Light-Driven Electrochemical Biosensing with DNA Origami-Assisted Hybrid Nanoantenna for Fumonisin B1 Monitoring.

The electrochemical detection of biosensors is largely governed by the changes in physical properties of redox probes, which are susceptible to electrode substrate effects, inhibiting sensor sensitivity. In this work, a light-driven electrochemical biosensor based on a hybrid nanoantenna was developed for the sensitive detection of fumonisin B1 (FB1). The hybrid nanoantenna sensing interface was constructed by coupling CdSe quantum dots (QDs)-DNA nanowire and graphdiyne oxide composites loaded with methylene blue and gold nanorods (GDYO-MB-Au NRs) using a tetrahedral DNA nanostructure, which acted as a light-driven unit and an amplification unit, respectively. The hybrid nanoantenna with light-driven properties facilitated the alteration in the chemical properties of MB at the sensing interface; that is, MB was degraded under light illumination. The stripping of the CdSe QDs-DNA nanowire triggered by the binding of FB1 could degrade the light-driven capability, thereby improving the electrochemical signal through depressing MB degradation. Taking advantage of the photodegradation of MB by the hybrid nanoantenna, the developed biosensor reduced the background signal and increased the detection sensitivity. The developed biosensor exhibited a linear detection range from 0.5 fg mL-1 to 10 pg mL-1 and a detection limit down to 0.45 fg mL-1. This strategy shows great promise for the fabrication of highly sensitive electrochemical biosensors.

Effects of aflatoxin and fumonisin on gene expression of growth factors and inflammation-related genes in a human hepatocyte cell line.

Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are mycotoxins widely distributed in maize and maized-based products, often occurring together. The implications of co-exposure to aflatoxin and fumonsin for human health are numerous, but a particular concern is the potential of FB1 to modulate AFB1 hepatotoxicity. This study evaluated the toxicity of these mycotoxins, alone or combined, in a human non-tumorigenic liver cell line, HHL-16 cells, and assessed the effects of AFB1 and FB1 on expression of genes involved in immune and growth factor pathways. The results demonstrated that in HHL-16 cells, both AFB1 and FB1 had dose-dependent and time-dependent toxicity, and the combination of them showed a synergistic toxicity in the cells. Moreover, AFB1 caused upregulation of IL6, CCL20, and BMP2, and downregulation of NDP. In combination of AFB1 with FB1, gene expression levels of IL6 and BMP2 were significantly higher compared to individual FB1 treatment, and had a tendency to be higher than individual AFB1 treatment. This study shows that FB1 may increase the hepatoxicity of AFB1 through increasing the inflammatory response and disrupting cell growth pathways.

Mild endoplasmic reticulum stress alleviates FB1-triggered intestinal pyroptosis via the Sec62-PERK pathway.

Fumonisin B1 (FB1), a water-soluble mycotoxin released by Fusarium moniliforme Sheld, is widely present in corn and its derivative products, and seriously endangers human life and health. Recent studies have reported that FB1 can lead to pyroptosis, however, the mechanisms by which FB1-induced pyroptosis remain indistinct. In the present study, we aim to investigate the mechanisms of pyroptosis in intestinal porcine epithelial cells (IPEC-J2) and the relationship between FB1-induced endoplasmic reticulum stress (ERS) and pyroptosis. Our experimental results showed that the pyroptosis protein indicators in IPEC-J2 were significantly increased after exposure to FB1. The ERS markers, including glucose-regulated Protein 78 (GRP78), PKR-like ER kinase protein (PERK), and preprotein translocation factor (Sec62) were also significantly increased. Using small interfering RNA silencing of PERK or Sec62, the results demonstrated that upregulation of Sec62 activates the PERK pathway, and activation of the PERK signaling pathway is upstream of FB1-induced pyroptosis. After using the ERS inhibitor 4-PBA reduced the FB1-triggered intestinal injury by the Sec62-PERK pathway. In conclusion, we found that FB1 induced pyroptosis by upregulating Sec62 to activate the PERK pathway, and mild ERS alleviates FB1-triggered damage. It all boils down to one fact, the study provides a new perspective for further, and improving the toxicological mechanism of FB1.

FvKex2 is required for development, virulence, and mycotoxin production in Fusarium verticillioides.

