Search Results (53)

Fusarium pseudograminearum (Fp) and soil salinity are two types of stress that interact in complex ways, potentially leading to more severe consequences on wheat growth and productivity. However, little is known about the colonization efficiency and the signal pathways of the beneficial Trichoderma longibrachiatum TG1 (TG1) in controlling wheat Fusarium crown rot caused by Fp, and enhancing wheat seedling growth under combined salinity and Fp stresses. Therefore, the present study aims to determine the colonization, phytohormone profile, and signaling pathway in TG1-treated wheat seedlings under salinity and Fp stresses. In a dual culture assay, TG1 exhibited a mycoparasitic effect on Fp growth by coiling, conidial attachment, and parasitism observed under fluorescent microscopy. In addition, TG1 colonized the outermost layers of the wheat seedling roots with biomass consisting of conidia and hyphae. Under 100 mM NaCl stress, the combined TG1+Fp-treated seedlings recorded a control efficacy of 47.01% for the wheat crown rot disease compared with Fp-alone-treated seedlings. The contents of indole-3-acetic acid (IAA), gibberellic acid (GA₃), abscisic acid (ABA) and jasmonic acid (JA) significantly increased by 72.16%, 86.91%, 20.04%, and 50.40%, respectively, in the combined TG1+Fp treatments, whereas the ethylene (ET) content decreased by 39.07% compared with Fp alone at day 14; and 5.07 and 2.78-fold increases in the expression of salicylic acid (SA) signaling pathway genes, such as pathogenesis-related protein 1 (PR1) and isochorismate synthase 1 (ICS1) genes were recorded respectively, in the combined TG1+Fp-treated seedlings compared with the control at day 14. Full article

Fusarium graminearum is a common plant pathogen among cereals worldwide. The application of chemical antifungal compounds is the most frequently used method in controlling F. graminearum. However, its excessive use and the genomic plasticity of the fungal genome lead to increased resistance levels to these chemical antifungal compounds. In this context, plant-derived compounds might play a role in protecting against Fusarium head blight (FHB) and crown rot (CR) as an alternative. In this study, we aimed to examine the antifungal effects of an essential oil obtained from Rosa damascena Mill. on the plant pathogen F. graminearum using molecular and analytical methods. The chemical composition of the essential oil was determined by GC-MS. The half effective concentration (EC₅₀) value of R. damascena essential oil (REO) for F. graminearum was determined as 604.25 µg mL⁻¹. Water-soluble tetrazolium 1 (WST-1) analyses revealed that REO caused cytotoxicity in F. graminearum. The potential oxidative stress and autophagic cell death capacity of REO towards F. graminearum was revealed via gene expression analysis and fluorescence microscopy. It was also revealed that, due to the plant-protective effect of REO, the disease severity of treated plants decreased by up to 27.78% in juvenile wheat seedlings infected by F. graminearum. Our data show that R. damascena essential oil might be used as an alternative natural ingredient in the field of plant protection. Full article

Debaryomyces hansenii naturally colonize wheat grain and can potentially inhibit the pathogens responsible for Fusarium crown rot (FCR). Seed dressing is a recommended method for protecting crops against FCR pathogens. The effectiveness of seed dressing with antagonistic yeasts in reducing the incidence of FCR remains insufficiently investigated. The aim of this study was to evaluate the effect of seed dressing with a triazole fungicide and a suspension of D. hansenii cells on the health status and development of durum wheat cultivars (Durasol and Floradur), and to analyze the structure of the mycobiome in the rhizosphere of seedlings. Under field conditions, the incidence of FCR was reduced by 57.1% by triticonazole and 35.7% by the biocontrol agent relative to the control treatment. Seed dressing with D. hansenii decreased the number of operational taxonomic units (OTUs) of Fusarium pathogens by 47.24% in cv. Durasol and 87.4% in cv. Floradur. The number of OTUs of autochthonous yeast species and Mortierellomycota increased in the rhizosphere of both durum wheat cultivars. The effectiveness of seed dressing with yeasts is determined by the quality and local adaptation of biocontrol agents. Full article

