A Network Approach of Gene Co-Expression in the Zea mays/Aspergillus flavus Pathosystem to Map Host/Pathogen Interaction Pathways
Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: PRJNA339565
ORGANISM(S): Zea mays Aspergillus flavus
PROVIDER: GSE85860 | GEO | 2017/05/09
SECONDARY ACCESSION(S): PRJNA339565
REPOSITORIES: GEO
Similar Datasets
Project description:The interaction between Aspergillus flavus and Zea mays is complex, and the identification of plant genes and pathways conferring resistance to the fungus has been challenging. Therefore authors undertook a systems biology approach involving dual RNA-seq to determine simultaneous response from the host and pathogen. What was dramatically highlighted in the analysis was upon infection there is uniformity in the development of the host and pathogen. This led to the development of host-pathogen index which was able to categorize the samples for down-stream system biology analysis. Additionally we were able to determine key genes in the pathways such as jasmonate, ethylene and ROS which were up-regulated in the studyThe stage of infection index used for the transcriptomic analysis revealed that A. flavus does not produce many transcripts initially during pathogenesis. It was found that when A. flavus was producing an abundance of transcripts, pathways involved the endosomal transport, aflatoxin production, sugar production and many others were up-regulated. In tandem, Z. mays had multiple resistance pathways, such as the phenylpropaniod, jasmonic acid and ethylene pathways that were up-regulated. The analysis of the gene regulatory networks revealed that multiple WRKY genes were targeting the activation of the resistance pathways. The analysis also revealed, for the first time, the activation of Z. mays resistance genes targeting A. flavus genes. Our results show that the plant-microbe interaction has multiple layers and that A. flavus transcriptionally reacts to the hostile environment of Z. mays. The interaction between Aspergillus flavus and Zea mays is complex, and the identification of plant genes and pathways conferring resistance to the fungus has been challenging. Therefore authors undertook a systems biology approach involving dual RNA-seq to determine simultaneous response from the host and pathogen. What was dramatically highlighted in the analysis was upon infection there is uniformity in the development of the host and pathogen. This led to the development of host-pathogen index which was able to categorize the samples for down-stream system biology analysis. Additionally we were able to determine key genes in the pathways such as jasmonate, ethylene and ROS which were up-regulated in the studyThe stage of infection index used for the transcriptomic analysis revealed that A. flavus does not produce many transcripts initially during pathogenesis. It was found that when A. flavus was producing an abundance of transcripts, pathways involved the endosomal transport, aflatoxin production, sugar production and many others were up-regulated. In tandem, Z. mays had multiple resistance pathways, such as the phenylpropaniod, jasmonic acid and ethylene pathways that were up-regulated. The analysis of the gene regulatory networks revealed that multiple WRKY genes were targeting the activation of the resistance pathways. The analysis also revealed, for the first time, the activation of Z. mays resistance genes targeting A. flavus genes. Our results show that the plant-microbe interaction has multiple layers and that A. flavus transcriptionally reacts to the hostile environment of Z. mays. The interaction between Aspergillus flavus and Zea mays is complex, and the identification of plant genes and pathways conferring resistance to the fungus has been challenging. Therefore authors undertook a systems biology approach involving dual RNA-seq to determine simultaneous response from the host and pathogen. What was dramatically highlighted in the analysis was upon infection there is uniformity in the development of the host and pathogen. This led to the development of host-pathogen index which was able to categorize the samples for down-stream system biology analysis. Additionally we were able to determine key genes in the pathways such as jasmonate, ethylene and ROS which were up-regulated in the studyThe stage of infection index used for the transcriptomic analysis revealed that A. flavus does not produce many transcripts initially during pathogenesis. It was found that when A. flavus was producing an abundance of transcripts, pathways involved the endosomal transport, aflatoxin production, sugar production and many others were up-regulated. In tandem, Z. mays had multiple resistance pathways, such as the phenylpropaniod, jasmonic acid and ethylene pathways that were up-regulated. The analysis of the gene regulatory networks revealed that multiple WRKY genes were targeting the activation of the resistance pathways. The analysis also revealed, for the first time, the activation of Z. mays resistance genes targeting A. flavus genes. Our results show that the plant-microbe interaction has multiple layers and that A. flavus transcriptionally reacts to the hostile environment of Z. mays.
