Maize-Aspergillus flavus miRNA
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ABSTRACT:
PROVIDER: PRJEB65097 | ENA |
REPOSITORIES: ENA
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Project description:Maize kernels are susceptible to infection by the opportunistic pathogen Aspergillus flavus. Infection results in reduction of grain quality and contamination of kernels with the highly carcinogenic mycotoxin, aflatoxin. To understand host response to infection by the fungus, transcription of approximately 9,000 maize genes were monitored during the host-pathogen interaction with a custom-designed Affymetrix GeneChip® DNA array. More than 1,000 maize genes were found differentially expressed at a fold change of 2 or greater. This included the up regulation of defense-related genes and signaling pathways. Transcriptional changes also were observed in primary metabolism genes. Starch biosynthetic genes were down regulated during infection, while genes encoding maize hydrolytic enzymes, presumably involved in the degradation of host reserves, were up regulated. These data indicate that infection of the maize kernel A. flavus induced metabolic changes in the kernel, including the production of a defense response, as well as a disruption in kernel development.
2014-05-14 | GSE57629 | GEO
Project description:Maize kernels are susceptible to infection by the opportunistic pathogen Aspergillus flavus. Infection results in reduction of grain quality and contamination of kernels with the highly carcinogenic mycotoxin, aflatoxin. To understand host response to infection by the fungus, transcription of approximately 9,000 maize genes were monitored during the host-pathogen interaction with a custom-designed Affymetrix GeneChip® DNA array. More than 1,000 maize genes were found differentially expressed at a fold change of 2 or greater. This included the up regulation of defense-related genes and signaling pathways. Transcriptional changes also were observed in primary metabolism genes. Starch biosynthetic genes were down regulated during infection, while genes encoding maize hydrolytic enzymes, presumably involved in the degradation of host reserves, were up regulated. These data indicate that infection of the maize kernel A. flavus induced metabolic changes in the kernel, including the production of a defense response, as well as a disruption in kernel development. Maize kernels were mock inoculated at the blister (R2) or dough (R4) stage or inoculated with A. flavus at the blister (R2), milk (R3), dough (R4), or dent (R5) stage, and harvested 4 days later. Each treatment consisted of three biological replications. For each biological replication, 8 kernels were ground and RNA was isolated and further processed.
2014-05-14 | E-GEOD-57629 | biostudies-arrayexpress
Project description:Several are the inputs which are able to modulate mycotoxin synthesis. In particular, when a fungus receives an external stimulus reacts by activating, through a quite well-defined signal cascade, an evident switch in its lifestyle. This profound change is also due to the activation of global gene regulators and, in particular, of transcription factors able to switch on the mycotoxin gene clusters expression. Aflatoxins (AF) are harmful carcinogenic compounds produced mainly by Aspergillus flavus and A. parasiticus. AF are produced during the contamination of maize kernels into the field, even if their role in phyto-toxicity is not yet assessed. Nevertheless, AF biosynthesis is tightly regulated by host-derived signals. Recently, the nature of some of these signals have been elucidated. In particular, a role in susceptibility and resistance of maize to A. flavus contamination has been assigned to some plant oxylipins. These findings draw a scenario in which a complex interplay is under way between A. flavus and maize. For uncovering all the implications of this cross-talk we decide to follow a holistic approach. In particular, we designed experimental conditions aimed to mimic the different phases of A. flavus infection cycle on maize and then by performing a microarray analysis on the harvested mycelia. The microarray data set has been processed for performing the differential expression analysis of almost 14000 gene probes, the pathway analysis based on the gene ontology and inter pro annotations, the secondary metabolites cluster co-expression analysis and an identification of groups of co-expressed neighbor genes, possibly associated with production of secondary metabolites. Analysis of 12 microarrays monitoring gene expression of Aspergillus flavus over various growth conditions
2013-09-19 | E-GEOD-28163 | biostudies-arrayexpress
Project description:Aflatoxin contamination caused by the opportunistic pathogen A. flavus is a major concern in maize production prior to harvest and during storage. Previous studies indicate that both constitutive and induced resistance are involved in maize kernel defense against A. flavus infection, little is known about molecular mechanisms of mature kernels in response to fungal infection. The purpose of this study is to determine gene expression differences in maize kernels between resistant and susceptible lines in response to A. flavus challenge. To avoid the environmental effects in the field inoculation, a laboratory based inoculation technique Kernel Screening Assay (KSA) was used to challenge kernels with A. flavus. After 72 hours incubation of inoculated and noninculated mature kernels, gene expression profiles of two Near Isogenic Lines (NIL) of Eyl25 (A. flavus resistant) and Eyl31 (A. flavus susceptible) were compared using oligonucleotide array.
2010-10-01 | GSE19883 | GEO
Project description:Several are the inputs which are able to modulate mycotoxin synthesis. In particular, when a fungus receives an external stimulus reacts by activating, through a quite well-defined signal cascade, an evident switch in its lifestyle. This profound change is also due to the activation of global gene regulators and, in particular, of transcription factors able to switch on the mycotoxin gene clusters expression. Aflatoxins (AF) are harmful carcinogenic compounds produced mainly by Aspergillus flavus and A. parasiticus. AF are produced during the contamination of maize kernels into the field, even if their role in phyto-toxicity is not yet assessed. Nevertheless, AF biosynthesis is tightly regulated by host-derived signals. Recently, the nature of some of these signals have been elucidated. In particular, a role in susceptibility and resistance of maize to A. flavus contamination has been assigned to some plant oxylipins. These findings draw a scenario in which a complex interplay is under way between A. flavus and maize. For uncovering all the implications of this cross-talk we decide to follow a holistic approach. In particular, we designed experimental conditions aimed to mimic the different phases of A. flavus infection cycle on maize and then by performing a microarray analysis on the harvested mycelia. The microarray data set has been processed for performing the differential expression analysis of almost 14000 gene probes, the pathway analysis based on the gene ontology and inter pro annotations, the secondary metabolites cluster co-expression analysis and an identification of groups of co-expressed neighbor genes, possibly associated with production of secondary metabolites.