Fusarium verticillioides is one of the most important fungal pathogens causing maize ear and stalk rots, thereby undermining global food security. Infected seeds are usually unhealthy for consumption due to contamination with fumonisin B1 (FB1) mycotoxin produced by the fungus as a virulence factor. Unveiling the molecular factors that determine fungal development and pathogenesis will help in the control and management of the diseases. Kex2 is a kexin-like Golgi-resident proprotein convertase that is involved in the activation of some important proproteins. Herein, we identified and functionally characterized FvKex2 in relation to F. verticillioides development and virulence by bioinformatics and functional genomics approaches. We found that FvKex2 is required for the fungal normal vegetative growth, because the growth of the ∆Fvkex2 mutant was significantly reduced on culture media compared to the wild-type and complemented strains. The mutant also produced very few conidia with morphologically abnormal shapes when compared with those from the wild type. However, the kexin-like protein was dispensable for the male role in sexual reproduction in F. verticillioides. In contrast, pathogenicity was nearly abolished on wounded maize stalks and sugarcane leaves in the absence of FvKEX2 gene, suggesting an essential role of Fvkex2 in the virulence of F. verticillioides. Furthermore, high-performance liquid chromatography analysis revealed that the ∆Fvkex2 mutant produced a significantly lower level of FB1 mycotoxin compared to the wild-type and complemented strains, consistent with the loss of virulence observed in the mutant. Taken together, our results indicate that FvKex2 is critical for vegetative growth, FB1 biosynthesis, and virulence, but dispensable for sexual reproduction in F. verticillioides. The study presents the kexin-like protein as a potential drug target for the management of the devastating maize ear and stalk rot diseases. Further studies should aim at uncovering the link between FvKex2 activity and FB1 biosynthesis genes. KEY POINTS: •The kexin-like protein FvKex2 contributes significantly to the vegetative growth of Fusarium verticillioides. •The conserved protein is required for fungal conidiation and conidial morphology, but dispensable for sexual reproduction. •Deletion of FvKEX2 greatly attenuates the virulence and mycotoxin production potential of F. verticillioides.

Recent advances in the degradation efficacy and mechanisms of mycotoxins in food by atmospheric cold plasma.

Food contaminated by mycotoxins has become a worldwide public problem with political and economic implications. Although a variety of traditional methods have been used to eliminate mycotoxins from agri-foods, the results have been somewhat less than satisfactory. As an emerging non-thermal processing technology, atmospheric cold plasma (ACP) has great potential for food decontamination. Herein, this review mainly presents the degradation efficiency of ACP on mycotoxins in vitro and agri-foods as well as its possible degradation mechanisms. Meanwhile, ACP effects on food quality, factors affecting the degradation efficiency and the toxicity of degradation products are also discussed. According to the literatures, ACP could efficiently degrade many mycotoxins (e.g., aflatoxin, deoxynivalenol, zearalenone, ochratoxin A, fumonisin, and T-2 toxin) both in vitro and various foods (e.g., hazelnut, peanut, maize, rice, wheat, barley, oat flour, and date palm fruit) with little effects on the nutritional and sensory properties of food. The degradation efficacy was dependent on many factors including ACP treatment parameter, working gas, mycotoxin property, and food substrate. The mycotoxin degradation by ACP was mainly attributed to the reactive oxygen and nitrogen species in ACP, which can damage the chemical bonds of mycotoxins, consequently reducing the toxicity of mycotoxins.

Resveratrol alleviates fumonisin-induced intestinal cytotoxicity by modulating apoptosis, tight junction, and inflammation in IPEC-J2 porcine intestinal epithelial cells.