2020-06-14 | GSE101899 | GEO
Project description:Aspergillus flavus is a pathogen of corn, peanut, and other crops which produces carcinogenic mycotoxins known as aflatoxins. Previous studies have shown that drought stress results in exacerbated aflatoxin production. Drought-associated oxidative stress caused by reactive oxygen species (ROS) is suspected to contribute to increased aflatoxin production during infection. Here, the responses of field isolates of A. flavus with varying degrees of aflatoxin production capability to H2O2-derived oxidative stress were examined using iTRAQ proteomics. Three isolates: AF13 (highly toxigenic), NRRL3357 (moderately toxigenic), and K54A (atoxigenic), were cultures in aflatoxin conducive yeast extract-sucrose (YES) medium amended with 0, 10, or 20/25mM of H2O2. Identified differentially expressed proteins were used for functional prediction, cellular localization, and pathway analyses to identify molecular mechanisms involved in A. flavus oxidative stress responses relative to aflatoxin production capability. Correlative analyses with previously obtained transcriptome data for the same isolates under the same experimental conditions was also performed with a low degree of correlation (r = 0.1114) observed between the protein and transcript data suggesting possible post-transcriptional regulation of oxidative stress responses. The identified stress responsive mechanisms provide a basis of investigating novel approaches of enhancing host resistance against aflatoxin contamination.
2018-02-27 | PXD007164 | Pride
Project description:Aspergillus flavus is one of the major fungal molds that colonize peanut in the field and during storage. The impact to human and animal health and to economy in agriculture and commerce are significant since this mold produces the most potent natural toxins, aflatoxins, which are carcinogenic, mutagenic, immunosuppressive, and teratogenic. A strain of marine Bacillus megaterium isolated from the Yellow Sea of East China was evaluated for its effect to inhibit aflatoxin formation through down-regulating aflatoxin pathway gene expression in A. flavus as demonstrated by genechip analysis in liquid medium and peanuts. The results showed that aflatoxin accumulation in potato dextrose broth liquid medium and liquid minimal medium was almost totally (more than 98%) inhibited by B. megaterium. The expression of many of the aflatoxin biosynthetic genes in the fungus was confirmed to be turned down. Some of the target genes down-regulated by B. megaterium within the whole genome and within the aflatoxin pathway gene cluster (aflF, aflT, aflS, aflJ, aflL, aflX) were identified. These target genes could be used for controlling aflatoxin contamination in crops such as corn, cotton, and peanut. Importantly, the expression of the regulatory gene aflS was found to be significantly down-regulated.
2013-10-22 | GSE51469 | GEO
Project description:Aspergillus flavus is one of the major fungal molds that colonize peanut in the field and during storage. The impact to human and animal health and to economy in agriculture and commerce are significant since this mold produces the most potent natural toxins, aflatoxins, which are carcinogenic, mutagenic, immunosuppressive, and teratogenic. A strain of marine Bacillus megaterium isolated from the Yellow Sea of East China was evaluated for its effect to inhibit aflatoxin formation through down-regulating aflatoxin pathway gene expression in A. flavus as demonstrated by genechip analysis in liquid medium and peanuts. The results showed that aflatoxin accumulation in potato dextrose broth liquid medium and liquid minimal medium was almost totally (more than 98%) inhibited by B. megaterium. The expression of many of the aflatoxin biosynthetic genes in the fungus was confirmed to be turned down. Some of the target genes down-regulated by B. megaterium within the whole genome and within the aflatoxin pathway gene cluster (aflF, aflT, aflS, aflJ, aflL, aflX) were identified. These target genes could be used for controlling aflatoxin contamination in crops such as corn, cotton, and peanut. Importantly, the expression of the regulatory gene aflS was found to be significantly down-regulated. The effect of B. megaterium on aflatoxin biosynthesis and genes expression of pathogen was firstly tested in potato dextrose broth (PDB) and glucose minimal salts medium (MM). The cell suspension of B. megaterium (concentration in PDB and MM was finally adjusted to 108 CFU/ml) or sterile distilled water as a control was added into the 100 ml beaker flask containing 15 ml PDB or MM, respectively. Then 100 M-NM-<l of spore suspension (5 M-CM-^W 106 spores/ml) of A. flavus were added into each beaker flask. After 48 h of incubation at 28M-BM-0C at 200 rpm, mycelia were collected, fresh frozen with liquid nitrogen, ground to a fine powder in liquid nitrogen, and stored at -80M-BM-0C for further analysis. The effect of B. megaterium on aflatoxin biosynthesis and genes expression in the A. flavus fungal pathogen was also tested in two types of peanut kernels, UF 715133-1 and Jinhua 1012, respectively. Peanut kernels were wounded (6 mm diameter and approximately 3 mm deep) using a sterile borer and then 20 M-NM-<l of 1 M-CM-^W 108 CFU/ml cell suspension of B. megaterium was inoculated on wounded peanut kernels respectively. Sterile distilled water was also used for inoculation as control. Two hours after bacterial inoculation, 10 M-NM-<l A. flavus spore suspension was inoculated into each wound at a concentration of 106 spores/ml. The kernels were placed in artificial weather chamber to maintain high humidity (85%) and incubated at 28M-BM-0C for 7 days. Each treatment was replicated three times with 20 peanut kernels in each test. The mycelia on kernels were harvested at day 7 and fresh frozen immediately in liquid nitrogen, ground into powder, and stored at -80M-BM-0C for further analysis.
