Identification and Confirmation of Virulence Factor Production from , a Causal Agent of Root Rot in Pulses.

is an aggressive pathogen of pulse crops and a causal agent in root rot disease that negatively impacts Canadian agriculture. This study reports the results of a targeted metabolomics-based profiling of secondary metabolism in an 18-strain panel of cultured axenically in multiple media conditions, in addition to an in planta infection assay involving four strains inoculated on two pea cultivars. Multiple secondary metabolites with known roles as virulence factors were detected which have not been previously associated with , including fungal decalin-containing diterpenoid pyrones (FDDPs), fusaoctaxins, sambutoxin and fusahexin, in addition to confirmation of previously reported secondary metabolites including enniatins, fusarins, chlamydosporols, JM-47 and others.

Poplar Leaf Bud Resin Metabolomics: Seasonal Profiling of Leaf Bud Chemistry in Populus trichocarpa Provides Insight Into Resin Biosynthesis.

Trees in the genus Populus synthesize sticky and fragrant resins to protect dormant leaf buds during winter. These resins contain diverse phenolic metabolites, in particular hydroxycinnamate esters and methylated flavonoids. P.

Pathogenicity and Metabolomic Characterization of and Challenge in Barley under Controlled Conditions.

Barley is the third most important cereal crop in terms of production in Canada, and Fusarium head blight (FHB) is one of the main fungal diseases of barley. FHB is caused by a species complex of Fusaria, of which Schwabe is the main causal species of FHB epidemics in Canada. Field surveys show that two or more species often co-exist within the same field or grain sample, and is reported as another important species in barley.

A cyclic lipopeptide from Fusarium graminearum targets plant membranes to promote virulence.

Microbial plant pathogens deploy amphipathic cyclic lipopeptides to reduce surface tension in their environment. While plants can detect these molecules to activate cellular stress responses, the role of these lipopeptides or associated host responses in pathogenesis are not fully clear. The gramillin cyclic lipopeptide is produced by the Fusarium graminearum fungus and is a virulence factor and toxin in maize.

Debunking the Myth of T-2/HT-2 Toxin Production.

is commonly detected in field surveys of head blight (FHB) of cereal crops and can produce a range of trichothecene mycotoxins. Although experimentally validated reports of strains producing T-2/HT-2 trichothecenes are rare, is frequently generalized in the literature as a producer of T-2/HT-2 toxins due to a single study from 2004 in which T-2/HT-2 toxins were detected at low levels from six out of forty-nine strains examined. To validate/substantiate the observations reported from the 2004 study, the producing strains were acquired and phylogenetically confirmed to be correctly assigned as ; however, no evidence of T-2/HT-2 toxin production was observed from axenic cultures.

Chromosome-level draft genome sequences of three isolates of the toxigenic fungus showing structural rearrangements.

The whole genomes of three strains were sequenced using Oxford Nanopore Technologies' MinION and assembled into complete, chromosome-level assemblies. The genome consists of eight conserved chromosomes, with evidence of inter-chromosomal structural rearrangements between strains.

Epistatic Relationship between and in the Regulation of Biosynthetic Gene Clusters in .

Genetic studies have shown that the MAP kinase MGV1 and the transcriptional regulator TRI6 regulate many of the same biosynthetic gene clusters (BGCs) in . This study sought to investigate the relationship between and in the regulatory hierarchy. Transgenic strains constitutively expressing and were generated to address both independent and epistatic regulation of BGCs by and .

Multiple UDP-Glycosyltransferases Contribute to the Production of 15-Acetyl-Deoxynivalenol-3-O-Glycoside When Confronted with .

Mycotoxins, derived from toxigenic fungi such as , and species have impacted the human food chain for thousands of years. Deoxynivalenol (DON), is a tetracyclic sesquiterpenoid type B trichothecene mycotoxin predominantly produced by and during the infection of corn, wheat, oats, barley, and rice. Glycosylation of DON is a protective detoxification mechanism employed by plants.

CRISPR-Cas9 Gene Editing and Secondary Metabolite Screening Confirm C16 Biosynthetic Gene Cluster Products as Decalin-Containing Diterpenoid Pyrones.

is a causal organism of Fusarium head blight in cereals and maize. Although a few secondary metabolites produced by are considered disease virulence factors, many molecular products of biosynthetic gene clusters expressed by during infection and their associated role in the disease are unknown. In particular, the predicted meroterpenoid products of the biosynthetic gene cluster historically designated as "C16" are likely associated with pathogenicity.

