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.

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.

A mutant cotton fatty acid desaturase 2-1d allele causes protein mistargeting and altered seed oil composition.

Background: Cotton (Gossypium sp.) has been cultivated for centuries for its spinnable fibers, but its seed oil also possesses untapped economic potential if, improvements could be made to its oleic acid content.

Results: Previous studies, including those from our laboratory, identified pima accessions containing approximately doubled levels of seed oil oleic acid, compared to standard upland cottonseed oil.

Putative Core Transcription Factors Affecting Virulence in during Infection of Maize.

is an opportunistic pathogen responsible for millions of dollars in crop losses annually and negative health impacts on crop consumers globally. strains have the potential to produce aflatoxin and other toxic secondary metabolites, which often increase during plant colonization. To mitigate the impacts of this international issue, we employ a range of strategies to directly impact fungal physiology, growth and development, thus requiring knowledge on the underlying molecular mechanisms driving these processes.

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.

Flavonoids Modulate the Accumulation of Toxins From in Maize Kernels.

is an opportunistic fungal pathogen capable of producing aflatoxins, potent carcinogenic toxins that accumulate in maize kernels after infection. To better understand the molecular mechanisms of maize resistance to growth and aflatoxin accumulation, we performed a high-throughput transcriptomic study using maize kernels infected with strain 3357. Three maize lines were evaluated: aflatoxin-contamination resistant line TZAR102, semi-resistant MI82, and susceptible line Va35.

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.

Chromosome-Level Aspergillus flavus Strain CA14 Genome Assembly.

We report here a chromosome-level genome assembly of the aflatoxigenic fungus strain CA14. This strain is the basis for numerous studies in fungal physiology and secondary metabolism. This full-length assembly will aid in subsequent genomics research.

Genome Sequences of 20 Georeferenced Aspergillus flavus Isolates.

Several agricultural commodities can be infected by , a fungus that can produce the carcinogen aflatoxin. Here, we report the whole-genome sequences for 20 georeferenced isolates collected from soil and corn under field conditions. This information contributes to an understanding of population structure and dynamics in a field environment.

The Transcriptional Regulator Hbx1 Affects the Expression of Thousands of Genes in the Aflatoxin-Producing Fungus .

In filamentous fungi, homeobox proteins are conserved transcriptional regulators described to control conidiogenesis and fruiting body formation. Eight homeobox () genes are found in the genome of the aflatoxin-producing ascomycete, While loss-of-function of seven of the eight genes had little to no effect on fungal growth and development, disruption of , resulted in aconidial colonies and lack of sclerotial production. Furthermore, the mutant was unable to produce aflatoxins B and B, cyclopiazonic acid and aflatrem.

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.

Secondary Metabolites: More than Just Aflatoxins.

is best known for producing the family of potent carcinogenic secondary metabolites known as aflatoxins. However, this opportunistic plant and animal pathogen also produces numerous other secondary metabolites, many of which have also been shown to be toxic. While about forty of these secondary metabolites have been identified from cultures, analysis of the genome has predicted the existence of at least 56 secondary metabolite gene clusters.

RNA interference-based silencing of the alpha-amylase (amy1) gene in Aspergillus flavus decreases fungal growth and aflatoxin production in maize kernels.

Expressing an RNAi construct in maize kernels that targets the gene for alpha-amylase in Aspergillus flavus resulted in suppression of alpha-amylase (amy1) gene expression and decreased fungal growth during in situ infection resulting in decreased aflatoxin production. Aspergillus flavus is a saprophytic fungus and pathogen to several important food and feed crops, including maize. Once the fungus colonizes lipid-rich seed tissues, it has the potential to produce toxic secondary metabolites, the most dangerous of which is aflatoxin.

Carbon Dioxide Mediates the Response to Temperature and Water Activity Levels in Aspergillus flavus during Infection of Maize Kernels.

is a saprophytic fungus that may colonize several important crops, including cotton, maize, peanuts and tree nuts. Concomitant with colonization is its potential to secrete mycotoxins, of which the most prominent is aflatoxin. Temperature, water activity (a) and carbon dioxide (CO₂) are three environmental factors shown to influence the fungus-plant interaction, which are predicted to undergo significant changes in the next century.

