Variations in Kojic Acid Production and Corn Infection Among Isolates Suggest a Potential Role as a Virulence Factor.

Kojic acid is a secondary metabolite with strong chelating and antioxidant properties produced by and . Although antioxidants and chelators are important virulence factors for plant pathogens, the ecological role of kojic acid remains unclear. We previously observed a greater gene expression of antioxidants, especially kojic acid, by non-aflatoxigenic when co-cultured with aflatoxigenic Aflatoxin production was also reduced.

Divergent corn population is composed of prolific conidium producers: Implications for saprophytic disease cycle.

The ascomycete fungus infects and contaminates corn, peanuts, cottonseed, and tree nuts with toxic and carcinogenic aflatoxins. Subdivision between soil and host plant populations suggests that certain strains are specialized to infect peanut, cotton, and corn despite having a broad host range. In this study, the ability of strains isolated from corn and/or soil in 11 Louisiana fields to produce conidia (field inoculum and male gamete) and sclerotia (resting bodies and female gamete) was assessed and compared with genotypic single-nucleotide polymorphism (SNP) differences between whole genomes.

Genomic and metabolomic diversity within a familial population of Aspergillus flavus.

Aspergillus flavus is an agriculturally significant micro-fungus having potential to contaminate food and feed crops with toxic secondary metabolites such as aflatoxin (AF) and cyclopiazonic acid (CPA). Research has shown A. flavus strains can overcome heterokaryon incompatibility and undergo meiotic recombination as teleomorphs.

Microbiota of maize kernels as influenced by infection in susceptible and resistant inbreds.

Background: Nearly everything on Earth harbors a microbiome. A microbiome is a community of microbes (bacteria, fungi, and viruses) with potential to form complex networks that involve mutualistic and antagonistic interactions. Resident microbiota on/in an organism are determined by the external environment, both biotic and abiotic, and the intrinsic adaptability of each organism.

Cumulative Effects of Non-Aflatoxigenic Volatile Organic Compounds to Abate Toxin Production by Mycotoxigenic Aspergilli.

Previously, authors reported that individual volatile organic compounds (VOCs) emitted by non-aflatoxigenic could act as a mechanism of biocontrol to significantly reduce aflatoxins and cyclopiazonic acid (CPA) produced by toxigenic strains. In this study, various combinations and volumes of three mycotoxin-reductive VOCs (2,3-dihydrofuran, 3-octanone and decane) were assessed for their cumulative impacts on four strains (LA1-LA4), which were then analyzed for changes in growth, as well as the production of mycotoxins, including aflatoxins, CPA and multiple indole diterpenes. Fungal growth remained minimally inhibited when exposed to various combinations of VOCs.

Dataset for transcriptomic profiles associated with development of sexual structures in .

Information on the transcriptomic changes that occur within sclerotia of during its sexual cycle is very limited and warrants further research. The findings will broaden our knowledge of the biology of and can provide valuable insights in the development or deployment of non-toxigenic strains as biocontrol agents against aflatoxigenic strains. This article presents transcriptomic datasets included in our research article entitled, "Development of sexual structures influences metabolomic and transcriptomic profiles in " [1], which utilized transcriptomics to identify possible genes and gene clusters associated with sexual reproduction and fertilization in .

Development of sexual structures influences metabolomic and transcriptomic profiles in Aspergillus flavus.

Sclerotium (female) fertility, the ability of a strain to produce ascocarps, influences internal morphological changes during sexual reproduction in Aspergillus flavus. Although sclerotial morphogenesis has been linked to secondary metabolite (SM) biosynthesis, metabolic and transcriptomic changes within A. flavus sclerotia during sexual development are not known.

Multi-kingdom microbiota analyses identify bacterial-fungal interactions and biomarkers of colorectal cancer across cohorts.

