title: Constitutive activation of a CC-NB-LRR protein alters morphogenesis through the cytokinin pathway in Arabidopsis.
abstract: 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.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0192, Japan.
authors.forename: Kadunari
authors.initials: K
authors.lastname: Igari
authors.forename: Sachiko
authors.initials: S
authors.lastname: Endo
authors.forename: Ken-ichiro
authors.initials: K
authors.lastname: Hibara
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Aida
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sakakibara
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Masao
authors.initials: M
authors.lastname: Tasaka
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003583:Cytokinins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007113:Immunity, Innate; D047908:Intracellular Signaling Peptides and Proteins; D000090263:Leucine-Rich Repeat Proteins; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009154:Mutation; D011506:Proteins / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D003583:Cytokinins; D047908:Intracellular Signaling Peptides and Proteins; D000090263:Leucine-Rich Repeat Proteins; D011506:Proteins; C453279:RIN4 protein, Arabidopsis; C095014:RPM1 protein, Arabidopsis; C089426:RPS2 protein, Arabidopsis; D020156:Salicylic Acid