A new bacterial consortia for management of Fusarium head blight in wheat.

Fusarium head blight (FHB) is a significantly important disease in cereals primarily caused by Fusarium species. FHB control is largely executed through chemical strategies, which are costlier to sustainable wheat production, resulting in leaning towards sustainable sources such as resistance breeding and biological control methods for FHB. The present investigation was aimed at evaluating newly identified bacterial consortium (BCM) as biocontrol agents for FHB and understanding the morpho-physiological traits associated with the disease resistance of spring wheat. Preliminary evaluation through antagonistic plate assay and in vivo assessment indicated that BCM effectively inhibited Fusarium growth in spring wheat, reducing area under disease progress curve (AUDPC) and deoxynivalenol (DON), potentially causing type II and V resistance, and improving single spike yield (SSPY). Endurance to FHB infection with the application of BCM is associated with better sustenance of spike photosynthetic performance by improving the light energy harvesting and its utilization. Correlation and path-coefficient analysis indicated that maximum quantum yield (QY_max) is directly influencing the improvement of SSPY and reduction of grain DON accumulation, which is corroborated by principal component analysis. The chlorophyll fluorescence traits identified in the present investigation might be applied as a phenotyping tool for the large-scale identification of wheat sensitivity to FHB.

A phase-separated protein hub modulates resistance to Fusarium head blight in wheat.

Fusarium head blight (FHB) is a devastating wheat disease. Fhb1, the most widely applied genetic locus for FHB resistance, is conferred by TaHRC of an unknown mode of action. Here, we show that TaHRC alleles distinctly drive liquid-liquid phase separation (LLPS) within a proteinaceous complex, determining FHB susceptibility or resistance. TaHRC-S (susceptible) exhibits stronger LLPS ability than TaHRC-R (resistant), and this distinction is further intensified by fungal mycotoxin deoxynivalenol, leading to opposing FHB symptoms. TaHRC recruits a protein class with intrinsic LLPS potentials, referred to as an "HRC-containing hub." TaHRC-S drives condensation of hub components, while TaHRC-R comparatively suppresses hub condensate formation. The function of TaSR45a splicing factor, a hub member, depends on TaHRC-driven condensate state, which in turn differentially directs alternative splicing, switching between susceptibility and resistance to wheat FHB. These findings reveal a mechanism for FHB spread within a spike and shed light on the roles of complex condensates in controlling plant disease.

Oerskovia flava sp. nov., a deoxynivalenol (DON)-degrading actinomycete isolated from the rhizosphere soil of long-term continuous cropping cucumber.

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-C15:0, iso-C16:0 and anteiso-C17:0. 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.

A Role in 15-Deacetylcalonectrin Acetylation in the Non-Enzymatic Cyclization of an Earlier Bicyclic Intermediate in Fusarium Trichothecene Biosynthesis.

The trichothecene biosynthesis in Fusarium begins with the cyclization of farnesyl pyrophosphate to trichodiene, followed by subsequent oxygenation to isotrichotriol. This initial bicyclic intermediate is further cyclized to isotrichodermol (ITDmol), a tricyclic precursor with a toxic trichothecene skeleton. Although the first cyclization and subsequent oxygenation are catalyzed by enzymes encoded by Tri5 and Tri4, the second cyclization occurs non-enzymatically. Following ITDmol formation, the enzymes encoded by Tri101, Tri11, Tri3, and Tri1 catalyze 3-O-acetylation, 15-hydroxylation, 15-O-acetylation, and A-ring oxygenation, respectively. In this study, we extensively analyzed the metabolites of the corresponding pathway-blocked mutants of Fusarium graminearum. The disruption of these Tri genes, except Tri3, led to the accumulation of tricyclic trichothecenes as the main products: ITDmol due to Tri101 disruption; a mixture of isotrichodermin (ITD), 7-hydroxyisotrichodermin (7-HIT), and 8-hydroxyisotrichodermin (8-HIT) due to Tri11 disruption; and a mixture of calonectrin and 3-deacetylcalonectrin due to Tri1 disruption. However, the ΔFgtri3 mutant accumulated substantial amounts of bicyclic metabolites, isotrichotriol and trichotriol, in addition to tricyclic 15-deacetylcalonectrin (15-deCAL). The ΔFgtri5ΔFgtri3 double gene disruptant transformed ITD into 7-HIT, 8-HIT, and 15-deCAL. The deletion of FgTri3 and overexpression of Tri6 and Tri10 trichothecene regulatory genes did not result in the accumulation of 15-deCAL in the transgenic strain. Thus, the absence of Tri3p and/or the presence of a small amount of 15-deCAL adversely affected the non-enzymatic second cyclization and C-15 hydroxylation steps.

