Search Results (187)

Maize (Zea may L.) is one of the most important crops worldwide, but ear rot poses a significant threat to its production. Diverse pathogens cause ear rot in China, with Fusarium spp. being predominant, especially Fusarium graminearum and Fusarium verticillioides. Current methods for the control of ear rot are limited, making the use of resistant germplasm resources an effective and economical management strategy. Earlier research focused on resistance to Fusarium ear rot (FER; caused by F. verticillioides) and Gibberella ear rot (GER; caused by F. graminearum), but assessing maize resistance to multiple major Fusarium spp. is critical in ensuring maize production. Thus, the resistance of 343 maize germplasm resources to ear rot caused by six Fusarium spp. (F. verticillioides, F. graminearum, F. proliferatum, F. meridionale, F. subglutinans, and F. temperatum) was evaluated in this study. Over three years, 69 and 77 lines resistant to six and five ear rot diseases, respectively, and 139 lines resistant to both FER and GER were identified. Moreover, the 343 germplasm resources were divided into eight heterotic groups, of which PH4CV was the most resistant one, whereas NSS and Pioneer Female were the least resistant ones. These findings provide a basis for the development of maize cultivars with broad-spectrum ear rot resistance. Full article

Biocontrol is one of the most promising alternatives to chemical preservatives for food preservation. This study investigated the biocontrol potential of yeasts isolated from raw milk cheese against spoilage moulds. Eighty-four native yeast strains were screened for antagonistic activity against Penicillium commune, Fusarium verticillioides, and Mucor plumbeus/racemosus via confrontation using a milk-based culture medium. Fifteen strains from the species Pichia jadinii, Kluyveromyces lactis, Kluyveromyces marxianus, and Geotrichum candidum exhibited significant antagonistic activity (inhibition zone > 2 mm) against M. plumbeus/racemosus and F. verticillioides. The modelling of the impact of ripening conditions revealed that temperature was the primary factor influencing yeast antagonism. In addition, notable variability at both species and strain levels was found. The antagonist activity was associated with different mechanisms depending on the species and strains. K. lactis stood out for its proteolytic activity and competition for iron and manganese. Additionally, two strains of this species (KL890 and KL904) were found to produce volatile organic compounds with antifungal properties (phenylethyl alcohol and 1-butanol-3-methyl propionate). G. candidum GC663 exhibited strong competition for space, as well as the ability to parasitise hyphae linked to its pectinase and β-glucanase activity. The latter enzymatic activity was detected in all P. jadinii strains, with P. jadinii PJ433 standing out due to its proteolytic activity. In a cheese matrix, the efficacy of eight yeast strains against three target moulds was assessed, highlighting the potential of G. candidum GC663 and P. jadinii PJ433 as biocontrol agents, exhibiting high and moderate efficacy, respectively, in controlling the growth of F. verticillioides and M. plumbeus/racemosus. Nonetheless, further research is necessary to elucidate their full spectrum of antifungal mechanisms and to validate their performance under industrial-scale conditions, including their impact on cheese quality. Full article

Fusarium spp. represent a critical threat to maize production and food safety due to their mycotoxin production. This study introduces a refined molecular identification protocol integrating four genomic regions—ITS1, IGS, TEF-1α, and β-TUB—for robust species differentiation of Fusarium spp. isolates from post-harvest maize in Bulgaria. The protocol enhances species resolution, especially for closely related taxa within the Fusarium fujikuroi species complex (FFSC). A newly optimized multiplex PCR strategy was developed using three primer sets, each designed to co-amplify a specific pair of toxigenic genes: fum6/fum8, tri5/tri6, and tri5/zea2. Although all five genes were analyzed, they were detected through separate two-target reactions, not in a single multiplex tube. Among 17 identified isolates, F. proliferatum (52.9%) dominated, followed by F. verticillioides, F. oxysporum, F. fujikuroi, and F. subglutinans. All isolates harbored at least one toxin biosynthesis gene, with 18% co-harboring genes for both fumonisins and zearalenone. This dual-protocol approach enhances diagnostic precision and supports targeted mycotoxin risk management strategies. Full article

