Search Results (78)

Bread and durum wheat are the most important staple crops, providing 55% of the carbohydrates and 20% of the daily caloric intake for nearly 40% of the global population. However, yield losses in durum wheat can reach up to 56% due to reductions in grain yield and agronomic traits. Local wheat production is increasingly declining because of biotic and abiotic stress. The severity of Fusarium crown and root rot diseases is influenced by cereal mono-culture, specific agronomic practices, and the cultivation of susceptible wheat cultivars. The review highlights current research on the causal agents, economic importance, and management practices of Fusarium crown and root rot diseases in North African countries. The review will contribute to the study of these diseases in wheat. Full article

Fusarium crown rot (FCR) is a devastating fungal disease of wheat in China that causes substantial yield losses and deterioration of grain quality. To clarify the pathogen composition and associated mycotoxin risks of FCR in Hebei Province, a comprehensive field survey was conducted during the critical growth stage from flowering to maturity (April to May) of the 2024 wheat season from 46 sites. Fungal isolates were obtained from symptomatic wheat stem bases and were identified through morphological and molecular analyses. In total, 156 Fusarium isolates were obtained, and from these isolates, 12 Fusarium species were identified based on species-specific PCR and DNA sequencing of the translation elongation factor 1-α (TEF1) loci. Of these Fusarium isolates, 118 were identified as Fusarium pseudograminearum, 16 identified as F. graminearum and the remaining isolates consisted of F. acuminatum, F. asiaticum, F. boothii, F. culmorum, F. equiseti, F. flocciferum, F. incarnatum, F. proliferatum, F. sinensis, and F. verticillioides. The results revealed that F. pseudograminearum with the 15ADON genotype was the predominant species, accounting for 75.64% of all the isolates, followed by F. graminearum. Trichothecene genotyping revealed that 91.53% of the F. pseudograminearum strains possessed the 15ADON genotype (108 isolates), while 8.47% exhibited the 3ADON genotype (10 isolates). Although differences were observed within F. pseudograminearum in MAT1-1 and MAT1-2 distributions among different sampling regions, a well-balanced mating type ratio was identified across Hebei Province. Population genetic analysis based on composite genotypes (trichothecene and mating type) revealed moderate to high genetic diversity within the F. pseudograminearum population. Recent studies on causal Fusarium species, trichothecene genotypes, and their distribution in China are compared and discussed. These findings may have implications in managing this significant fungal disease. Full article

Fusarium crown rot (FCR), caused by Fusarium pseudograminearum, is a devastating wheat disease leading to significant yield losses worldwide. However, the pathogenic mechanism of F. pseudograminearum and its resistance to fungicides remain poorly understood. In this study, we identified a hypothetical gene encoding GPI-anchored protein, designated FpPer1, by screening a T-DNA insertion mutant library of F. pseudograminearum for tebuconazole resistance. The ΔFpper1 mutant exhibited increased sensitivity to the triazole antifungal drugs and fludioxonil. Additionally, the deletion of FpPER1 impaired fungal growth, conidiation, and pathogenicity in barley leaves and wheat coleoptiles. Furthermore, the ΔFpper1 mutant displayed enhanced susceptibility to various environmental stresses, including NaCl, CR, sorbitol, H₂O₂, and SDS. The mutant also showed reduced penetration peg formation and impaired reactive oxygen species (ROS) scavenging ability during infection. Subcellular localization analysis revealed that FpPer1-GFP co-localized with the endoplasmic reticulum (ER) marker RFP-HDEL in both conidia and hyphae, indicating its localization in the ER. In summary, our findings demonstrate that FpPER1 plays an important role in pathogenicity and fungicide resistance in F. pseudograminearum. This study not only provides a theoretical foundation for understanding fungal virulence mechanisms but also offers practical insights for developing novel fungicide strategies. Full article

