Discovery and Development of Luvangetin from Zanthoxylum avicennae as a New Fungicide Candidate for Fusarium verticillioides.

Pathogenic fungi pose a significant threat to crop yields and human healthy, and the subsequent fungicide resistance has greatly aggravated these agricultural and medical challenges. Hence, the development of new fungicides with higher efficiency and greater environmental friendliness is urgently required. In this study, luvangetin, isolated and identified from the root of Zanthoxylum avicennae, exhibited wide-spectrum antifungal activity in vivo and in vitro. Integrated omics and in vitro and in vivo transcriptional analyses revealed that luvangetin inhibited GAL4-like Zn(II)2Cys6 transcriptional factor-mediated transcription, particularly the FvFUM21-mediated FUM cluster gene expression, and decreased the biosynthesis of fumonisins inFusarium verticillioides. Moreover, luvangetin binds to the double-stranded DNA helix in vitro in the groove mode. We isolated and identified luvangetin, a natural metabolite from a traditional Chinese edible medicinal plant and uncovered its multipathogen resistance mechanism. This study is the first to reveal the mechanism underlying the antifungal activity of luvangetin and provides a promising direction for the future use of plant-derived natural products to prevent and control plant and animal pathogenic fungi.

A novel fluorescent aptasensor for sensitive and selective detection of environmental toxins fumonisin B1 based on enzyme-assisted dual recycling amplification and 2D δ-FeOOH-NH2 nanosheets.

Fumonisin (FB) is a pervasive hazardous substance in the environment, presenting significant threats to human health and ecological systems. Thus, the selective and sensitive detection of fumonisin B1 (FB1) is crucial due to its high toxicity and wide distribution in corn, oats, and related products. In this work, we developed a novel and versatile fluorescent aptasensor by combining enzyme-assisted dual recycling amplification with 2D δ-FeOOH-NH2 nanosheets for the determination of FB1. The established CRISPR/Cas12a system was activated by using activator DNA (aDNA), which was released via a T7 exonuclease-assisted recycling reaction. Additionally, the activated Cas12a protein was utilized for non-specifically cleavage of the FAM-labeled single-stranded DNA (ssDNA-FAM) anchored on δ-FeOOH-NH2 nanosheets. The pre-quenched fluorescence signal was restored due to the desorption of the cleaved ssDNA-FAM. Due to the utilization of this T7 exonuclease-Cas12a-δ-FeOOH-NH2 aptasensor for signal amplification, the detection range of FB1 was expanded from 1 pg/mL to 100 ng/mL, with a limit of detection (LOD) as low as 0.45 pg/mL. This study not only provides novel insights into the development of fluorescence biosensors based on 2D nanomaterials combined with CRISPR/Cas12a, but also exhibits remarkable applicability in detecting other significant targets.

The Effects of T-2 Toxin, Deoxynivalenol, and Fumonisin B1 on Oxidative Stress-Related Genes in the Kidneys of Laying Hens.

In the context of nephrotoxic risks associated with environmental contaminants, this study focused on the impact of mycotoxin exposure on the renal health of laying hens, with particular attention to oxidative stress pathways. Sixty laying hens were assigned to three groups-a control group (CON), a low-dose mycotoxin group (LOW), and a high-dose mycotoxin group (HIGH)-and monitored for 72 h. Mycotoxin contamination involved T-2/HT-2 toxin, DON/3-AcDON/15-AcDON, and FB1 at their EU-recommended levels (low mix) and at double doses (high mix). Clinical assessments revealed no signs of toxicity or notable weight changes. Analysis of the glutathione redox system parameters demonstrated that the reduced glutathione content was lower than that in the controls at 48 h and higher at 72 h. Glutathione peroxidase activity increased in response to mycotoxin exposure. In addition, the gene expression patterns of key redox-sensitive pathways, including Keap1-Nrf2-ARE and the AhR pathway, were examined. Notably, gene expression profiles revealed dynamic responses to mycotoxin exposure over time, underscoring the intricate interplay of redox-related mechanisms in the kidney. This study sheds light on the early effects of mycotoxin mixtures on laying hens' kidneys and their potential for oxidative stress.