Fumonisins are common contaminants in the global food and environment, pose a variety of health risks to humans and animals. However, the method of mitigating fumonisin toxicity is still unclear. Resveratrol is a natural compound with antioxidant and anti-inflammatory properties. In this study, the protective effect of resveratrol against fumonisin-induced intestinal toxicity was investigated by the porcine intestinal epithelial cell line (IPEC-J2). The cells were treated with 0-40 µM fumonisin for 24 or 48 h with or without the 24 h resveratrol (15 µM) pretreatment. The data showed that resveratrol could alleviate the fumonisin B1 (FB1)-induced decrease in cell viability and amplify in membrane permeability. At the same time, it could reduce the accumulation of intracellular reactive oxygen species and increase the expression ranges of Nrf2 and downstream genes (SOD1 and NQO-1), thereby counteracting FB1-induced apoptosis. Furthermore, resveratrol was able to reduce the expression levels of inflammatory factors (TNF-α, IL-1ß, and IL-6), increase the expression levels of tight junction proteins (Claudin-1, Occludin, and ZO-1), and the integrity of the IPEC-J2 monolayer. Our data also showed that resveratrol could attenuate the toxicity of the co-occurrence of three fumonisins. It is implied that resveratrol represents a promising protective approach for fumonisin, even other mycotoxins in the future. This provided a new strategy for further blocking and controlling the toxicity of fumonisin, subsequently avoiding adverse effects on the human and animal health.

Gold nanoparticles-doped MXene heterostructure for ultrasensitive electrochemical detection of fumonisin B1 and ampicillin.

Early transition metal carbides (MXene) hybridized by precious metals open a door for innovative electrochemical biosensing device design. Herein, we present a facile one-pot synthesis of gold nanoparticles (AuNPs)-doped two-dimensional (2D) titanium carbide MXene nanoflakes (Ti3C2Tx/Au). Ti3C2Tx MXene exhibits high electrical conductivity and yields synergistic signal amplification in conjunction with AuNPs leading to excellent electrochemical performance. Thus Ti3C2Tx/Au hybrid nanostructure can be used as an electrode platform for the electrochemical analysis of various targets. We used screen-printed electrodes modified with the Ti3C2Tx/Au electrode and functionalized with different biorecognition elements to detect and quantify an antibiotic, ampicillin (AMP), and a mycotoxin, fumonisin B1 (FB1). The ultralow limits of detection of 2.284 pM and 1.617 pg.mL-1, which we achieved respectively for AMP and FB1 are far lower than their corresponding maximum residue limits of 2.8 nM in milk and 2 to 4 mg kg-1 in corn products for human consumption set by the United States Food and Drug Administration. Additionally, the linear range of detection and quantification of AMP and FB1 were, respectively, 10 pM to 500 nM and 10 pg mL-1 to 1 µg mL-1. The unique structure and excellent electrochemical performance of Ti3C2Tx/Au nanocomposite suggest that it is highly suitable for anchoring biorecognition entities such as antibodies and oligonucleotides for monitoring various deleterious contaminants in agri-food products.

Oral Exposure to Low Concentration of Fumonisin B2, but Not Fumonisin B1, Significantly Exacerbates the Pathophysiology of Imiquimod-Induced Psoriasis in Mice.

This study aimed to determine whether oral fumonisin exposure contributes to the development of psoriasis. Oral administration of fumonisin B1 (FB1, 0.1 mg/kg) or fumonisin B2 (FB2, 0.1 mg/kg) was conducted for 10 days, in addition to the induction of psoriatic symptoms through topical application of 5% imiquimod cream from day 6 to day 10 (5 days) in female BALB/c mice. The results demonstrated that oral administration of FB2 significantly exacerbated psoriatic symptoms, including skin thickness, itching behavior, transepidermal water loss, immune cell infiltration in the dermis, and proinflammatory cytokine production. However, no changes were observed following exposure to FB1. Our results confirm that oral exposure to FB2 adversely affects the pathogenesis of psoriasis by increasing skin thickness and impairing barrier function.

NIR-HSI as a tool to predict deoxynivalenol and fumonisins in maize kernels: a step forward in preventing mycotoxin contamination.

BACKGROUND: Maize is frequently contaminated with deoxynivalenol (DON) and fumonisins B1 (FB1) and B2 (FB2). In the European Union, these mycotoxins are regulated in maize and maize-derived products. To comply with these regulations, industries require a fast, economic, safe, non-destructive and environmentally friendly analysis method. RESULTS: In the present study, near-infrared hyperspectral imaging (NIR-HSI) was used to develop regression and classification models for DON, FB1 and FB2 in maize kernels. The best regression models presented the following root mean square error of cross validation and ratio of performance to deviation values: 0.848 mg kg-1 and 2.344 (DON), 3.714 mg kg-1 and 2.018 (FB1) and 2.104 mg kg-1 and 2.301 (FB2). Regarding classification, European Union legal limits for DON and FB1 + FB2 were selected as thresholds to classify maize kernels as acceptable or not. The sensitivity and specificity were 0.778 and 1 for the best DON classification model and 0.607 and 0.938 for the best FB1 + FB2 classification model. CONCLUSION: NIR-HSI can help reduce DON and fumonisins contamination in the maize food and feed chain. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Development of a fumonisin-sensitive Saccharomyces cerevisiae indicator strain and utilization for activity testing of candidate detoxification genes.

