The Emerging NA3 Population Produces High Levels of Mycotoxins in Wheat and Barley.

() is the primary causal agent of Fusarium head blight (FHB) in wheat, barley, and other small grains in North America and worldwide. FHB results in yield reduction and contaminates grain with mycotoxins that pose threats to human and livestock health. Three genetically distinct North American (NA) populations of have been characterized, which are generally associated with differences in their predominant trichothecene chemotype: NA1/15-acetyl-deoxynivalenol (15-ADON), NA2/3-acetyl-deoxynivalenol (3-ADON), and NA3/3α-acetoxy, 7,15-dihydroxy-12,13-epoxytrichothec-9-ene (NX-2).

Monoclonal-Antibody-Based Immunoassays for the Mycotoxins NX-2 and NX-3 in Wheat.

The fungal infestation of crops can cause major economic losses. Toxins produced by the causative fungi (mycotoxins) represent a potential safety hazard to people and livestock consuming them. One such mycotoxin is deoxynivalenol (DON, also known as vomitoxin), a trichothecene associated with Fusarium Head Blight of wheat.

Analysis of substrate specificity of cytochrome P450 monooxygenases involved in trichothecene toxin biosynthesis.

Trichothecenes are a structurally diverse family of toxic secondary metabolites produced by certain species of multiple fungal genera. All trichothecene analogs share a core 12,13-epoxytrichothec-9-ene (EPT) structure but differ in presence, absence and types of substituents attached to various positions of EPT. Formation of some of the structural diversity begins early in the biosynthetic pathway such that some producing species have few trichothecene biosynthetic intermediates in common.

Elevated CO Can Worsen Fusarium Head Blight Disease Severity in Wheat but the QTL Provides Reliable Disease Resistance.

Fusarium head blight (FHB) is a destructive fungal disease of wheat that causes significant economic loss due to lower yields and the contamination of grain with fungal toxins (mycotoxins), particularly deoxynivalenol (DON). FHB disease spread and mycotoxin contamination has been shown to worsen at elevated CO, therefore, it is important to identify climate-resilient FHB resistance. This work evaluates whether wheat with the quantitative trait locus (QTL), the most widely deployed FHB resistance locus in wheat breeding programs, provides reliable disease resistance at elevated CO.

Manipulating atmospheric CO concentration induces shifts in wheat leaf and spike microbiomes and in pathogen communities.

Changing atmospheric composition represents a source of uncertainty in our assessment of future disease risks, particularly in the context of mycotoxin producing fungal pathogens which are predicted to be more problematic with climate change. To address this uncertainty, we profiled microbiomes associated with wheat plants grown under ambient vs. elevated atmospheric carbon dioxide concentration [CO] in a field setting over 2 years.

Bioactivity of brassica seed meals and its compounds as ecofriendly larvicides against mosquitoes.

Strategic, sustainable, and ecofriendly alternatives to chemical pesticides are needed to effectively control mosquitoes and reduce the incidence of their vectored diseases. We evaluated several Brassicaceae (mustard family) seed meals as sources of plant derived isothiocyanates produced from the enzymatic hydrolysis of biologically inactive glucosinolates for the control of Aedes aegypti (L., 1762).

Insights into the Aggressiveness of the Emerging North American Population 3 (NA3) of .

In the United States and Canada, () is the predominant etiological agent of Fusarium head blight (FHB), an economically devastating fungal disease of wheat and other small grains Besides yield losses, FHB leads to grain contamination with trichothecene mycotoxins that are harmful to plant, human, and livestock health. Three genetic North American populations of , differing in their predominant trichothecene chemotype (i.e.

A Novel Trichothecene Toxin Phenotype Associated with Horizontal Gene Transfer and a Change in Gene Function in .

trichothecenes are among the mycotoxins of most concern to food and feed safety. Production of these mycotoxins and presence of the trichothecene biosynthetic gene () cluster have been confirmed in only two multispecies lineages of : the - (Incarnatum) and (Sambucinum) species complexes. Here, we identified and characterized a cluster in a species that has not been formally described and is represented by sp.

Feeding thermally processed spray-dried egg whites, singly or in combination with 15-acetyldeoxynivalenol or peroxidized soybean oil on growth performance, digestibility, intestinal morphology, and oxidative status in nursery pigs.

Two experiments (EXP) determined the susceptibility of spray-dried egg white (SDEW) to oxidation (heating at 100 °C for 72 h; thermally processed, TP) and whether feeding TP-SDEW, 15-acetyldeoxynivalenol (15-ADON), or peroxidized soybean oil (PSO), singularly or in combination, would affect pig performance, intestinal morphology, digestibility, and markers of oxidative stress in nursery pigs. In EXP 1, 32 pigs (7.14 kg body weight, BW) were placed individually into pens and fed diets containing either 12% SDEW, 6% TP-SDEW plus 6% SDEW, or 12% TP-SDEW.

Effect of Farnesol in Physiology and in Fungal-Plant Interaction.

Farnesol is an isoprenoid intermediate in the mevalonate (MVA) pathway and is produced by the dephosphorylation of farnesyl diphosphate. Farnesol plays a central role in cell growth and differentiation, controls production of ubiquinone and ergosterol, and participates in the regulation of filamentation and biofilm formation. Despite these important functions, studies of farnesol in filamentous fungi are limited, and information on its effects on antifungal and/or biocontrol activity is scarce.

disease resistance QTL does not exacerbate wheat grain protein loss at elevated CO.

Fusarium head blight, a devastating cereal crop disease, can cause significant yield losses and contaminate grain with hazardous fungal toxins. Concerningly, recent evidence indicates that substantial grain protein content loss is likely to occur in wheat that is moderately resistant to head blight when it is grown at elevated CO. Although wheat breeders in North America utilize a number of resistance sources and genes to reduce pathogen damage, the gene is widely deployed.

