Jasmonic Acid-Induced VQ-Motif-Containing Protein OsVQ13 Influences the OsWRKY45 Signaling Pathway and Grain Size by Associating with OsMPK6 in Rice

Int J Mol Sci. 2019 Jun 14;20(12):2917. doi: 10.3390/ijms20122917.


Jasmonic acid (JA) is a plant hormone that plays an important role in the defense response and stable growth of rice. In this study, we investigated the role of the JA-responsive valine-glutamine (VQ)-motif-containing protein OsVQ13 in JA signaling in rice. OsVQ13 was primarily located in the nucleus and cytoplasm. The transgenic rice plants overexpressing OsVQ13 exhibited a JA-hypersensitive phenotype and increased JA-induced resistance to Xanthomonas oryzae pv. oryzae (Xoo), which is the bacteria that causes rice bacterial blight, one of the most serious diseases in rice. Furthermore, we identified a mitogen-activated protein kinase, OsMPK6, as an OsVQ13-associating protein. The expression of genes regulated by OsWRKY45, an important WRKY-type transcription factor for Xoo resistance that is known to be regulated by OsMPK6, was upregulated in OsVQ13-overexpressing rice plants. The grain size of OsVQ13-overexpressing rice plants was also larger than that of the wild type. These results indicated that OsVQ13 positively regulated JA signaling by activating the OsMPK6-OsWRKY45 signaling pathway in rice.

Keywords: MAP kinase; grain development; jasmonate; rice bacterial blight; salicylic acid.

MeSH terms

  • Cyclopentanes / metabolism*
  • Disease Resistance / genetics
  • Edible Grain / genetics
  • Edible Grain / growth & development
  • Edible Grain / metabolism
  • Mitogen-Activated Protein Kinases / metabolism*
  • Oryza / genetics*
  • Oryza / growth & development
  • Oryza / metabolism
  • Oryza / microbiology
  • Oxylipins / metabolism*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Signal Transduction*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Xanthomonas / pathogenicity


  • Cyclopentanes
  • Oxylipins
  • Plant Proteins
  • Transcription Factors
  • jasmonic acid
  • Mitogen-Activated Protein Kinases