Untargeted metabolomics screening reveals unique secondary metabolite production from section .

section is comprised of many species that infect a broad diversity of important crop plants and cause post-harvest spoilage. section species, such as and , are prolific producers of secondary metabolites that act as virulence factors of disease and are mycotoxins that accumulate in infected tissues-metabolites that can vary in their spectrum of production between individuals from the same fungal species. Untargeted metabolomics profiling of secondary metabolite production using mass spectrometry is an effective means to detect phenotypic anomalies in secondary metabolism within a species.

Untargeted Metabolomic Profiling of Fungal Species Populations.

This chapter describes protocols for the development of consensus chemical phenotypes or "metabolomes" of fungal populations using ultra-high pressure liquid chromatography coupled to high resolution mass spectrometry (UPLC-HRMS). Isolates are cultured using multiple media conditions to elicit the expression of diverse secondary metabolite biosynthetic gene clusters. The mycelium and spent culture media are extracted using organic solvents and profiled by ultra-high pressure chromatography coupled with a high resolution Thermo Orbitrap XL mass spectrometer with the ability to trap and fragment ions to general MS spectra.

CRISPR/Cas9 disruption of UGT71L1 in poplar connects salicinoid and salicylic acid metabolism and alters growth and morphology.

Salicinoids are salicyl alcohol-containing phenolic glycosides with strong antiherbivore effects found only in poplars and willows. Their biosynthesis is poorly understood, but recently a UDP-dependent glycosyltransferase, UGT71L1, was shown to be required for salicinoid biosynthesis in poplar tissue cultures. UGT71L1 specifically glycosylates salicyl benzoate, a proposed salicinoid intermediate.

Extraction methods for untargeted metabolomics influence enzymatic activity in diverse soils.

Soil organic matter (SOM) is the largest carbon pool in terrestrial ecosystems and underpins the health and productivity of soil. Accurate characterization of its chemical composition will improve our understanding of biotic and abiotic processes regulating its stabilization. Our purpose in this study was to estimate the loss of SOM by microbial and exoenzymatic activity that might occur when soil is extracted for analysis of representative low molecular weight mass features using untargeted metabolomics.

Evolution of the Ergot Alkaloid Biosynthetic Gene Cluster Results in Divergent Mycotoxin Profiles in Sclerotia.

Research into ergot alkaloid production in major cereal cash crops is crucial for furthering our understanding of the potential toxicological impacts of upon Canadian agriculture and to ensure consumer safety. An untargeted metabolomics approach profiling extracts of sclerotia from four different grain crops separated the strains into two distinct metabolomic classes based on ergot alkaloid content. Variances in alkaloid profiles were correlated to genetic differences within the gene of the ergot alkaloid biosynthetic gene cluster from previously published genomes and from newly sequenced, long-read genome assemblies of Canadian strains.

A metabolomic study of vegetative incompatibility in Cryphonectria parasitica.

Vegetative incompatibility (VI) is a form of non-self allorecognition in filamentous fungi that restricts conspecific hyphal fusion and the formation of heterokaryons. In the chestnut pathogenic fungus, Cryphonectria parasitica, VI is controlled by six vic loci and has been of particular interest because it impedes the spread of hypoviruses and thus biocontrol strategies. We use nuclear magnetic resonance and high-resolution mass spectrometry to characterize alterations in the metabolome of C.

Apicidin biosynthesis is linked to accessory chromosomes in Fusarium poae isolates.

Background: Fusarium head blight is a disease of global concern that reduces crop yields and renders grains unfit for consumption due to mycotoxin contamination. Fusarium poae is frequently associated with cereal crops showing symptoms of Fusarium head blight. While previous studies have shown F.

Accessory Chromosome-Acquired Secondary Metabolism in Plant Pathogenic Fungi: The Evolution of Biotrophs Into Host-Specific Pathogens.

