Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 7 of 7
Full-Text Articles in Entire DC Network
Characterization Of The Integrated Signaling Network Of Burkholderia Glumae For The Regulation Of Virulence-Related Function In The Bacterial Pathogenesis Of Rice Plants, Tiago De Paula Lelis
Characterization Of The Integrated Signaling Network Of Burkholderia Glumae For The Regulation Of Virulence-Related Function In The Bacterial Pathogenesis Of Rice Plants, Tiago De Paula Lelis
LSU Doctoral Dissertations
Bacterial panicle blight of rice (BPB) caused by Burkholderia glumaeis a major bacterial disease of rice in many rice-producing areas worldwide. Managing the disease is still very difficult due to the lack of effective methods. B. glumaestrains show phenotypic and genomic variations; however, little variation was detected in the known virulence-related genes. In the present study, the complete genome of B. glumae257sh-1, a natural avirulent strain, was sequenced and analyzed. Several spontaneous mutations in the regulatory genes of these avirulent strains were identified. Presumably, the accumulation of these mutations can have a negative effect on the normal …
Genetic And Transcriptomic Analyses Of The Rice Pathogenic Bacterium, Burkholderia Glumae, Reveal The Important Roles Of The Regulatory Gene, Tepr, For Bacterial Survival In Environmental Stresses, Jingyu Peng
LSU Master's Theses
Burkholderia glumae causes bacterial panicle blight in rice by producing the phytotoxin, toxoflavin, as a major virulence factor. Production of toxoflavin is negatively regulated by tepR, which encodes a sigma 54-dependent response regulator. In order to gain insights into the comprehensive biological functions of tepR, the genome-wide transcriptional profile dependent on tepR was analyzed through comparative transcriptome analysis between a tepR defective mutant and the wild-type strain, resulting in the identification of 238 differentially expressed genes (DEGs). Gene Ontology (GO) enrichment analysis indicated that genes involved in flagella assembly and stress response were highly enriched in tepR defective strain. Kyoto …
Characterization Of A Σ54-Dependent Response Regulator, Tepr, In The Rice-Pathogenic Bacterium Burkholderia Glumae And Development Of Biocontrol Strategies For Bacterial Panicle Blight Of Rice, Surendra Osti
LSU Master's Theses
Bacterial panicle blight, caused by Burkholderia glumae, is a major bacterial disease of rice in Louisiana. This bacterium contains several virulence factors required for disease development such as toxoflavin, lipase and flagella. In a genome-wide search for regulatory factors related to the virulence of B. glumae, tepR was identified as a negative regulator for toxoflavin production and found to encode a sigma 54-dependent response regulator. TepR is homologous to LuxO, a quorum-sensing signaling component of Vibrio spp. A markerless tepR deletion mutant of B. glumae 336gr-1, LSUPB401, produced more toxoflavin and showed higher lipase and protease activities compared to the …
Integrated Functional Anlaysis Of Quorum-Sensing In The Rice Pathogenic Bacterium Burkholderia Glumae, Ruoxi Chen
Integrated Functional Anlaysis Of Quorum-Sensing In The Rice Pathogenic Bacterium Burkholderia Glumae, Ruoxi Chen
LSU Doctoral Dissertations
Quorum sensing (QS) is a cell-to-cell communication mechanism that allows bacterial cells to collectively behave like a multicellular organism. It regulates the expression of toxoflavin, one of the major virulence factors of the rice pathogen, Burkholderia glumae. The QS system of B. glumae is mediated by the core genes, tofI and tofR. N-octanoyl-L-homoserine lactone, the primary QS signal molecule of B. glumae, is synthesized by tofI and binds to the cognate receptor tofR at the quorum point. However, tofI and tofR null mutants produce toxoflavin in certain growth conditions, indicating the presence of tofI- and tofR-independent pathways for toxoflavin production. …
A Genetic Study On The Virulence Mechanism Of Burkholderia Glumae And, Rice Resistance To Bacterial Panicle Blight And Sheath Blight, Hari Sharan Karki
A Genetic Study On The Virulence Mechanism Of Burkholderia Glumae And, Rice Resistance To Bacterial Panicle Blight And Sheath Blight, Hari Sharan Karki
LSU Doctoral Dissertations
Burkholderia glumae is a rice pathogenic bacterium that causes bacterial panicle blight. Some strains of this pathogen produce dark brown pigments when grown on the casamino-acid peptone glucose (CPG) agar medium. A pigment-positive and highly virulent strain of B. glumae, 411gr-6, was randomly mutagenized with mini-Tn5gus, and the resulting mini-Tn5gus derivatives showing altered pigmentation phenotypes were screened on CPG agar plates to identify the genetic elements governing the pigmentation of B. glumae. In this study, several positive and negative regulators, for the pigmentation of B. glumae were identified. During this study, a novel two-component regulatory system (TCRS) composed of the …
Comparative Genomics, Transcriptome Analysis And Characterization Of Selected Regulatory Genes Of Burkholderia Glumae, Felix Francis
Comparative Genomics, Transcriptome Analysis And Characterization Of Selected Regulatory Genes Of Burkholderia Glumae, Felix Francis
LSU Master's Theses
Burkholderia glumae is the primary causal agent of bacterial panicle blight of rice, which is becoming a major threat to global rice production. The genome of a highly virulent B. glumae strain, 336gr-1 that was isolated from rice in Louisiana, was sequenced to better understand the genome-scale characteristics, particularly that of its pathogenicity. Comparative genomic analyses with another strain, BGR1 that was isolated from Korea, revealed several unique regions present in the genomes of these two geographically separated phytopathogenic bacteria. Genome plasticity, primarily caused by a horizontal gene transfer, was observed in these closely related strains of Burkholderia that are …
A Molecular Genetic Study On The Tofl/Tofr Quorum-Sensing System Of Burkholderia Glumae: The Major Pathogen That Causes Bacterial Panicle Blight Of Rice, Ruoxi Chen
LSU Master's Theses
Burkholderia glumae is the major causal agent of an economically important rice disease, bacterial panicle blight (BPB). The known virulence factors of B. glumae share the TofI/TofR quorum sensing system as their regulator. tofI and tofR genes encode the N-acyl homoserine lactone (AHL) synthase for the B. glumae quorum sensing signals, N-octanoyl homoserine lactone (C8-HSL) and N-hexanoyl homoserine lactone (C6-HSL), and the receptor for AHL, respectively. To better understand the relationship between quorum sensing and known virulence factors (toxoflavin, flagella and lipase), as well as, putative virulence factors (i.e. extracellular polysaccharide), mutagenetic and phenotypic analyses were applied to this study. …