Malt bagasse is the primary solid waste product from the brewing process, with notable environmental implications. Due to its nutritional value, it has potential as animal feed, primarily through ensilage. Alfalfa pellets can enhance this silage by adding digestible nitrogen and fibre. However, the high moisture content favours microbial contamination, particularly by fungi like Fusarium, which produces harmful mycotoxins. This study evaluated the impact of winter silage on fungal diversity, Fusarium presence, and mycotoxin contamination in malt bagasse, comparing the pre- and post-silage stages with the addition of alfalfa pellets. Results showed a diverse range of fungi, including Mucor, Cladosporium, Fusarium, and Penicillium, as well as yeasts. Fungal contamination was higher before silage, although the addition of alfalfa increased it after silage was produced. Fusarium verticillioides was the most common Fusarium species. Mycotoxin analysis detected DON (1.4 ppb) in only one sample. A two-month winter silage process under cold-temperate conditions appears to reduce fungal contamination and preserve feed quality. These findings support silage as a circular strategy to manage brewery waste safely, but further research and policy measures are needed to minimise biological risks in the brewing and livestock sectors amid climate change. Full article

Fusarium verticillioides is one of the pathogenic fungi causing maize ear rot, and its secreted fumonisins accumulated in plants pose significant threats to human health. To reduce the incidence of maize ear rot and fumonisin contamination, this study isolated numerous endophytic fungi from maize plants. Through inhibition zone and dual culture assays, an endophytic fungal strain, FJ284, demonstrating notable antifungal activity against F. verticillioides was screened. 18S rDNA gene sequencing was employed for fungal identification, and the sequences were deposited in NCBI GenBank. FJ284 was identified as Penicillium oxalicum. The ethyl acetate extract of P. oxalicum was analyzed using gas chromatography–mass spectrometry (GC-MS), revealing 52 compounds, including several secondary metabolites with documented anticancer, antimicrobial, and antioxidant activities. Furthermore, a spectroscopic method was developed to assess the inhibitory effect of strain FJ284 against F. verticillioides, showing maximum inhibition at 48 h. Finally, Ultra-High-Performance Liquid Chromatography–Mass Spectrometry (UHPLC-MS) analyses confirmed that FJ284 significantly inhibited three fumonisins (suppression rates > 50%), with efficacy ranked as fumonisin B3 (FB3) > fumonisin B2 (FB2) > fumonisin B1 (FB1). Full article

Fusarium verticillioides is a globally prevalent phytopathogenic fungus responsible for multiple diseases in maize and a major producer of the mycotoxin fumonisin B1 (FB1), a highly toxic fungal secondary metabolite (FSM). The histone code, which includes reversible modifications such as acetylation and methylation, plays a critical role in regulating chromatin structure and gene expression. In fungi, di- and tri-methylation of histone H3 at lysine 9 (H3K9me2/3) serves as a key epigenetic mark associated with heterochromatin formation and transcriptional repression. In this study, we identified and characterized a putative heterochromatin protein 1 (HP1) family member in F. verticillioides, designated FvHP1, based on conserved domain architecture and phylogenetic analyses. FvHP1 retains essential residues required for H3K9me2/3 recognition, supporting its functional conservation within the HP1 protein family. Phenotypic analysis of the ΔFvHP1 mutant revealed impaired vegetative growth, reduced conidiation and virulence, and altered FB1 mycotoxin production. Additionally, the accumulation of red pigment in the mutant was linked to the deregulation of secondary metabolism, specifically the overproduction of fusarubin-type naphthoquinones, such as 8-O-methylnectriafurone. These results support the role of FvHP1 in facultative heterochromatin-mediated repression of sub-telomeric biosynthetic gene clusters, including the pigment-associated PGL1 cluster. Our findings provide new insights into the epigenetic regulation of fungal pathogenicity and metabolite production, as well as the first evidence of a functional HP1 homolog in F. verticillioides. Full article

