Hydrogen peroxide-regulated genes in the Medicago truncatula-Sinorhizobium meliloti symbiosis

New Phytol. 2013 Apr;198(1):179-189. doi: 10.1111/nph.12120. Epub 2013 Jan 24.


Reactive oxygen species (ROS), particularly hydrogen peroxide (H(2)O(2)), play an important role in signalling in various cellular processes. The involvement of H(2)O(2) in the Medicago truncatula-Sinorhizobium meliloti symbiotic interaction raises questions about its effect on gene expression. A transcriptome analysis was performed on inoculated roots of M. truncatula in which ROS production was inhibited with diphenylene iodonium (DPI). In total, 301 genes potentially regulated by ROS content were identified 2 d after inoculation. These genes included MtSpk1, which encodes a putative protein kinase and is induced by exogenous H(2)O(2) treatment. MtSpk1 gene expression was also induced by nodulation factor treatment. MtSpk1 transcription was observed in infected root hair cells, nodule primordia and the infection zone of mature nodules. Analysis with a fluorescent protein probe specific for H(2)O(2) showed that MtSpk1 expression and H(2)O(2) were similarly distributed in the nodule infection zone. Finally, the establishment of symbiosis was impaired by MtSpk1 downregulation with an artificial micro-RNA. Several genes regulated by H(2)O(2) during the establishment of rhizobial symbiosis were identified. The involvement of MtSpk1 in the establishment of the symbiosis is proposed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gene Expression Regulation, Plant / drug effects*
  • Genes, Plant / genetics*
  • Hydrogen Peroxide / pharmacology*
  • Lipopolysaccharides / pharmacology
  • Medicago truncatula / drug effects
  • Medicago truncatula / enzymology
  • Medicago truncatula / genetics*
  • Medicago truncatula / microbiology*
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Onium Compounds / pharmacology
  • Phenotype
  • Phosphotransferases (Alcohol Group Acceptor) / genetics
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism
  • Reactive Oxygen Species / metabolism
  • Reproducibility of Results
  • Root Nodules, Plant / cytology
  • Root Nodules, Plant / drug effects
  • Root Nodules, Plant / genetics
  • Root Nodules, Plant / microbiology
  • Sinorhizobium meliloti / drug effects
  • Sinorhizobium meliloti / genetics
  • Sinorhizobium meliloti / physiology*
  • Symbiosis / drug effects
  • Symbiosis / genetics*
  • Transcription, Genetic / drug effects


  • Lipopolysaccharides
  • MicroRNAs
  • Onium Compounds
  • Reactive Oxygen Species
  • diphenyleneiodonium
  • Hydrogen Peroxide
  • Phosphotransferases (Alcohol Group Acceptor)
  • sphingosine kinase