Fusarium Toxins in Cereals: Occurrence, Legislation, Factors Promoting the Appearance and Their Management

Diversity and Exploration of Endophytic Bacilli for the Management of Head Scab (Fusarium graminearum) of Wheat

Fusarium graminearum causing head scab (HS) or head blight (HB) disease in wheat is one of the nasty fungi reported to cause significant grain quality and yield loss. Biological control using endophytic bacteria has emerged as a prospective option for containing fungal diseases in an environmentally benevolent, durable, and sustainable manner. In this regard, 112 endophytic bacilli were isolated from the anthesis stage (Zadok’s growth stage 65) from five different wheat genotypes with an aim to identify prospective antagonistic strains against F. graminearum. The molecular identity of the strains was confirmed by matching 16S rRNA sequences of bacterial strains with the gene sequences of type strains available in the National Center for Biotechnology Information database and reported 38 different species of Bacillus in all the five wheat cultivars. Further, it has been observed that only fourteen strains (B. clarus NOK09, B. mojavensis NOK16, B. subtilis NOK33, B. rugosus NOK47, B. mojavensis NOK52, B. clarus NOK59, B. coahuilensis NOK72, B. cabrialesii NOK78, B. cabrialesii NOK82, B. rugosus NOK85, B. amyloliquefaciens NOK89, B. australimaris NOK95, B. pumilus NOK103, and B. amyloliquefaciens NOK109) displayed in-vitro antagonistic effect against Fusarium graminearum fungus. Furthermore, the three endophytic Bacillus strains showing the strongest antagonistic effect (>70% of growth inhibition of fungal mycelium) under in-vitro antagonistic assay were selected for field experiments. In a two-year consecutive field study, a combination of three strains (B. clarus NOK09 + B. subtilis NOK33 + B. amyloliquefaciens NOK109) displayed a remarkable reduction in HS disease index by 81.47% and 77.85%, respectively. Polymerase chain reaction assay detected three genes (ituD, bmyC, and srfA) involved in antibiotic biosynthesis pathways. Additional attributes such as potassium solubilization, siderophore release, and hydrolytic enzyme (protease, lipase, amylase, chitinase, and pectinase) synthesis have been observed in these strains. Overall, the present study was successful in profiling endophytic bacilli and selecting the combination of effective antagonistic endophytic Bacillus strains that could be the best alternative for the sustainable and ecological sound management of HS disease in wheat under field conditions.

Variation in Tocochromanols Level and Mycotoxins Content in Sweet Maize Cultivars after Inoculation with Fusarium verticillioides and F. proliferatum

A major problem in maize production is the contamination of the grain with Fusarium spp., mainly F. proliferatum and F. verticillioides and their secondary metabolites—mycotoxins. Under biotic stress conditions, caused by a fungal pathogen, plants initiate a series of defense mechanisms that may cause quantitative and qualitative changes in the composition of phenolic compounds. We analyzed the resistance of four sweet maize cultivars (Syngenta Group: Overland, Sweetstar, GSS 8529, Shinerock) to the infection with Fusarium verticillioides and F. proliferatum isolates, along with fumonisins B₁, B₂, and B₃ grain contamination and the levels of tocopherols and tocotrienols accumulated. Differences in ear rot levels were found between the cultivars and isolates used. The phenotypic evaluation positively correlated with the concentrations of fumonisins. The results obtained also indicate a significant dependence on tocochromanols content in sweet maize cultivars tested on the infection of plants with Fusarium isolates and fumonisin biosynthesis. Further studies are needed to investigate the mechanisms of the plant reaction and the effect of different levels of tocopherols and tocotrienols on Fusarium resistance and grain contamination with mycotoxins.

Influence of Agronomic Factors on Mycotoxin Contamination in Maize and Changes during a 10-Day Harvest-Till-Drying Simulation Period: A Different Perspective

Agronomic factors can affect mycotoxin contamination of maize, one of the most produced cereals. Maize is usually harvested at 18% moisture, but it is not microbiologically stable until it reaches 14% moisture at the drying plants. We studied how three agronomic factors (crop diversification, tillage system and nitrogen fertilization rate) can affect fungal and mycotoxin contamination (deoxynivalenol and fumonisins B₁ and B₂) in maize at harvest. In addition, changes in maize during a simulated harvest-till-drying period were studied. DON content at harvest was higher for maize under intensive tillage than using direct drilling (2695 and 474 μg kg⁻¹, respectively). We found two reasons for this: (i) soil crusting in intensive tillage plots caused the formation of pools of water that created high air humidity conditions, favouring the development of DON-producing moulds; (ii) the population of Lumbricus terrestris, an earthworm that would indirectly minimize fungal infection and mycotoxin production on maize kernels, is reduced in intensive tillage plots. Therefore, direct drilling is a better approach than intensive tillage for both preventing DON contamination and preserving soil quality. Concerning the simulated harvest-till-drying period, DON significantly increased between storage days 0 and 5. Water activity dropped on the 4th day, below the threshold for DON production (around 0.91). From our perspective, this study constitutes a step forward towards understanding the relationships between agronomic factors and mycotoxin contamination in maize, and towards improving food safety.

Occurrence of mycotoxins in pulses

Pulses, dry grains of the Fabaceae family used for food and feed, are particularly important agricultural products with increasing commercial and nutritional relevance. Similar to other plant commodities, pulses can be affected by fungi in the field and during postharvest. Some of these fungi produce mycotoxins, which can seriously threaten human and animal health by causing acute poisoning and chronic effects. In this review, information referring to the analysis and occurrence of these compounds in pulses is summarized. An overview of the aims pursued, and of the methodologies employed for mycotoxin analysis in the different reports is presented, followed by a comprehensive review of relevant articles on mycotoxins in pulses, categorized according to the geographical region, among other considerations. Moreover, special attention was given to the effect of climatic conditions on microorganism infestation and mycotoxin accumulation. Furthermore, the limited literature available was considered to look for possible correlations between the degree of fungal infection and the mycotoxin incidence in pulses. In addition, the potential effect of certain phenolic compounds on reducing fungi infestation and mycotoxin accumulation was reviewed with examples on beans. Emphasis was also given to a specific group of mycotoxins, the phomopsins, that mainly impact lupin. Finally, the negative consequences of mycotoxin accumulation on the physiology and development of contaminated seeds and seedlings are presented, focusing on the few reports available on pulses. Given the agricultural and nutritional potential that pulses offer for human well-being, their promotion should be accompanied by attention to food safety issues, and mycotoxins might be among the most serious threats. Practical Application: According to the manuscript template available in the website, this section is for "JFS original research manuscripts ONLY; optional". Since we are publishing in CRFSFS this requirement will not be done.

Searching for the Fusarium spp. Which Are Responsible for Trichothecene Contamination in Oats Using Metataxonomy to Compare the Distribution of Toxigenic Species in Fields from Spain and the UK

The contamination of oats with Fusarium toxins poses a high risk for food safety. Among them, trichothecenes are the most frequently reported in European oats, especially in northern countries. The environmental conditions related to the climate change scenario might favour a distribution shift in Fusarium species and the presence of these toxins in Southern European countries. In this paper, we present an ambitious work to determine the species responsible for trichothecene contamination in Spanish oats and to compare the results in the United Kingdom (UK) using a metataxonomic approach applied to both oat grains and soil samples collected from both countries. Regarding T-2 and HT-2 toxin producers, F. langsethiae was detected in 38% and 25% of the oat samples from the UK and Spain, respectively, and to the best of our knowledge, this is the first report of the detection of this fungus in oats from Spain. The relevant type B trichothecene producer, F. poae, was the most frequently detected Fusarium species in oats from both origins. Other important trichothecene producers, such as the Fusarium tricinctum species complex or Fusarium cerealis, were also frequently detected in oat fields. Many Fusarium toxins, including T-2 and HT-2 toxins, deoxynivalenol, or nivalenol, were detected in oat samples. The results obtained in this work revealed a clear change in the distribution of trichothecene producers and the necessity to establish the potential of these species to colonize oats and their ability to produce mycotoxins.