Effects of ferulic acid combined with light irradiation on deoxynivalenol and its production in Fusarium graminearum.

This study aimed to investigate the effects of ferulic acid (FA), a natural phenolic phytochemical, in combination with light irradiation at three wavelengths (365, 385 and 405 nm) on the concentration and toxicity of deoxynivalenol (DON), a mycotoxin produced by Fusarium graminearum. Moreover, this study examined the influence of the combination treatment on DON production in the cultured fungus. FA activated by light at a peak wavelength of 365 nm exhibited the most effective decrease in DON concentration of the tested wavelengths; a residual DON ratio of 0.23 at 24 h exposure was observed, compared with the initial concentration. The reduction in DON using 365-nm light was dependent on the concentration of FA, with a good correlation (r2 = 0.979) between the rate constants of DON decrease and FA concentration, which was confirmed by a pseudo-first-order kinetics analysis of the photoreaction with different FA concentrations (50-400 mg/L) for 3 h. The viability of HepG2 cells increased by 56.7% following in vitro treatment with a mixture containing the photoproducts obtained after treatment with 20 mg/L DON and 200 mg/L FA under 365-nm irradiation for 6 h. These results suggested that the photoreaction of FA under 365-nm irradiation induces the detoxification of DON through degradation or modification of DON. The antifungal effects of the combination (FA and 365-nm light) on F. graminearum were investigated. Conidia treated with the combination did not show additive or synergistic inhibition of fungal biomass and DON production in 7-day cultivated fungal samples compared with samples after single treatment. However, successive treatment, composed of 90 min irradiation at 365 nm and then treatment with 200 mg/L FA for 90 min in the dark, suppressed fungal growth and DON yield to 70% and 25% of the untreated sample level, respectively. This photo-technology involving the two treatment methods of 365-nm irradiation and FA addition as a food-grade phenolic acid in combination or successively, can aid in developing alternative approaches to eliminate fungal contaminants in the fields of environmental water and agriculture. However, further research is required to explore the underlying mechanisms of DON decontamination and its biosynthesis in F. graminearum.

Advances in Understanding Fusarium graminearum: Genes Involved in the Regulation of Sexual Development, Pathogenesis, and Deoxynivalenol Biosynthesis.

The wheat head blight disease caused by Fusarium graminearum is a major concern for food security and the health of both humans and animals. As a pathogenic microorganism, F. graminearum produces virulence factors during infection to increase pathogenicity, including various macromolecular and small molecular compounds. Among these virulence factors, secreted proteins and deoxynivalenol (DON) are important weapons for the expansion and colonization of F. graminearum. Besides the presence of virulence factors, sexual reproduction is also crucial for the infection process of F. graminearum and is indispensable for the emergence and spread of wheat head blight. Over the last ten years, there have been notable breakthroughs in researching the virulence factors and sexual reproduction of F. graminearum. This review aims to analyze the research progress of sexual reproduction, secreted proteins, and DON of F. graminearum, emphasizing the regulation of sexual reproduction and DON synthesis. We also discuss the application of new gene engineering technologies in the prevention and control of wheat head blight.

Mycobiome mediates the interaction between environmental factors and mycotoxin contamination in wheat grains.

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.

Nucleoside Diphosphate Kinase FgNdpk Is Required for DON Production and Pathogenicity by Regulating the Growth and Toxisome Formation of Fusarium graminearum.

Nucleoside diphosphate kinases (NDPKs) are nucleotide metabolism enzymes that play different physiological functions in different species. However, the roles of NDPK in phytopathogen and mycotoxin production are not well understood. In this study, we showed that Fusarium graminearum FgNdpk is important for vegetative growth, conidiation, sexual development, and pathogenicity. Furthermore, FgNdpk is required for deoxynivalenol (DON) production; deletion of FgNDPK downregulates the expression of DON biosynthesis genes and disrupts the formation of FgTri4-GFP-labeled toxisomes, while overexpression of FgNDPK significantly increases DON production. Interestingly, FgNdpk colocalizes with the DON biosynthesis proteins FgTri1 and FgTri4 in the toxisome, and coimmunoprecipitation (Co-IP) assays show that FgNdpk associates with FgTri1 and FgTri4 in vivo and regulates their localizations and expressions, respectively. Taken together, these data demonstrate that FgNdpk is important for vegetative growth, conidiation, and pathogenicity and acts as a key protein that regulates toxisome formation and DON biosynthesis in F. graminearum.