Interactions between water activity and temperature on the Aspergillus flavus transcriptome and aflatoxin B production.

Effects of Aspergillus flavus colonization of maize kernels under different water activities (a; 0.99 and 0.91) and temperatures (30, 37°C) on (a) aflatoxin B (AFB) production and (b) the transcriptome using RNAseq were examined.

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.

RNA sequencing of an nsdC mutant reveals global regulation of secondary metabolic gene clusters in Aspergillus flavus.

The filamentous fungus, Aspergillus flavus (A. flavus) is an opportunistic pathogen capable of invading a number of crops and contaminating them with toxic secondary metabolites such as aflatoxins. Characterizing the molecular mechanisms governing growth and development of this organism is vital for developing safe and effective strategies for reducing crop contamination.

Phytohormonal networks promote differentiation of fiber initials on pre-anthesis cotton ovules grown in vitro and in planta.

The number of cotton (Gossypium sp.) ovule epidermal cells differentiating into fiber initials is an important factor affecting cotton yield and fiber quality. Despite extensive efforts in determining the molecular mechanisms regulating fiber initial differentiation, only a few genes responsible for fiber initial differentiation have been discovered.

Comparative transcriptome analysis of short fiber mutants Ligon-lintless 1 and 2 reveals common mechanisms pertinent to fiber elongation in cotton (Gossypium hirsutum L.).

Understanding the molecular processes affecting cotton (Gossypium hirsutum) fiber development is important for developing tools aimed at improving fiber quality. Short fiber cotton mutants Ligon-lintless 1 (Li1) and Ligon-lintless 2 (Li2) are naturally occurring, monogenic mutations residing on different chromosomes. Both mutations cause early cessation in fiber elongation.

A transcript profiling approach reveals an abscisic acid-specific glycosyltransferase (UGT73C14) induced in developing fiber of Ligon lintless-2 mutant of cotton (Gossypium hirsutum L.).

Ligon lintless-2, a monogenic dominant cotton (Gossypium hirsutum L.) fiber mutation, causing extreme reduction in lint fiber length with no pleiotropic effects on vegetative growth, represents an excellent model system to study fiber elongation. A UDP-glycosyltransferase that was highly expressed in developing fibers of the mutant Ligon lintless-2 was isolated.

Transcript profiling by microarray and marker analysis of the short cotton (Gossypium hirsutum L.) fiber mutant Ligon lintless-1 (Li1).

Background: Cotton fiber length is very important to the quality of textiles. Understanding the genetics and physiology of cotton fiber elongation can provide valuable tools to the cotton industry by targeting genes or other molecules responsible for fiber elongation. Ligon Lintless-1 (Li1) is a monogenic mutant in Upland cotton (Gossypium hirsutum) which exhibits an early cessation of fiber elongation resulting in very short fibers (< 6 mm) at maturity.

Characterization of BEAF mutations isolated by homologous recombination in Drosophila.

The Drosophila BEAF-32A and BEAF-32B proteins bind to the scs' insulator and to hundreds of other sites on Drosophila chromosomes. These two proteins are encoded by the same gene. We used ends-in homologous recombination to generate the null BEAF(AB-KO) allele and also isolated the BEAF(A-KO) allele that eliminates production of only the BEAF-32A protein.

The Drosophila boundary element-associated factors BEAF-32A and BEAF-32B affect chromatin structure.

Binding sites for the Drosophila boundary element-associated factors BEAF-32A and -32B are required for the insulator activity of the scs' insulator. BEAF binds to hundreds of sites on polytene chromosomes, indicating that BEAF-utilizing insulators are an important class in Drosophila. To gain insight into the role of BEAF in flies, we designed a transgene encoding a dominant-negative form of BEAF under GAL4 UAS control.