal infections. This review presents current achievements and prospects for the application of CRISPR-Cas technology to increase the resistance of major agricultural crops to fungal diseases. The implementation of these approaches contributes to the creation of highly productive and resistant varieties, which is crucial for ensuring food security in the context of climate change. Full article

Rhizoctonia solani (Rs) and Sclerotinia sclerotiorum (Ss) are devastating pathogens of rice and rapeseed, contributing 20–69% and 10–50% of yield losses, respectively. These pathogens develop resistant overwintering and/or oversummering sclerotia, which serve as inocula for infection in the subsequent season under favorable conditions. The present study was designed to investigate the month-wise variation in microbial diversity by mixing Rs and Ss sclerotia separately in rice-rapeseed rotation field soil, thereby identifying key microbial players associated with specific sclerotia and their implications for subsequent crops. Therefore, we incubated 2.5 g of Rs and Ss sclerotia in 100 g of soil for 3 months to mimic the field conditions and subjected month-wise soil samples to 16S rRNA and ITS2 sequencing. Data analysis of bacterial communities revealed diversity, richness, and evenness in Ss treated soil samples compared to the control, while fungal communities exhibited less diversity. These results were also evident in PCoA and hierarchical clustering, where control and treated samples were scattered in 16S rRNA and ITS sequencing. Genus level diversity exhibited enrichment of bacterial genera with known beneficial potential, notably Acidibacter, Stenotrophobacter, Sphingomonas, Flavisolibacter, Gaiella, and Neobacillus in control. Beneficial bacterial genera such as Ramlibacter, Geomonas, Kofleria, Nitrospira, and Paraflavitalea were enriched in Ss treated soil samples. The addition of Ss and Rs sclerotia activated several beneficial fungi, notably Trichoderma, Talaromyces, Clonostachys in Ss treated samples, and Vermispora, Hyalorbilia, Mortierella, Lecanicillium in Rs treated samples. Additionally, Rs treated soil samples also activated pathogenic genera, including Typhula, Fusarium, and Rhizoctonia. Sclerotia in soil modulates the microbiome and activates beneficial and pathogenic microbes. During the off-season, the Sclerotinia inoculum pressure in the soil reduces, and it is safe to grow crops next season. Whereas, in the case of Rhizoctonia infected soil, it is suggested to avoid growing crops susceptible to wilt, root rot, and blight. However, field experiments to understand the pathogen–pathogen interactions around the sclerotiosphere require further exploration. Full article

Studies of microbial degradation of historic woods are essential to help protect and preserve these important cultural properties. The USS Cairo is a historic Civil War gunboat and one of the first steam-powered and ironclad ships used in the American Civil War. Built in 1861, the ship sank in the Yazoo River of Mississippi in 1862 after a mine detonated and tore a hole in the port bow. The ship remained on the river bottom and was gradually buried with sediments for over 98 years. After recovery of the ship, it remained exposed to the environment before the first roofed structure was completed in 1980, and it has been displayed under a tensile fabric canopy with open sides at the Vicksburg National Military Park in Vicksburg, Mississippi. Concerns over the long-term preservation of the ship initiated this investigation to document the current condition of the wooden timbers, identify the fungi that may be present, and determine the elemental composition resulting from past wood-preservative treatments. Micromorphological characteristics observed using scanning electron microscopy showed that many of the timbers were in advanced stages of degradation. Eroded secondary cell walls leaving a weak framework of middle lamella were commonly observed. Soft rot attack was prevalent, and evidence of white and brown rot degradation was found in some wood. DNA extraction and sequencing of the ITS region led to the identification of a large group of diverse fungi that were isolated from ship timbers. Soft rot fungi, including Alternaria, Chaetomium, Cladosporium, Curvularia, Xylaria and others, and white rot fungi, including Bjerkandera, Odontoefibula, Phanerodontia, Phlebiopsis, Trametes and others, were found. No brown rot fungi were isolated. Elemental analyses using induced coupled plasma spectroscopy revealed elevated levels of all elements as compared to sound modern types of wood. High concentrations of boron, copper, iron, lead, zinc and other elements were found, and viable fungi were isolated from this wood. Biodegradation issues are discussed to help long-term conservation efforts to preserve the historic ship for future generations. Full article