Role of Tocochromanols in Tolerance of Cereals to Biotic Stresses: Specific Focus on Pathogenic and Toxigenic Fungal Species

Fungal pathogens capable of producing mycotoxins are one of the main threats to the cultivation of cereals and the safety of the harvested kernels. Improving the resistance of crops to fungal disease and accumulation of mycotoxins is therefore a crucial issue. Achieving this goal requires a deep understanding of plant defense mechanisms, most of them involving specialized metabolites. However, while numerous studies have addressed the contribution of phenylpropanoids and carotenoids to plant chemical defense, very few have dealt with tocochromanols. Tocochromanols, which encompass tocopherols and tocotrienols and constitute the vitamin E family, are widely distributed in cereal kernels; their biosynthetic pathway has been extensively studied with the aim to enrich plant oils and combat vitamin E deficiency in humans. Here we provide strong assumptions arguing in favor of an involvement of tocochromanols in plant–fungal pathogen interactions. These assumptions are based on both direct effects resulting from their capacity to scavenge reactive oxygen species, including lipid peroxyl radicals, on their potential to inhibit fungal growth and mycotoxin yield, and on more indirect effects mainly based on their role in plant protection against abiotic stresses.

Multi-Locus Genome-Wide Association Studies to Characterize Fusarium Head Blight (FHB) Resistance in Hard Winter Wheat

Fusarium head blight (FHB), caused by the fungus Fusarium graminearum Schwabe is an important disease of wheat that causes severe yield losses along with serious quality concerns. Incorporating the host resistance from either wild relatives, landraces, or exotic materials remains challenging and has shown limited success. Therefore, a better understanding of the genetic basis of native FHB resistance in hard winter wheat (HWW) and combining it with major quantitative trait loci (QTLs) can facilitate the development of FHB-resistant cultivars. In this study, we evaluated a set of 257 breeding lines from the South Dakota State University (SDSU) breeding program to uncover the genetic basis of native FHB resistance in the US hard winter wheat. We conducted a multi-locus genome-wide association study (ML-GWAS) with 9,321 high-quality single-nucleotide polymorphisms (SNPs). A total of six distinct marker-trait associations (MTAs) were identified for the FHB disease index (DIS) on five different chromosomes including 2A, 2B, 3B, 4B, and 7A. Further, eight MTAs were identified for Fusarium-damaged kernels (FDK) on six chromosomes including 3B, 5A, 6B, 6D, 7A, and 7B. Out of the 14 significant MTAs, 10 were found in the proximity of previously reported regions for FHB resistance in different wheat classes and were validated in HWW, while four MTAs represent likely novel loci for FHB resistance. Accumulation of favorable alleles of reported MTAs resulted in significantly lower mean DIS and FDK score, demonstrating the additive effect of FHB resistance alleles. Candidate gene analysis for two important MTAs identified several genes with putative proteins of interest; however, further investigation of these regions is needed to identify genes conferring FHB resistance. The current study sheds light on the genetic basis of native FHB resistance in the US HWW germplasm and the resistant lines and MTAs identified in this study will be useful resources for FHB resistance breeding via marker-assisted selection.

Lactic Acid Bacteria as Potential Biocontrol Agents for Fusarium Head Blight Disease of Spring Barley

Fusarium head blight (FHB) is a devastating disease encountered by spring-grown barley. Traditionally, synthetic chemicals have been used to control this disease on small grain cereals. A move toward biological control agents as part of sustainable agriculture is pertinent due to the evolutionary mechanisms employed by fungal diseases to circumvent current protection strategies. This study evaluated the effect of six lactic acid bacteria isolates on the development of FHB under in vitro and glasshouse conditions. The relative expression of Fusarium marker genes and transcription factors under Fusarium infection was examined. Dual-culture assays observed inhibition zones of up to 10 and 17% of total plate area for L. amylovorus FST 2.11 and L. brevis R2Δ, respectively. Detached leaf assays validated the antifungal activity and showed the potential of all test isolates to significantly inhibit sporulation of Fusarium culmorum and Fusarium graminearum strains. Spray inoculation of lactic acid bacteria to barley spikelets prior to Fusarium spore application significantly reduced disease severity for five candidates (P < 0.05) under glasshouse conditions. Mycotoxin analysis revealed the ability of L. amylovorus DSM20552 to significantly reduce deoxynivalenol content in spikelets (P < 0.05). A preliminary gene expression study showed the positive influence of lactic acid bacteria on the expression of important defense-related marker genes and transcription factors upon FHB. These results indicate the potential of lactic acid bacteria to be included as part of an integrated pest management strategy for the management of FHB disease. This strategy will reduce FHB severity and deoxynivalenol (DON) contamination of spring barley, leading to high acceptance in the grain market.

Assembly, Annotation, and Comparative Whole Genome Sequence of Fusarium verticillioides Isolated from Stored Maize Grains

Fusarium verticillioides is a plant pathogenic fungus affecting a wide range of crops worldwide due to its toxigenic properties. F. verticillioides BIONCL4 strain was isolated from stored maize grain samples in India, and produces high amount of fumonisin B1 (FB1). We report a comparative genomic analysis of F. verticillioides, covering the basic genome information, secretome, and proteins involved in host–pathogen interactions and mycotoxin biosynthesis. Whole-genome sequencing (WGS) was performed using the Illumina platform with an assembly size of 42.91 Mb, GC content of 48.24%, and 98.50% coverage with the reference genome (GCA000149555). It encodes 15,053 proteins, including 2058 secretory proteins, 676 classical secretory proteins, and 569 virulence and pathogenicity-related proteins. There were also 1447 genes linked to carbohydrate active enzymes (CaZymes) and 167 genes related to mycotoxin production. Furthermore, F. verticillioides genome comparison revealed information about the species’ evolutionary history. The overall study helps in disease prevention and management of mycotoxins to ensure food safety.

A review of toxigenic fungi and mycotoxins in feeds and food commodities in West Africa

Fungal contamination is a threat to food safety in West Africa with implications for food and feed due to their climate, which is characterised by high temperatures and high relative humidity, which are environmental favourable for fast fungal growth and mycotoxin production. This report gives perspective on studies on toxigenic fungi (Aspergillus, Fusarium and Penicillium) and their toxins, mainly aflatoxins, fumonisins and ochratoxins commonly found in some West African countries, including Benin, Burkina Faso, Gambia, Ghana, Ivory Coast, Mali, Nigeria, Senegal, Sierra Leone, and Togo. Only four of these countries have mycotoxins regulations in place for feeds and food products (Ghana, Ivory Coast, Nigeria, and Senegal). Food commodities that are widely consumed and were thoroughly investigated in this region include cereals, peanuts, cassava chips (flakes), cassava flour, chilies, peanuts, locust beans, melon, and yam products. In conclusion, authorities and scientists needed to consider research and approaches to monitor mycotoxins in foods and feeds produced and consumed in West Africa.