Lysobacter, a genus of Gram-negative bacteria, is known for producing antibiotic compounds, making it a promising biocontrol agent against crop pathogens. As part of the soil microbiome, Lysobacter species cooccur with a variety of microorganisms in the ecosystem. However, little is known about bioactive natural products involved in Lysobacter’s interactions with other organisms. This study investigated interactions between Lysobacter sp. 3655 and two economically important fungal pathogens, Fusarium graminearum and Fusarium verticillioides. We discovered a Lysobacter molecule that is dramatically suppressed when co-culturing with the fungi, and the structure of this molecule was determined to be pyrrole-2-carboxylic acid (P2C). Chitin, a primary component of fungal cell walls, also suppressed P2C production in Lysobacter. Exogenous P2C addition promoted formation of Lysobacter biofilms within a range of concentrations, suggesting its potential role as a signaling molecule. Previously reported result showed that the mutation of the global regulator Clp in Lysobacter enzymogenes led to drastic increase of biofilm formation. Intriguingly, while P2C increased the biofilm formation in the wildtype of L. enzymogenes, it reduced the biofilms in the Clp mutant. Together, these findings reveal P2C as a novel signaling molecule mediating the interaction between Lysobacter and surrounding fungal species, highlighting its role in Lysobacter adaptation in response to environmental conditions. Full article

Common in Fungal Extracellular Membrane (CFEM) effectors, a unique class of fungal-specific proteins, play critical roles in host-pathogen interactions. While CFEM proteins have been extensively characterized in phytopathogens, their presence and functions in Fusarium verticillioides remained unexplored. Here, we systematically identified 19 CFEM-containing proteins in F. verticillioides, among which FvCFEM12 exhibited secretory activity and plant infection-induced expression. Functional characterization revealed that FvCFEM12 suppressed Bax- and INF1-triggered cell death in Nicotiana benthamiana leaves. Furthermore, heterologous expression of FvCFEM12 in maize leaves using P. syringae strain D36E can compromise immune responses against bacterial pathogens. Deletion of FvCFEM12 impaired fungal virulence, altered hyphal morphology, and reduced cell wall stress tolerance. Interestingly, FvCFEM12 physically interacted with the maize wall-associated receptor kinase ZmWAK17ET, and targeted silencing of ZmWAK17 in maize enhanced susceptibility to F. verticillioides. Our findings revealed that FvCFEM12 is a dual-function effector that suppresses plant immunity and maintains fungal cell wall integrity, thereby orchestrating fungal pathogenicity at the host–pathogen interface. Full article

Fumonisins are polyketide-derived mycotoxins posing significant health threats to humans and animals. Among these, fumonisin B₁ (FB₁) is the most prevalent mycotoxin, primarily produced by Fusarium verticillioides, especially in maize and its derived products. Tangeretin, a polymethoxyflavonoid, has been identified as having potential medicinal properties, particularly as an antioxidant. To evaluate the antifungal and anti-mycotoxigenic properties of tangeretin and to elucidate the mechanisms underlying its inhibitory effects, assessments of fungal growth, FB₁ production, conidial germination, and cellulase activity, antioxidant capacity and enzyme activities, transcriptomic analysis and gene deletion experiments were conducted. Consequently, tangeretin significantly curtailed fungal growth and FB₁ production and provided protection against pathogenic infection on corn. It affected genes associated with fungal growth, conidial development, and antioxidant response. Furthermore, tangeretin interfered with the supply of biosynthetic substrate necessary for fumonisin production, particularly impacting pathways involved in alanine metabolism, pyruvate metabolism, fatty acid degradation, and sphingolipid metabolism. Notably, tangeretin downregulated four biosynthetic genes (Fum2, Fum3, Fum10 and Fum11) that are involved in the final steps of fumonisin formation. It likely disrupted the MAPK signaling pathway and targeted a putative NmrA- and HSCARG-like protein Fv_Tan1, which was identified as having positive effects on fungal growth and mycotoxin biosynthesis. This study presents a promising approach for controlling fumonisin contamination in agricultural settings. Full article