2013-09-19 | GSE28163 | GEO
Project description:Aflatoxin contamination caused by the opportunistic pathogen A. flavus is a major concern in maize production prior to harvest and during storage. Previous studies indicate that both constitutive and induced resistance are involved in maize kernel defense against A. flavus infection, little is known about molecular mechanisms of mature kernels in response to fungal infection. The purpose of this study is to determine gene expression differences in maize kernels between resistant and susceptible lines in response to A. flavus challenge. To avoid the environmental effects in the field inoculation, a laboratory based inoculation technique Kernel Screening Assay (KSA) was used to challenge kernels with A. flavus. After 72 hours incubation of inoculated and noninculated mature kernels, gene expression profiles of two Near Isogenic Lines (NIL) of Eyl25 (A. flavus resistant) and Eyl31 (A. flavus susceptible) were compared using oligonucleotide array. Direct comparisons were designed. The comparisons of NIL Eyl25 and Eyl31 include: Treated/Control, Control/Control and Treated/Treated. After 72 hours incubation under KSA conditions, forty seeds used in each A. flavus inoculated and noninculated group were bulked to extract total RNA. Four technical replications were performed in each comparison including two dye-swaps, total 16 hybridization reactions.
2010-10-01 | E-GEOD-19883 | biostudies-arrayexpress
Project description:The experiment consisted of a field design containing two maize inbred lines Va35 and Mp313E. Va35 has yellow kernels and is susceptible to kernel infection by Aspergillus flavus (A. flavus). Mp313E is a white dent maize inbred line and was released primarily as a source of resistance to kernel infection by A. flavus. The test ears were inoculated with Aspergillus flavus and collected two days after inoculation. Non-inoculated ears collected 16 days after pollination were also used as a control. The microarray experimental design was a randomized complete block design with three replications. One microarray slide was used for each field plot. Each slide contained the inoculated and non-inoculated sub-treatments. A second slide for one replication of each genotype contained a dye swap for the inoculation treatment and three subsamples (dots) within the slide represented each contig. Keywords: Direct comparison
2007-11-09 | GSE9546 | GEO
Project description:Aflatoxins are toxic and carcinogenic secondary metabolites produced by the fungi Aspergillus flavus and A. parasiticus. In order to better understand the molecular mechanisms that regulate aflatoxin production, the biosynthesis of the toxin in A. flavus and A. parasticus grown in yeast extract sucrose media supplemented with 50 mM tryptophan (Trp) were examined. A. flavus grown in the presence of 50 mM tryptophan was found to have significantly reduced aflatoxin B1 and B2 biosynthesis, while A. parasiticus cultures had significantly increased B1 and G1 biosynthesis. Microarray analysis of RNA extracted from fungi grown under these conditions revealed seventy seven genes that are expressed significantly different between A. flavus and A. parasiticus, including the aflatoxin biosynthetic genes aflD (nor-1), aflE (norA), and aflO (omtB). It is clear that the regulatory mechanisms of aflatoxin biosynthesis in response to Trp in A. flavus and A. parasiticus are different. These candidate genes may serve as regulatory factors of aflatoxin biosynthesis. Keywords: Aflatoxin, Aspergillus, flavus, Amnio Acids, Tryptophan
2007-06-07 | GSE6182 | GEO
Project description:RNA-seq was used to compare differential gene expressions for Aspergillus flavus wild type strain and ASPES transcription factor deletion strains.The goals of this study are to explore the aflatoxin regulation pathway in A. flavus.
2018-12-25 | GSE107025 | GEO
Project description:Aspergillus flavus and A. parasiticus are two of the most important aflatoxin-producing species that contaminate agricultural commodities worldwide. Both species are heterothallic and undergo sexual reproduction in laboratory crosses. Here, we examine the possibility of interspecific matings between A. flavus and A. parasiticus. These species can be distinguished morphologically and genetically, as well as by their mycotoxin profiles. Aspergillus flavus produces both B aflatoxins and cyclopiazonic acid (CPA), B aflatoxins or CPA alone, or neither mycotoxin; Aspergillus parasiticus produces B and G aflatoxins or the aflatoxin precursor O-methylsterigmatocystin, but not CPA. Only four out of forty-five attempted interspecific crosses between compatible mating types of A. flavus and A. parasiticus were fertile and produced viable ascospores. Single ascospore strains from each cross were isolated and were shown to be recombinant hybrids using multilocus genotyping and array comparative genome hybridization. Conidia of parents and their hybrid progeny were haploid and predominantly monokaryons and dikaryons based on flow cytometry. Multilocus phylogenetic inference showed that experimental hybrid progeny were grouped with naturally occurring A. flavus L strain and A. parasiticus. Higher total aflatoxin concentrations in some F1 progeny strains compared to midpoint parent aflatoxin levels indicate synergism in aflatoxin production; moreover, three progeny strains synthesized G aflatoxins that were not produced by the parents, and there was evidence of putative allopolyploidization in one strain. These results suggest that hybridization is an important diversifying force resulting in the genesis of novel toxin profiles in these agriculturally important species.
2015-10-01 | GSE61981 | GEO