The potential of soil microbial communities to transform deoxynivalenol in agricultural soils-a soil microcosm study.

Infestation of cereal fields with toxigenic Fusarium species is identified as an environmental source for the mycotoxin deoxynivalenol (DON). During rain events, DON may be washed off from infested plants and enter the soil, where microbial transformation may occur. Although some studies showed DON transformation potential of soil microbial communities in liquid soil extracts, these findings can not be transferred to environmental conditions. Accordingly, microbial transformation of DON in soil has to be investigated under realistic conditions, e.g., microcosms mimicking field situations. In this study, we investigated the potential of soil microbial communities to transform DON in six different agricultural soils at two levels (0.5 and 5 µg g-1). The dissipation and the formation of transformation products were investigated in a period of 35 days and compared to a sterilized control. In addition, we measured soil respiration and applied the phospholipid-derived fatty acid (PLFA) analysis to assess whether soil microbial community characteristics are related to the microbial transformation potential. Dissipation of DON in non-sterilized soils was fast (50% dissipation within 0.6-3.7 days) compared to the sterile control where almost no dissipation was observed. Thus, dissipation was mainly attributed to microbial transformation. We verified that small amounts of DON are transformed to 3-keto-deoxynivalenol (3-keto-DON) and 3-epi-deoxynivalenol (3-epi-DON), which were not detectable after 16-day incubation, indicating further transformation processes. There was a trend towards faster transformation in soils with active and large microbial communities and low fungi-to-bacteria ratio.

Baicalin ameliorates the gut barrier function and intestinal microbiota of broiler chickens.

The deoxynivalenol (DON)-contaminated feeds can impair chicken gut barrier function, disturb the balance of the intestinal microbiota, decrease chicken growth performance and cause major economic loss. With the aim of investigating the ameliorating effects of baicalin on broiler intestinal barrier damage and gut microbiota dysbiosis induced by DON, a total of 150 Arbor Acres broilers are used in the present study. The morphological damage to the duodenum, jejunum, and ileum caused by DON is reversed by treatment with different doses of baicalin, and the expression of tight junction proteins (ZO-1, claudin-1, and occludin) is also significantly increased in the baicalin-treated groups. Moreover, the disturbance of the intestinal microbiota caused by DON-contaminated feed is altered by baicalin treatment. In particular, compared with those in the DON group, the relative abundances of Lactobacillus, Lachnoclostridium, Ruminiclostridium and other beneficial microbes in the baicalin-treated groups are significantly greater. However, the percentage of unclassified_f__Lachnospiraceae in the baicalin-treated groups is significantly decreased in the DON group. Overall, the current results demonstrate that different doses of baicalin can improve broiler intestinal barrier function and the ameliorating effects on broiler intestinal barrier damage may be related to modulations of the intestinal microbiota.

Investigating Metabolic Plant Response toward Deoxynivalenol Accumulation in Four Winter Cereals.

Deoxynivalenol (DON) is a phytotoxic agent supporting the spread of fungal diseases in cereals worldwide, i.e., fusarium head blight. It is known that DON accumulation may elicit changes in plant secondary metabolites in response to pathogen attack. This study maps the changes in selected secondary metabolite classes upon DON contamination occurring in fifteen Triticum spp. genotypes, among them emmer, spelt, and soft wheat, and 2 tritordeum varieties, cultivated in two different sites and over two harvest years. The main phenolic classes (i.e., alkylresorcinols, soluble, and cell-wall bound phenolic acids) were targeted analyzed, while changes in the lipidome signature were collected through untargeted HRMS experiments. The results, obtained across multiple Triticum species and in open fields, confirmed the modulation of first-line biological pathways already described in previous studies involving single cereal species or a limited germplasm, thus reinforcing the involvement of nonspecific chemical defenses in the plant response to pathogen attack.

Regulation of TRI5 expression and deoxynivalenol biosynthesis by a long non-coding RNA in Fusarium graminearum.