Fusarium crown rot, a widespread and destructive disease affecting cereal crops (particularly wheat and barley), is primarily caused by the soil-borne fungal pathogen Fusarium pseudograminearum. Secondary metabolites (SMs) play a crucial role in colonization and host tissue invasion by pathogenic fungi. In this study, we investigated the functional role of FpTox2, a secondary metabolite-related gene in F. pseudograminearum. An FpTox2 deletion mutant exhibited significantly reduced radial growth compared to wild-type F. pseudograminearum. Notably, the mutant strain completely lost conidiation capacity under induced conditions. Furthermore, although it showed decreased sensitivity to the cell membrane inhibitor sodium dodecyl sulfate (SDS), the mutant demonstrated enhanced susceptibility to NaCl, a metal ion stressor. Most importantly, the pathogen’s virulence was markedly attenuated in wheat stem base infections following FpTox2 deletion, and we demonstrated that FpTox2 regulates pathogen virulence by influencing deoxynivalenol production. In conclusion, FpTox2 is crucial for vegetative growth, asexual development, abiotic stress responses, and full virulence in F. pseudograminearum. Full article

Fusarium culmorum is the causal agent of root rot and crown rot in soft wheat. The aim of this study was to investigate the control mechanism of Talaromyces pinophilus HD25G2 as a biocontrol agent against F. culmorum. This involved the isolation and molecular identification of Fusarium and Talaromyces strains from soft wheat. The assay included the inhibition test of F. culmorum mycelial growth on potato dextrose agar and soft wheat media at two water activity values (0.98 and 0.95), its production of mycotoxins, and the fungal cell wall-degrading enzymes implicated in the antagonistic effect of T. pinophilus. The results showed that T. pinophilus and its extract free of cells reduced the growth of F. culmorum by over 55%. Interestingly, the T. pinophilus HD25G2 showed high chitinase, protease, and cellulose production on solid media. In addition, chitinolytic and proteolytic activities were estimated at the values of 1.72 ± 0.02UI and 0.49 ± 0.01UI, respectively. However, the mycotoxin evaluation assay revealed that F. culmorum HD15C10 produced zearalenone (ZEA) and the biocontrol agent enhanced its production, but the early inoculation of T. pinophilus, before F. culmorum growth onset, inhibited 100% its growth and, therefore, prevented the presence of ZEA. Hence, this strain can be proposed as a biocontrol agent against F. culmorum, and it can be further investigated for biocontrol of Fusarium root and crown rot in vivo. Full article

Wheat (Triticum aestivum L.) is a crucial global food crop. The intensive crop farming, monoculture cultivation, and impact of climate change affect the susceptibility of wheat cultivars to biotic stresses, mainly caused by soil fungal pathogens, especially those belonging to the genus Fusarium. This situation threatens yield and grain quality through root and crown rot. While conventional chemical fungicides face resistance issues and environmental concerns, biological alternatives like seed priming with natural metabolites are gaining attention. Polyamines, including putrescine, spermidine, and spermine, are attractive priming agents influencing plant development and abiotic stress responses. Spermine in particular shows potential for in vitro antifungal activity against Fusarium. Optimising spermine concentration for seed priming is crucial to maximising protection against Fusarium infection while ensuring robust plant growth. In this research, we explored the potential of the polyamine spermine as a seed treatment to enhance wheat resilience, aiming to identify a sustainable alternative to synthetic fungicides. Our findings revealed that a six-hour seed soak in spermine solutions ranging from 0.5 to 5 mM did not delay germination or seedling growth. In fact, the 5 mM concentration significantly stimulated root weight and length. In complementary in vitro assays, we evaluated the antifungal activity of spermine (0.5–5 mM) against three Fusarium species. The results demonstrated complete inhibition of Fusarium culmorum growth at 5 mM spermine. A less significant effect on Fusarium graminearum and little to no impact on Fusarium oxysporum were found. The performed analysis revealed that the spermine had a fungistatic effect against the pathogen, retarding the mycelium growth of F. culmorum inoculated on the seed surface. A pot experiment with Bulgarian soft wheat cv. Sadovo-1 was carried out to estimate the effect of seed priming with spermine against infection with isolates of pathogenic fungus F. culmorum on plant growth and disease severity. Our results demonstrated that spermine resulted in a reduced distribution of F. culmorum and improved plant performance, as evidenced by the higher fresh weight and height of plants pre-treated with spermine. This research describes the efficacy of spermine seed priming as a novel strategy for managing Fusarium root and crown rot in wheat. Full article