Postharvest fungal rot causes significant economic losses in the agroindustry. Current control methods involving the use of synthetic fungicides are becoming increasingly ineffective and pose environmental risks. This necessitates exploring sustainable alternatives, such as essential oils derived from medicinal plants, to achieve safer and effective disease control. This research examined the chemical composition and efficacy of essential oils from Aloysia citriodora, Aloysia polystachya and their compounds against the postharvest rot fungi Monilinia fructicola, Monilinia laxa, and Botrytis cinerea. The main compounds of essential oils were analyzed by GC/MS and revealed differences in their composition. A. citriodora is characterized by the presence of spathulenol and caryophyllene oxide. In contrast, A. polystachya is characterized by the predominance of carvone. The results show that the essential oil of A. citriodora and the compound farnesol are able to inhibit the three pathogens. Notably, against M. fructicola, the EC₅₀ values were 61.89 μg/mL and 72.18 μg/mL, respectively. Against B. cinerea, the EC₅₀ values were 85.34 μg/mL and 47.6 μg/mL. Molecular docking also showed that farnesol has affinity for the enzyme succinate dehydrogenase suggesting a possible mechanism of action. This compound and A. citriodora essential oil show potential in the control of phytopathogens. Full article

Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins play evolutionarily conserved roles in intracellular vesicle trafficking and membrane fusion across eukaryotes. In pathogenic fungi, various SNARE homologs have been shown to critically regulate host infection processes. Here, we characterize the functional roles of CfSec22 in the sweet potato black rot pathogen Ceratocystis fimbriata. Phylogenetic and domain analyses demonstrate that CfSec22 shares homology with Sec22 proteins from Saccharomyces cerevisiae (ScSec22), Magnaporthe oryzae (MoSec22), and other fungi, containing both the characteristic Longin homology domain and V-SNARE domain. Functional studies reveal that CfSec22 regulates growth, conidiation, and virulence of C. fimbriata. Deletion of CfSEC22 resulted in abnormal vacuole morphology and impaired endocytosis. The ΔCfsec22 mutant displayed heightened sensitivity to diverse stress conditions: oxidative, endoplasmic reticulum, and cell wall stressors. Subcellular localization studies confirmed the endoplasmic reticulum residence of CfSec22. Finally, we established that CfSec22 regulates the secretion of virulence-associated proteins and is required for the induction of ipomeamarone in infected sweet potato tissues. Together, our findings demonstrate that CfSec22-mediated vesicle trafficking serves as a critical regulatory mechanism supporting growth, conidiogenesis, and pathogenicity in C. fimbriata. Full article

Atractylodes macrocephala Koidz. (A. macrocephala), a medicinal plant extensively used in traditional Chinese medicine, is greatly susceptible to root rot under continuous monoculture, leading to serious yield and quality losses. To develop a sustainable control strategy, we isolated the endophytic bacterium Bacillus velezensis (B. velezensis) Amzn015 from healthy A. macrocephala plants and assessed its biocontrol efficacy and underlying mechanisms. In vitro assays showed that Amzn015 significantly inhibited Fusarium oxysporum and other phytopathogenic fungi by disrupting hyphal morphology and reducing spore viability. Pot experiments confirmed its effectiveness in reducing disease incidence and promoting plant growth. Mechanistically, Amzn015 induced reactive oxygen species accumulation and upregulated key defense responsive genes involved in salicylic acid, jasmonic acid/ethylene, and phenylpropanoid signaling pathways. The findings imply that Amzn015 synchronously activates systemic acquired resistance and induced systemic resistance in A. macrocephala. This dual activation contributes to enhanced immunity and plant vigor under pathogen challenge. Our findings offer fresh perspectives on the biocontrol potential of endophytic B. velezensis Amzn015 and support its application as an eco-friendly agent for managing root rot in medicinal crops. Full article