Golgi-localized calcium/manganese transporters FgGdt1 and FgPmr1 regulate fungal development and virulence by maintaining Ca2+ and Mn2+ homeostasis in Fusarium graminearum

Calcium and manganese transporters play important roles in regulating Ca²⁺ and Mn²⁺ homeostasis in cells, which is necessary for the normal physiological activities of eukaryotes. Gdt1 and Pmr1 function as calcium/manganese transporters in the Golgi apparatus. However, the functions of Gdt1 and Pmr1 have not been previously characterized in the plant pathogenic fungus Fusarium graminearum. Here, we identified and characterized the biological functions of FgGdt1 and FgPmr1 in F. graminearum. Our study shows that FgGdt1 and FgPmr1 are both localized to the cis- and medial-Golgi. Disruption of FgGdt1 or FgPmr1 in F. graminearum caused serious defects in vegetative growth, conidiation, sexual development and significantly decreased virulence in wheat but increased deoxynivalenol (DON) production. Importantly, FgGdt1 is involved in Ca²⁺ and Mn²⁺ homeostasis and the severe phenotypic defects of the ΔFggdt1 mutant were largely due to loss of FgGdt1 function in Mn²⁺ transportation. FgGdt1-mCherry colocalizes with FgPmr1-GFP at the Golgi, and FgGDT1 exerts its biological function upstream of FgPMR1. Taken together, our results collectively demonstrate that the cis- and medial-Golgi-localized proteins FgGdt1 and FgPmr1 regulate Ca²⁺ and Mn²⁺ homeostasis of the Golgi apparatus, and this function is important in modulating the growth, development, DON biosynthesis and pathogenicity of F. graminearum.

Mycotoxins of Concern in Children and Infant Cereal Food at European Level: Incidence and Bioaccessibility

Cereals are of utmost importance for the nutrition of infants and children, as they provide important nutrients for their growth and development and, in addition, they are easily digestible, being the best choice for the transition from breast milk/infant formula to solid foods. It is well known that children are more susceptible than adults to toxic food contaminants, such as mycotoxins, common contaminants in cereals. Many mycotoxins are already regulated and controlled according to strict quality control standards in Europe and around the world. There are, however, some mycotoxins about which the level of knowledge is lower: the so-called emerging mycotoxins, which are not yet regulated. The current review summarizes the recent information (since 2014) published in the scientific literature on the amounts of mycotoxins in infants’ and children’s cereal-based food in Europe, as well as their behaviour during digestion (bioaccessibility). Additionally, analytical methods used for mycotoxin determination and in vitro methods used to evaluate bioaccessibility are also reported. Some studies demonstrated the co-occurrence of regulated and emerging mycotoxins in cereal products used in children’s food, which highlights the need to adopt guidelines on the simultaneous presence of more than one mycotoxin. Although very little research has been done on the bioaccessibility of mycotoxins in these food products, very interesting results correlating the fiber and lipid contents of such products with a higher or lower bioaccessibility of mycotoxins were reported. LC-MS/MS is the method of choice for the detection and quantification of mycotoxins due to its high sensibility and accuracy. In vitro static digestion models are the preferred ones for bioaccessibility evaluation due to their simplicity and accuracy.

Functional bioplastics from food residual: Potentiality and safety issues

Plastic pollution and food waste are two global issues with much in common. Plastic containers were introduced as a practical and easy remedy to improve food preservation and reduce the risk of creating waste, but ironically, to address one problem, another has been made worse. The spread of single-use containers has dramatically increased the amount of plastic that has to be discarded, and the most urgent task is now to find a solution to what has become part of the problem. An innovative way around it consists of promoting the valorization of food residues by turning them into novel materials for packaging. Although the results are promising, the aim of completely replacing plastics with biodegradable materials still seems far from being achieved. This review illustrates the main strategies adopted thus far to produce new bioplastic materials and composites from waste resources and focuses on the pros and cons of the food recovery process to look for the aspects that represent an obstacle to the development of the circular food economy on an industrial scale.

The control of Fusarium growth and decontamination of produced mycotoxins by lactic acid bacteria

Global crop and food contamination with mycotoxins are one of the primary worldwide concerns, while there are several restrictions regarding approaching conventional physical and chemical mycotoxins decontamination methods due to nutrition loss, sensory attribute reduction in foods, chemical residual, inconvenient operation, high cost of equipment, and high energy consumption of some methods. In this regard, the overarching challenges of mycotoxin contamination in food and food crops require the development of biological decontamination strategies. Using certain lactic acid bacteria (LAB) as generally recognized safe (GRAS) compounds is one of the most effective alternatives due to their potential to release antifungal metabolites against various fungal factors species. This review highlights the potential applications of LAB as biodetoxificant agents and summarizes their decontamination activities against Fusarium growth and Fusarium mycotoxins released into food/feed. Firstly, the occurrence of Fusarium and the instrumental and bioanalytical methods for the analysis of mycotoxins were in-depth discussed. Upgraded knowledge on the biosynthesis pathway of mycotoxins produced by Fusarium offers new insightful ideas clarifying the function of these secondary metabolites. Moreover, the characterization of LAB metabolites and their impact on the decontamination of the mycotoxin from Fusarium, besides the main mechanisms of mycotoxin decontamination, are covered. While the thematic growth inhibition of Fusarium and decontamination of their mycotoxin by LAB is very complex, approaching certain lactic acid bacteria (LAB) is worth deeper investigations.

In Vitro Effects of Lemon Balm Extracts in Reducing the Growth and Mycotoxins Biosynthesis of Fusarium culmorum and F. proliferatum

The objectives of this research were to obtain the extracts of lemon balm (Melissa officinalis) using supercritical CO2 (SC-CO2) and methanol as co-solvent and evaluate the antifungal activity of those extracts against two selected strains of Fusarium species (Fusarium culmorum and Fusarium proliferatum). The extraction conditions were set at 40 and 60 °C and 250 bar. The obtained extracts were characterized in terms of antifungal activity on potato dextrose agar media (PDA). The results showed that the extraction parameters had different effects on mycelium growth and mycotoxins biosynthesis reduction. All studied lemon balm extracts (1, 2.5, 5, 7.5, and 10%) inhibited the growth of F. proliferatum and F. culmorum mycelia compared to the control. The lemon balm extracts significantly reduced ergosterol content and synthesized mycotoxins in both tested strains. These findings support the antifungal activity of lemon balm extracts against F. proliferatum and F. culmorum. However, more research on other Fusarium species is needed, as well as in vivo applications, before considering lemon balm extracts as a natural alternative to synthetic fungicides.

Endocrine Disruptors and Endometrial Cancer: Molecular Mechanisms of Action and Clinical Implications, a Systematic Review

It has been widely demonstrated that endocrine disruptors play a central role in various physiopathological processes of human health. In the literature, various carcinogenic processes have been associated with endocrine disruptors. A review of the molecular mechanisms underlying the interaction between endocrine disruptors and the endometrial cancer has been poorly developed. A systematic review was performed using PubMed^®/MEDLINE. A total of 25 in vivo and in vitro works were selected. Numerous endocrine disruptors were analyzed. The most relevant results showed how Bisphenol A (BPA) interacts with the carcinogenesis process on several levels. It has been demonstrated how BPA can interact with hormonal receptors and with different transcription proliferative and antiproliferative factors. Furthermore, the effect of Polycyclic aromatic hydrocarbons on Aryl hydrocarbon receptors was investigated, and the role of flame retardants in promoting proliferation and metastasis was confirmed. The results obtained demonstrate how the mechanisms of action of endocrine disruptors are manifold in the pathophysiology of endometrial cancer, acting on different levels of the cancerogenesis process.

