Search Results (306)

The soil-borne fungal pathogen Verticillium dahliae causes devastating vascular wilt disease in numerous crops, including cotton. In this study, we reveal that VdSOX1, a highly conserved sarcosine oxidase gene, is significantly upregulated during host infection and plays a multifaceted role in fungal physiology and pathogenicity. Functional deletion of VdSOX1 leads to increased fungal virulence, accompanied by enhanced microsclerotia formation, elevated carbon source utilization, and pronounced upregulation of effector genes, including over 50 predicted secreted proteins genes. Moreover, the VdSOX1 knockout strains suppress the expression of key defense-related transcription factors in cotton, such as WRKY, MYB, AP2/ERF, and GRAS families, thereby impairing host immune responses. Transcriptomic analyses confirm that VdSOX1 orchestrates a broad metabolic reprogramming that links nutrient acquisition to immune evasion. Our findings identify VdSOX1 as a central regulator that promotes V. dahliae virulence by upregulating effector gene expression and suppressing host immune responses, offering novel insights into the molecular basis of host–pathogen interactions and highlighting potential targets for disease management. Full article

Background: In recent years, changes in climate conditions and long-term continuous cropping have led to the increased occurrence of Verticillium wilt in various cotton-growing regions, causing significant economic losses in cotton production. Research has shown that volatile substances are closely linked to plant disease resistance; however, studies on their roles in the response of cotton to Verticillium wilt, including their relationship with gene regulation, are limited. Methods: In this study, the transcriptomes and metabolomes of Xinluzao 57 (a highly susceptible Verticillium wilt variety) and 192,868 (a highly resistant Verticillium wilt variety) were sequenced at different time points after inoculation with Verticillium wilt. Results: A total of 21,911 commonly differentially expressed genes (DEGs) were identified within and between the materials, and they were clustered into eight groups. Significant annotations were made in pathways related to amino acids and anthocyanins. Metabolomics identified and annotated 26,200 volatile metabolites across nine categories. A total of 158 differentially accumulated metabolites (DAMs) were found within and between the materials; three clusters were identified, and the 10 metabolites with the most significant fold changes were highlighted. Weighted gene coexpression network analysis (WGCNA) revealed that 13 genes were significantly correlated with guanosine, 6 genes were correlated with 2-deoxyerythritol, and 32 genes were correlated with raffinose. Conclusions: Our results provide a foundation for understanding the role of volatile substances in the response of cotton to Verticillium wilt and offer new gene resources for future research on Verticillium wilt resistance. Full article

Verticillium wilt is characterized by chlorosis in leaves and is a devastating disease in eggplant. Early diagnosis, prior to the manifestation of symptoms, enables targeted management of the disease. In this study, we aim to detect early leaf wilt in eggplant leaves caused by Verticillium dahliae by integrating multispectral imaging with machine learning and deep learning techniques. Multispectral and chlorophyll fluorescence images were collected from leaves of the inbred eggplant line 11-435, including data on image texture, spectral reflectance, and chlorophyll fluorescence. Subsequently, we established a multispectral data model, fusion information model, and multispectral image–information fusion model. The multispectral image–information fusion model, integrated with a two-dimensional convolutional neural network (2D-CNN), demonstrated optimal performance in classifying early-stage Verticillium wilt infection, achieving a test accuracy of 99.37%. Additionally, transfer learning enabled us to diagnose early leaf wilt in another eggplant variety, the inbred line 14-345, with an accuracy of 84.54 ± 1.82%. Compared to traditional methods that rely on visible symptom observation and typically require about 10 days to confirm infection, this study achieved early detection of Verticillium wilt as soon as the third day post-inoculation. These findings underscore the potential of the fusion model as a valuable tool for the early detection of pre-symptomatic states in infected plants, thereby offering theoretical support for in-field detection of eggplant health. Full article