Oregano (Origanum vulgare) cultivation is of great economic importance in Peru. Tacna stands out as its main producer. However, the presence of phytopathogenic fungi represents a challenge for its production. This study aimed to characterize both the morphological and molecular levels of the causal agent of crown and root rot in a crop field in the Camilaca district, Candarave, Tacna. To this end, systematic sampling was carried out using the five-gold method, collecting plants with typical symptoms. Fungi were isolated from diseased roots and characterized using macroscopic and microscopic morphological analysis as well as sequencing and multilocus phylogenetic analysis (ITS, 28S, HIS3, TEF1, TUB2). In addition, pathogenicity tests were performed on healthy plants to confirm the infectivity of the isolates. The results demonstrated that root rot was caused by a complex of phytopathogenic fungi through phylogenetic analysis of Dactylonectria torresensis, Fusarium oxysporum, F. iranicum, and F. redolens. These findings represent the first report of these species as causal agents of oregano root rot in Peru, highlighting the need for integrated management strategies that reduce the economic impact of these diseases and contribute to the sustainability of the crop in key producing regions such as Tacna. Full article

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

Strawberries are planted globally as an important crop. Fusarium oxysporum f. sp. fragariae (Fof), a haploid mitosporic, pathogenic fungus with obvious host specificity, is responsible for an economically devastating soil-borne disease seriously threatening strawberry. Fusarium oxysporum is distributed in soils worldwide and causes vascular wilt and root rot disease in over 100 plant species. However, the formae speciales of F. oxysporum commonly have a very narrow host range, often restricted to a single host plant species. We isolated and identified pathogenic F. oxysporum from diseased strawberry samples collected from different provinces in China. Further analysis showed that among the 55 F. oxysporum isolates, only 70.91% belonged to Fof, and the remaining 29.09% were named Fo. The mycelial growth of Fof was faster than that of Fo at 20, 30, and 35 °C. The sporulation ability of Fof was weaker than that of Fo, and Fof presented a significantly higher germination rate under high temperatures. Fof and Fo from strawberry were not pathogenic to tomato or cucumber plants, and Fof showed significantly higher pathogenicity on strawberry than Fo. To explore the pathogenic mechanism of Fof, we knocked out SIX10 in Fof. The mycelial growth rate of ΔFofSIX10 was significantly slower than that of the wild type, but there were no significant differences in spore production. The pathogenicity of ΔFofSIX10 to strawberry was significantly weakened, showing decreased severity of symptoms, indicated by root and crown rot, and wilt. Our research provides a basis for understanding the interaction between F. oxysporum and the host strawberry and the occurrence and management of Fusarium disease on strawberry. Full article

In recent years, strawberry cultivation in Spain has been increasingly affected by new and re-emerging fungal diseases. The most significant emerging diseases in Spain include those caused by Neopestalotiopsis spp. Maharachch., K.D.Hyde & Crous and Fusarium oxysporum f. sp. fragariae Winks & Y.N. Williams. These pathogens are difficult to control due to their pathogenic variability (presence of pathotypes and/or races), the lack of knowledge about the susceptibility of the different cultivars, the limited availability of effective fumigants, and the absence of sufficient information about their sources of inoculum. Both pathogens can cause root and crown rot, leading to plant collapse and significant losses for strawberry producers. Several factors have contributed to the rise of these diseases in Spain: (i) the gradual ban on key soil fumigants has left the crop vulnerable; (ii) there has been a notable diversification in the origin of mother plants used in cultivation, with plants now sourced from various countries, increasing the risk of long-distance pathogen spread; (iii) the introduction of numerous new strawberry varieties, which exposes more genotypes to pathogenic infections; and (iv) changes in planting times, leading to younger and more vulnerable plants being exposed to heat stress, as well as an increase in disease susceptibility. Neopestalotiopsis spp. and Fusarium oxysporum f. sp. fragariae have also become major threats to strawberry crops worldwide, spreading through nursery plants and the movement of plant material. The latest research findings in Spain on both pathogens are highlighted in this manuscript. 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