Antagonistic Activity of Fungal Strains against Fusarium Crown Rot

The crown rot of wheat is a destructive soil-borne pathogen that severely reduces the yield and quality of wheat. This study aimed to screen and identify the antagonistic strains against Fusarium pseudograminearum (Fp), which is the dominant pathogen associated with the crown rot of wheat in China, and evaluate their biosynthetic potential. The antagonistic strains were screened via a dual-culture antagonism assay, and then identified by combining the morphological characteristics and internal transcribed spacer gene sequencing. The polyketide synthases (PKS-I and PKS-II) and non-ribosomal peptide synthetase (NRPS) genes in the antagonistic strains were detected via specific amplification of chromosomal DNA. Eleven out of 157 fungal strains, including six strains with matrix competition and five strains with antibiosis, were obtained. The eleven antagonistic strains belonged to the following four genera: Alternaria, Botryosphaeria, Phoma and Talaromyces. The inhibition rate of six strains with matrix competition was greater than 50%, with B. dothidea S2-22 demonstrating the highest at 80.3%. The width of the inhibition zone of T. trachyspermus R-17 among the five strains with antibiosis was the widest at 11 mm. Among the eleven antagonistic strains, three strains of A. alternata and the strain P. moricola only contained the PKS-II gene, the strain A. tenuissima contained PKS-I and PKS-II genes, three strains of B. dothidea contained PKS-II and NRPS genes, while three strains of T. trachyspermus did not contain any genes. These results demonstrated potential strains for the biocontrol of the crown rot of wheat. In particular, T. trachyspermus R-17 can be investigated further as a promising agent, and the active substances secreted by antagonistic strains may be synthesized by other pathways.

Fusarium metabolites in maize from regions of Northern Serbia in 2016-2017

The main objective of this study was to determine the presence of Fusarium metabolites in maize samples collected from different regions of Northern Serbia (Bačka, Banat and Srem) during a period of two years (2016-2017). A total of 458 maize samples were analysed by liquid chromatography-tandem mass spectrometry. A total of 40 metabolites were detected, where 94% of the samples contained at least 5 metabolites. Fumonisins (including B₁, B₂, B₃ and B₄), moniliformin and bikaverin were the most frequent (80-98%) Fusarium metabolites in both years. Furthermore, in samples from 2016, fumonisin A₁ and A₂, deoxynivalenol, deoxynivalenol-3-glucoside, zearalenone, culmorin, 15-hydroxyculmorin, fusapyron, fusaproliferin and aurofusarin were detected with frequencies of 58-80%. Levels of certain Fusarium metabolites in 2016 were higher on average due to increased humidity when compared to 2017, which was characterised by warm and dry conditions.

Mycosubtilin Produced by Bacillus subtilis ATCC6633 Inhibits Growth and Mycotoxin Biosynthesis of Fusarium graminearum and Fusarium verticillioides

Fusarium graminearum and Fusarium verticillioides are fungal pathogens that cause diseases in cereal crops, such as Fusarium head blight (FHB), seedling blight, and stalk rot. They also produce a variety of mycotoxins that reduce crop yields and threaten human and animal health. Several strategies for controlling these diseases have been developed. However, due to a lack of resistant cultivars and the hazards of chemical fungicides, efforts are now focused on the biocontrol of plant diseases, which is a more sustainable and environmentally friendly approach. In the present study, the lipopeptide mycosubtilin purified from Bacillus subtilis ATCC6633 significantly suppressed the growth of F. graminearum PH-1 and F. verticillioides 7600 in vitro. Mycosubtilin caused the destruction and deformation of plasma membranes and cell walls in F. graminearum hyphae. Additionally, mycosubtilin inhibited conidial spore formation and germination of both fungi in a dose-dependent manner. In planta experiments demonstrated the ability of mycosubtilin to control the adverse effects caused by F. graminearum and F. verticillioides on wheat heads and maize kernels, respectively. Mycosubtilin significantly decreased the production of deoxynivalenol (DON) and B-series fumonisins (FB1, FB2 and FB3) in infected grains, with inhibition rates of 48.92, 48.48, 52.42, and 59.44%, respectively. The qRT-PCR analysis showed that mycosubtilin significantly downregulated genes involved in mycotoxin biosynthesis. In conclusion, mycosubtilin produced by B. subtilis ATCC6633 was shown to have potential as a biological agent to control plant diseases and Fusarium toxin contamination caused by F. graminearum and F. verticillioides.

Arabidopsis P4 ATPase-mediated cell detoxification confers resistance to Fusarium graminearum and Verticillium dahliae

Many toxic secondary metabolites produced by phytopathogens can subvert host immunity, and some of them are recognized as pathogenicity factors. Fusarium head blight and Verticillium wilt are destructive plant diseases worldwide. Using toxins produced by the causal fungi Fusarium graminearum and Verticillium dahliae as screening agents, here we show that the Arabidopsis P4 ATPases AtALA1 and AtALA7 are responsible for cellular detoxification of mycotoxins. Through AtALA1-/AtALA7-mediated vesicle transport, toxins are sequestered in vacuoles for degradation. Overexpression of AtALA1 and AtALA7 significantly increases the resistance of transgenic plants to F. graminearum and V. dahliae, respectively. Notably, the concentration of deoxynivalenol, a mycotoxin harmful to the health of humans and animals, was decreased in transgenic Arabidopsis siliques and maize seeds. This vesicle-mediated cell detoxification process provides a strategy to increase plant resistance against different toxin-associated diseases and to reduce the mycotoxin contamination in food and feed.

Enniatin B and Deoxynivalenol Activity on Bread Wheat and on Fusarium Species Development

Fusarium head blight (FHB) is a devastating wheat disease, mainly caused by Fusarium graminearum (FG)-a deoxynivalenol (DON)-producing species. However, Fusarium avenaceum (FA), able to biosynthesize enniatins (ENNs), has recently increased its relevance worldwide, often in co-occurrence with FG. While DON is a well-known mycotoxin, ENN activity, also in association with DON, is poorly understood. This study aims to explore enniatin B (ENB) activity, alone or combined with DON, on bread wheat and on Fusarium development. Pure ENB, DON, and ENB+DON (10 mg kg^-1) were used to assess the impacts on seed germination, seedling growth, cell death induction (trypan blue staining), chlorophyll content, and oxidative stress induction (malondialdehyde quantification). The effect on FG and FA growth was tested using ENB, DON, and ENB+DON (10, 50, and 100 mg kg^-1). Synergistic activity in the reduction of seed germination, growth, and chlorophyll degradation was observed. Conversely, antagonistic interaction in cell death and oxidative stress induction was found, with DON counteracting cellular stress produced by ENB. Fusarium species responded to mycotoxins in opposite directions. ENB inhibited FG development, while DON promoted FA growth. These results highlight the potential role of ENB in cell death control, as well as in fungal competition.

Analysis of Stored Wheat Grain-Associated Microbiota Reveals Biocontrol Activity among Microorganisms against Mycotoxigenic Fungi

Wheat grains are colonized by complex microbial communities that have the potential to affect seed quality and susceptibility to disease. Some of the beneficial microbes in these communities have been shown to protect plants against pathogens through antagonism. We evaluated the role of the microbiome in seed health: in particular, against mycotoxin-producing fungi. Amplicon sequencing was used to characterize the seed microbiome and determine if epiphytes and endophytes differ in their fungal and bacterial diversity and community composition. We then isolated culturable fungal and bacterial species and evaluated their antagonistic activity against mycotoxigenic fungi. The most prevalent taxa were found to be shared between the epiphytic and endophytic microbiota of stored wheat seeds. Among the isolated bacteria, Bacillus strains exhibited strong antagonistic properties against fungal pathogens with noteworthy fungal load reduction in wheat grain samples of up to a 3.59 log₁₀ CFU/g compared to untreated controls. We also found that a strain of the yeast, Rhodotorula glutinis, isolated from wheat grains, degrades and/or metabolizes aflatoxin B₁, one of the most dangerous mycotoxins that negatively affects physiological processes in animals and humans. The mycotoxin level in grain samples was significantly reduced up to 65% in the presence of the yeast strain, compared to the untreated control. Our study demonstrates that stored wheat grains are a rich source of bacterial and yeast antagonists with strong inhibitory and biodegradation potential against mycotoxigenic fungi and the mycotoxins they produce, respectively. Utilization of these antagonistic microorganisms may help reduce fungal and mycotoxin contamination, and potentially replace traditionally used synthetic chemicals.