During prolonged storage of garlic scapes (Allium sativum L.), the proliferation of microorganisms, particularly fungi, frequently results in postharvest rot, which negatively impacts both product quality and market value. Carvacrol, a promising natural food preservative, exhibits broad-spectrum bioactivity against various microorganisms. In this study, a specific pathogenic fungal strain causing postharvest rot in garlic scapes, designated as HQ, was initially isolated from symptomatic garlic scapes. Based on a combination of physiological characteristics and molecular identification techniques, the HQ strain was identified as Aspergillus niger. Our findings further demonstrated that carvacrol exhibits significant in vitro inhibitory effects against Aspergillus niger with an EC₅₀ value of 75.99 μg/L. Moreover, scanning electron microscopy (SEM) observations revealed that carvacrol induces irreversible morphological and structural changes in the hyphae, resulting in deformation and rupture. Additionally, integrated transcriptomic and proteomic analyses indicated that carvacrol primarily targets the cell wall integrity (CWI) signaling pathway within the mitogen-activated protein kinase (MAPK) signaling pathway in Aspergillus niger, thereby compromising cell membrane integrity and stability, which ultimately suppresses fungal growth and proliferation. Full article

As an important complementation of plant genetic traits, seed endophytes (SEs) have garnered significant attention due to their crucial roles in plant germination and early seedling establishment. In this study, we employed both culture-dependent and amplicon sequencing-based approaches to characterize the endophytic microbiome in seed samples derived from different individual Panax notoginseng plants. Additionally, we evaluated the antagonistic activity of isolated culturable bacterial SEs against the root rot pathogens Fusarium solani and F. oxysporum. Our results demonstrated that a greater sampling quantity substantially increased the species richness (Observed OTUs) and diversity of seed endophytic microbiota, underscoring the importance of seed population size in facilitating the vertical transmission of diverse endophytes to progeny. The endophytic communities (including both fungi and bacteria) exhibited a conserved core microbiota alongside host-specific rare taxa, forming a phylogenetically and functionally diverse endophytic resource pool. Core bacterial genera included Streptococcus, Methylobacterium-Methylorubrum, Sphingomonas, Burkholderia-Caballeronia-Paraburkholderia, Pantoea, Halomonas, Acinetobacter, Pseudomonas, Vibrio, and Luteibacter, while core fungal genera comprised Davidiella, Thermomyces, Botryotinia, Myrothecium, Haematonectria, and Chaetomium. Among 256 isolated endophytic bacterial strains, 11 exhibited strong inhibitory effects on the mycelial growth of F. solani and F. oxysporum. Further evaluation revealed that two antagonistic strains, Bacillus cereus and B. toyonensis, significantly enhanced seed germination and plant growth in P. notoginseng, and effectively suppressed root rot disease in seedlings. These findings highlight the potential use of SEs as biocontrol agents and growth promoters in sustainable agriculture. Full article

Ginger holds significant economic importance in both China and worldwide agriculture. Fungi from the family Plectosphaerellaceae are globally recognized as aggressive plant pathogens. However, the effects of Plectosphaerellaceae species on ginger have been poorly understood. In this research, we identified two novel Musidium species (M. shandongensis sp. nov. and M. zingiberis sp. nov.), one newly recorded species (Gibellulopsis serrae) and one new host record (Plectosphaerella cucumerina) from the rotten rhizomes and roots of ginger in Shandong Province, China, utilizing morphological observations combined with multilocus phylogenetic analysis of the 28S large subunit (LSU), internal transcribed spacer (ITS) region, and translation elongation factor 1-alpha (TEF1-α) gene, along with pathogenicity analyses. Key diagnostic features include M. shandongensis exhibiting abundant mycelium ropes and coils, M. zingiberis showing dark olivaceous colonies, G. serrae producing brown chlamydospores, and P. cucumerina displaying conspicuous guttulae conidia. Comparative analyses with closely related taxa were based on detailed morphological descriptions, illustrations, and phylogenetic analyses. Artificial inoculation of healthy ginger in vitro and in vivo assays caused characteristic symptoms, such as wilt, leaf yellowing, and rhizome necrosis, identical to those observed on naturally infected plants. Our findings broaden current knowledge on the diversity of Plectosphaerellaceae associated with ginger, revealing them as serious threats to ginger cultivation in China. Full article

