Growth Parameter Components of Adaptive Specificity during Experimental Evolution of the UVR-Inducible Mutator Pseudomonas cichorii 302959

• Published in: PloS one Vol. 6; no. 1; p. e15975
• Main Authors: Weigand, Michael R., Tran, Vinh N., Sundin, George W.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14.01.2011; Public Library of Science (PLoS)
• Subjects: Activation; Adaptation; Adaptation, Physiological; Analysis; Bacteria; Biological evolution; Biology; Cell cycle; Deoxyribonucleic acid; Directed Molecular Evolution; DNA; DNA damage; DNA polymerases; DNA repair; DNA Repair - genetics; E coli; Environmental conditions; Environmental stress; Epiphytes; Escherichia coli; Evolution; Evolution & development; Evolution (Biology); Exposure; Fitness; Genetic Enhancement; Genetic Fitness; Genetics; Genotype & phenotype; Growth; Growth conditions; Laboratories; Microorganisms; Mutagens - pharmacology; Mutation; Plant pathology; Plants - microbiology; Pseudomonas; Pseudomonas - genetics; Pseudomonas cichorii; Radiation (Physics); Radiation damage; Radiation Tolerance - genetics; Repair; Reproductive fitness; Studies; U.V. radiation; Ultraviolet radiation; Ultraviolet Rays - adverse effects; United States > US; East Lansing Michigan; Michigan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0015975

Mutagenic DNA repair (MDR) transiently increases mutation rate through the activation of low-fidelity repair polymerases in response to specific, DNA-damaging environmental stress conditions such as ultraviolet radiation (UVR) exposure. These repair polymerases also confer UVR tolerance, intimately linking mutability and survival in bacteria that colone habitats subject to regular UVR exposure. Here, we investigate adaptive specificity in experimental lineages of the highly UVR-mutable epiphytic plant pathogen Pseudomonas cichorii 302959. Relative fitness measurements of isolates and population samples from replicate lineages indicated that adaptive improvements emerged early in all lineages of our evolution experiment and specific increases in relative fitness correlated with distinct improvements in doubling and lag times. Adaptive improvements gained under UVR and non-UVR conditions were acquired preferentially, and differentially contributed to relative fitness under varied growth conditions. These results support our earlier observations that MDR activation may contribute to gains in relative fitness without impeding normal patterns of adaptive specificity in P. cichorii 302959.