Accessory chromosomes are strain- or pathotype-specific chromosomes that exist in addition to the core chromosomes of a species and are generally not considered essential to the survival of the organism. Among pathogenic fungal species, accessory chromosomes harbor pathogenicity or virulence factor genes, several of which are known to encode for secondary metabolites that are involved in plant tissue invasion. Accessory chromosomes are of particular interest due to their capacity for horizontal transfer between strains and their dynamic "crosstalk" with core chromosomes.

Transcriptome analysis implicates secondary metabolite production, redox reactions, and programmed cell death during allorecognition in Cryphonectria parasitica.

The underlying molecular mechanisms of programmed cell death associated with fungal allorecognition, a form of innate immunity, remain largely unknown. In this study, transcriptome analysis was used to infer mechanisms activated during barrage formation in vic3-incompatible strains of Cryphonectria parasitica, the chestnut blight fungus. Pronounced differential expression occurred in barraging strains of genes involved in mating pheromone (mf2-1, mf2-2), secondary metabolite production, detoxification (including oxidative stress), apoptosis-related, RNA interference, and HET-domain genes.

DNA Methylation Is Responsive to the Environment and Regulates the Expression of Biosynthetic Gene Clusters, Metabolite Production, and Virulence in .

Histone modifications play a significant role in the regulation of biosynthetic gene clusters (BGCs) in the phytopathogen , by contrast, epigenetic regulation by DNA methyltransferases (DNMTs) is less documented. In this study, we characterized two DNMTs (FgDIM-2 and FgRID) in , with homologies to "Deficient in methylation" (DIM-2) and "Repeat-induced point (RIP) deficient" (RID) from Neurospora. The loss of DNMTs resulted in not only a decrease in average methylation density in the nutrient-poor, compared to nutrient-rich conditions, but also differences in the genes expressed between the WT and the DNMT mutant strains, implicating the external environment as an important trigger in altering DNA methylation patterns.

Four phylogenetic species of ergot from Canada and their characteristics in morphology, alkaloid production, and pathogenicity.

Four ergot species (, and ) were recognized based on analyses of DNA sequences from multiple loci, including two housekeeping genes, RNA polymerase II second largest subunit (), and translation elongation factor 1-α (), and a single-copy ergot alkaloid synthesis gene () encoding chanoclavine I synthase oxidoreductase. Morphological features, ergot alkaloid production, and pathogenicity on five common cereal crops of each species were evaluated and presented in taxonomic descriptions. A synoptic key was also provided for identification.

Activation of biosynthetic gene clusters by the global transcriptional regulator TRI6 in Fusarium graminearum.

In F. graminearum, the transcription factor TRI6 positively regulates the trichothecene biosynthetic gene cluster (BGC) leading to the production of the secondary metabolite 15-acetyl deoxynivalenol. Secondary metabolites are not essential for survival, instead, they enable the pathogen to successfully infect its host.

A continental scale spatial investigation of lake sediment organic compositions using sedimentomics.

Sedimentomics is a new method used to investigate carbon cycling in sediment organic matter. This untargeted method, based on metabolomics workflows, was used to investigate the molecular composition of sediment organic matter across northern Canada (Nunavut and Northwest Territories). Unique "lake districts" were defined using unsupervised clustering based on changes in sediment organic carbon compositions across space.

Transcriptomic and Exometabolomic Profiling Reveals Antagonistic and Defensive Modes of Action Against .

The mycoparasite ACM941 is under development as a biocontrol organism against , the causative agent of Fusarium head blight in cereals. To identify molecular factors associated with this interaction, the transcriptomic and exometabolomic profiles of and GZ3639 were compared during coculture. Prior to physical contact, the antagonistic activity of correlated with a response heavily dominated by upregulation of polyketide synthase gene clusters, consistent with the detected accumulation of corresponding secondary metabolite products.

gen. nov. and sp. nov., a cryophilic yeast from ancient permafrost and melted sea ice.

A cryophilic basidiomycetous yeast unable to grow at 18 °C or higher temperatures was isolated from a subsurface permafrost layer collected in the Eastern Swiss Alps and from melted sea ice collected in the Artic at Frobisher Bay, Nunavut, Canada. Phylogenetic analyses employing combined sequences of the D1/D2 domain and ITS region indicated that the two new isolates belong to the family of the class but are distantly related to any of the currently recognized species and genera. Consequently, the novel genus , and the novel species (type strain PYCC 8347=CBS 16055) are proposed to accommodate this cryophilic yeast.