Deoxynivalenol (DON) is the most frequently detected mycotoxin in cereal grains and processed food or feed. Two transcription factors, Tri6 and Tri10, are essential for DON biosynthesis in Fusarium graminearum. In this study we conduct stranded RNA-seq analysis with tri6 and tri10 mutants and show that Tri10 acts as a master regulator controlling the expression of sense and antisense transcripts of TRI6 and over 450 genes with diverse functions. TRI6 is more specific for regulating TRI genes although it negatively regulates TRI10. Two other TRI genes, including TRI5 that encodes a key enzyme for DON biosynthesis, also have antisense transcripts. Both Tri6 and Tri10 are essential for TRI5 expression and for suppression of antisense-TRI5. Furthermore, we identify a long non-coding RNA (named RNA5P) that is transcribed from the TRI5 promoter region and is also regulated by Tri6 and Tri10. Deletion of RNA5P by replacing the promoter region of TRI5 with that of TRI12 increases TRI5 expression and DON biosynthesis, indicating that RNA5P suppresses TRI5 expression. However, ectopic constitutive overexpression of RNA5P has no effect on DON biosynthesis and TRI5 expression. Nevertheless, elevated expression of RNA5P in situ reduces TRI5 expression and DON production. Our results indicate that TRI10 and TRI6 regulate each other's expression, and both are important for suppressing the expression of RNA5P, a long non-coding RNA with cis-acting inhibitory effects on TRI5 expression and DON biosynthesis in F. graminearum.

Overview of T-2 Toxin Enterotoxicity: From Toxic Mechanisms and Detoxification to Future Perspectives.

Fusarium species produce a secondary metabolite known as T-2 toxin, which is the primary and most harmful toxin found in type A trichothecenes. T-2 toxin is widely found in food and grain-based animal feed and endangers the health of both humans and animals. T-2 toxin exposure in humans and animals occurs primarily through food administration; therefore, the first organ that T-2 toxin targets is the gut. In this overview, the research progress, toxicity mechanism, and detoxification of the toxin T-2 were reviewed, and future research directions were proposed. T-2 toxin damages the intestinal mucosa and destroys intestinal structure and intestinal barrier function; furthermore, T-2 toxin disrupts the intestinal microbiota, causes intestinal flora disorders, affects normal intestinal metabolic function, and kills intestinal epidermal cells by inducing oxidative stress, inflammatory responses, and apoptosis. The primary harmful mechanism of T-2 toxin in the intestine is oxidative stress. Currently, selenium and plant extracts are mainly used to exert antioxidant effects to alleviate the enterotoxicity of T-2 toxin. In future studies, the use of genomic techniques to find upstream signaling molecules associated with T-2 enterotoxin toxicity will provide new ideas for the prevention of this toxicity. The purpose of this paper is to review the progress of research on the intestinal toxicity of T-2 toxin and propose new research directions for the prevention and treatment of T-2 toxin toxicity.

Trichothecenes and Fumonisins: Key Players in Fusarium-Cereal Ecosystem Interactions.

Fusarium fungi produce a diverse array of mycotoxic metabolites during the pathogenesis of cereals. Some, such as the trichothecenes and fumonisins, are phytotoxic, acting as non-proteinaceous effectors that facilitate disease development in cereals. Over the last few decades, we have gained some depth of understanding as to how trichothecenes and fumonisins interact with plant cells and how plants deploy mycotoxin detoxification and resistance strategies to defend themselves against the producer fungi. The cereal-mycotoxin interaction is part of a co-evolutionary dance between Fusarium and cereals, as evidenced by a trichothecene-responsive, taxonomically restricted, cereal gene competing with a fungal effector protein and enhancing tolerance to the trichothecene and resistance to DON-producing F. graminearum. But the binary fungal-plant interaction is part of a bigger ecosystem wherein other microbes and insects have been shown to interact with fungal mycotoxins, directly or indirectly through host plants. We are only beginning to unravel the extent to which trichothecenes, fumonisins and other mycotoxins play a role in fungal-ecosystem interactions. We now have tools to determine how, when and where mycotoxins impact and are impacted by the microbiome and microfauna. As more mycotoxins are described, research into their individual and synergistic toxicity and their interactions with the crop ecosystem will give insights into how we can holistically breed for and cultivate healthy crops.

Self-cascade deoxynivalenol detoxification by an artificial enzyme with bifunctions of dehydrogenase and aldo/keto reductase from genome mining.