Endophytes of Brazilian Medicinal Plants With Activity Against Phytopathogens

Plant diseases caused by phytopathogens are responsible for significant crop losses worldwide. Resistance induction and biological control have been exploited in agriculture due to their enormous potential. In this study, we investigated the antimicrobial potential of endophytic fungi of leaves and petioles of medicinal plants Vochysia divergens and Stryphnodendron adstringens located in two regions of high diversity in Brazil, Pantanal, and Cerrado, respectively. We recovered 1,304 fungal isolates and based on the characteristics of the culture, were assigned to 159 phenotypes. One isolate was selected as representative of each phenotype and studied for antimicrobial activity against phytopathogens. Isolates with better biological activities were identified based on DNA sequences and phylogenetic analyzes. Among the 159 representative isolates, extracts from 12 endophytes that inhibited the mycelial growth (IG) of Colletotrichum abscissum (≥40%) were selected to expand the antimicrobial analysis. The minimum inhibitory concentrations (MIC) of the extracts were determined against citrus pathogens, C. abscissum, Phyllosticta citricarpa and Xanthomonas citri subsp. citri and the maize pathogen Fusarium graminearum. The highest activity against C. abscissum were from extracts of Pseudofusicoccum stromaticum CMRP4328 (IG: 83% and MIC: 40 μg/mL) and Diaporthe vochysiae CMRP4322 (IG: 75% and MIC: 1 μg/mL), both extracts also inhibited the development of post-bloom fruit drop symptoms in citrus flowers. The extracts were promising in inhibiting the mycelial growth of P. citricarpa and reducing the production of pycnidia in citrus leaves. Among the isolates that showed activity, the genus Diaporthe was the most common, including the new species D. cerradensis described in this study. In addition, high performance liquid chromatography, UV detection, and mass spectrometry and thin layer chromatography analyzes of extracts produced by endophytes that showed high activity, indicated D. vochysiae CMRP4322 and P. stromaticum CMRP4328 as promising strains that produce new bioactive natural products. We report here the capacity of endophytic fungi of medicinal plants to produce secondary metabolites with biological activities against phytopathogenic fungi and bacteria. The description of the new species D. cerradensis, reinforces the ability of medicinal plants found in Brazil to host a diverse group of fungi with biotechnological potential.

Biocontrol Agents Reduce Progression and Mycotoxin Production of Fusarium graminearum in Spikelets and Straws of Wheat

The aim of this study was to evaluate the interactions between wheat plant (spikelets and straws), a strain of mycotoxigenic pathogen Fusarium graminearum and commercial biocontrol agents (BCAs). The ability of BCAs to colonize plant tissue and inhibit the pathogen or its toxin production was observed throughout two phases of the life cycle of pathogens in natural conditions (colonization and survival). All evaluated BCAs showed effective reduction capacities of pathogenic traits. During establishment and the expansion stage, BCAs provoked an external growth reduction of F. graminearum (77–93% over the whole kinetic studied) and mycotoxin production (98–100% over the whole kinetic studied). Internal growth of pathogen was assessed with digital droplet polymerase chain reaction (ddPCR) and showed a very strong reduction in the colonization of the internal tissues of the spikelet due to the presence of BCAs (98% on average). During the survival stage, BCAs prevented the formation of conservation perithecia of the pathogen on wheat straw (between 88 and 98% of perithecia number reduction) and showed contrasting actions on the ascospores they contain, or perithecia production (−95% on average) during survival form. The mechanisms involved in these different interactions between F. graminearum and BCAs on plant matrices at different stages of the pathogen’s life cycle were based on a reduction of toxins, nutritional and/or spatial competition, or production of anti-microbial compounds.

Integrated Mycotoxin Management System in the Feed Supply Chain: Innovative Approaches

Exposure to mycotoxins is a worldwide concern as their occurrence is unavoidable and varies among geographical regions. Mycotoxins can affect the performance and quality of livestock production and act as carriers putting human health at risk. Feed can be contaminated by various fungal species, and mycotoxins co-occurrence, and modified and emerging mycotoxins are at the centre of modern mycotoxin research. Preventing mould and mycotoxin contamination is almost impossible; it is necessary for producers to implement a comprehensive mycotoxin management program to moderate these risks along the animal feed supply chain in an HACCP perspective. The objective of this paper is to suggest an innovative integrated system for handling mycotoxins in the feed chain, with an emphasis on novel strategies for mycotoxin control. Specific and selected technologies, such as nanotechnologies, and management protocols are reported as promising and sustainable options for implementing mycotoxins control, prevention, and management. Further research should be concentrated on methods to determine multi-contaminated samples, and emerging and modified mycotoxins.

Transcriptome Alterations of an in vitro-Selected, Moderately Resistant, Two-Row Malting Barley in Response to 3ADON, 15ADON, and NIV Chemotypes of Fusarium graminearum

Fusarium head blight caused by Fusarium graminearum is a devastating disease of malting barley. Mycotoxins associated with contaminated grain can be transferred from malt to beer and pose a health risk to consumers. In western Canada, F. graminearum has undergone an adaptive shift from 15ADON constituency to dominance by virulent 3ADON-producers; likewise, NIV-producers have established in regions of southern United States. Lack of adapted resistance sources with adequate malting quality has promoted the use of alternative breeding methodologies, such as in vitro selection. We studied the low-deoxynivalenol characteristic of in vitro selected, two-row malting barley variety "Norman" by RNAseq in contrast to its parental line "CDC Kendall," when infected by 15ADON-, 3ADON-, and NIV-producing isolates of F. graminearum. The current study documents higher mycotoxin accumulation by 3ADON isolates, thereby representing increased threat to barley production. At 72-96-h post infection, significant alterations in transcription patterns were observed in both varieties with pronounced upregulation of the phenylpropanoid pathway and detoxification gene categories (UGT, GST, CyP450, and ABC), particularly in 3ADON treatment. Defense response was multitiered, where differential expression in "Norman" associated with antimicrobial peptides (thionin 2.1, defensing, non-specific lipid-transfer protein) and stress-related proteins, such as late embryogenesis abundant proteins, heat-shock, desiccation related, and a peroxidase (HvPrx5). Several gene targets identified in "Norman" would be useful for application of breeding varieties with reduced deoxynivalenol content.

Effect of Naturally Occurring Compounds on Fumonisin Production and fum Gene Expression in Fusarium verticillioides

Fusarium verticillioides, one of the most common pathogens in maize, is responsible for yield losses and reduced kernel quality due to contamination by fumonisins (FBs). Two F. verticillioides isolates that differed in their ability to produce FBs were treated with a selection of eight natural phenolic compounds with the aim of identifying those that were able to decrease toxin production at concentrations that had a limited effect on fungal growth. Among the tested compounds, ellagic acid and isoeugenol, which turned out to be the most effective molecules against fungal growth, were assayed at lower concentrations, while the first retained its ability to inhibit toxin production in vitro, the latter improved both the fungal growth and FB accumulation. The effect of the most effective phenolic compounds on FB accumulation was also tested on maize kernels to highlight the importance of appropriate dosages in order to avoid conditions that are able to promote mycotoxin biosynthesis. An expression analysis of genes involved in FB production allowed more detailed insights into the mechanisms underlying the inhibition of FBs by phenolic compounds. The expression of the fum gene was generally down-regulated by the treatments; however, some treatments in the low-producing F. verticillioides strain up-regulated fum gene expression without improving FB production. This study showed that although different phenolic compounds are effective for FB reduction, they can modulate biosynthesis at the transcription level in opposite manners depending on strain. In conclusion, on the basis of in vitro and in vivo screening, two out of the eight tested phenols (ellagic acid and carvacrol) appear to be promising alternative molecules for the control of FB occurrence in maize.

