The role of ColRS two-component regulatory system in rhizosphere colonization and tolerance to abiotic stress in Pseudomonas aeruginosa
department or school: Science, Faculty of
department or school: Microbiology and Immunology, Department of
data provider: DSpace
degree campus: UBCV
creator: Zhang, Yue
issued: 2021-04-21T20:39:41Z
issued: 2021
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Pseudomonas aeruginosa is a versatile bacterium found ubiquitously in the environment and is an opportunistic pathogen of diverse organisms, including animals and plants. A key determinant of bacterial adaptability is the ability to sense and respond appropriately to environmental stimuli. ColRS is a two-component regulatory system previously shown to be required for P. fluorescens colonization of plant roots (the “rhizosphere”) and P. aeruginosa virulence in C. elegans; however, the mechanisms by which ColRS regulates fitness in a host environment are unknown. I found that colR and colS deletion mutants in P. aeruginosa were significantly impaired in their ability to colonize the rhizosphere of Arabidopsis. In addition, we showed that colR in the P. aeruginosa cystic fibrosis epidemic isolate, LESB58, is required for virulence in a mouse abscess model. Using RNA-seq, I found a total of 128 genes that were dysregulated in the colR mutant in the rhizosphere, many of which have products that are predicted to localize to the cytoplasmic or outer membranes, suggesting ColRS may function in maintaining membrane integrity. Using P. aeruginosa transposon insertion mutants in colR-dependent genes, I identified novel genes required for rhizosphere colonization, including the protein tyrosine phosphatase tpbA, diacylglycerol kinase dgkA, and a type 2 phosphatidic acid phosphatase. Lastly, I showed that P. aeruginosa colR is required for tolerance to high levels of iron, zinc, and manganese, and for growth at acidic pH. Because functional analysis of rhizosphere gene expression showed that high iron concentration and low pH are stresses that may be present in the rhizosphere, the ColRS two-component system likely promotes P. aeruginosa colonization of the Arabidopsis rhizosphere through regulation of genes required to protect against these stresses.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/77862
note: The role of ColRS two-component regulatory system in rhizosphere colonization and tolerance to abiotic stress in Pseudomonas aeruginosa by Yue Zhang B.Sc., The University of British Columbia, 2018 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Microbiology and Immunology) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) April 2021 © Yue Zhang, 2021 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled: The role of ColRS two-component regulatory system in rhizosphere colonization and tolerance to abiotic stress in Pseudomonas aeruginosa submitted by Yue Zhang in partial fulfillment of the requirements for the degree of Master of Science in Microbiology and Immunology Examining Committee: Cara H. Haney, Assistant Professor, Department of Microbiology and Immunology Supervisor Carolina Tropini, Assistant Professor, Department of Microbiology and Immunology Supervisory Committee Member James W. Kronstad, Professor, Department of Microbiology and Immunology Additional Examiner Additional Supervisory Committee Members: Robert E. W. Hancock, Professor, Department of Microbiology and Immunology Supervisory Committee Member iii Abstract Pseudomonas aeruginosa is a versatile bacterium found ubiquitously in the environment and is an opportunistic pathogen of diverse organisms, including animals and plants. A key determinant of bacterial adaptability is the ability to sense and respond appropriately to environmental stimuli. ColRS is a two-component regulatory system previously shown to be required for P. fluorescens colonization of plant roots (the “rhizosphere”) and P. aeruginosa virulence in C. elegans; however, the mechanisms by which ColRS regulates fitness in a host environment are unknown. I found that colR and colS deletion mutants in P. aeruginosa were significantl…
has type: Thesis/Dissertation
date issued: 2021-05
is shown at: 10.14288/1.0396867
language: eng
degree discipline: Microbiology and Immunology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/77862