Constitutive activation of a CC-NB-LRR protein alters morphogenesis through the cytokinin pathway in Arabidopsis

Plant J. 2008 Jul;55(1):14-27. doi: 10.1111/j.1365-313X.2008.03466.x.


Possible links between plant defense responses and morphogenesis have been postulated, but their molecular nature remains unknown. Here, we introduce the Arabidopsis semi-dominant mutant uni-1D with morphological defects. UNI encodes a coiled-coil nucleotide-binding leucine-rich-repeat protein that belongs to the disease resistance (R) protein family involved in pathogen recognition. The uni-1D mutation causes the constitutive activation of the protein, which is stabilized by the RAR1 function in a similar way as in other R proteins. The uni-1D mutation induces the upregulation of the Pathogenesis-related gene via the accumulation of salicylic acid, and evokes some of the morphological defects through the accumulation of cytokinin. The rin4 knock-down mutation, which causes the constitutive activation of two R proteins, RPS2 and RPM1, induces an upregulation of cytokinin-responsive genes and morphological defects similar to the uni-1D mutation, indicating that the constitutive activation of some R proteins alters morphogenesis through the cytokinin pathway. From these data, we propose that the modification of the cytokinin pathway might be involved in some R protein-mediated responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cytokinins / metabolism*
  • Gene Expression Regulation, Plant*
  • Genes, Plant
  • Immunity, Innate
  • Intracellular Signaling Peptides and Proteins
  • Leucine-Rich Repeat Proteins
  • Molecular Sequence Data
  • Morphogenesis*
  • Mutation
  • Proteins / metabolism
  • Salicylic Acid / metabolism
  • Signal Transduction
  • Up-Regulation


  • Arabidopsis Proteins
  • Carrier Proteins
  • Cytokinins
  • Intracellular Signaling Peptides and Proteins
  • Leucine-Rich Repeat Proteins
  • Proteins
  • RIN4 protein, Arabidopsis
  • RPM1 protein, Arabidopsis
  • RPS2 protein, Arabidopsis
  • Salicylic Acid