Effects of trichothecene production by isolates from bean-field soils on the defense response, growth and development of bean plants ().

The trichothecene toxin-producing fungus has potential as a biological control agent. However, most biocontrol studies have focused only on one strain, IBT 40837. In the current study, three isolates recovered from bean-field soils produced the trichothecene harzianum A (HA) and trichodermol, the latter being an intermediate in the HA biosynthesis.

Identification of polyketide synthase genes required for aspinolide biosynthesis in Trichoderma arundinaceum.

The fungus Trichoderma arundinaceum exhibits biological control activity against crop diseases caused by other fungi. Two mechanisms that likely contribute to this activity are upregulation of plant defenses and production of two types of antifungal secondary metabolites: the sesquiterpenoid harzianum A (HA) and the polyketide-derived aspinolides. The goal of the current study was to identify aspinolide biosynthetic genes as part of an effort to understand how these metabolites contribute to the biological control activity of T.

Modification of Deoxynivalenol by a Fungal Laccase Paired with Redox Mediator TEMPO.

Mycotoxins such as deoxynivalenol introduce a health risk to the food supply and are costly to manage or avoid. Technologies for reducing or eliminating the toxicity of deoxynivalenol could be useful in a variety of processes, such as in preserving the value as animal feed of byproducts of ethanol production. We characterized transformation products of deoxynivalenol that were formed by the combination of a fungal laccase paired with the chemical mediator 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), using chromatography, mass spectrometry, and nuclear magnetic resonance spectroscopy.

Fusarium head blight resistance exacerbates nutritional loss of wheat grain at elevated CO.

The nutritional integrity of wheat is jeopardized by rapidly rising atmospheric carbon dioxide (CO) and the associated emergence and enhanced virulence of plant pathogens. To evaluate how disease resistance traits may impact wheat climate resilience, 15 wheat cultivars with varying levels of resistance to Fusarium Head Blight (FHB) were grown at ambient and elevated CO. Although all wheat cultivars had increased yield when grown at elevated CO, the nutritional contents of FHB moderately resistant (MR) cultivars were impacted more than susceptible cultivars At elevated CO, the MR cultivars had more significant differences in plant growth, grain protein, starch, fructan, and macro and micro-nutrient content compared with susceptible wheat.

Effects of Atmospheric CO and Temperature on Wheat and Corn Susceptibility to and Deoxynivalenol Contamination.

This work details the impact of atmospheric CO and temperature conditions on two strains of their disease damage, pathogen growth, mycotoxin accumulation, and production per unit fungal biomass in wheat and corn. An elevated atmospheric CO concentration, 1000 ppm CO, significantly increased the accumulation of deoxynivalenol in infected plants. Furthermore, growth in cool growing conditions, 20 °C/18 °C, day and night, respectively, resulted in the highest amounts of pathogen biomass and toxin accumulation in both inoculated wheat and corn.

Distribution, Function, and Evolution of a Gene Essential for Trichothecene Toxin Biosynthesis in .

Trichothecenes are terpenoid toxins produced by species in 10 fungal genera, including species of . The trichothecene biosynthetic gene () cluster typically includes the gene, which encodes a terpene synthase that catalyzes formation of trichodiene, the parent compound of all trichothecenes. The two species, and , that have been examined are unique in that is located outside the cluster in a genomic region that does not include other known genes.

DNA Sequence-Based Identification of : A Work in Progress.

Accurate species-level identification of an etiological agent is crucial for disease diagnosis and management because knowing the agent's identity connects it with what is known about its host range, geographic distribution, and toxin production potential. This is particularly true in publishing peer-reviewed disease reports, where imprecise and/or incorrect identifications weaken the public knowledge base. This can be a daunting task for phytopathologists and other applied biologists that need to identify in particular, because published and ongoing multilocus molecular systematic studies have highlighted several confounding issues.

Weeds Harbor Species that Cause Malformation Disease of Economically Important Trees in Western Mexico.

Mango malformation disease (MMD) caused by spp. is an important limiting factor in most production areas worldwide. and have been reported as causing MMD in Mexico.

Malformation Disease in (Rosy Trumpet) Caused by in Mexico.

(rosy trumpet) is an economically important neotropical tree in Mexico that is highly valued for the quality of its wood, which is used for furniture, crafts, and packing, and for its use as an ornamental and shade tree in parks and gardens. During surveys conducted in the lower Balsas River Basin region in the states of Guerrero and Michoacán, symptoms of floral malformation were detected in trees. The main objectives of this study were to describe this new disease, to determine its causal agent, and to identify it using DNA sequence data.

Correction: Phylogenetic diversity, trichothecene potential, and pathogenicity within Fusarium sambucinum species complex.

[This corrects the article DOI: 10.1371/journal.pone.

Use of the volatile trichodiene to reduce Fusarium head blight and trichothecene contamination in wheat.

Fusarium graminearum is the primary cause of Fusarium head blight (FHB), one of the most economically important diseases of wheat worldwide. FHB reduces yield and contaminates grain with the trichothecene mycotoxin deoxynivalenol (DON), which poses a risk to plant, human and animal health. The first committed step in trichothecene biosynthesis is formation of trichodiene (TD).

Phylogenetic diversity, trichothecene potential, and pathogenicity within Fusarium sambucinum species complex.

The Fusarium sambucinum species complex (FSAMSC) is one of the most taxonomically challenging groups of fusaria, comprising prominent mycotoxigenic plant pathogens and other species with various lifestyles. Among toxins produced by members of the FSAMSC, trichothecenes pose the most significant threat to public health. Herein a global collection of 171 strains, originating from diverse hosts or substrates, were selected to represent FSAMSC diversity.