IMPORTANCE: Fumonisins can cause diseases in animals and humans consuming Fusarium-contaminated food or feed. The search for microbes capable of fumonisin degradation, or for enzymes that can detoxify fumonisins, currently relies primarily on chemical detection methods. Our constructed fumonisin B1-sensitive yeast strain can be used to phenotypically detect detoxification activity and should be useful in screening for novel fumonisin resistance genes and to elucidate fumonisin metabolism and resistance mechanisms in fungi and plants, and thereby, in the long term, help to mitigate the threat of fumonisins in feed and food.

Fungal composition, quantification of mycotoxins, and enzyme activity in processed Solanum tuberosum Linn (potato) products stored at different relative humidity.

AIM: Postharvest loss of potatoes at the peak of harvest is of global concern. This study aimed to determine the quality of stored processed potato products based on fungal composition, mycotoxin contamination, and fungal enzyme activity. MATERIALS AND METHODS: Potato products from three cultivars (Caruso, Marabel, and Nicola) were grouped as peeled or unpeeled, oven- or sun-dried, and all samples were in flour form. Samples were incubated separately for 6 weeks at 25%, 74%, and 87% relative humidities (RH) at 25°C. The pH, moisture content (MC), visible deterioration, mycotoxin, fungal identity by DNA sequencing, and enzyme activity were determined. RESULTS: Results of grouped products (based on variety, drying, and peeling method) revealed that MC increased in the oven-dried samples and the pH value reduced after incubation. About 26% of the products at 87% RH showed visible deterioration, low amounts of fumonisin were detected in fermented potato product and nine fungal genera were identified across the three RH levels. Enzyme activities by Aspergillus niger, Fusarium circinatum, and Rhizopus stolonifer isolates were confirmed. CONCLUSION: RH influenced deterioration and fungal activities in some stored processed potato products. Low levels of fumonisin were detected.

Roles of Ear Injury, Infestation, and Vector Activity by Ostrinia furnacalis (Asian Corn Borer) and Conogethes punctiferalis (Yellow Peach Moth) in Fusarium verticillioides Infection and Kernel Fumonisin Level.

Field experiments were conducted to evaluate the roles of two corn borers, Asian corn borer (ACB), Ostrinia furnacalis and yellow peach moth (YPM), Conogethes punctiferalis, in Fusarium verticillioides infection using green fluorescent protein (GFP) as a marker. Effects of insect injury, manual injury, and insecticide application on fumonisin production also were assessed. In this study, third instars of ACB and YPM significantly increased GFP-tagged F. verticillioides infection compared with the control, regardless of the fungal inoculation method. Besides acquiring F. verticillioides spores from leaf surfaces and transmitting them to ears, larvae of the ACB and YPM also injure maize ears, which allows F. verticillioides from leaves or silk to infect ears more easily. This suggests that ACB and YPM larvae are vectors of F. verticillioides, which can increase the occurrence of ear rot. Manual injuries significantly increased GFP-tagged F. verticillioides infection of ears, while effective insect control significantly reduced F. verticillioides infection of ears. Insecticide control of borers also significantly reduced fumonisin content in kernels. Larval infestations significantly increased fumonisins in kernels to levels higher than or very close to the European Union threshold (4,000 µg kg-1). Significant and high correlations among corn borer attack, F. verticillioides severity, and kernel fumonisin levels were discovered, confirming the important role of ACB and YPM activity in F. verticillioides infection and kernel fumonisin production.

Chronic oral exposure to low-concentration fumonisin B2 significantly exacerbates the inflammatory responses of allergies in mice via inhibition of IL-10 release by regulatory T cells in gut-associated lymphoid tissue.