Birch stands, dominated by Betula pendula Roth, are a common feature of boreal forests. Within the Krasnoyarsk (central) group of regions, they are concentrated in the taiga, subtaiga and forest steppe zones of actively managed forests, represented by stands of seed and shoot origin. The health and productivity of birch forests is often determined by the activity of wood-decay fungi, which leads to rot and decay in trees. The objective of the research is to evaluate the impact of stem rot on birch forests in the study area, with a focus on key ecological and silvicultural factors. The research methods employed included a reconnaissance survey of birch forests, a detailed forest pathology survey of forest stands on research plots (31 pcs.), comprehensive macroscopic diagnostics of stem rot, identification of xylotrophic fungi by basidiomes, integrated assessment of forest health, graph analytics and statistical data analysis. Stem rot has been identified in all birch forests in the study area. In shoot origin stands, the incidence rate has reached the stage of the disease center (i.e., more than 10% of trees are infected). The following wood-decay fungi have been detected on the trunks of living trees affected by rot: Fomes fomentarius, Fomitopsis pinicola, Inonotus obliquus, Phellinus igniarius, and Trametes versicolor. The infection typically infects trees via spores, finding entry through dying branches or mechanical and thermal wounds on trunks. In trees of shoot origin, stem rot is frequently transmitted via mycelium from stumps left after felling. This, in conjunction with diminished immunity, contributes to a substantially elevated incidence of stem rot in comparison to stands of seed origin. The research has not established a reliable correlation between the incidence of stem rot and forest stand characteristics due to the impact of human activity on birch forests (e.g., cutting, fires, tree injury). At the same time, no reliable connection has been established between the spread of stem rot and the stage of recreational disturbance. Trees of various sizes are affected by stem rot, usually proportional to their representation in the structure of the forest stand. The disease has a detrimental effect on the trees, which is clearly evident in the decline of forest health. Full article

A study was carried out to identify the filamentous fungi and yeasts present in rotten wine grapes from two subzones of the Southern oasis of Mendoza winegrowing region, to assess the occurrence of tenuazonic acid (TA), a mycotoxin produced by the Alternaria genus, and to evaluate the wine spoilage potential of the associated yeasts in vitro and during microvinifications. The main fungal genera present were Alternaria (69.3%), followed by Aspergillus (16.8%), Penicillium (9.3%), and Cladosporium (4.6%), while the dominant yeast species Metschnikowia pulcherrima (23.1%), Aureobasidium pullulans (20.2%) and Hanseniaspora uvarum (13.0%) were followed by H. vineae (11.6%), Zygosaccharomyces bailii (10.4%), and H. guilliermondii (9.2%). Additionally, 94.1% of the rotten samples were contaminated with TA, with the highest level found in the Cabernet Sauvignon variety. No geographic association was found in the incidence of the different fungal genera or yeast species, nor in the occurrence of TA. Almost all of the tested yeasts produced H₂S, the majority of the Hanseniaspora strains produced acetic acid, and only one M. pulcherrima strain produced off-flavours in in vitro tests. Wines co-fermented with H. uvarum L144 and S. cerevisiae showed higher volatile acidity and lower fruity aroma and taste intensity. Therefore, processing bunch rot could pose a toxicological and microbiological risk to winemaking due to the high incidence of Alternaria and TA, as well as the potential of the associated yeasts to spoil wine. Full article