ARR1, a transcription factor for genes immediately responsive to cytokinins.
Cytokinins are a class of phytohormones involved in various physiological events of plants. The Arabidopsis sensor histidine kinase CRE1 was recently reported to be a cytokinin receptor. We used a steroid-inducible system to show that the transcription factor-type response regulator ARR1 directs transcriptional activation of the ARR6 gene, which responds to cytokinins without de novo protein synthesis. This fact, together with characteristics of ARR1-overexpressing plants and arr1 mutant plants, indicates that the phosphorelay to ARR1, probably from CRE1, constitutes an intracellular signal transduction occurring immediately after cytokinin perception.
Sakai
H
H
Laboratory of Molecular Biology, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
Honma
T
T
Aoyama
T
T
Sato
S
S
Kato
T
T
Tabata
S
S
Oka
A
A
D000225:Adenine / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins; D001593:Benzyl Compounds; D015152:Blotting, Northern; D002455:Cell Division / Q000187:drug effects; D003513:Cycloheximide / Q000494:pharmacology; D003583:Cytokinins / Q000378:metabolism* / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007701:Kinetin; D010641:Phenotype; D010940:Plant Proteins / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011687:Purines; D011956:Receptors, Cell Surface / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
C117138:ARR1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D001593:Benzyl Compounds; D003583:Cytokinins; D004268:DNA-Binding Proteins; D010940:Plant Proteins; D011500:Protein Synthesis Inhibitors; D011687:Purines; D011956:Receptors, Cell Surface; D014157:Transcription Factors; D003907:Dexamethasone; D003513:Cycloheximide; D011494:Protein Kinases; C421783:WOL protein, Arabidopsis; D000225:Adenine; C480551:benzylaminopurine; D007701:Kinetin