Evaluating Acheta domesticus (Orthoptera: Gryllidae) for the reduction of fumonisin B1 levels in livestock feed.

Mycotoxins that contaminate grain can cause the devaluation of agricultural products and create health risks for the consumer. Fumonisins are one such mycotoxin. Produced primarily by Fusarium verticillioides (Hypocreales: Nectriaceae) (Nirenberg, 1976) on corn, fumonisins' economic impact can be significant by causing various diseases in livestock if contaminated corn is not monitored and removed from animal feed. Finding safe alternatives to the destruction and waste of contaminated grain and restoring its economic value is needed for a sustainable future. Safe reintroduction into the farm food web may be possible through a consumable intermediary such as insects. This study demonstrates the suitability of the house cricket, Acheta domesticus L., as an alternative protein source in domestic animal feed by quantifying fumonisin B1 (FB1) levels in their subsequent insect meal and frass. Small colonies of 2nd instar A. domesticus were reared to 5th instar adults on nutrient-optimized corn-based diets treated with 4 levels of FB1 from 0 to 20 ppm. Increasing levels of FB1 had no adverse effects on the survivorship or growth of A. domesticus. Insect meals prepared from A. domesticus had significantly lower levels of FB1, at 3%-5% of their respective diets, while frass did not differ significantly from their diet. The successful rearing to adulthood of A. domesticus on fumonisin-contaminated diet paired with lower levels of FB1 in their processed insect meal supports the idea that more sustainable agricultural practices can be developed through remediation of low-value mycotoxin-contaminated grain with safer, higher-value insects as livestock feed components.

Evaluation of the efficacy of cinnamon oil on Aspergillus flavus and Fusarium proliferatum growth and mycotoxin production on paddy and polished rice: Towards a mitigation strategy.

In the present investigation, the effect of cinnamon oil (CO) (10, 30, 50 and 70 %) on the growth rate (mm/day) and aflatoxin B1 (AFB1) and fumonisin B1 (FB1) production of Aspergillus flavus (AF01) and Fusarium proliferatum (FP01) isolates, respectively was determined at optimum water activities (0.95 and 0.99 aw) and temperatures (25, 30 and 35 °C) on paddy and polished rice grains. The results showed that the growth rate, AFB1 and FB1 production of all the fungal isolates decreased with an increase in CO concentrations on both matrices. AF01 and FP01 failed to grow under all conditions on paddy at 50 % of CO concentration whereas both fungi were completely inhibited (No Growth-NG) at 70 % of CO on polished rice. Regarding mycotoxin production, 30 % of CO concentrations could inhibit AFB1 and FB1 production in both matrices (No Detection-ND). In this study, the production of mycotoxins was significantly influenced by cinnamon oil compared to the growth of both fungi. These results indicated the promising potential of CO in improving the quality of rice preservation in post-harvest; however, further investigations should be evaluated on the effects on the qualitative characteristics of grains. Especially, the prospective application of CO in rice storage in industry scales to mitigate mycotoxin contamination need also to be further researched. Moreover, collaboration between researchers, agricultural experts, and food industry should be set up to achieve effective and sustainable strategies for preserving rice.

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.

Fungal Species and Mycotoxins Associated with Maize Ear Rots Collected from the Eastern Cape in South Africa.

Maize production in South Africa is concentrated in its central provinces. The Eastern Cape contributes less than 1% of total production, but is steadily increasing its production and has been identified as a priority region for future growth. In this study, we surveyed ear rots at maize farms in the Eastern Cape, and mycotoxins were determined to be present in collected samples. Fungal isolations were made from mouldy ears and species identified using morphology and DNA sequences. Cladosporium, Diplodia, Fusarium and Gibberella ear rots were observed during field work, and of these, we collected 78 samples and isolated 83 fungal strains. Fusarium was identified from Fusarium ear rot (FER) and Gibberella ear rot (GER) and Stenocarpella from Diplodia ear rot (DER) samples, respectively. Using LC-MS/MS multi-mycotoxin analysis, it was revealed that 83% of the collected samples contained mycotoxins, and 17% contained no mycotoxins. Fifty percent of samples contained multiple mycotoxins (deoxynivalenol, 15-acetyl-deoxynivalenol, diplodiatoxin and zearalenone) and 33% contained a single mycotoxin. Fusarium verticillioides was not isolated and fumonisins not detected during this survey. This study revealed that ear rots in the Eastern Cape are caused by a wide range of species that may produce various mycotoxins.