Bacillus thuringiensis (Bt) is widely recognized as the most important microbial pesticide controlling various insect pests and diseases due to its insecticidal crystal proteins (ICPs) and antimicrobial metabolites. The current study investigates the biocontrol potential of B. thuringiensis GBAC46 against the fungal pathogen Fusarium verticillioides and the insect pest Spodoptera frugiperda through multiple mechanisms. Phenotypic experiments revealed that GBAC46 effectively inhibited F. verticillioides growth by inducing reactive oxygen species (ROS) accumulation and showed enhanced larvicidal activity against second instar S. frugiperda larvae. Pot experiments showed that feeding by S. frugiperda enhanced F. verticillioides infection in maize. The Bt strain GBAC46 effectively controlled both pests and diseases in greenhouse maize seedlings. Applying the Bt strain GBAC46 reduced feeding damage from S. frugiperda, decreased leaf yellowing and wilting caused by F. verticillioides, and improved growth indicators such as plant height, fresh weight, and dry weight. RT-qPCR results revealed that the Bt strain GBAC46 induced key defense genes in maize involved in activating salicylic acid, jasmonic acid, and ethylene pathways. The overall study demonstrated and confirmed the GBAC46 strain as a promising microbial agent for disease and pest management. Full article

The biotechnological potential of the lactic acid bacterial genus Weissella has not been fully unearthed. Since Weissella have not been tested against Fusaria and their mycotoxins, newly isolated Weissella confusa strains were characterized and tested for their antifungal capacities on Fusarium plant pathogens. W. confusa BF2 and ML2 successfully inhibited Fusarium verticillioides NCIM 1100, F. verticillioides NCIM 1099, Fusarium graminearum MTCC 2089, and Fusarium oxysporum MTCC 284 in co-cultures. Ethyl acetate extracts of the cell-free culture supernatants (CFCS) of W. confusa also exhibited antifungal activity against the tested fungal cultures. The main mycotoxins of Fusaria were tested against the Weissella isolates. In MRS broth, W. confusa BF2 was resistant to the Fusarium mycotoxins (deoxynivalenol, zearalenone, T2, and fumonisin B1), while the ML2 strain showed 22.1–24.5% growth inhibition. Meanwhile, neither bacterium showed potential in mycotoxin reduction. The study highlighted that W. confusa BF2 and ML2 and their CFCS are suitable for Fusarium growth inhibition, as shown on surface-sterilized peanuts and wheat grains, but not for mycotoxin elimination. Full article

In this study, the gene ZmPR5, associated with resistance to ear rot, was identified through transcriptome data analysis of the maize inbred line J1259. The gene was subsequently cloned and its function was investigated. The ZmPR5 gene comprises an open reading frame of 525 base pairs, encoding a protein of 175 amino acids. ZmPR5 was overexpressed in Arabidopsis and the ZmPR5EMS mutant in maize, and they were subjected to q-PCR and measurements of antioxidant enzyme activities (POD, SOD, CAT, MDA), electrical conductivity, and chlorophyll content. The results indicate that the expression of ZmPR5 is up-regulated upon infection by Fusarium verticillioides, with significant differences observed in the activities of POD, SOD, CAT, MDA, electrical conductivity, and chlorophyll content. The study found that ZmPR5 is localized in the nucleus and interacts with Zm00001d020492 (WRKY53) and Zm00001d042140 (glucA). Trypan blue staining revealed that the stained area in the ZmPR5EMS mutant of maize was significantly larger than that in B73. The expression of ZmPR5 is closely associated with resistance to maize ear rot. Full article