Soilborne diseases cause losses of 45–70% in faba bean in Ethiopia. Studies were undertaken to define soilborne pathogens and their complexes in Ethiopia. First, the severity of root rot was assessed in 150 field sites across seven Ethiopian regions. Soil samples were collected, and the DNA of 29 pests and pathogens was quantified using a commercial quantitative PCR (qPCR) soil testing service. There was a very high incidence rate of Macrophomina phaseolina, as well as Pythium clades F and I. The other detected species in order of incidence included Fusarium redolens, Rhizoctonia solani, Aphanomyces euteiches, Phytophthora megasperma, Sclerotinia sclerotiorum and S. minor, and Verticillium dahliae, as well as low levels of Thielaviopsis basicola. Five anastomosis groups (AG) of R. solani, namely AG2.1, AG2.2, AG3, AG4, and AG5, were detected, of which AG2.2 and AG4 were most prevalent. We believe this is the first report of occurrence for Ethiopia of A. euteiches, Ph. megasperma, T. basicola, and the five AGs for R. solani. There were very high incidence rates of the foliar pathogens Botrytis cinerea, B. fabae, Didymella pinodes, and Phoma pinodella and of the nematode Pratylenchus thornei, followed by P. neglectus and P. penetrans. The root rot severity and distribution varied significantly across regions, as well as with soil types, soil pH, and soil drainage. Subsequently, metabarcoding of the soil DNA was undertaken using three primer pairs targeting fungi (ITS2), Fusarium species (TEF1 α), and Oomycetes (ITS1Oo). The ITS2 and TEF1α primers emphasized F. oxysporum as the most abundant soilborne fungal pathogen and highlighted F. ananatum, F. brachygibbosum, F. brevicaudatum, F. clavum, F. flagelliforme, F. keratoplasticum, F. napiforme, F. nelsonii, F. neocosmosporiellum, F. torulosum, and F. vanettenii as first reports of occurrence for Ethiopia. The ITS1Oo primer confirmed Pythium spp. as the most prevalent of all Oomycetes. Full article

Background: Verticillium wilt (VW), caused by the fungal pathogen Verticillium dahliae, is a destructive disease that severely compromises cotton yield and fiber quality. Pyrimidine nucleotides, as essential metabolites and nucleic acid components, play critical roles in plant development and stress responses. However, genes involved in pyrimidine metabolism, especially their roles in disease resistance, remain largely uncharacterized in plants. Methods: Ghir_D05G039120, a gene encoding uridine kinase, shown to be associated with VW resistance in our previous study, was cloned and named as GhUKL4. The differential expression of GhUKL4 between the resistant and susceptible cultivars at multiple time points post-inoculation with V. dahliae was analyzed by quantitative real-time PCR (qRT-PCR), and the uracil phosphoribosyl transferase (UPRT) and uridine 5′-monophosphate kinase (UMPK) domains were verified by analyzing the amino acid sequences of GhUKL4. The role of GhUKL4 in the defense against VW infection was estimated by silencing GhUKL4 in the resistant and susceptible cultivars using virus-induced gene silencing (VIGS) analysis. Results: There were significant differences in the expression level of Ghir_D05G039120/ GhUKL4 among resistant and susceptible cotton lines. GhUKL4 contains UPRTase and UMPK domains, and there was one SNP between the resistant and susceptible cultivars in its 3′-UTR region. The silencing of GhUKL4 reduced cotton’s resistance to VW through mediating hormone signaling (JA) and oxidative stress (ROS) pathways. Conclusions: GhUKL4, encoding UMPK and UPRTase domain proteins, is a new regulatory factor associated with VW resistance in Gossypium hirsutum through fine-tuning JA-signalling and ROS bursting. Full article

Verticillium longisporum, a soil-borne fungus responsible for Verticillium wilt, primarily colonizes members of the Brassicaceae family. Using Arabidopsis thaliana roots as an experimental host, we systematically identify V. longisporum-responsive genes and pathways through comprehensive transcriptomic analysis, alongside screening of potential hub genes and evaluation of infection-associated regulatory mechanisms. The GSE62537 dataset was retrieved from the Gene Expression Omnibus database. After performing GEO2R analysis and filtering out low-quality data, 222 differentially expressed genes (DEGs) were identified, of which 184 were upregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed on these DEGs. A protein–protein interaction network was constructed using the STRING database. CytoHubba and CytoNCA plugins in Cytoscape v3.10.3 were used to analyze and evaluate this network; six hub genes and four functional gene modules were identified. The GeneMANIA database was used to construct a co-expression network for hub genes. Systematic screening of transcription factors within the 14 DEGs revealed the inclusion of the hub gene NAC042. Integrative bioinformatics analysis centered on NAC042 enabled prediction of a pathogen-responsive regulatory network architecture. We report V. longisporum-responsive components in Arabidopsis, providing insights for disease resistance studies in Brassicaceae crops. Full article