Wheat Fusarium crown rot (FCR), mainly caused by Fusarium pseudograminearum, is one of the most important diseases. Some mycoviruses are reported to have a hypovirulence trait and considered as a biocontrol agent for plant fungal diseases. In most cases, mycovirus biological effects have not been explored clearly. In this study, we identified and characterized a novel isolate of double-stranded RNA (dsRNA) mycovirus, Fusarium graminearum dsRNA mycovirus 4 (FgV4), from a new host, an isolate WC9-2 of F. pseudograminearum. The genome of FgV4-WC9-2 includes two dsRNA segments of 2194 bp and 1738 bp. FgV4-WC9-2 dsRNA1 contains a single open reading frame (ORF1), which encodes a protein of 675 amino acids (aa) and has a conserved RNA-dependent RNA polymerase (RdRp) domain. FgV4-WC9-2 dsRNA2 contains two discontinuous ORFs (ORF2-1 and ORF2-2) that code for hypothetical proteins with unknown function. Biological characteristics research has shown that FgV4-WC9-2 infection did not change the colony morphology, but it could significantly decrease colony growth rate. FgV4-WC9-2 could also reduce the sporulation ability, change the conidia size and reduce the pathogenicity of the host to a certain extent. This study is the first to describe a hypovirulence-associated orthocurvulavirus infecting F. pseudograminearum, which has the potential to assist with FCR disease biological management. Full article

Drought and Fusarium crown and root rot (FCRR) are major stresses impacting durum wheat growth. This study aimed to evaluate the antifungal activity of endophytic bacteria against FCRR pathogens and their drought tolerance, as well as assess their effects on wheat growth under normal irrigation, drought stress, and F. culmorum-induced root rot. Sixty bacterial isolates from durum wheat plants in Jordan were tested for antagonism against F. culmorum and drought tolerance. Ten isolates were selected based on their antagonistic activity and drought tolerance for further molecular identification. Greenhouse experiments showed that several endophytes, including Bacillus amyloliquefaciens (isolate 52), Bacillus licheniformis (isolates 37 and 38), and Paenibacillus ehimensis (isolate 60), exhibited significant growth promotion under both normal and drought stress conditions. Isolate 52 demonstrated high antagonistic activity against F. culmorum and very high drought tolerance, making it a promising candidate for biocontrol and biofertilizer development. Furthermore, bacterial treatments significantly reduced FCRR severity, with reductions of up to 82% under normal conditions and up to 61% under drought stress. These findings suggest that endophytic bacteria can enhance durum wheat resilience to both drought and Fusarium infections, offering a sustainable solution for improving wheat productivity in stress-prone environments. Full article

Fusarium pseudograminearum (Fpg) is a significant pathogen responsible for fusarium crown rot (FCR) in wheat (Triticum aestivum L.), a disease with devastating impacts on crop yield. The utilization of biocontrol bacteria to combat fungal diseases in plants is a cost-effective, eco-friendly, and sustainable strategy. In this trial, an endophytic bacterial species, designated as SW, was isolated from the roots of wheat. The strain exhibited potent antagonistic effects against Fpg and reduced the FCR disease severity index by 76.07 ± 0.33% in a greenhouse pot trial. Here, 10⁶ colony-forming units (CFUs)/mL of the SW strain was determined to be the minimum dose required to exhibit the antagonism against Fpg. The strain was identified as Bacillus atrophaeus using genome sequencing and comparison with type strains in the NCBI database. Whole-genome sequencing analysis revealed that SW harbors genes for siderophores, antifungal metabolites, and antibiotics, which are key contributors to its antagonistic activity. Additionally, the strain’s ability to utilize various carbon and nitrogen sources, successfully colonize wheat root tissues as an endophyte, and form biofilms are critical attributes for promoting plant growth. In summary, these findings demonstrate the ability of Bacillus atrophaeus to control FCR disease in wheat in a sustainable agricultural setting. Full article