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.

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.

Financial losses due to fumonisin contamination in the Texas High Plains maize.

Fumonisins are one of the main problems affecting maize production in the Texas High Plains (THP), where its agroclimatic conditions make it a perennial hotspot for mycotoxin contamination. In 2017, a fumonisin outbreak in the THP maize motivated stakeholders' request to repeal a subsection of the Texas Administrative Code, §61.61(a)(7) (Fumonisin Rule), and its related Texas Feed Industry Memorandum (Memo 5-20), which previously permitted the blending of maize containing high fumonisin levels with maize containing ≥ 5 mg/kg under state authority, and pivot to FDA fumonisin guidance. Shortly after, the USDA Risk Management Agency (RMA's) reintroduced Discount Factors (DFs) in annual Special Provisions (SP) that outline price reductions related to fumonisin contamination in maize. In this research, we estimate the potential economic burden posed by these changes through a two-part approach. In part one, we construct a decision model that explores the final disposition of fumonisin-contaminated maize based on blending permissions, fumonisin levels, and crop insurance status. In part two, we estimate the economic impact by inserting output values of the decision model into financial equations that consider testing costs, transportation fees, and discounts from crop insurance and grain elevators when applicable. Our economic analysis projects that the financial losses during a THP crop year with high fumonisin levels could range from $15.1 to $135.5 million without the option to blend under conditions of the revised RMA discount schedule. Findings further highlight crop insurance as the most promising risk management strategy for farmers in areas susceptible to fumonisin contamination.

Apocynin exerts neuroprotective effects in fumonisin b1-induced neurotoxicity via attenuation of oxidative stress and apoptosis in an animal model.

The Fusarium verticillioides produces a mycotoxin, that is, fumonisin b1 (Fb1), which commonly infects corn and agricultural commodities. The Fb1 showed hepatotoxicity, neurotoxicity, and carcinogenicity in animals. Hence, the present investigation aimed to evaluate the effect of apocynin (AP) on Fb1-induced neurotoxic effects and its mechanism in the mice model and cell line. The male Balb/c mice, with the 6.75 mg/kg bwt of Fb1 were injected subcutaneously for 5 days to induce neurotoxicity. A significant elevation of serotonin (5-HT) was observed in mice treated with Fb1 in the whole brain showing biogenic amines may reflect Fb1 neurotoxicity, but the negatively regulated mechanisms were attenuated by the pretreatment of AP. In addition, AP pretreatment normalized apoptotic changes in histology and immunohistochemistry studies. In Western blotting studies, apoptotic genes were upregulated and oxidative stress genes were downregulated due to Fb1 treatment; while treating with AP, these gene expressions were rectified. Further cell cytotoxicity was investigated by MTT and lactate dehydrogenase (LDH) assays in SH-SY5Y cell line. MTT and LDH assays indicated the IC50 value to be 150 µM of Fb1, which was protected by 100 µg of AP. The electron microscopy evaluated the Fb1-induced apoptotic conditions and its cell morphology recovery by AP. These results suggest that nicotinamide adenine dinucleotide phosphate hydrogen oxidase-mediated reactive oxygen species is the primary upstream signal leading to increased Fb1-mediated neurotoxicity in mice. The use of the antioxidant AP reversed the toxin-induced oxidative stress and apoptosis by its antioxidant potency.

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.

Does alteration of fumonisin production in Fusarium verticillioides lead to volatolome variation?

