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Environmental factors significantly impact grain mycobiome assembly and mycotoxin contamination. However, there is still a lack of understanding regarding the wheat mycobiome and the role of fungal communities in the interaction between environmental factors and mycotoxins. In this study, we collected wheat grain samples from 12 major wheat-producing provinces in China during both the harvest and storage periods. Our aim was to evaluate the mycobiomes in wheat samples with varying deoxynivalenol (DON) contamination levels and to confirm the correlation between environmental factors, the wheat mycobiome, and mycotoxins. The results revealed significant differences in the wheat mycobiome and co-occurrence network between contaminated and uncontaminated wheat samples. Fusarium was identified as the main differential taxon responsible for inducing DON contamination in wheat. Correlation analysis identified key factors affecting mycotoxin contamination. The results indicate that both environmental factors and the wheat mycobiome play significant roles in the production and accumulation of DON. Environmental factors can affect the wheat mycobiome assembly, and wheat mycobiome mediates the interaction between environmental factors and mycotoxin contamination. Furthermore, a random forest (RF) model was developed using key biological indicators and environmental features to predict DON contamination in wheat with accuracies exceeding 90 %. The findings provide data support for the accurate prediction of mycotoxin contamination and lay the foundation for the research on biological control technologies of mycotoxin through the assembly of synthetic microbial communities., Competing Interests: Declaration of competing interest The authors affirm that this study was carried out without any business or monetary affiliations that might be perceived as potential conflicts of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Fusarium crown rot (FCR), caused by Fusarium pseudograminearum , significantly impacts wheat yield and quality in China's Huanghuai region. The rapid F. pseudograminearum epidemic and FCR outbreak within a decade remain unexplained. In this study, two high-quality, chromosome-level genomes of F. pseudograminearum strains producing 3-acetyl-deoxynivalenol (3AcDON) and 15-acetyl-deoxynivalenol (15AcDON) toxins were assembled. Additionally, 38 related strains were resequenced. Genomic differences such as single nucleotide polymorphisms (SNPs), insertions/deletions (indels), and structural variations (SVs) among F. pseudograminearum strains were analyzed. The whole-genome SNP locus-based population classification mirrored the toxin chemotype (3AcDON and 15AcDON)-based classification, indicating the presence of genes associated with the trichothecene toxin gene cluster. Further analysis of differential SNP, indel, and SV loci between the 3AcDON and 15AcDON populations revealed a predominant connection to secondary metabolite synthesis genes. Notably, the majority of the secondary metabolite biosynthesis gene cluster loci were located in SNP-dense genomic regions, suggesting high mutability and a possible contribution to F. pseudograminearum population structure and environmental adaptability. This study provides insightful perspectives on the distribution and evolution of F. pseudograminearum and for forecasting the spread of wheat FCR, thereby aiding in the development of preventive measures and control strategies., Competing Interests: The author(s) declare no conflict of interest.

The deoxynivalenol (DON)-degrading bacterium JB1-3-2  T was isolated from a rhizosphere soil sample of cucumber collected from a greenhouse located in Zhenjiang, Eastern China. The JB1-3-2  T strain is a Gram-stain-positive, nonmotile and round actinomycete. Growth was observed at temperatures between 15 and 40 ℃ (optimum, 35 ℃), in the presence of 15% (w/v) NaCl (optimum, 3%), and at pH 3 and 11 (optimum, 7). The major cellular fatty acids identified were anteiso-C 15:0 , iso-C 16:0 and anteiso-C 17:0 . Genome sequencing revealed a genome size of 4.11 Mb and a DNA G + C content of 72.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the JB1-3-2  T strain was most closely related to type strains of the Oerskovia species, with the highest sequence similarity to Oerskovia turbata NRRL B-8019  T (98.2%), and shared 98.1% sequence identity with other valid type strains of this genus. Digital DNA‒DNA hybridization (dDDH) and average nucleotide identity (ANI) showed 21.8-22.2% and 77.2-77.3% relatedness, respectively, between JB1-3-2  T and type strains of the genus Oerskovia. Based on genotypic, phylogenetic, chemotaxonomic, physiological and biochemical characterization, Oerskovia flava, a novel species in the genus Oerskovia, was proposed, and the type strain was JB1-3-2  T (= CGMCC 1.18555  T  = JCM 35248  T ). Additionally, this novel strain has a DON degradation ability that other species in the genus Oerskovia do not possess, and glutathione-S-transferase was speculated to be the key enzyme for strain JB1-3-2  T to degrade DON., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Pathogens within Fusarium species are the primary agents of Fusarium head blight (FHB) of wheat, which bring about yield reduction and deoxynivalenol (DON) contamination and are of great concern worldwide. DON-producing Fusarium species can be classified into 3-acetyldeoxynivalenol (3ADON) and 15-acetyldeoxynivalenol (15ADON) chemotypes according to the trichothecene metabolites they produce. The detection of these two chemotypes of pathogens is paramount to the successful implementation of disease management strategies and pathogen-related DON forecasting models. In this study, a duplex droplet digital PCR (duplex ddPCR) assay was developed that allowed for the simultaneous quantitation of 3ADON and 15ADON chemotypes of DON-producing Fusarium species. The assay specificity was tested against 30 isolates of target Fusarium species and several non-target Fusarium species that are frequently isolated from wheat in China. Analyzing 90 wheat samples collected from the North China plain and Yangtze River plain demonstrated that the duplex ddPCR assay coupled with magnetic bead-based DNA extraction was competent for investigating composition of 3ADON and 15ADON chemotypes in Chinese wheat. This assay will be useful for monitoring the epidemic and geographic distribution of 3ADON and 15ADON chemotypes of FHB pathogens, which will help with the disease control and DON management., (Copyright © 2021. Published by Elsevier B.V.)

