Characterization of CRISPR-Cas systems in the Ralstonia solanacearum species complex
| Autor: | Poliane Alfenas-Zerbini, André da Silva Xavier, Sylvain Moineau, Geneviève M. Rousseau, Alessandra Gonçalves de Melo, Juliana Cristina Fraleon de Almeida, Denise M. Tremblay, Rafael Reis de Rezende |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
0301 basic medicine Phylotype Genetics Ralstonia solanacearum biology 030106 microbiology food and beverages Soil Science Virulence Plant Science biology.organism_classification 01 natural sciences Genome humanities 03 medical and health sciences Ralstonia Phylogenetics CRISPR Agronomy and Crop Science Molecular Biology Gene 010606 plant biology & botany |
| Zdroj: | Molecular Plant Pathology. 20:223-239 |
| ISSN: | 1464-6722 |
| DOI: | 10.1111/mpp.12750 |
| Popis: | Clustered regularly interspaced short palindromic repeats (CRISPRs) are composed of an array of short DNA repeat sequences separated by unique spacer sequences that are flanked by associated (Cas) genes. CRISPR-Cas systems are found in the genomes of several microbes and can act as an adaptive immune mechanism against invading foreign nucleic acids, such as phage genomes. Here, we studied the CRISPR-Cas systems in plant-pathogenic bacteria of the Ralstonia solanacearum species complex (RSSC). A CRISPR-Cas system was found in 31% of RSSC genomes present in public databases. Specifically, CRISPR-Cas types I-E and II-C were found, with I-E being the most common. The presence of the same CRISPR-Cas types in distinct Ralstonia phylotypes and species suggests the acquisition of the system by a common ancestor before Ralstonia species segregation. In addition, a Cas1 phylogeny (I-E type) showed a perfect geographical segregation of phylotypes, supporting an ancient acquisition. Ralstoniasolanacearum strains CFBP2957 and K60T were challenged with a virulent phage, and the CRISPR arrays of bacteriophage-insensitive mutants (BIMs) were analysed. No new spacer acquisition was detected in the analysed BIMs. The functionality of the CRISPR-Cas interference step was also tested in R. solanacearum CFBP2957 using a spacer-protospacer adjacent motif (PAM) delivery system, and no resistance was observed against phage phiAP1. Our results show that the CRISPR-Cas system in R. solanacearum CFBP2957 is not its primary antiviral strategy. |
| Databáze: | OpenAIRE |
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