The worldwide occurrence of wheat crown rot, predominantly caused by the pathogen Fusarium pseudograminearum, has a serious impact on wheat production. Numerous microorganisms have been employed as biocontrol agents, exhibiting effectiveness in addressing a wide array of plant pathogens through various pathways. The mycelium of the white-rot fungus Phanerochaete chrysosporium effectively inhibits the growth of F. pseudograminearum by tightly attaching to it and forming specialized penetrating structures. This process leads to the release of intracellular inclusions and the eventual disintegration of pathogen cells. Furthermore, volatile organic compounds and fermentation products produced by P. chrysosporium exhibit antifungal properties. A comprehensive understanding of the mechanisms and modalities of action will facilitate the advancement and implementation of this biocontrol fungus. In order to gain a deeper understanding of the mycoparasitic behavior of P. chrysosporium, transcriptome analyses were conducted to examine the interactions between P. chrysosporium and F. pseudograminearum at 36, 48, and 84 h. During mycoparasitism, the up-regulation of differentially expressed genes (DEGs) encoding fungal cell-wall-degrading enzymes (CWDEs), iron ion binding, and mycotoxins were mainly observed. Moreover, pot experiments revealed that P. chrysosporium not only promoted the growth and quality of wheat but also hindered the colonization of F. pseudograminearum in wheat seedlings. This led to a delay in the development of stem base rot, a reduction in disease severity and incidence, and the activation of the plant’s self-defense mechanisms. Our study provides important insights into the biocontrol mechanisms employed by P. chrysosporium against wheat crown rot caused by F. pseudograminearum. Full article

Wheat is a vital global food crop, yet it faces challenges in saline–alkali soils where Fusarium crown rot significantly impacts growth. Variations in wheat growth across regions are often attributed to uneven terrain. To explore these disparities, we examined well-growing and poorly growing wheat samples and their rhizosphere soils. Measurements included wheat height, root length, fresh weight, and Fusarium crown rot severity. Well-growing wheat exhibited greater height, root length, and fresh weight, with a lower Fusarium crown rot disease index compared to poorly growing wheat. Analysis of rhizosphere soil revealed higher alkalinity; lower nutrient levels; and elevated Na, K, and Ca levels in poorly growing wheat compared to well-growing wheat. High-throughput sequencing identified a higher proportion of unique operational taxonomic units (OTUs) in poorly growing wheat, suggesting selection for distinct fungal species under stress. FUNGuild analysis indicated a higher prevalence of pathogenic microbial communities in poorly growing wheat rhizosphere soil. This study underscores how uneven terrains in saline–alkali soils affect pH, nutrient dynamics, mineral content, wheat health, and rhizosphere fungal community structure. Full article

The acetylation of histone lysine residues regulates multiple life processes, including growth, conidiation, and pathogenicity in filamentous pathogenic fungi. However, the specific function of each lysine residue at the N-terminus of histone H3 in phytopathogenic fungi remains unclear. In this study, we mutated the N-terminal lysine residues of histone H3 in Fusarium pseudograminearum, the main causal agent of Fusarium crown rot of wheat in China, which also produces deoxynivalenol (DON) toxins harmful to humans and animals. Our findings reveal that all the FpH3^K9R, FpH3^K14R, FpH3^K18R, and FpH3^K23R mutants are vital for vegetative growth and conidiation. Additionally, FpH3K14 regulates the pathogen’s sensitivity to various stresses and fungicides. Despite the slowed growth of the FpH3^K9R and FpH3^K23R mutants, their pathogenicity towards wheat stems and heads remains unchanged. However, the FpH3^K9R mutant produces more DON. Furthermore, the FpH3^K14R and FpH3^K18R mutants exhibit significantly reduced virulence, with the FpH3^K18R mutant producing minimal DON. In the FpH3^K9R, FpH3^K14R, FpH3^K18R, and FpH3^K23R mutants, there are 1863, 1400, 1688, and 1806 downregulated genes, respectively, compared to the wild type. These downregulated genes include many that are crucial for growth, conidiation, pathogenicity, and DON production, as well as some essential genes. Gene ontology (GO) enrichment analysis indicates that genes downregulated in the FpH3^K14R and FpH3^K18R mutants are enriched for ribosome biogenesis, rRNA processing, and rRNA metabolic process. This suggests that the translation machinery is abnormal in the FpH3^K14R and FpH3^K18R mutants. Overall, our findings suggest that H3 N-terminal lysine residues are involved in regulating the expression of genes with important functions and are critical for fungal development and pathogenicity. Full article