Despite recent progress in our understanding of the association between the gut microbiome and colorectal cancer (CRC), multi-kingdom gut microbiome dysbiosis in CRC across cohorts is unexplored. We investigated four-kingdom microbiota alterations using CRC metagenomic datasets of 1,368 samples from 8 distinct geographical cohorts. Integrated analysis identified 20 archaeal, 27 bacterial, 20 fungal and 21 viral species for each single-kingdom diagnostic model.

Genetic Responses and Aflatoxin Inhibition during Co-Culture of Aflatoxigenic and Non-Aflatoxigenic .

Aflatoxin is a carcinogenic mycotoxin produced by . Non-aflatoxigenic (Non-tox) isolates are deployed in corn fields as biocontrol because they substantially reduce aflatoxin contamination via direct replacement and additionally via direct contact or touch with toxigenic (Tox) isolates and secretion of inhibitory/degradative chemicals. To understand touch inhibition, HPLC analysis and RNA sequencing examined aflatoxin production and gene expression of Non-tox isolate 17 and Tox isolate 53 mono-cultures and during their interaction in co-culture.

Practical considerations will ensure the continued success of pre-harvest biocontrol using non-aflatoxigenic strains.

There is an important reason for the accelerated use of non-aflatoxigenic to mitigate pre-harvest aflatoxin contamination… it effectively addresses the imperative need for safer food and feed. Now that we have decades of proof of the effectiveness of as biocontrol, it is time to improve several aspects of this strategy. If we are to continue relying heavily on this form of aflatoxin mitigation, there are considerations we must acknowledge, and actions we must take, to ensure that we are best wielding this strategy to our advantage.

Draft Genome Sequences of 20 Aspergillus flavus Isolates from Corn Kernels and Cornfield Soils in Louisiana.

is a common saprophyte and opportunistic fungal pathogen that infects plants, animals, and humans. It also produces numerous toxic and nontoxic secondary metabolites. Here, we report the draft genome sequences of 20 isolates, belonging to 16 vegetative compatibility groups, from Louisiana corn kernels and cornfield soils.

Characterization of morphological changes within stromata during sexual reproduction in .

contaminates agricultural products worldwide with carcinogenic aflatoxins that pose a serious health risk to humans and animals. The fungus survives adverse environmental conditions through production of sclerotia. When fertilized by a compatible conidium of an opposite mating type, a sclerotium transforms into a stroma within which ascocarps, asci, and ascospores are formed.

Secondary Metabolite Dereplication and Phylogenetic Analysis Identify Various Emerging Mycotoxins and Reveal the High Intra-Species Diversity in .

is one of the most important mycotoxigenic species from the genus , due to its ability to synthesize the potent hepatocarcinogen, aflatoxin B. Moreover, this fungus is capable of producing several other toxic metabolites from the class of indole-tetramates, non-ribosomal peptides, and indole-diterpenoids. Populations of are characterized by considerable diversity in terms of morphological, functional and genetic features.

Development of Genomic Resources for the Powdery Mildew, .

Powdery mildews (PMs) are important plant pathogens causing widespread damage. Here, we report the first draft genome of , the causative agent of PM of flowering dogwood, . The assembled genome was 63.

Whole genome comparison of Aspergillus flavus L-morphotype strain NRRL 3357 (type) and S-morphotype strain AF70.

Aspergillus flavus is a saprophytic fungus that infects corn, peanuts, tree nuts and other agriculturally important crops. Once the crop is infected the fungus has the potential to secrete one or more mycotoxins, the most carcinogenic of which is aflatoxin. Aflatoxin contaminated crops are deemed unfit for human or animal consumption, which results in both food and economic losses.

Genome sequence of an aflatoxigenic pathogen of Argentinian peanut, Aspergillus arachidicola.

Background: Aspergillus arachidicola is an aflatoxigenic fungal species, first isolated from the leaves of a wild peanut species native to Argentina. It has since been reported in maize, Brazil nut and human sputum samples. This aflatoxigenic species is capable of secreting both B and G aflatoxins, similar to A.

Global population structure and adaptive evolution of aflatoxin-producing fungi.