Verticillium wilt, caused by Verticillium dahliae, poses a significant threat to olive trees (Olea europaea L.). The isolation of endophytic Streptomyces strains from olive roots has led to the discovery of several strains showing strong antifungal activity against V. dahliae, as demonstrated through in vitro and small-scale soil experiments. Molecular analyses confirmed that strain OE54 belongs to Streptomyces iranensis. The main antifungal compound identified in this strain was rapamycin. Rapamycin displayed potent antifungal effects, notably inhibiting conidiospore germination (IC₅₀ = 87.36 μg/mL) and the hyphal growth of V. dahliae, with a minimum inhibitory concentration (MIC₅₀) of 3.91 ng/mL. Additionally, a second rapamycin-producing strain, OE57^T, was isolated. Phenotypic and genotypic analyses indicated that OE57^T represents a new species, which is proposed to be named Streptomyces lacaronensis sp. nov., with OE57^T designated as the type strain (=DSM 118741^T; CECT 31164^T). The discovery of two endophytic rapamycin-producing Streptomyces strains residing within olive roots is especially notable, given the rarity of rapamycin production among microorganisms. These findings highlight the potential of rapamycin-producing Streptomyces strains in developing biofertilizers to manage V. dahliae and reduce the impact of Verticillium wilt on olive trees and other crops. Full article

Olive trees are generally considered a species well-adapted to drought, but the impact of water shortage is of critical importance on olive production. For this reason, developing tolerant cultivars could be an effective strategy to mitigate the impact of drought in the future. Characterizing drought stress tolerance in olive is a complex task due to the numerous traits involved in this response. In this study, plant growth, pressure–volume curves, gas-exchange and chlorophyll fluorescence traits, and stomata characteristics were monitored in nine cultivars to assess the effects of mild and severe drought stress conditions induced by withholding water for 7 and 21 days, respectively, and were compared to a well-watered control treatment. The plant materials evaluated included traditional cultivars, as well as new developed cultivars suited for high-density hedgerow olive orchards or resistant to verticillium wilt. Significant differences between cultivars were observed for most evaluated traits, with more pronounced differences under severe drought conditions. A multivariate analysis of the complete dataset recorded throughout the evaluation period allowed for the identification of promising cultivars under stress conditions (‘Sikitita’, ‘Sikitita-2’, and ‘Martina’) as well as highly discriminative traits that could serve as key selection parameters in future breeding programs. Full article

In recent years, the excessive use of pesticides has raised environmental and health concerns, which has led to research into natural alternatives. Essential oils may represent a sustainable solution to this problem. In this study, essential oils from Thymbra capitata (L.) Cav., Eucalyptus globulus Labill, and Mentha piperita L. were analyzed by GC–MS and tested in vitro using the poisoned food technique against six olive pathogen fungi: Alternaria sp., Arthrinium marii, Colletotrichum acutatum, Fomitiporia mediterranea, Fusarium solani, and Verticillium dahliae. T. capitata essential oil (0.1 g/L) showed the highest antifungal activity when compared to E. globulus and M. piperita essential oils, which exhibited significantly lower efficacy against the tested olive phytopathogenic fungi. GC–MS analysis revealed that carvacrol is the main compound (76.1%) in T. capitata essential oil. A comparison of the inhibitory effect of T. capitata essential oil (0.1 g/L) and carvacrol (0.07 g/L) on selected fungal strains showed similar results, with carvacrol slightly more effective, although the differences were mostly statistically insignificant, except for C. acutatum. To the authors knowledge, this is the first study demonstrating the inhibitory effect of Thymbra capitata essential oil against A. marii and F. mediterranea. The results of this study represent a basis for the development of new biochemical biopesticides based on T. capitata essential oil as a useful tool for the contrast of some fungal olive tree diseases. Full article

Potato early dying disease complex (PED) leads to premature senescence and rapid decline in potato plants. Unlike potato wilt caused solely by Verticillium species, PED symptoms are more severe due to the synergistic effects of multiple pathogens, including root-lesion nematodes, fungi such as Colletotrichum and Fusarium, and soft-rot bacteria. To investigate the microbiome responsible for PED, soil and stem samples from healthy-looking and symptomatic plants were analyzed using amplicon-targeted next-generation sequencing (Illumina MiSeq and PacBio technologies). Samples were collected from four locations in New Brunswick, Canada from fields previously rotated with barley or oat. Comparative analysis of the bacterial, fungal, and eukaryotic diversity in soil samples showed minimal differences, with only bacterial alpha diversity influenced by the plant health status. Verticillium dahliae was abundant in all soil samples, and its abundance was significantly higher in the stems of diseased plants. Additional fungal species implicated in PED, including Plectosphaerella cucumerina, Colletotrichum coccodes, Botrytis sp., and Alternaria alternata, were also identified in the stems. This study highlights the complex, plant-associated microbial interactions underlying PED and provides a foundation for microbiome-informed disease management strategies. Full article

