High-resolution transcriptomic analyses of Sinorhizobium sp. NGR234 bacteroids in determinate nodules of Vigna unguiculata and indeterminate nodules of Leucaena leucocephala

PLoS One. 2013 Aug 2;8(8):e70531. doi: 10.1371/journal.pone.0070531. Print 2013.

Abstract

The rhizobium-legume symbiosis is a model system for studying mutualistic interactions between bacteria and eukaryotes. Sinorhizobium sp. NGR234 is distinguished by its ability to form either indeterminate nodules or determinate nodules with diverse legumes. Here, we presented a high-resolution RNA-seq transcriptomic analysis of NGR234 bacteroids in indeterminate nodules of Leucaena leucocephala and determinate nodules of Vigna unguiculata. In contrast to exponentially growing free-living bacteria, non-growing bacteroids from both legumes recruited several common cellular functions such as cbb3 oxidase, thiamine biosynthesis, nitrate reduction pathway (NO-producing), succinate metabolism, PHB (poly-3-hydroxybutyrate) biosynthesis and phosphate/phosphonate transporters. However, different transcription profiles between bacteroids from two legumes were also uncovered for genes involved in the biosynthesis of exopolysaccharides, lipopolysaccharides, T3SS (type three secretion system) and effector proteins, cytochrome bd ubiquinol oxidase, PQQ (pyrroloquinoline quinone), cytochrome c550, pseudoazurin, biotin, phasins and glycolate oxidase, and in the metabolism of glutamate and phenylalanine. Noteworthy were the distinct expression patterns of genes encoding phasins, which are thought to be involved in regulating the surface/volume ratio of PHB granules. These patterns are in good agreement with the observed granule size difference between bacteroids from L. leucocephala and V. unguiculata.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers / metabolism*
  • Fabaceae / genetics*
  • Fabaceae / metabolism
  • Fabaceae / microbiology*
  • Gene Expression Profiling
  • Gene Expression Regulation, Bacterial*
  • Genes, Bacterial / genetics*
  • High-Throughput Nucleotide Sequencing*
  • Oligonucleotide Array Sequence Analysis
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sinorhizobium / genetics*
  • Sinorhizobium / growth & development
  • Symbiosis

Substances

  • Biomarkers
  • RNA, Messenger

Grants and funding

This study was funded by National Natural Science Foundation of China (31200002), National Natural Science Foundation of China (31170002), and Innovative Project of State Key Laboratory of Agrobiotechnology (SKLAB) Grant (2012SKLAB01-9). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.