Fusarium verticillioides can systematically infect maize through seeds, triggering stalk rot and ear rot at a later stage, thus resulting in yield loss and quality decline. Seeds carrying F. verticillioides are unsuitable for storage and pose a serious threat to human and animal health due to the toxins released by the fungus. Previously, the candidate gene ZmC2GnT was identified, using linkage and association analysis, as potentially implicated in maize seed resistance to F. verticillioides; however, its disease resistance mechanism remained unknown. Our current study revealed that ZmC2GnT codes an N-acetylglucosaminyltransferase, using sequence structure and evolutionary analysis. The candidate gene association analysis revealed multiple SNPs located in the UTRs and introns of ZmC2GnT. Cloning and comparing ZmC2GnT showed variations in the promoter and CDS of resistant and susceptible materials. The promoter of ZmC2GnT in the resistant parent contains one extra cis-element ABRE associated with the ABA signal, compared to the susceptible parent. Moreover, the amino acid sequence of ZmC2GnT in the resistant parent matches that of B73, but the susceptible parent contains ten amino acid alterations. The resistant material BT-1 and the susceptible material N6 were used as parents to observe the expression level of the ZmC2GnT. The results revealed that the expression of ZmC2GnT in disease-resistant maize seeds was significantly up-regulated after infection with F. verticillioides. After treatment with F. verticillioides or ABA, the expression activity of the ZmC2GnT promoter increased significantly in the resistant material, but no discernible difference was detected in the susceptible material. When ZmC2GnT from resistant and susceptible materials was overexpressed in Arabidopsis thaliana, the seeds’ resistance to F. verticillioides increased, although there was no significant difference between the two types of overexpressed plants. Our study revealed that ZmC2GnT could participate in the immune process of plants against pathogenic fungus. ZmC2GnT plays a significant role in regulating the disease-resistance process of maize seeds, laying the foundation for future research into the regulatory mechanism and the development of new disease-resistant maize varieties. Full article

As significant fungal pathogens of crops, Fusaria species contaminate various food and feed commodities. Some of the Fusarium spp. secondary metabolites (e.g., trichothecenes, zearalenone, and fumonisins) are widely known toxic molecules (mycotoxins) with chronic and acute effects on humans and animals. The growing demand for safer, pesticide-free food drives us to increase biological control during crop growing. Recent research suggests that lactic acid bacteria (LABs) as biocontrol are the best choice for extenuating Fusarium mycotoxins. Newly isolated LABs were tested as antifungal agents against Fusarium verticillioides, F. graminearum, and F. oxysporum. The characterized and genetically identified LABs belonged to Limosilactobacillus fermentum (SD4) and Lactiplantibacillus plantarum (FCW4 and CB2) species. All tested LABs and their cell-free culture supernatants showed antagonism on the MRS solid medium. The antifungal activity was also demonstrated on surface-sterilized wheat and peanuts. The germination test of corn kernels proved that the LAB strains SD4 and FCW4 significantly (p < 0.05) enhanced root and shoot development in plantlets while simultaneously suppressing the outgrowth of F. verticillioides. Small-scale corn silage fermentation revealed the significant effects of SD4 supplementation (decreased zearalenone, lower mold count, and total reduction of deoxynivalenol) within the mixed populations. Full article

Maize productivity has remained low and has worsened in the wake of a changing climate, resulting in new invasive pests, with pests that were earlier designated as minor becoming major and with pathogens being transported by pests and/or entering their feeding sites. A study was conducted in 2021 in the Kisumu and Makueni counties, Kenya, to determine how different maize cropping systems affect insect diversity, insect damage to maize, and insects’ ability to spread mycotoxigenic fungi in pre-harvest maize. The field experiments used a randomized complete block design, with the four treatments being maize monocrop, maize intercropped with beans, maize–bean intercrop with the addition of Trichoderma harzianum at planting, and push–pull technology. The FAW, Spodoptera frugiperda (J.E Smith) (Lepidoptera: Noctuidae), was the most damaging pest in the two regions. The push–pull and the maize–bean intercropping technologies significantly reduced the maize foliage and ear damage caused by the FAW. Beetles passively spread mycotoxigenic Aspergillus spp. and Fusarium verticillioides on pre-harvest maize. Maize weevils, namely, Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae), and Carpophilus dimidiatus Fabricius, 1792 (Coleoptera: Nitidulidae), earwigs, namely, Forficula spp. L. (Dermaptera: Forficulidae), and carpenter ants, namely, Camponotus spp. L. (Hymenoptera: Formicidae) carried the highest number of spores on their exoskeletons. This study stresses the role of insects in the spread of fungi on pre-harvest maize and their possible control by intercropping and other cropping technologies. Full article