Aflatoxins produced by several species in section are a significant problem in agriculture and a continuous threat to human health. To provide insights into the biology and global population structure of species in section , a total of 1,304 isolates were sampled across six species ( and ) from single fields in major peanut-growing regions in Georgia (USA), Australia, Argentina, India, and Benin (Africa). We inferred maximum-likelihood phylogenies for six loci, both combined and separately, including two aflatoxin cluster regions ( and ) and four noncluster regions ( and ), to examine population structure and history.

Aspergillus korhogoensis, a Novel Aflatoxin Producing Species from the Côte d'Ivoire.

Several strains of a new aflatoxigenic species of , , were isolated in the course of a screening study involving species from section found contaminating peanuts () and peanut paste in the Côte d'Ivoire. Based on examination of four isolates, this new species is described using a polyphasic approach. A concatenated alignment comprised of nine genes (, , , , , , , and ) was subjected to phylogenetic analysis, and resulted in all four strains being inferred as a distinct clade.

Evolution of polyketide synthesis in a Dothideomycete forest pathogen.

Fungal secondary metabolites have many important biological roles and some, like the toxic polyketide aflatoxin, have been intensively studied at the genetic level. Complete sets of polyketide synthase (PKS) genes can now be identified in fungal pathogens by whole genome sequencing and studied in order to predict the biosynthetic potential of those fungi. The pine needle pathogen Dothistroma septosporum is predicted to have only three functional PKS genes, a small number for a hemibiotrophic fungus.

Unravelling the Diversity of the Cyclopiazonic Acid Family of Mycotoxins in Aspergillus flavus by UHPLC Triple-TOF HRMS.

Cyclopiazonic acid (α-cyclopiazonic acid, α-CPA) is an indole-hydrindane-tetramic acid neurotoxin produced by various fungal species, including the notorious food and feed contaminant . Despite its discovery in cultures approximately 40 years ago, its contribution to the mycotoxin burden is consistently minimized by our focus on the more potent carcinogenic aflatoxins also produced by this fungus. Here, we report the screening and identification of several CPA-type alkaloids not previously found in cultures.

Draft Genome Sequence of an Aflatoxigenic Aspergillus Species, A. bombycis.

Aspergillus bombycis was first isolated from silkworm frass in Japan. It has been reportedly misidentified as A. nomius due to their macro-morphological and chemotype similarities.

Molecular Diversity of Seed-borne Fusarium Species Associated with Maize in India.

A total of 106 maize seed samples were collected from different agro-climatic regions of India. Sixty-two Fusarium isolates were recovered, 90% of which were identified as Fusarium verticillioides based on morphological and molecular characters. Use of the tef-1α gene corrected/refined the morphological species identifications of 11 isolates, and confirmed those of the remaining isolates.

Draft Genome Sequences of Two Closely Related Aflatoxigenic Aspergillus Species Obtained from the Ivory Coast.

Aspergillus ochraceoroseus and Aspergillus rambellii were isolated from soil detritus in Taï National Park, Ivory Coast, Africa. The Type strain for each species happens to be the only representative ever sampled. Both species secrete copious amounts of aflatoxin B1 and sterigmatocystin, because each of their genomes contains clustered genes for biosynthesis of these mycotoxins.

Genomic sequence of the aflatoxigenic filamentous fungus Aspergillus nomius.

Background: Aspergillus nomius is an opportunistic pathogen and one of the three most important producers of aflatoxins in section Flavi. This fungus has been reported to contaminate agricultural commodities, but it has also been sampled in non-agricultural areas so the host range is not well known. Having a similar mycotoxin profile as A.

Enhanced diversity and aflatoxigenicity in interspecific hybrids of Aspergillus flavus and Aspergillus parasiticus.

Aspergillus flavus and A. parasiticus are the two most important aflatoxin-producing fungi responsible for the contamination of agricultural commodities worldwide. Both species are heterothallic and undergo sexual reproduction in laboratory crosses.