Fusarium verticillioides, a major fungal pathogen of maize, produces fumonisins, mycotoxins of global food safety concern. Control practices are needed to reduce the negative health and economic impacts of fumonisins. Therefore, we investigated volatile organic compounds (VOCs) emitted by fumonisin-producing (wild-type) and nonproducing (mutant) strains of F. verticillioides. VOC emissions were analyzed by gas chromatography-mass spectrometry following inoculation of maize kernels, and fumonisin accumulation was analyzed by high-performance liquid chromatography. Mutants emitted VOCs, including ethyl 3-methylbutanoate, that the wild type did not emit. In particular, ANOVA analysis showed significant differences between mutants and wild type for 4 VOCs which emission was correlated with absence of fumonisins. Exogenous ethyl 3-methylbutanoate reduced growth and fumonisin production in wild-type F. verticillioides, showing its potential in biocontrol. Together, our findings offer valuable insights into how mycotoxin production can impact VOC emissions from F. verticillioides and reveal a potential biocontrol strategy to reduce fumonisin contamination.

Genome-wide transcriptome analysis of toxigenic Fusarium verticillioides in response to variation of temperature and water activity on maize kernels.

Fusarium verticillioides is one of the important mycotoxigenic pathogens of maize since it causes severe yield losses and produces fumonisins (FBs) to threaten human and animal health. Previous studies showed that temperature and water activity (aw) are two pivotal environmental factors affecting F. verticillioides growth and FBs production during maize storage. However, the genome-wide transcriptome analysis of differentially expressed genes (DEGs) in F. verticillioides under the stress combinations of temperature and aw has not been studied in detail. In this study, DEGs of F. verticillioides and their related regulatory pathways were analyzed in response to the stress of temperature and aw combinations using RNA-Seq. The results showed that the optimal growth conditions for F. verticillioides were 0.98 aw and 25 °C, whereas the highest per-unit yield of the fumonisin B1 (FB1) was observed at 0.98 aw and 15 °C. The RNA-seq analysis showed that 9648 DEGs were affected by temperature regardless of aw levels, whereas only 218 DEGs were affected by aw regardless of temperature variations. Gene Ontology (GO) analysis revealed that a decrease in temperature at both aw levels led to a significant upregulation of genes associated with 24 biological processes, while three biological processes were downregulated. Furthermore, when aw was decreased at both temperatures, seven biological processes were significantly upregulated and four were downregulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that the genes, whose expression was upregulated when the temperature decreased, were predominantly associated with the proteasome pathway, whereas the genes, whose expression was downregulated when the aw decreased, were mainly linked to amino acid metabolism. For the FB1, except for the FUM15 gene, the other 15 biosynthetic-related genes were highly expressed at 0.98 aw and 15 °C. In addition, the expression pattern analysis of other biosynthetic genes involved in secondary metabolite production and regulation of fumonisins production was conducted to explore how this fungus responds to the stress combinations of temperature and aw. Overall, this study primarily examines the impact of temperature and aw on the growth of F. verticillioides and its production of FB1 using transcriptome data. The findings presented here have the potential to contribute to the development of novel strategies for managing fungal diseases and offer valuable insights for preventing fumonisin contamination in food and feed storage.

Assessment of dietary exposure and levels of mycotoxins in sorghum from Niger State of Nigeria.

This study reports levels of mycotoxins in sorghum from Niger State, Nigeria, and provides a comprehensive assessment of their potential health risks by combining mycotoxin levels and dietary exposure assessment. A total of 240 samples of red and white sorghum were collected from both stores and markets across four microclimatic zones. Fungal species were identified using a dilution plate method. Aflatoxins (AFs), deoxynivalenol, nivalenol, and ochratoxin (OTA) were quantified using HPLC, whereas cyclopiazonic acid, fumonisins (FUMs) and zearalenone were quantified using ELISA. A. flavus and A. fumigatus were dominant fungal species followed by F. verticilloides, A. oryzae and P. verrucosum. Aflatoxins (mean: 29.97 µg/kg) were detected in all samples, whereas OTA (mean: 37.5 µg/kg) and FUMs (mean: 3269.8 µg/kg) were detected in 72% and 50% of the samples, respectively. Mycotoxins frequently co-occurred in binary mixtures of AFs + OTA and AFs + FUMs. Dietary exposure estimates were highest for FUMs at 230% of TDI and margin of exposures (MOEs) for both AFs and OTA (<10,000) indicating a potential risk associated with combined exposure to AFs and OTA. The Risk of hepatocellular carcinoma cases (HCC/year) attributable to AFs and OTA exposure from sorghum was estimated to be 5.99 × 105 and 0.24 × 105 cases for HBsAg + individuals based on 13.6% HBV incidence. Similarly, the HCC/year for AFs and OTA were assessed to be 3.59 × 105 and 0.14 × 105 at an 8.1% prevalence rate. Therefore, the results of this study demonstrate the high prevalence and dietary exposure to mycotoxins through sorghum consumption, raising public health and trade concerns.

