Project description:Female genital tract (FGT) diseases such as bacterial vaginosis (BV) and sexually transmitted infections are prevalent in South Africa, with young women being at an increased risk. Since imbalances in the FGT microbiome are associated with FGT diseases, it is vital to investigate the factors that influence FGT health. The mycobiome plays an important role in regulating mucosal health, especially when the bacterial component is disturbed. However, we have a limited understanding of the FGT mycobiome since many studies have focused on bacterial communities and have neglected low abundance taxonomic groups, such as fungi. To reduce this knowledge deficit, we present the first large-scale metaproteomic study to define the taxonomic composition and potential functional processes of the FGT mycobiome in South African reproductive-age women. We examined FGT fungal communities present in 123 women by collecting lateral vaginal wall swabs for liquid chromatography-tandem mass spectrometry.
Project description:Summary: Salmonella enterica serovar Typhimurium strain 14028s transcriptome response to lettuce medium (LM) and lettuce root exudates (LX) to minimal medium (MM). Purpose: Salmonella mRNA profile, when grown in different media was compared to minimal medium to reveal environment specific transcriptional changes. Methods: mRNA profiles were generated using Illumina HiSeq in triplicates. The sequences were analysed using Bowtie2 followed by Cufflinks.
2019-06-10 | GSE123152 | GEO
Project description:Cross-phytogroup assessment of foliar epiphytic mycobiome
Project description:Increasing evidence of Pseudomonas aeruginosa on fresh plant-based foods raises food safety concerns. While internalization of pathogens such as Salmonella enterica in vegetables such as lettuce is well documented, corresponding data for P. aeruginosa are lacking. Moreover, climate change-associated temperature shifts may influence the plant microbiota and the presence of human pathogens. This study investigates the internalization and temperature-dependent gene expression of P. aeruginosa PAO1 on green oak leaf lettuce as a model system. For this purpose, oak leaf lettuce was cultivated in soil inoculated with P. aeruginosa PAO1_sfGFP_UHH07, and internalization was analyzed using confocal laser scanning microscopy. Temperature-dependent transcriptomic changes of P. aeruginosa PAO1 were assessed by analyzing differentially expressed genes following plant inoculation and incubation at 18 and 22 °C, respectively. P. aeruginosa PAO1 is capable of internalizing into the roots of oak leaf lettuce, but a translocation into leaves was not detected. Transcriptomic analyses showed that a moderate temperature increase shifts bacterial gene expression, with virulence genes upregulated at 22 °C and persistence-associated genes predominating at 18 °C. These results show that temperature influences the persistence and pathogenic potential of P. aeruginosa present on oak leaf lettuce, highlighting potential impacts of climate change on food safety.
Project description:A combined approach of evaluating ozone (O3)-caused foliar injury symptom and global gene expression profiling was used to identify potential genes associated with severity of injury on leaves of O3 (200 ppb)-fumigated (1, 12, 24, 48, and 72 h) two-week-old rice (cv. Nipponbare) seedling along with appropriate control. Foliar injuries were evaluated up to 72 h using both qualitative visual scale and quantitative RGB (red-green-blue) image analysis methods. The (R-G)/(R+G) was found as the optimal quantitative RGB parameter to assess the foliar injury. Large-scale transcript profiling of leaves identified 270 genes linked with foliar injury. Of these genes, the expression levels of 139 genes showed significant differences (P < 0.05) between leaves without and with injury symptoms. When a rigorous correlation test was applied on these genes for their expression changes and relative (R-G)/(R+G) parameters, the expression of 93 genes were found to increase with increased foliar severity up to 72 h, showing a positive, tight correlation between a subset of gene expression and commonly observed O3-triggerred symptom of foliar injury with correlation coefficient below -0.80. Of 93 genes, genes involved in metabolism (29%) formed a major functional category. Reconstruction of the metabolic networks with identified metabolic genes provided insight into the cellular responses such as photorespiration, biosynthesis of secondary metabolites, and detoxification. The O3 effect on these cellular responses has been previously reported based on physiological and biochemical studies, validating our approach used in this study to globally identify O3-responsive biomarkers tightly linked with foliar injury symptom. This study provides evidence for the presence of large number of genes associated with the foliar injury symptom than thought before, and could serve as a resource of potential biomarkers to study mechanisms of visible injury development by O3. Comparison between healthy rice seedling leaves and ozone treated (for 48 h and 72 h) rice seedling leaves was performed. Three biological replicates (5 leaves in each replicate; pooled) were used, and dye-swaped.