2013-10-22 | E-GEOD-51469 | biostudies-arrayexpress
Project description:To better understand the effect of temperature on mycotoxin biosynthesis, RNA-Seq technology was used to profile the Aspergillus flavus transcriptome under different temperature conditions. This approachallowed us to quantify transcript abundance for over 80% of fungal genes including 1,153 genes that were differentially expressed at 30M-BM-0C and 37M-BM-0C. Wleven of the 55 secondary metabolite clusters were up-regulated at the lower temperature, including aflatoxin biosynthesis genes, which were among the most highly up-expressed genes. On average, transcript abundance for the 30 aflatoxin biosynthesis genes was 3,300 times greater at 30M-BM-0C as compared to 37M-BM-0C. The results are consistent with the view that high temperature negatively affects aflatoxin production by turning down transcription of the two key transcriptional regulators, aflR and aflS. Subtle changes in the expression levels of aflS to aflR appear to control transcription activation of the aflatoxin cluster. 2 samples examined: from the fungus grown at 30M-BM-0C and 37M-BM-0C
2011-06-16 | E-GEOD-30031 | biostudies-arrayexpress
Project description:To better understand the effect of temperature on mycotoxin biosynthesis, RNA-Seq technology was used to profile the Aspergillus flavus transcriptome under different temperature conditions. This approachallowed us to quantify transcript abundance for over 80% of fungal genes including 1,153 genes that were differentially expressed at 30°C and 37°C. Wleven of the 55 secondary metabolite clusters were up-regulated at the lower temperature, including aflatoxin biosynthesis genes, which were among the most highly up-expressed genes. On average, transcript abundance for the 30 aflatoxin biosynthesis genes was 3,300 times greater at 30°C as compared to 37°C. The results are consistent with the view that high temperature negatively affects aflatoxin production by turning down transcription of the two key transcriptional regulators, aflR and aflS. Subtle changes in the expression levels of aflS to aflR appear to control transcription activation of the aflatoxin cluster.
2011-06-16 | GSE30031 | GEO
Project description:purpose: to further gain insight into the effect of RGS proteins on aflatoxin biosynthesis in A. flavus NRRL3357. methods: two mutants ΔrgsA and ΔrgsE separately compared to WT were chose to conduct the analysis of transcriptomics. results: 1750 DEGs are found, including 720 upregulated genes and 1030 downregulated genes in (ΔrgsA vs WT); aflB, aflD, aflF, aflG, aflN, aflP, aflS from ΔrgsE were transcriptionally reduced relative to ΔrgsA in their expressions.
2022-02-21 | GSE196717 | 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:Aspergillus flavus contaminates crops during preharvest and post-harvest periods and produce carcinogenic mycotoxin aflatoxins posing severe threat to food safety and human health. To identify potential targets to tackle aflatoxin contamination, we have characterized a novel Afper1, sharing sequence identity with the yeast protein per1, regulating cell development and secondary metabolism in A. flavus. Notably, proteomics analysis revealed that the enzymes involved in extracellular hydrolases, conidial development, ER homeostasis, and aflatoxin biosynthesis significantly varied. Unexpectedly, enzymes participated in scavenging ROS including catA, catB, cpeB, and sodM were significantly downregulated and the accumulated ROS and sensitivity to hydrogen peroxide were confirmed by experiments. Surprisingly, Afper1 deletion significantly unregulated heterochromatin protein (HepA) and downregulated GNAT family acetyltransferase involved in heterochromatin formation. Accompanying the accumulated ROS and chromatin remodelling, enzymes participating in aflatoxins, ustiloxin B, and gliotoxin were impaired. These results implied that Afper1 affected chromatin remodelling and disturbed ER homeostasis leading to the accumulation of ROS, and ultimately resulted in growth defect and impaired secondary metabolites biosynthesis.
2022-07-13 | PXD030015 | Pride
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