Due to the severe health risks for human and animal caused by the intake of toxic deoxynivalenol (DON) derived from Fusarium species, elimination DON in food and feed has been initiated as a critical issue. Enzymatic cascade catalysis by dehydrogenase and aldo-keto reductase represents a fascinating strategy for DON detoxification. Here, one quinone-dpendent alcohol dehydrogenase DADH oxidized DON into less-toxic 3-keto-DON and NADPH-dependent aldo-keto reductase AKR13B3 reduced 3-keto-DON into relatively non-toxic 3-epi-DON were identified from Devosia strain A6-243, indicating that degradation of DON on C3 are two-step sequential cascade processes. To establish the bifunctions, fusion enzyme linking DADH and AKR13B3 was successfully assembled to promote one-step DON degradations with accelerated specific activity and efficiency, resulting 93.29 % of DON removal rate in wheat sample. Three-dimensional simulation analysis revealed that the bifunctional enzyme forms an artificial intramolecular channel to minimize the distance of intermediate from DADH to AKR13B3 for two-step enzymatic reactions, and thereby accelerates this enzymatic process. As the first report of directing single step DON detoxification by an interesting bifunctional artificial enzyme, this work revealed a facile and eco-friendly approach to detoxify DON with application potential and gave valuable insights into execute other mycotoxin detoxification for ensuring food safety.

Fhb7-GST catalyzed glutathionylation effectively detoxifies the trichothecene family.

Trichothecene (TCN) contamination in food and feed is a serious challenge due to the negative health and economic impacts. Here, we confirmed that the glutathione S-transferase (GST) Fhb7-GST could broadly catalyze type A, type B and type D TCNs into glutathione epoxide adducts (TCN-13-GSHs). To evaluate the toxicity of TCN-13-GSH adducts, we performed cell proliferation assays in vitro, which demonstrated decreased cytotoxicity of the adducts. Moreover, in vivo assays (repeated-dose treatment in mice) confirmed that TCN-13-GSH adducts were dramatically less toxic than the corresponding TCNs. To establish whether TCN-13-GSH was metabolized back to free toxin during digestion, single-dose metabolic tests were performed in rats; DON-13-GSH was not hydrolyzed in vivo, but rather was quickly metabolized to another low-toxicity compound, DON-13-N-acetylcysteine. These results demonstrate the promise of Fhb7-GST as a candidate of detoxification enzyme potentially applied in TCN-contaminated agricultural samples, minimizing the detrimental effects of the mycotoxin.

Structure-Guided Steric Hindrance Engineering of Devosia Strain A6-243 Quinone-Dependent Dehydrogenase to Enhance Its Catalytic Efficiency.

Deoxynivalenol (DON), the most widely distributed mycotoxin worldwide, causes severe health risks for humans and animals. Quinone-dependent dehydrogenase derived from Devosia strain A6-243 (DADH) can degrade DON into less toxic 3-keto-DON and then aldo-keto reductase AKR13B3 can reduce 3-keto-DON into relatively nontoxic 3-epi-DON. However, the poor catalytic efficiency of DADH made it unsuitable for practical applications, and it has become the rate-limiting step of the two-step enzymatic cascade catalysis. Here, structure-guided steric hindrance engineering was employed to enhance the catalytic efficiency of DADH. After the steric hindrance engineering, the best mutant, V429G/N431V/T432V/L434V/F537A (M5-1), showed an 18.17-fold increase in specific activity and an 11.04-fold increase in catalytic efficiency (kcat/Km) compared with that of wild-type DADH. Structure-based computational analysis provided information on the increased catalytic efficiency in the directions that attenuated steric hindrance, which was attributed to the reshaped substrate-binding pocket with an expanded catalytic binding cavity and a favorable attack distance. Tunnel analysis suggested that reshaping the active cavity by mutation might alter the shape and size of the enzyme tunnels or form one new enzyme tunnel, which might contribute to the improved catalytic efficiency of M5-1. These findings provide a promising strategy to enhance the catalytic efficiency by steric hindrance engineering.

Evaluation of Immunomodulatory Effects of Fusarium Mycotoxins Using Bacterial Endotoxin-Stimulated Bovine Epithelial Cells and Macrophages in Co-Culture.