Fungicides play a crucial role in conventional agriculture for disease control, but their prolonged use raises health and environmental concerns. Fusarium culmorum (F. culmorum), a major wheat pathogen causing Fusarium head blight (FHB) and Fusarium crown rot (FCR), poses significant mycotoxigenic threats. The application of natural plant extracts has been proven to fight against phytopathogenic fungi. This study aimed to a field experiment that was carried out at the Field Experimental Station of the Institute of Plant Protection—National Research Institute in Winna Góra, Poland, during the 2022/2023 season to evaluate the potential of Lamium album (L. album) flower extract as a foliar spray against mycotoxigenic fungi in two winter wheat varieties: Arkadia and Julius. The supercritical carbon dioxide extraction method (SC-CO₂) was employed to obtain the L. album flower extract. Ergosterol (ERG) and mycotoxin accumulation in the harvested wheat grains were analyzed using chromatography-based methods. The results demonstrated a notable reduction in ERG content in the field plots treated with L. album flower extract, from 26.07 µg/g (control group) to 8.91 µg/g (extract-treated group) for Arkadia and from 70.02 µg/g (control group) to 30.20 µg/g (extract-treated group) for Julius. The treatment with L. album reduced mycotoxin biosynthesis in both varieties, with deoxynivalenol (DON) and zearalenone (ZEN) production significantly decreased. Additionally, Arkadia exhibited greater resistance to Fusarium infection, and the antifungal effect of L. album was more pronounced than in the Julius variety, which proved to be more sensitive. In conclusion, L. album flower extract exhibited promising antifungal effects in field experiments to fight against F. culmorum in winter wheat varieties, suggesting a potential alternative to synthetic fungicides. However, as complete prevention of mycotoxin contamination was not achieved, further research is warranted to optimize extract concentrations and conduct long-term analyses to consider this plant extract as a sustainable control agent. Full article

Fusarium crown rot (FCR) in wheat is a prevalent soil-borne disease worldwide and poses a significant threat to the production of wheat (Triticum aestivum) in China, with F. pseudograminearum being the dominant pathogen. Currently, there is a shortage of biocontrol resources to control FCR induced by F. pseudograminearum, along with biocontrol mechanisms. In this study, we have identified 37 strains of biocontrol bacteria displaying antagonistic effects against F. pseudograminearum from over 8000 single colonies isolated from soil samples with a high incidence of FCR. Among them, QY43 exhibited remarkable efficacy in controlling FCR. Further analysis identified the isolate QY43 as Pseudomonas aeruginosa, based on its colony morphology and molecular biology. In vitro, QY43 significantly inhibited the growth, conidial germination, and the pathogenicity of F. pseudograminearum. In addition, QY43 exhibited a broad spectrum of antagonistic activities against several plant pathogens. The genomics analysis revealed that there are genes encoding potential biocontrol factors in the genome of QY43. The experimental results confirmed that QY43 secretes biocontrol factor siderophores and pyocyanin. In summary, QY43 exhibits a broad spectrum of antagonistic activities and the capacity to produce diverse biocontrol factors, thereby showing substantial potential for biocontrol applications to plant disease. Full article

In China, Fusarium pseudograminearum has emerged as a major pathogen causing Fusarium crown rot (FCR) and caused significant losses. Studies on the pathogen’s properties, especially its mating type and trichothecene chemotypes, are critical with respect to disease epidemiology and food/feed safety. There are currently few available reports on these issues. This study investigated the species composition, mating type idiomorphs, and trichothecene genotypes of Fusarium spp. causing FCR in Henan, China. A significant shift in F. pseudograminearum-induced FCR was found in the present study. Of the 144 purified strains, 143 were F. pseudograminearum, whereas only 1 Fusarium graminearum was identified. Moreover, a significant trichothecene-producing capability of F. pseudograminearum strains from Henan was observed in this work. Among the 143 F. pseudograminearum strains identified, F. pseudograminearum with a 15ADON genotype was found to be predominant (133 isolates), accounting for 92.36% of all strains, followed by F. pseudograminearum with a 3ADON genotype, whereas only one NIV genotype strain was detected. Overall, a relatively well-balanced 1:1 ratio of the F. pseudograminearum population was found in Henan. To the best of our knowledge, this is the first study that has examined the Fusarium populations responsible for FCR across the Henan wheat-growing region. Full article