Contamination with fumonisins produced by Fusarium spp. is rapidly growing in both developing and developed countries. The purpose of this study was to determine whether oral exposure to fumonisin contributed to the development of allergic diseases. We initially examined the immunotoxic potential of short-term, oral administration of fumonisin B1 (FB1, 1 mg/kg) and fumonisin B2 (FB2, 1 mg/kg), both naturally occurring fumonisins, using a BALB/c mouse model of allergic contact dermatitis and Dermatophagoides farina-induced asthma. Using an NC/nga mouse model of atopic dermatitis (AD), we evaluated the adverse effects of subchronic oral exposure to low concentrations of FB2 (2 or 200 µg/kg). Finally, we explored the influence of FB2 on regulatory T cell proliferation and function in mesenteric lymph nodes after 1-week oral exposure to FB2 in BALB/c mice. Oral exposure to FB2 markedly exacerbated the symptoms of allergy, including skin thickness, histological evaluation, immunocyte proliferation, and proinflammatory cytokine production, although no change was observed following exposure to FB1. Furthermore, oral exposure to low concentrations of FB2 considerably exacerbated the AD scores, skin thickness, transepidermal water loss, histological features, and proinflammatory cytokine production. The aggravated allergic symptoms induced by oral exposure to FB2 could be attributed to the direct inhibition of IL-10 production by regulatory T cells in mesenteric lymph nodes. Our findings indicate that the recommended maximum fumonisin level should be reconsidered based on the potential for allergy development.

Mycological and Multiple Mycotoxin Surveillance of Sorghum and Pearl Millet Produced by Smallholder Farmers in Namibia.

Mycological (mycotoxigenic Fusarium and aflatoxigenic Aspergillus spp.) and multiple mycotoxins [aflatoxin B1 (AFB1), fumonisin B (FB), deoxynivalenol and zearalenone] surveillance was conducted on raw whole grain sorghum (Sorghum bicolor) and pearl millet (Pennisetum glaucum) produced on smallholder farms, and processed products sold at open markets in northern Namibia. Fungal contamination was determined with morphological methods as well as with quantitative Real-Time PCR (qPCR). The concentrations of multiple mycotoxins in samples were determined with liquid chromatography tandem mass spectrometry. The incidence of mycotoxigenic Fusarium spp., Aspergillus flavus and A. parasiticus, as well as the concentrations of AFB1 and FB were significantly (P < 0.001) higher in the malts as compared to the raw whole grains, with Aspergillus spp. and AFB1 exhibiting the highest contamination (P < 0.001). None of the analysed mycotoxins were detected in the raw whole grains. Aflatoxin B1 above the regulatory maximum level set by the European Commission was detected in sorghum (2 of 10 samples; 20%; 3-11 µg/kg) and pearl millet (6 of 11 samples; 55%; 4-14 µg/kg) malts. Low levels of FB1 (6 of 10 samples; 60%; 15-245 µg/kg) were detected in sorghum malts and no FB was detected in pearl millet malts. Contamination possibly occurred postharvest, during storage, and/or transportation and processing. By critically monitoring the complete production process, the sources of contamination and critical control points could be identified and managed. Mycotoxin awareness and sustainable education will contribute to reducing mycotoxin contamination. This could ultimately contribute to food safety and security in northern Namibia where communities are exposed to carcinogenic mycotoxins in their staple diet.

Targeted sphingolipidomics indicates increased C22-C24:16 ratios of virtually all assayed classes in liver, kidney, and plasma of fumonisin-fed chickens.