Critical Assessment of Mycotoxins in Beverages and Their Control Measures

Mycotoxins are secondary metabolites of filamentous fungi that contaminate food products such as fruits, vegetables, cereals, beverages, and other agricultural commodities. Their occurrence in the food chain, especially in beverages, can pose a serious risk to human health, due to their toxicity, even at low concentrations. Mycotoxins, such as aflatoxins (AFs), ochratoxin A (OTA), patulin (PAT), fumonisins (FBs), trichothecenes (TCs), zearalenone (ZEN), and the alternaria toxins including alternariol, altenuene, and alternariol methyl ether have largely been identified in fruits and their derived products, such as beverages and drinks. The presence of mycotoxins in beverages is of high concern in some cases due to their levels being higher than the limits set by regulations. This review aims to summarize the toxicity of the major mycotoxins that occur in beverages, the methods available for their detection and quantification, and the strategies for their control. In addition, some novel techniques for controlling mycotoxins in the postharvest stage are highlighted.

Mycotoxins Biocontrol Methods for Healthier Crops and Stored Products

Contamination of crops with phytopathogenic genera such as Fusarium, Aspergillus, Alternaria, and Penicillium usually results in mycotoxins in the stored crops or the final products (bread, beer, etc.). To reduce the damage and suppress the fungal growth, it is common to add antifungal substances during growth in the field or storage. Many of these antifungal substances are also harmful to human health and the reduction of their concentration would be of immense importance to food safety. Many eminent researchers are seeking a way to reduce the use of synthetic antifungal compounds and to implement more eco-friendly and healthier bioweapons against fungal proliferation and mycotoxin synthesis. This paper aims to address the recent advances in the effectiveness of biological antifungal compounds application against the aforementioned fungal genera and their species to enhance the protection of ecological and environmental systems involved in crop growing (water, soil, air) and to reduce fungicide contamination of food derived from these commodities.

Tick defensin γ-core reduces Fusarium graminearum growth and abrogates mycotoxins production with high efficiency

Fusarium graminearum is a major fungal pathogen affecting crops of worldwide importance. F. graminearum produces type B trichothecene mycotoxins (TCTB), which are not fully eliminated during food and feed processing. Therefore, the best way to minimize TCTB contamination is to develop prevention strategies. Herein we show that treatment with the reduced form of the γ-core of the tick defensin DefMT3, referred to as TickCore3 (TC3), decreases F. graminearum growth and abrogates TCTB production. The oxidized form of TC3 loses antifungal activity, but retains anti-mycotoxin activity. Molecular dynamics show that TC3 is recruited by specific membrane phospholipids in F. graminearum and that membrane binding of the oxidized form of TC3 is unstable. Capping each of the three cysteine residues of TC3 with methyl groups reduces its inhibitory efficacy. Substitutions of the positively-charged residues lysine (Lys) 6 or arginine 7 by threonine had the highest and the lesser impact, respectively, on the anti-mycotoxin activity of TC3. We conclude that the binding of linear TC3 to F. graminearum membrane phospholipids is required for the antifungal activity of the reduced peptide. Besides, Lys6 appears essential for the anti-mycotoxin activity of the reduced peptide. Our results provide foundation for developing novel and environment-friendly strategies for controlling F. graminearum.

A Phenome-Wide Association Study of the Effects of Fusarium graminearum Transcription Factors on Fusarium Graminearum Virus 1 Infection

The Fusarium graminearum virus 1 (FgV1) causes noticeable phenotypic changes such as reduced mycelial growth, increase pigmentation, and reduced pathogenicity in its host fungi, Fusarium graminearum. Previous study showed that the numerous F. graminearum genes including regulatory factors were differentially expressed upon FgV1 infection, however, we have limited knowledge on the effect(s) of specific transcription factor (TF) during FgV1 infection in host fungus. Using gene-deletion mutant library of 657 putative TFs in F. graminearum, we transferred FgV1 by hyphal anastomosis to screen transcription factors that might be associated with viral replication or symptom induction. FgV1-infected TF deletion mutants were divided into three groups according to the mycelial growth phenotype compare to the FgV1-infected wild-type strain (WT-VI). The FgV1-infected TF deletion mutants in Group 1 exhibited slow or weak mycelial growth compare to that of WT-VI on complete medium at 5 dpi. In contrast, Group 3 consists of virus-infected TF deletion mutants showing faster mycelial growth and mild symptom compared to that of WT-VI. The hyphal growth of FgV1-infected TF deletion mutants in Group 2 was not significantly different from that of WT-VI. We speculated that differences of mycelial growth among the FgV1-infected TF deletion mutant groups might be related with the level of FgV1 RNA accumulations in infected host fungi. By conducting real-time quantitative reverse transcription polymerase chain reaction, we observed close association between FgV1 RNA accumulation and phenotypic differences of FgV1-infected TF deletion mutants in each group, i.e., increased and decreased dsRNA accumulation in Group 1 and Group 3, respectively. Taken together, our analysis provides an opportunity to identify host's regulator(s) of FgV1-triggered signaling and antiviral responses and helps to understand complex regulatory networks between FgV1 and F. graminearum interaction.

Molecular and epigenetic modes of Fumonisin B1 mediated toxicity and carcinogenesis and detoxification strategies

Fumonisin B₁ (FB₁) is a natural contaminant of agricultural commodities that has displayed a myriad of toxicities in animals. Moreover, it is known to be a hepatorenal carcinogen in rodents and may be associated with oesophageal and hepatocellular carcinomas in humans. The most well elucidated mode of FB₁-mediated toxicity is its disruption of sphingolipid metabolism; however, enhanced oxidative stress, endoplasmic reticulum stress, autophagy, and alterations in immune response may also play a role in its toxicity and carcinogenicity. Alterations to the host epigenome may impact on the toxic and carcinogenic response to FB₁. Seeing that the contamination of FB₁ in food poses a considerable risk to human and animal health, a great deal of research has focused on new methods to prevent and attenuate FB₁-induced toxic consequences. The focus of the present review is on the molecular and epigenetic interactions of FB₁ as well as recent research involving FB₁ detoxification.

Occurrence of Fusarium spp. in Maize Grain Harvested in Portugal and Accumulation of Related Mycotoxins during Storage

Maize is an important worldwide commodity susceptible to fungal contamination in the field, at harvest, and during storage. This work aimed to determine the occurrence of Fusarium spp. in maize grains produced in the Tagus Valley region of Portugal and the levels of related mycotoxins in the 2018 harvest and during their storage for six months in barrels, mimicking silos conditions. Continuous monitoring of temperature, CO2, and relative humidity levels were done, as well as the concentration of mycotoxins were evaluated and correlated with the presence of Fusarium spp. F. verticillioides was identified as the predominant Fusarium species. Zearalenone, deoxynivalenol and toxin T2 were not found at harvest and after storage. Maize grains showed some variability in the levels of fumonisins (Fum B1 and Fum B2). At the harvest, fumonisin B1 ranged from 1297 to 2037 µg/kg, and fumonisin B2 ranged from 411 to 618 µg/kg. Fumonisins showed a tendency to increase (20 to 40%) during six months of storage. Although a correlation between the levels of fumonisins and the monitoring parameters was not established, CO2 levels may be used to predict fungal activity during storage. The composition of the fungal population during storage may predict the incidence of mycotoxins.