Project description:Calcium deficiency response in liverwort, Arabidopsis and lettuce: (1) Marchantia polymorpha: M. polymorpha wildtype and Gβ-null mutant plants (Tak-1, gpb1-2) were grown in control liquid Yamagami media (2 mM Ca) for 6 days. For RNA-seq experiments, 6 day old gemmalings were transferred to calcium deficiency (0 mM Ca) media. Samples were collected at 48 h after the transfer. The transcriptomic profiles were collected from two independent batches. In total four biological replicates were used for each condition and each genotype for a total of 16 samples. (2) Arabidopsis thaliana: For Arabidopsis RNA-seq experiment, 6-day old seedlings grown on ½ strength MS media with sucrose were transferred to Yamagami media with 2 mM or 0 mM CaCl2 and treated for 7 days. (3) Lactuca Sativa: For lettuce RNA-seq, 4-day old seedlings grown on water agar (1%) were transferred to Yamagami media with 2 mM or 0.15 mM CaCl2 and treated for 7 days. In total four and three biological replicates were used for each condition for a total of 8 and 6 samples respectively for Arabidopsis and lettuce.
Project description:A combined approach of evaluating ozone (O3)-caused foliar injury symptom and global gene expression profiling was used to identify potential genes associated with severity of injury on leaves of O3 (200 ppb)-fumigated (1, 12, 24, 48, and 72 h) two-week-old rice (cv. Nipponbare) seedling along with appropriate control. Foliar injuries were evaluated up to 72 h using both qualitative visual scale and quantitative RGB (red-green-blue) image analysis methods. The (R-G)/(R+G) was found as the optimal quantitative RGB parameter to assess the foliar injury. Large-scale transcript profiling of leaves identified 270 genes linked with foliar injury. Of these genes, the expression levels of 139 genes showed significant differences (P < 0.05) between leaves without and with injury symptoms. When a rigorous correlation test was applied on these genes for their expression changes and relative (R-G)/(R+G) parameters, the expression of 93 genes were found to increase with increased foliar severity up to 72 h, showing a positive, tight correlation between a subset of gene expression and commonly observed O3-triggerred symptom of foliar injury with correlation coefficient below -0.80. Of 93 genes, genes involved in metabolism (29%) formed a major functional category. Reconstruction of the metabolic networks with identified metabolic genes provided insight into the cellular responses such as photorespiration, biosynthesis of secondary metabolites, and detoxification. The O3 effect on these cellular responses has been previously reported based on physiological and biochemical studies, validating our approach used in this study to globally identify O3-responsive biomarkers tightly linked with foliar injury symptom. This study provides evidence for the presence of large number of genes associated with the foliar injury symptom than thought before, and could serve as a resource of potential biomarkers to study mechanisms of visible injury development by O3.
Project description:Leafy green vegetables, such as lettuce, have been increasingly implicated in outbreaks of foodborne illnesses due to contamination by Escherichia coli O157:H7. While E. coli can survive in soils, colonize plants, and survive on produce, very little is known about the interaction of E. coli with the roots of growing lettuce plants. In these studies a combination of microarray analyses and microbial genetics were used to gain a comprehensive understanding of bacterial genes involved in the colonization and growth of E. coli K12 on lettuce roots using a hydroponic assay system. Here we report that after three days of interaction with lettuce roots, 193 and 131 genes were significantly up-regulated and down-regulated at least 1.5 fold, respectively. Forty-five out of the 193 up-regulated genes (23%) were involved in protein synthesis and were highly induced. Genes involved in stress response, attachment and biofilm formation were up-regulated in E. coli when they interacted with lettuce roots under conditions of hydroponic growth. In particular crl, a gene regulating the cryptic csgA gene for curli production, was significantly up regulated. The crl, csgA and fliN mutants had a reduced capacity to attach to roots as determined by bacterial counts and by confocal laser scanning microscopy. Our microarray data showed that E. coli K12 increased the synthesis of proteins indicated that a dramatic change was induced in the physiology of the microorganism. This study indicates that E. coli K12 can efficiently colonize lettuce roots by using attachment and biofilm modulation genes and can readily adapt to the rhizosphere of lettuce plants. Further studies are needed to better characterize this interaction in pathogenic strains of this species. Escherichia coli MG1655 strains were grown in the lettuce rhizosphere for three days. Transcriptional profiling of E. coli was compared between cells grown with and without rhizosphere . Three biological replicates of each treatment were prepared, and six microarray slides were used.