The biological properties of sphinganine-(d18:0)-, sphingosine-(d18:1)-, deoxysphinganine-(m18: 0)-, deoxysphingosine-(m18:1)-, deoxymethylsphinganine-(m17:0)-, deoxymethylsphingosine-(m17:1)-, sphingadienine-(d18:2)-, and phytosphingosine-(t18:0)-sphingolipids have been reported to vary, but little is known about the effects of fumonisins, which are mycotoxins that inhibit ceramide synthase, on sphingolipids other than those containing d18:0 and d18:1. Thirty chickens divided into three groups received a control diet or a diet containing 14.6 mg FB1 + FB2/kg for 14 and 21 days. No effects on health or performance were observed, while the effects on sphingoid bases, ceramides, sphingomyelins, and glycosylceramides in liver, kidney, and plasma varied. The t18:0 forms were generally unaffected by fumonisins, while numerous effects were found for m18:0, m18:1, d18:2, and the corresponding ceramides, and these effects appeared to be similar to those observed for d18:0-, and d18:1-ceramides. Partial least square discriminant analysis showed that d18:1- and d18:0-sphingolipids are important variables for explaining the partitioning of chickens into different groups according to fumonisins feeding, while m17:1-, m18:0-, m18:1-, d18:2-, and t18:0-sphingolipids are not. Interestingly, the C22-C24:C16 ratios measured for each class of sphingolipid increased in fumonisin-fed chickens in the three assayed matrices, whereas the total amounts of the sphingolipid classes varied. The potential use of C22-C24:C16 ratios as biomarkers requires further study.

Natural mycotoxin contamination in dog food: A review on toxicity and detoxification methods.

Nowadays, the companion animals (dogs or other pets) are considered as members of the family and have established strong emotional relationships with their owners. Dogs are long lived compared to food animals, so safety, adequacy, and efficacy of dog food is of great importance for their health. Cereals, cereal by-products as well as feedstuffs of plant origin are commonly employed food resources in dry food, yet are potential ingredients for mycotoxins contamination, so dogs are theoretically more vulnerable to exposure when consumed daily. Aflatoxins (AF), deoxynivalenol (DON), fumonisins (FUM), ochratoxin A (OTA), and zearalenone (ZEA) are the most frequent mycotoxins that might present in dog food and cause toxicity on the growth and metabolism of dogs. An understanding of toxicological effects and detoxification methods (physical, chemical, or biological approaches) of mycotoxins will help to improve commercial ped food quality, reduce harm and minimize exposure to dogs. Herein, we outline a description of mycotoxins detected in dog food, toxicity and clinical findings in dogs, as well as methods applied in mycotoxins detoxification. This review aims to provide a reference for future studies involved in the evaluation of the risk, preventative strategies, and clear criteria of mycotoxins for minimizing exposure, reducing harm, and preventing mycotoxicosis in dog.

Antifungal activities of a novel triazole fungicide, mefentrifluconazole, against the major maize pathogen Fusarium verticillioides.

Fusarium ear rot (FER) is a serious fungal disease occurring the late growth stage of maize. FER not only reduces the yield of maize but also causes mycotoxin contamination, which affects the quality of maize and threatens human and animal health. Fusarium verticillioides is the predominant causative pathogen of FER worldwide. At present, there is no registered fungicide for use against maize FER in China. The novel isopropyl alcohol-triazole fungicide mefentrifluconazole (MFZ) has been shown to be effective against several Fusarium spp., but little is known about its specific activity against F. verticillioides. MFZ exhibited strong antifungal activities against 50 strains of F. verticillioides collected from the major maize-growing areas in China. MFZ inhibited mycelial growth, conidium production, germination and germ tube elongation of F. verticillioides. MFZ treatment significantly reduced fumonisin production and the expression levels of fumonisin biosynthetic genes. Genome-wide transcriptional profiling of F. verticillioides in response to MFZ indicated that the expression of genes involved in ergosterol biosynthesis, including fungicide target genes (cyp51 genes), was significantly downregulated by MFZ. MFZ treatment resulted in reduced ergosterol production and increased glycerol and malonaldehyde production as well as relative conductivity in F. verticillioides. A 2-year field experiment showed a significant reduction in FER severity in maize after spraying with MFZ at the tasseling stage. This study evaluated the potential of MFZ to control FER in maize and provides insights into its antifungal activities and mechanism of action against F. verticillioides.

Asian Corn Borer (Ostrinia furnacalis) Infestation Increases Fusarium verticillioides Infection and Fumonisin Contamination in Maize and Reduces the Yield.

