Constitutive activation of a CC-NB-LRR protein alters morphogenesis through the cytokinin pathway in Arabidopsis.
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.
Igari
Kadunari
K
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0192, Japan.
Endo
Sachiko
S
Hibara
Ken-ichiro
K
Aida
Mitsuhiro
M
Sakakibara
Hitoshi
H
Kawasaki
Tsutomu
T
Tasaka
Masao
M
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
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