Mycotoxins are secondary metabolites produced by a variety of fungi that contaminate animal food and feeds and are capable of inducing a wide range of toxicities. Predictive in vitro models represent valuable substitutes for animal experiments to assess the toxicity of mycotoxins. The complexities of the interactions between epithelial and innate immune cells, vital for upholding barrier integrity and averting infections, remain inadequately understood. In the current study, a co-culture model of bovine epithelial cells (MAC-T) and macrophages (BoMac) was used to investigate the impact of exposure to Fusarium mycotoxins, namely deoxynivalenol (DON), zearalenone (ZEN), enniatin B (ENB), and beauvericin (BEA), on the inflammatory response elicited by the bacterial lipopolysaccharide (LPS) endotoxin. The MAC-T cells and BoMac were seeded on the apical side of a Transwell membrane and in the lower chamber, respectively, and mycotoxin exposure on the apical side of the membrane was carried out with the different mycotoxins (LC20; concentrations that elicited 20% cytotoxicity) for 48 h followed by an LPS immunity challenge for 24 h. The culture supernatants were collected from the basolateral compartment and these samples were submitted for cytokine/chemokine multiplex analysis. RNA-Seq analysis was performed using total RNA extracted from the MAC-T cells to acquire a more detailed insight into their cellular functions. The multiplex analysis indicated that IFN-γ, IL-1α, IL-8, and MCP-1 were significantly induced post-DON treatment when compared to control cells, and levels of IL-1α and IL-8 were enhanced significantly in all mycotoxin-treated groups post-LPS challenge. Analysis of the sequencing results showed that there were 341, 357, and 318 differentially expressed MAC-T cell genes that were up-regulated in the DON, ENB, and BEA groups, respectively. Gene ontology and pathway analysis revealed that these DEGs were significantly enriched in various biological processes and pathways related to inflammation, apoptosis signaling, and Wnt signaling. These results provide a comprehensive analysis of the co-culture cytokine/chemokine production and MAC-T cells' gene expression profiles elicited by Fusarium mycotoxins, which further contributes to the understanding of early endotoxemia post-mycotoxin exposure.

Effective protective agents against organ toxicity of deoxynivalenol and their detoxification mechanisms: A review.

Deoxynivalenol (DON) is one of the most prevalent mycotoxins in feed, which causes organ toxicity in animals. Therefore, reducing DON-induced organ toxicity can now be accomplished effectively using protective agents. This review provides an overview of multiple studies on a wide range of protective agents and their molecular mechanisms against DON organ toxicity. Protective agents include plant extracts, yeast products, bacteria, peptides, enzymes, H2, oligosaccharides, amino acids, adsorbents, vitamins and selenium. Among these, biological detoxification of DON using microorganisms to reduce the toxicity of DON without affecting the growth performance of pigs may be the most promising detoxification strategy. This paper also evaluates future developments related to DON detoxification and discusses the detoxification role and application potential of protective agents. This paper provides new perspectives for future research and development of safe and effective feed additives.

Loop Evolutionary Patterns Shape Catalytic Efficiency of TRI101/201 for Trichothecenes: Insights into Protein-Substrate Interactions.

Trichothecenes are highly toxic mycotoxins produced by Fusarium fungi, while TRI101/201 family enzymes play a crucial role in detoxification through acetylation. Studies on the substrate specificity and catalytic kinetics of TRI101/201 have revealed distinct kinetic characteristics, with significant differences observed in catalytic efficiency toward deoxynivalenol, while the catalytic efficiency for T-2 toxin remains relatively consistent. In this study, we used structural bioinformatics analysis and a molecular dynamics simulation workflow to investigate the mechanism underlying the differential catalytic activity of TRI101/201. The findings revealed that the binding stability between trichothecenes and TRI101/201 hinges primarily on a hydrophobic cage structure within the binding site. An intrinsic disordered loop, termed loop cover, defined the evolutionary patterns of the TRI101/201 protein family that are categorized into four subfamilies (V1/V2/V3/M). Furthermore, the unique loop displayed different conformations among these subfamilies' structures, which served to disrupt (V1/V2/V3) or reinforce (M) the hydrophobic cages. The disrupted cages enhanced the water exposure of the hydrophilic moieties of substrates like deoxynivalenol and thereby hindered their binding to the catalytic sites of V-type enzymes. In contrast, this water exposure does not affect substrates like T-2 toxin, which have more hydrophobic substituents, resulting in a comparable catalytic efficiency of both V- and M-type enzymes. Overall, our studies provide theoretical support for understanding the catalytic mechanism of TRI101/201, which shows how an intrinsic disordered loop could impact the protein-ligand binding and suggests a direction for rational protein design in the future.