Smoke tree (Cotinus coggygria) is an important component of the urban landscape and represents red-leaf scenery in Beijing; however, Verticillium wilt, caused by Verticillium dahliae, has caused high mortality of smoke trees. Traditional control methods, such as chemical root irrigation and trunk injection, are problematic due to environmental pollution and potential plant damage. This study aimed to explore effective prevention and control methods for Verticillium wilt of smoke tree across different regions of red-leaf scenery in Beijing. In 2023, 240 smoke trees from the Pofengling Park of Beijing were selected for the study. Four different fungicides, a plant growth regulator and a biocontrol agent were tested. Three application methods (root irrigation, trunk spraying, and a combination of both) were used in the different trials. Based on the results of the 2023 trial, control trials were conducted under the disease classification in 2024 at key red-leaf scenery regions, such as Xiangshan Park, Xishan Park, and Pofengling Park. The bioagents of Bacillus subtilis root irrigation combined with the trunk spraying treatment group showed the best disease control effects. Calculated by the change in disease index in the treatment and blank groups, the corrective control effect in the treatment group reached 104.55%, and 60% of the plants remained healthy, indicating that this method of disease control was the most effective. Propiconazole root irrigation also had a significant effect on diseased smoke trees. Furthermore, validation experiments conducted in 2024 confirmed that various combinations of root irrigation and trunk spraying provided strong preventive and therapeutic effects on Verticillium wilt. In conclusion, the graded control measures demonstrated effective control of wilt at different disease index grades. This study offers an effective and practical solution for controlling Verticillium wilt, benefiting both environmental sustainability and landscape health. Full article

Background: Verticillium wilt, which is a soil-borne vascular disease, causes serious economic losses worldwide. Various toxins secreted by V. dahliae are key factors that lead to wilt symptoms. Methods: The Vd-toxins CIA, indazole, and 3ICD were labeled with fluorescence groups, respectively, to observe the transport pathway. Transcriptome sequencing and qRT-PCR were employed to assess the expression patterns under Vd-toxin treatment. Results: AtALA1 and AtALA7 were up-regulated by V. dahliae and LC-toxins, and overexpression of either AtALA1 or AtALA7 increased Arabidopsis resistance against LC-toxins. Overexpression of AtALA1 improved the resistance of Arabidopsis to 4MBA, 3ICD, and indazole, while AtALA7 enhanced resistance to 4MBA, 3ICD, and CIA. AtALA7-overexpressing plants showed a stronger capability to transport CIA^FITC and 3ICD^5-FAM into vacuoles, while AtALA1-overexpressing plants accumulated indazole^5-FAM and 3ICD^5-FAM. Aggregation of AtALA1 and AtALA7 enhances the resistance of plants to V. dahliae. Conclusions: Arabidopsis P4-ATPase genes AtALA1 and AtALA7 mediated cell detoxification by transporting different Vd-toxins to vacuoles for degradation, thereby increasing resistance to Verticillium wilt. Full article

Verticillium wilt (VW), induced by the soil-borne fungus Verticillium dahliae, represents a significant threat to global cotton production. Phenylalanine ammonia-lyase (PAL) is an essential enzyme in lignin metabolism that helps plants defend themselves against pathogenic fungal. Nonetheless, its role in imparting resistance to V. dahliae in cotton required further investigation. This study identified the GhPAL9 (GH_D04G1247) as a crucial gene in cotton resistance to V. dahliae via RNA-seq analysis, demonstrating significant upregulation in the resistant variety Xinluzao84. Bioinformatics analysis revealed the conserved evolutionary relationship of GhPAL9 with PAL homologs across various species and highlighted stress-responsive cis-elements in its promoter region. The expression of GhPAL9 was rapidly activated in roots, stems, and leaves following infection with V. dahliae, peaking between 2 and 8 h post inoculation (hpi). Silencing GhPAL9 through virus-induced gene silencing (VIGS) technology intensified disease symptoms, elevated relative fungal biomass, and diminished lignin accumulation, thereby affirming its function in cotton resistance to V. dahliae. The overexpression of GhPAL9 in Arabidopsis improved resistance to V. dahliae, and the OE-GhPAL9 transgenic lines demonstrated reduced disease severity and diminished relative fungal biomass. The results gave us new information about how VW resistance at the molecular level, which established that GhPAL9 acted as a positive regulator to increase resistance to VW via lignin accumulation. Full article