Objective: To investigate the deoxynivalenol(DON) contamination level of steamed buns sold in market of Shandong Province, and assess the dietary exposure risk of DON from steamed buns to residents of Shandong Province., Methods: DON contaminated steamed buns sold in the market were collected by the simple random sampiling method in July of 2016 was analyzed by high performance liquid chromatography tandem mass spectrometry method. The exposure daily intake(EDI) and the hazard quotient(HQ) of DON intake from steamed buns to residents of Shandong Province was calculated based on Monte Carlo., Results: Among 105 samples, the contamination rate of DON was 100%. The mean value of DON was 111. 10 μg/kg, and the maximum was 848. 33 μg/kg that less than the limit value, 1000 μg/kg of DON in GB 2761-2017, 100 percent pass rate. The mean EDI of groups for steamed buns eater population were higher than that of entire population. 7-12 years old groups had the highest mean EDI that was 1. 04 μg/kg and 1. 32 μg/kg respectively for entire population and steamed buns eater population. The HQ of DON intake from steamed buns for different population groups presents a multi-probability distribution. It was 83. 5% of entire population and 80. 4% of steamed buns eater population that the DON health risk were at a safe level. The unacceptability probability values of DON health risk were 29. 9% and 35. 5%, respectively for the 7-12 years old groups of entire population and steamed buns eater population. There was 0. 1%-1. 1% of entire population and steamed buns eater population which HQ was equal or greater than 10, and the main risk sensitive factor was the DON content of steamed buns., Conclusion: The steamed buns sold in market of Shandong Province were generally contaminated DON. The DON content of steamed buns was at qualified level although which had significant difference of different region. Not only the entire population but also steamed buns eater population of Shandong residents had health risk hazards of DON from steamed buns, and the probability values were 16. 5%, 19. 6%, respectively. The probability values of HQ that was equal or greater than 10 were 0. 1% and 0. 2% of the entire population and steamed buns eater population. The 7-12 years old groups were a high-risk group that dietary exposure risk of DON were derived from steamed buns.

Members of the Fusarium graminearum species complex (FGSC) are important pathogens on wheat, maize, barley, and rice in China. Harvested grains are often contaminated by mycotoxins, such as the trichothecene nivalenol (NIV) and deoxynivalenol (DON) and the estrogenic mycotoxin zearalenone (ZEN), which is a big threat to humans and animals. In this study, 97 isolates were collected from maize, wheat, and rice in Jiangsu and Anhui provinces in 2013 and characterized by species- and chemotype-specific PCR. F. graminearum sensu stricto (s. str.) was predominant on maize, while most of the isolates collected from rice and wheat were identified as F. asiaticum. Fusarium isolates from three hosts varied in trichothecene chemotypes. The 3-acetyldeoxynivalenol (3ADON) chemotype predominated on wheat and rice population, while 15ADON was prevailing in the remaining isolates. Sequence analysis of the translation elongation factor 1α and trichodiene synthase indicated the accuracy of the above conclusion. Additionally, phylogenetic analysis suggested four groups with strong correlation with species, chemotype, and host. These isolates were also evaluated for their sensitivity to carbendazim and mycotoxins production. The maize population was less sensitive than the other two. The DON levels were similar in three populations, while those isolates on maize produced more ZEN. More DON was produced in carbendazim resistant strains than sensitive ones, but it seemed that carbendazim resistance had no effect on ZEN production in wheat culture.

One hundred and forty three airborne Fusarium isolates in chicken houses belonging to seven Fusarium species were analyzed by PCR with Tri5 gene as a specific marker of mycotoxin product . The result of Tri5 gene sequence analysis indicates that the PCR amplification products were 89%-96% identical to the previously reported Tri5 genes, which were all amplified from four F. poae isolates. T-2 toxin and DON was measured by immunoaffinity column and high performance liquid chromatography in Tri5-positive F. poae isolates after being cultured at constant and alternating temperatures. The production of T-2 toxin under alternating temperatures was 14 and 53 times higher than those at constant temperature of 8 °C and 25 °C. No DON was detected under either testing temperature condition. It is concluded that T-2 toxin-producing F. poae isolates were present in poultry houses, and the concentration of T-2 toxin produced by Tri5-positive F. poae isolates was increased under alternating temperatures. The application of Tri5-PCR associated with IMC-HPLC is an effective and accurate method for rapid detection of T-2 and DON mycotoxins.