RNA sequencing analysis of the broad-host-range strain Sinorhizobium fredii NGR234 identifies a large set of genes linked to quorum sensing-dependent regulation in the background of a traI and ngrI deletion mutant.
- Link:
- Autor/in:
- Erscheinungsjahr:
- 2014
- Medientyp:
- Text
- Schlagworte:
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- Bacterial Secretion Systems/genetics
- Flagella/genetics
- Gene Expression Profiling
- Gene Regulatory Networks
- Host Specificity
- Ligases/genetics
- Metabolic Networks and Pathways/genetics
- Quorum Sensing
- Sequence Analysis, RNA
- Sequence Deletion
- Sinorhizobium fredii/genetics
- Beschreibung:
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The alphaproteobacterium Sinorhizobium fredii NGR234 has an exceptionally wide host range, as it forms nitrogen-fixing nodules with more legumes than any other known microsymbiont. Within its 6.9-Mbp genome, it encodes two N-acyl-homoserine-lactone synthase genes (i.e., traI and ngrI) involved in the biosynthesis of two distinct autoinducer I-type molecules. Here, we report on the construction of an NGR234-ΔtraI and an NGR234-ΔngrI mutant and their genome-wide transcriptome analysis. A high-resolution RNA sequencing (RNA-seq) analysis of early-stationary-phase cultures in the NGR234-ΔtraI background suggested that up to 316 genes were differentially expressed in the NGR234-ΔtraI mutant versus the parent strain. Similarly, in the background of NGR234-ΔngrI 466 differentially regulated genes were identified. Accordingly, a common set of 186 genes was regulated by the TraI/R and NgrI/R regulon. Coregulated genes included 42 flagellar biosynthesis genes and 22 genes linked to exopolysaccharide (EPS) biosynthesis. Among the genes and open reading frames (ORFs) that were differentially regulated in NGR234-ΔtraI were those linked to replication of the pNGR234a symbiotic plasmid and cytochrome c oxidases. Biotin and pyrroloquinoline quinone biosynthesis genes were differentially expressed in the NGR234-ΔngrI mutant as well as the entire cluster of 21 genes linked to assembly of the NGR234 type III secretion system (T3SS-II). Further, we also discovered that genes responsible for rhizopine catabolism in NGR234 were strongly repressed in the presence of high levels of N-acyl-homoserine-lactones. Together with nodulation assays, the RNA-seq-based findings suggested that quorum sensing (QS)-dependent gene regulation appears to be of higher relevance during nonsymbiotic growth rather than for life within root nodules.
- Lizenz:
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- info:eu-repo/semantics/openAccess
- Quellsystem:
- Forschungsinformationssystem der UHH
Interne Metadaten
- Quelldatensatz
- oai:www.edit.fis.uni-hamburg.de:publications/d5a2b229-2c7e-41eb-bcd0-085ab0f88a93