Potato early dying (PED) disease complex is often called the Verticillium wilt of potato and is considered one of the most economically devastating diseases of potato worldwide. The severity of the disease greatly increases with the association of the soil-borne pathogens Verticillium dahliae and V. albo-atrum and the root lesion nematode (Pratylenchus sp.). Recently, an increase in wilt disease symptoms and a sharp decline in marketable tuber yield were observed in New Brunswick (NB), Canada. A survey of 71 fields, along with eight fumigated and eight non-fumigated fields, was carried out to determine and quantify nematodes and Verticillium in the soil. Techniques used included plate counts for Verticillium (CFU/g soil), real-time qPCR (RT-qPCR) for V. dahliae (cell/g soil), and nematode identification and counts (# of nematodes/kg of soil). The survey results of the 71 fields revealed that 55 fields had Verticillium sp. ranging from 2 to 66 CFU/g of soil by the plate method, and 68 fields had high V. dahliae ranging from 261 to 27,471 cell/g of soil by RT-qPCR method. All fields had high numbers of root lesion nematodes ranging from 560 to 14,240 nematodes/kg of soil. There was an uneven distribution of PED incidence in potato fields at various locations of NB. Fumigation with Chloropicrin significantly reduced the numbers of root lesion nematodes by 34.1–99.0%, Verticillium sp. CFU/g of soil by 50–100%, and V. dahliae cell/g soil by 38–91% in the eight fumigated fields. The management of the PED complex with various disease management products under field conditions was also studied in a field plot trial setup. The nematicide Velum applied in-furrow at the recommended label rate decreased the numbers of root lesion nematodes by up to 66% compared to other products. The combination of both Velum + Aprovia and the application of ammonium-lignosulfonate significantly reduced V. dahliae by 190.55% and 274.24%, respectively, compared to other products. The fungicide Aprovia applied in-furrow at the recommended rate for the management of Verticillium wilt significantly reduced Verticillium sp. CFU/g of soil in treated soil by 73.3% compared to Velum, Mustgrow, Senator PSPT, Vapam, ammonium-lignosulfonate, Nimitz, and the untreated control. Disease management products increased potato marketable yield by 27.38–97.74%. The results of this study suggest that the root lesion nematode and V. dahliae have a ubiquitous distribution in the fields cultivated with potatoes in NB. The co-infection of potato by both V. dahliae and the root lesion nematode can greatly increase the severity of PED. Fumigation with Chloropicrin significantly reduced the levels of root lesion nematodes and Verticillium in all fumigated fields. Management practices of PED using the fungicide Aprovia, the nematicide Velum, and a combination of both Velum + Aprovia had the greatest effect in reducing the population density of the root lesion nematode and Verticillium dahliae in soils of commercial potato fields in New Brunswick. Full article

Verticillium stripe, a soilborne disease of canola (Brassica napus) caused by Verticillium longisporum, was first identified on the Canadian Prairies in 2014. Despite its increasing incidence, the impact of this disease on canola yields has not been quantified. To address this gap, the relationship between Verticillium stripe severity and yield was investigated in two canola hybrids, ‘45H31’ and ‘CS2000’, at two infested field sites near St. Albert, Alberta, in 2020 and 2021. In 2020, a year with above-average rainfall, both hybrids developed moderate levels of the disease, whereas in 2021, a drought year, symptoms and signs of infection were milder. Regression analysis indicated that seed yield per plant declined with increasing Verticillium stripe severity in both years of the study. In both hybrids, the relationship between disease severity and yield was best explained by second-degree quadratic equations. Although single-plant seed yield declined by up to 80% with increasing Verticillium stripe severity, these reductions did not translate into significant yield losses at the plot level, suggesting that losses experienced by individual plants were offset by reduced competition among the surviving plants. These results underscore the complexity of assessing disease impacts solely based on symptom severity. Full article