Occurrence of Fusarium Mycotoxins and Their Modified Forms in Forage Maize Cultivars

Forage maize is often infected by mycotoxin-producing Fusarium fungi during plant growth, which represent a serious health risk to exposed animals. Deoxynivalenol (DON) and zearalenone (ZEN) are among the most important Fusarium mycotoxins, but little is known about the occurrence of their modified forms in forage maize. To assess the mycotoxin contamination in Northern Germany, 120 natural contaminated forage maize samples of four cultivars from several locations were analysed by liquid chromatography-high resolution mass spectrometry (LC-HRMS) for DON and ZEN and their modified forms deoxynivalenol-3-glucoside (DON3G), the sum of 3- and 15-acetyl-deoxynivalenol (3+15-AcDON), α- and β-zearalenol (α-ZEL, β-ZEL). DON and ZEN occurred with high incidences (100 and 96%) and a wide range of concentrations, reaching levels up to 10,972 and 3910 µg/kg, respectively. Almost half of the samples (46%) exceeded the guidance value in complementary and complete feeding stuffs for ZEN (500 µg/kg), and 9% for DON (5000 µg/kg). The DON related mycotoxins DON3G and 3+15-AcDON were also present in almost all samples (100 and 97%) with amounts of up to 3038 and 2237 µg/kg and a wide range of concentrations. For the ZEN metabolites α- and β-ZEL lower incidences were detected (59 and 32%) with concentrations of up to 423 and 203 µg/kg, respectively. Forage maize samples were contaminated with at least three co-occurring mycotoxins, whereby 95% of all samples contained four or more mycotoxins with DON, DON3G, 3+15-AcDON, and ZEN co-occurring in 93%, together with α-ZEL in 57% of all samples. Positive correlations were established between concentrations of the co-occurring mycotoxins, especially between DON and its modified forms. Averaged over all samples, ratios of DON3G/DON and 3+15-AcDON/DON were similar, 20.2 and 20.5 mol%; cultivar-specific mean ratios ranged from 14.6 to 24.3 mol% and 15.8 to 24.0 mol%, respectively. In total, 40.7 mol% of the measured DON concentration was present in the modified forms DON3G and 3+15-AcDON. The α-ZEL/ZEN ratio was 6.2 mol%, ranging from 5.2 to 8.6 mol% between cultivars. These results demonstrate that modified mycotoxins contribute substantially to the overall mycotoxin contamination in forage maize. To avoid a considerable underestimation, it is necessary to analyse modified mycotoxins in future mycotoxin monitoring programs together with their parent forms.

Trichothecenes in Food and Feed, Relevance to Human and Animal Health and Methods of Detection: A Systematic Review

Trichothecene mycotoxins are sesquiterpenoid compounds primarily produced by fungi in taxonomical genera such as Fusarium, Myrothecium, Stachybotrys, Trichothecium, and others, under specific climatic conditions on a worldwide basis. Fusarium mold is a major plant pathogen and produces a number of trichothecene mycotoxins including deoxynivalenol (or vomitoxin), nivalenol, diacetoxyscirpenol, and T-2 toxin, HT-2 toxin. Monogastrics are sensitive to vomitoxin, while poultry and ruminants appear to be less sensitive to some trichothecenes through microbial metabolism of trichothecenes in the gastrointestinal tract. Trichothecene mycotoxins occur worldwide however both total concentrations and the particular mix of toxins present vary with environmental conditions. Proper agricultural practices such as avoiding late harvests, removing overwintered stubble from fields, and avoiding a corn/wheat rotation that favors Fusarium growth in residue can reduce trichothecene contamination of grains. Due to the vague nature of toxic effects attributed to low concentrations of trichothecenes, a solid link between low level exposure and a specific trichothecene is difficult to establish. Multiple factors, such as nutrition, management, and environmental conditions impact animal health and need to be evaluated with the knowledge of the mycotoxin and concentrations known to cause adverse health effects. Future research evaluating the impact of low-level exposure on livestock may clarify the potential impact on immunity. Trichothecenes are rapidly excreted from animals, and residues in edible tissues, milk, or eggs are likely negligible. In chronic exposures to trichothecenes, once the contaminated feed is removed and exposure stopped, animals generally have an excellent prognosis for recovery. This review shows the occurrence of trichothecenes in food and feed in 2011-2020 and their toxic effects and provides a summary of the discussions on the potential public health concerns specifically related to trichothecenes residues in foods associated with the exposure of farm animals to mycotoxin-contaminated feeds and impact to human health. Moreover, the article discusses the methods of their detection.

Evaluating the Antifungal Activity of α-Bisabolol in Association with NaCl on Fusarium oxysporum in Maize Grains

Fusarium infections result in reduced maize grain (Zea mays L.) yields and notable impacts on human and animal health. Research involving natural products to control fungi in food is a promising alternative. Combinations of α-bisabolol (AB) and sodium chloride (NaCl) may suggest the use of lower effective concentrations of the drugs. This study aimed to evaluate the antifungal potential of AB associated with NaCl against Fusarium oxysporum strains isolated from maize. Minimum inhibitory concentrations (MICs) values of AB and NaCl were determined by microdilution, and an association study was performed (checkerboard). Effects on fungal mycelial growth (poisoned substrate technique) and a maize grain contamination model were analyzed. AB presented MIC values ranging from 128 and 1024 μg/mL; NaCl inhibited fungal growth at 16,384 μg/mL. The AB/NaCl association study revealed synergism by decreasing inhibitory concentrations by eight times. In corn kernels, AB and NaCl, whether isolated (at MIC) or in association (at sub-inhibitory concentrations), significantly inhibited in vitro mycelial growth (P < 0.05). Further analysis of liquid from a canned maize sample also revealed the fungistatic effects of the compounds associations (P < 0.05). The results confirm the antifungal potential of AB, whether isolated or in association with NaCl to control F. oxysporum in maize.

Incidence of Fusarium Mycotoxins in Wheat and Maize from Albania

In this study, ten Fusarium toxins were analysed in wheat and maize commodities from Albania. In total, 71 samples of wheat and 45 samples of maize were collected from different producing regions. The analytical procedure consisted of a simple one-step sample extraction followed by the determination of toxins using liquid chromatography coupled with tandem mass spectrometry. Fusarium toxins were found in 23% of the analysed wheat samples and in 78% of maize samples. In maize samples, most often fumonisins B1 (FB1) and B2 (FB2) were found. They were present in 76% of samples. They were detected in all positive samples except in one with concentrations ranging from 59.9 to 16,970 μg/kg. The sum of FB1 and FB2 exceeded the EU maximum permitted level (4000 μg/kg) in 31% of maize samples. In wheat samples, the only detected Fusarium mycotoxin was deoxynivalenol (DON), present in 23% of samples. In one sample with the concentration of 1916 μg/kg, the EU maximum permitted level (1250 μg/kg) was exceeded. This is the first report on the presence of Fusarium toxins in wheat and maize grains cultivated in Albania.

Double Gamers-Can Modified Natural Regulators of Higher Plants Act as Antagonists against Phytopathogens? The Case of Jasmonic Acid Derivatives

As key players in biotic stress response of plants, jasmonic acid (JA) and its derivatives cover a specific and prominent role in pathogens-mediated signaling and hence are promising candidates for a sustainable management of phytopathogenic fungi. Recently, JA directed antimicrobial effects on plant pathogens has been suggested, supporting the theory of oxylipins as double gamers in plant-pathogen interaction. Based on these premises, six derivatives (dihydrojasmone and cis-jasmone, two thiosemicarbazonic derivatives and their corresponding complexes with copper) have been evaluated against 13 fungal species affecting various economically important herbaceous and woody crops, such as cereals, grapes and horticultural crops: Phaeoacremonium minimum, Neofusicoccum parvum, Phaeomoniella chlamydospora, Fomitiporia mediterranea, Fusarium poae, F. culmorum, F. graminearum, F. oxysporum f. sp. lactucae,F. sporotrichioides, Aspergillus flavus, Rhizoctonia solani,Sclerotinia spp. and Verticillium dahliae. The biological activity of these compounds was assessed in terms of growth inhibition and, for the two mycotoxigenic species A. flavus and F. sporotrichioides, also in terms of toxin containment. As expected, the inhibitory effect of molecules greatly varied amongst both genera and species; cis-jasmone thiosemicarbazone in particular has shown the wider range of effectiveness. However, our results show that thiosemicarbazones derivatives are more effective than the parent ketones in limiting fungal growth and mycotoxins production, supporting possible applications for the control of pathogenic fungi.