Fusarium crown rot (FCR), primarily caused by Fusarium pseudograminearum, has emerged as a new threat to wheat production and quality in North China. Genetic enhancement of wheat resistance to FCR remains the most effective approach for disease control. In this study, we phenotyped 435 Chinese wheat cultivars through FCR inoculation at the seedling stage in a greenhouse. Our findings revealed that only approximately 10.8% of the wheat germplasms displayed moderate or high resistance to FCR. A genome-wide association study (GWAS) using high-density 660K SNP led to the discovery of a novel quantitative trait locus on the long arm of chromosome 3B, designated as Qfcr.hebau-3BL. A total of 12 significantly associated SNPs were closely clustered within a 1.05 Mb physical interval. SNP-based molecular markers were developed to facilitate the practical application of Qfcr.hebau-3BL. Among the five candidate FCR resistance genes within the Qfcr.hebau-3BL, we focused on TraesCS3B02G307700, which encodes a protein kinase, due to its expression pattern. Functional validation revealed two transcripts, TaSTK1.1 and TaSTK1.2, with opposing roles in plant resistance to fungal disease. These findings provide insights into the genetic basis of FCR resistance in wheat and offer valuable resources for breeding resistant varieties. Full article

Fusarium crown rot (FCR), caused by the fungal pathogen Fusarium pseudograminearum (Fp), is a major constraint to cereal production worldwide. The pathogen restricts the movement of solutes within the plant due to mycelial colonisation of vascular tissue. Yield loss and quality downgrades are exacerbated by this disease under water stress conditions. Plant root systems are adaptive and can alter their architecture to optimise production in response to changes in environment and plant health. This plasticity of root systems typically favours resource acquisition of primarily water and nutrients. This study examined the impact of FCR on the root system architecture of multiple commercial bread and durum wheat varieties. Root system growth was recorded in-crop in large transparent rhizoboxes allowing visualization of root architecture over time. Furthermore, electrical resistivity tomography was used to quantify spatial root activity vertically down the soil profile. Results demonstrated a significant reduction in the total root length and network area with the inoculation of FCR. Electrical resistivity measurements indicated that the spatial pattern of water use for each cultivar was influenced differently from infection with FCR over the growing season. Specifically temporal water use can be correlated with FCR tolerance of the varieties marking this investigation the first to link root architecture and water use as tolerance mechanisms to FCR infection. This research has implications for more targeted selection of FCR tolerance characteristics in breeding programs along with improved specific varietal management in-crop. Full article

Fusarium pseudograminearum is one of the major fungal pathogens that cause Fusarium crown rot (FCR) worldwide and can lead to a substantially reduced grain yield and quality. Transcription factors play an important role in regulating growth and pathogenicity in plant pathogens. In this study, we identified a putative Zn(II)₂Cys₆ fungal-type domain-containing transcription factor and named it FpUme18. The expression of FpUME18 was induced during the infection of wheat by F. pseudograminearum. The ΔFpume18 deletion mutant showed defects in growth, conidial production, and conidial germination. In the responses to the cell wall, salt and oxidative stresses, the ΔFpume18 mutant inhibited the rate of mycelial growth at a higher rate compared with the wild type. The staining of conidia and mycelia with lipophilic dye FM4-64 revealed a delay in endocytosis when FpUME18 was deleted. FpUME18 also positively regulated the expression of phospholipid-related synthesis genes. The deletion of FpUME18 attenuated the pathogenicity of wheat coleoptiles. FpUME18 also participated in the production of the DON toxin by regulating the expression of TRI genes. Collectively, FpUme18 is required for vegetative growth, conidiation, stress response, endocytosis, and full virulence in F. pseudograminearum. Full article