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.

Longan Polysaccharides with Covalent Selenylation Combat the Fumonisin B1-Induced Cell Toxicity and Barrier Disruption in Intestinal Epithelial (IEC-6) Cells.

In this study, the soluble, but non-digestible, longan (Dimocarpus longan Lour.) polysaccharides (LP) were extracted from dried longan fruits and then chemically selenylated to produce two selenylated products, namely SeLP1 and SeLP2, with different selenylation extents. The aim was to investigate their protective effects on rat intestinal epithelial (IEC-6) cells exposed to the food toxin fumonisin B1 (FB1). LP only contained total Se content of less than 0.01 g/kg, while SeLP1 and SeLP2 were measured with respective total Se content of up to 1.46 and 4.79 g/kg. The cell viability results showed that these two selenylated products were more efficient than LP in the IEC-6 cells in alleviating FB1-induced cell toxicity, suppressing lactate dehydrogenase (LDH) release, and decreasing the generation of intracellular reactive oxygen species (ROS). These two selenylated products were also more effective than LP in combating FB1-induced barrier disruption via increasing the transepithelial electric resistance (TEER), reducing the paracellular permeability, decreasing the mitochondrial membrane potential (MMP) loss, and maintaining cell barrier integrity by upregulating the tight-junction-related genes and proteins. FB1 caused cell oxidative stress and barrier dysfunction by activating the MAPK and mitochondrial apoptosis signaling pathways, while SeLP1 and SeLP2 could regulate the tMAPK- and apoptosis-related proteins to suppress the FB1-mediated activation of the two pathways. Overall, SeLP2 was observed to be more active than SeLP1 in the IEC-6 cells. In conclusion, the chemical selenylation of LP caused an activity enhancement to ameliorate the FB1-induced cell cytotoxicity and intestinal barrier disruption. Meanwhile, the increased selenylation of LP would endow the selenylated product SeLP2 with more activity.

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.

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.

Effects of maize genotypes, nitrogen rates and sources in yield, nutritional status, and fumonisins incidence.

The maize yield, nutritional status, and grain fumonisins concentration were evaluated in different genotypes, doses, and nitrogen sources (N) in two years and three locations. Two experiments were carried out in each area and year in an experimental design of a subdivided plot with four replications. One experiment involved a 4x2 factorial treatment: four nitrogen (N) doses (0, 80, 160, and 240 kg ha-1) in coverage and having urea as a source of N and two genotypes. Another experiment involved a 4x2 factorial treatment: four N sources: urea, urea covered with polymer, ammonium nitrate, and ammonium nitrate + urea (UAN), at a dose of 160 kg ha-1, in two genotypes. The genotype generally influenced maize yield more than N doses and sources, mainly due to the bushy stunt/corn stunt tolerance of AG7098 PRO2 and AG8677 PRO2. The N doses linearly increased the N leaf content. However, the N sources did not affect the N leaf content. The N doses and sources had no significant effect on the content of fumonisins, which was affected only by the genotypes in Sete Lagoas in 2016 (N doses experiment) and 2017 (N sources experiment). The hybrids, P3630H and AG8677PRO2 (Sete Lagoas, 2016, N doses experiment and 2017, N sources experiment, respectively) exceeded the Brazilian legislation for Maximum Tolerance Limit for fumonisins in corn grains, which is 5,000 µg kg-1. The best result was obtained with AG7098 PRO2, with yields (above 10,000 kg ha-1) and fumonisins consistently below 5,000 µg kg-1. Therefore, the selection of corn hybrids is a strategy to reduce the occurrence of fumonisins in the grains.