Genetic analyses of native Fusarium head blight resistance in two spring wheat populations identifies QTL near the B1, Ppd-D1, Rht-1, Vrn-1, Fhb1, Fhb2, and Fhb5 loci

QTL analyses of two bi-parental mapping populations with AC Barrie as a parent revealed numerous FHB-resistance QTL unique to each population and uncovered novel variation near Fhb1. Fusarium head blight (FHB) is a destructive disease of wheat worldwide, leading to severe yield and quality losses. The genetic basis of native FHB resistance was examined in two populations: a recombinant inbred line population from the cross Cutler/AC Barrie and a doubled haploid (DH) population from the cross AC Barrie/Reeder. Numerous QTL were detected among the two mapping populations with many being cross-specific. Photoperiod insensitivity at Ppd-D1 and dwarfing at Rht-B1 and Rht-D1 was associated with increased FHB susceptibility. Anthesis date QTL at or near the Vrn-A1 and Vrn-B1 loci co-located with major FHB-resistance QTL in the AC Barrie/Reeder population. The loci were epistatic for both traits, such that DH lines with both late alleles were considerably later to anthesis and had reduced FHB symptoms (i.e., responsible for the epistatic interaction). Interestingly, AC Barrie contributed FHB resistance near the Fhb1 locus in the Cutler population and susceptibility in the Reeder population. Analyses of the Fhb1 candidate genes PFT and TaHRC confirmed that AC Barrie, Cutler, and Reeder do not carry the Sumai-3 Fhb1 gene. Resistance QTL were also detected at the expected locations of Fhb2 and Fhb5. The native FHB-resistance QTL detected near Fhb1, Fhb2, and Fhb5 do not appear to be as effective as Fhb1, Fhb2, and Fhb5 from Sumai-3. The presence of awns segregated at the B1 awn inhibitor locus in both populations, but was only associated with FHB resistance in the Cutler/AC Barrie population suggesting linkage caused the association rather than pleiotropy.

Dynamic Remote Sensing Prediction for Wheat Fusarium Head Blight by Combining Host and Habitat Conditions

Remote sensing technology provides a feasible option for early prediction for wheat Fusarium head blight (FHB). This study presents a methodology for the dynamic prediction of this classic meteorological crop disease. Host and habitat conditions were comprehensively considered as inputs of the FHB prediction model, and the advantages, accuracy, and generalization ability of the model were evaluated. Firstly, multi-source satellite images were used to predict growth stages and to obtain remote sensing features, then weather features around the predicted stages were extracted. Then, with changes in the inputting features, the severity of FHB was dynamically predicted on February 18, March 6, April 23, and May 9, 2017. Compared to the results obtained by the Logistic model, the prediction with the Relevance Vector Machine performed better, with the overall accuracy on these four dates as 0.71, 0.78, 0.85, and 0.93, and with the area under the receiver operating characteristic curve as 0.66, 0.67, 0.72, and 0.75. Additionally, compared with the prediction with only one factor, the integration of multiple factors was more accurate. The results showed that when the date of the remote sensing features was closer to the heading or flowering stage, the prediction was more accurate, especially in severe areas. Though the habitat conditions were suitable for FHB, the infection can be inhibited when the host’s growth meets certain requirements.

The role of Serendipita indica and Lactobacilli mixtures on mitigating mycotoxins and heavy metals' risks of contaminated sewage sludge and its composts

Accumulation of the Municipal Sewage Sludge (MSS) is considered as one of the most harmful renewable ecological and human health problems. MSS is a renewable resource that could be used as a soil organic amendment. This study aims to reduce the Heavy Metals (HMs) from the sludge content and sludge compost. Furthermore, this study is considered the first to assess the mycotoxins content in sludge and sludge compost via a new biological treatment using the fungus Serendipita indica or a mixture of lactic acid bacteria, thus providing safer nutrients for the soil amendment for a longer time and preserving human health. The HMs and mycotoxins were determined. The results exhibited that the biotic remediation of bio-solid waste and sewage sludge compost succeeded; a new bio-treated compost with a very low content of heavy metals and almost mycotoxins-free contents was availed. Also, the results indicated that the Lactobacilli mixture realized the best results in reducing heavy metals contents and mycotoxins. Afterward, S. indica. biotic remediation of bio-solid waste and sewage sludge compost minimized the health risk hazards affecting the human food chain, allowing for the different uses of sludge to be safer for the environment.

The effects of feed naturally contaminated with Fusarium mycotoxins on the thymus in suckling piglets

In this study, feed naturally containing Fusarium mycotoxins was fed to gilts during the perinatal period, and the effects on the thymus were investigated in one-week-old piglets. Twenty gilts were divided into equal control (0.26 mg deoxynivalenol, DON) and experimental (5.08 mg DON, 0.09 mg zearalenone and 21.61 mg fusaric acid per kg of feed) groups. One suckling piglet from each litter (n = 20) was sacrificed at one week of age to obtain thymus samples for further analysis. The cortex to medulla ratio of the thymus was morphometrically analysed using NIS Elements BR (Nikon) software. Paraffin-embedded thymus sections were stained to quantify apoptosis (with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling - TUNEL method), cellular proliferation (Ki-67) and macrophages (MAC 387). The results showed that the thymus cortex (P = 0.023) to medulla (P = 0.023) ratio was significantly lower in the experimental group. The number of apoptotic cells (cortex, P = 0.010, medulla, P = 0.001) and the number of proliferating cells in the thymus cortex (P = 0.001) and medulla (P < 0.001) were significantly higher in the experimental group. Our results indicate that feeding Fusarium mycotoxins to a parent animal during the perinatal period induces significant alterations in the thymus of one-week-old piglets, which indicates an immunosuppressive effect in piglets.

Moving from qPCR to Chip Digital PCR Assays for Tracking of some Fusarium Species Causing Fusarium Head Blight in Cereals

Fusarium Head Blight (FHB) is one of the major diseases affecting small-grain cereals, worldwide spread and responsible for severe yield and quality losses annually. Diagnostic tools, able to track Fusarium species even in the early stages of infection, can contribute to mycotoxins' risk control. Among DNA-based technologies for Fusarium detection, qPCR (single and multiplex assays) is currently the most applied method. However, pathogen diagnostics is now enforced by digital PCR (dPCR), a breakthrough technology that provides ultrasensitive and absolute nucleic acid quantification. In our work, a panel of chip digital PCR assays was developed to quantify Fusarium graminearum, F.culmorum, F. sporotrichioides, F. poae and F. avenaceum. The primers/probes combinations were evaluated on pure fungal samples with cdPCR technique, in comparison with the qPCR approach. Moreover, the cdPCR assays were applied to quantify Fusarium in durum wheat and oat samples, naturally contaminated or spiked with fungal DNA. For a better evaluation of infection level in plants, duplex assays were developed, able to co-amplify both plant and fungal DNA. To the best of our knowledge, this is the first study directed to the application of digital PCR to Fusarium diagnosis in plants.