Project description:Bacterial pathogen Burkholderia glumae and fungal pathogen Fusarium graminearum cause similar disease symptoms and are often co-isolated from rice heads, inferring interactions between the two pathogens. F. graminearum is resistant to the bacterial toxin toxoflavin, a strong anti-microbial activity, produced by B. glumae. We isolated a toxoflavin-sensitive mutant from transcription factor deletion mutant library of F. graminearum. To understand genome-wide transcriptional profiling, we performed RNA-seq analyses of F. graminearum wild-type strain GZ03639 and toxoflavin-sensitive mutant strain, ∆GzZC190, under toxoflavin condition.
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare NGS-derived transcriptome profiling (RNA-seq) and transposon insertion mutagenesis (Tnseq) libraries of Lon deletions compared to wt Caulobacter crescentus. Methods: See Methods section of The Lon protease links nucleotide metabolism with proteotoxic stress for information regarding methods or contact lead correspondence. Briefly, Samples for RNAseq were extracted from wt and lon deletion strains grown to mid exponential phase. Methods: See Methods section of The Lon protease links nucleotide metabolism with proteotoxic stress for information regarding methods or contact lead correspondence. Briefly, Samples for Tnseq were generated by Eztn5 transposon mutagenesis. Conclusions: Our study represents the first detailed analysis of lon deletion comparison to wt caulobacter transcriptomes, with biologic replicates, generated by RNA-seq technology.
Project description:Bacterial pathogen Burkholderia glumae and fungal pathogen Fusarium graminearum cause similar disease symptoms and often co-isolated from rice heads, inferring interactions between the two pathogens. F. graminearum is resistant to the bacterial toxin toxoflavin, a strong anti-microbial activity, produced by B. glumae. We isolated toxoflavin-sensitive mutants from transcription factor deletion mutant library of F. graminearum. To understand genome-wide transcriptional profiling, we performed RNA-seq analyses of F. graminearum wild-type strain GZ03639 and toxoflavin-sensitive mutant strains (∆GzZC190, ∆GzC2H008, ∆GzbZIP005) under toxoflavin condition.
Project description:Lon protease is known to regulate various transcriptional regulators in other bacterial organisms. To understand whether lon protease is involved in transcriptional changes in Vibrio cholerae, wholel-genome level transcriptional profiling was performed using custom microarrays. Transcriptomes of lonA mutant and wild-type strains were compared in this study.
Project description:Lon protease is known to regulate various transcriptional regulators in other bacterial organisms. To understand whether lon protease is involved in transcriptional changes in Vibrio cholerae, wholel-genome level transcriptional profiling was performed using custom microarrays. Transcriptomes of lonA mutant and wild-type strains were compared in this study. Three biological replicates of wild-type and lonA mutant strains were used for this study. Reference RNA sample was harvested from wild-type strain.
Project description:Burkholderia glumae causes rice grain rot and sheath rot by producing toxoflavin, whose expression is regulated by quorum sensing (QS). The QS systems of the bacterium rely on N-octanoyl homoserine lactone, synthesized by TofI and its cognate receptor TofR, to activate toxoflavin biosynthesis genes and an IclR-type transcriptional regulator gene, qsmR. To understand genome-wide transcriptional profiling of QS signaling, we employed RNA-Seq of the wild type Burkholderia glumae BGR1 and two QS-defective mutants, BGS2 (BGR1 tofI::Ω) and BGS9 (BGR1 qsmR::Ω), with two different types of culture conditions including 6hr liquid culture (before onset QS) and 10hr liquid culture (after onset QS). 3 samples examined: Burkholderia glumae BGR1 wild type, and two QS-defective mutants, BGS2 (BGR1 tofI::Ω) and BGS9 (BGR1 qsmR::Ω). Two conditions: cultured in LB media for 6hrs or 10hrs.
Project description:The bacterial Lon protease participates in a variety of biological processes. In Pseudomonas syringae, mutation of lon is known to activate hrpL and a few hrpL-regulated genes in the rich medium. The elevated expression of hrpL and hrpL-regulated genes results from of increased stability of HrpR, the transcriptional activator of hrpL, in the lon mutant. Here we conducted a microarray analysis to determine genes that are differently expressed in the lon- mutant of P. s. pv. tomato DC3000 grown in the rich medium KB. Most genes induced in the lon- mutant belong to the HrpL-regulon or are related to the transcription, protein synthesis, and energy metabolism. The major group of genes reduced in the lon- mutant is related to cell wall biogenesis. The HrpL-regulated genes exhibit different induction patterns in the lon- mutant, suggesting the involvement of regulators additional to HrpL in regulating these genes. Compared with the wild type bacteria, the lon- mutants exhibit elevated hrpL expression in KB medium but reduced hrpL expression in the minimal medium (MM). The reduced hrpL RNA is correlated with the reduced hrpR and hrpS RNAs, suggesting that the Lon-mediated regulation of hrpL involves different mechanisms in KB and MM. Consistent with the reduced expression of the hrpL in MM, the lon- mutants are less pathogenic on host plants. Keywords: Expression profiles of lonB mutant in KB
Project description:Lon protease plays vital roles in many biological processes in Pseudomonas syringae, including type III secretion systems (T3SS), transcription regulation, protein synthesis and energy metabolism. Lon also functions as a transcriptional regulator in other bacterial species (e.g., Escherichia coli and Brevibacillus thermoruber). Therefore, we hypothesise that Lon has dual functions in P. syringae. To reveal the molecular mechanisms of Lon as a transcriptional regulator and protease under different environmental conditions, we used a combination of transcriptome sequencing (RNA-seq), chromatin immunoprecipitation sequencing (ChIP-seq) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify the genes or proteins regulated by Lon. As a transcriptional regulator, Lon bound to the promoter regions of PSPPH_4788, gacA, fur, gntR, clpS, lon and glyA and consequently regulated 1-dodecanol oxidation activity, motility, pyoverdine production, gluconokinase activity, N-end rule pathway, lon expression and serine hydroxymethyltransferase (SHMT) activity in King’s B medium (KB). In minimal medium (MM), Lon regulated SHMT activity and lon expression by binding to the promoter regions of glyA and lon, respectively. As a protease, Lon regulated the T3SS and metabolic pathways (e.g., amino acid metabolism). In MM, Lon regulated the polysaccharide metabolic process by controlling PSPPH_0514, AlgA, CysD and PSPPH_4991. Taken together, these data demonstrate that Lon acts as a transcriptional regulator or protease in different environments and tunes its virulence and metabolic functions accordingly.