Field trials based on manual infestation of the Asian corn borer (ACB) (Ostrinia furnacalis [Guenée]) and Fusarium verticillioides (Nirenberg) atomization were conducted on four maize hybrids to investigate the relationship between ACB infestation and F. verticillioides infection, yield loss, and fumonisin contamination in maize. Analysis of fumonisins B1 and B2 was carried out using an LC-MS/MS system. In this study, manual ACB infestation significantly promoted F. verticillioides infection (both symptomatic and symptomless) and grain fumonisin levels. Ear rot incidence and severity, symptomless kernel infection, and fumonisin contamination were significantly correlated to each other and to ACB damage severity. Manual ACB infestation increased fumonisin levels from 580 to 4,418 µg/kg in 2018; 6,059 to 10,681 µg/kg in 2019 spring-sown maize (2019A); and 2,042 to 5,060 µg/kg in 2019 summer-sown maize (2019B), with the threshold of the European Union (EU) being 4,000 µg/kg. The threshold was exceeded in spring of 2019 in untreated controls. Regarding yield, significant negative correlation between ACB damage and ear weight was observed in three seasons. These results indicated that ACB infestation can lead to severe quality degradation and yield loss of maize. Kernel fumonisin levels may exceed the concentration threshold of the EU in certain conditions, threatening the health of livestock and humans. Measures should be taken to reduce ACB infestation to ensure food and feed security.

Plant Metabolites Affect Fusarium proliferatum Metabolism and In Vitro Fumonisin Biosynthesis.

Fusarium proliferatum is a common hemi-biotrophic pathogen that infect a wide range of host plants, often leading to substantial crop loss and yield reduction. F. proliferatum synthesizes various mycotoxins, and fumonisins B are the most prevalent. They act as virulence factors and specific effectors that elicit host resistance. The effects of selected plant metabolites on the metabolism of the F. proliferatum strain were analyzed in this study. Quercetin-3-glucoside (Q-3-Glc) and kaempferol-3-rutinoside (K-3-Rut) induced the pathogen's growth, while DIMBOA, isorhamnetin-3-O-rutinoside (Iso-3-Rut), ferulic acid (FA), protodioscin, and neochlorogenic acid (NClA) inhibited fungal growth. The expression of seven F. proliferatum genes related to primary metabolism and four FUM genes was measured using RT-qPCR upon plant metabolite addition to liquid cultures. The expression of CPR6 and SSC1 genes was induced 24 h after the addition of chlorogenic acid (ClA), while DIMBOA and protodioscin reduced their expression. The transcription of FUM1 on the third day of the experiment was increased by all metabolites except for Q-3-Glc when compared to the control culture. The expression of FUM6 was induced by protodioscin, K-3-Rut, and ClA, while FA and DIMBOA inhibited its expression. FUM19 was induced by all metabolites except FA. The highest concentration of fumonisin B1 (FB1) in control culture was 6.21 µg/mL. Protodioscin did not affect the FB content, while DIMBOA delayed their synthesis/secretion. Flavonoids and phenolic acids displayed similar effects. The results suggest that sole metabolites can have lower impacts on pathogen metabolism and mycotoxin synthesis than when combined with other compounds present in plant extracts. These synergistic effects require additional studies to reveal the mechanisms behind them.

Prenatal Fumonisin Exposure Impairs Bone Development via Disturbances in the OC/Leptin and RANKL/RANK/OPG Systems in Weaned Rat Offspring.

The goal of the current study was to examine the effects of prenatal exposure to fumonisins (FBs) on bone properties and metabolism in weaned rat offspring divided into groups intoxicated with FBs at either 0 (the 0 FB group), 60 (the 60 FB group), or 90 mg/kg b.w. 0 (the 90 FB group). Female and male offspring exposed to FBs at a dose of 60 mg/kg b.w. had heavier femora. Mechanical bone parameters changed in a sex and FBs dose-dependent manner. Growth hormone and osteoprotegerin decreased in both sexes, regardless of FBs dose. In males osteocalcin decreased, while receptor activator for nuclear factor kappa-Β ligand increased regardless of FBs dose; while in females changes were dose dependent. Leptin decreased in both male FBs-intoxicated groups, bone alkaline phosphatase decreased only in the 60 FB group. Matrix metalloproteinase-8 protein expression increased in both female FBs-intoxicated groups and decreased in male 90 FB group. Osteoprotegerin and tissue inhibitor of metalloproteinases 2 protein expression decreased in males, regardless of FBs dose, while nuclear factor kappa-Β ligand expression increased only in the 90 FB group. The disturbances in bone metabolic processes seemed to result from imbalances in the RANKL/RANK/OPG and the OC/leptin systems.