AHK5 histidine kinase regulates root elongation through an ETR1-dependent abscisic acid and ethylene signaling pathway in Arabidopsis thaliana.
The Arabidopsis thaliana genome encodes a small family of histidine (His) protein kinases, some of which have redundant functions as ethylene receptors, whereas others serve as cytokinin receptors. The most poorly characterized of these is authentic histidine kinase 5 (AHK5; also known as cytokinin-independent 2, CKI2). Here we characterize three independent ahk5 mutants, and show that they have a common phenotype. Our results suggest that AHK5 His-kinase acts as a negative regulator in the signaling pathway in which ethylene and ABA inhibit the root elongation through ETR1 (an ethylene receptor).
Iwama
Ayako
A
Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Furocho, Chikusa-ku, Nagoya, Japan.
Yamashino
Takafumi
T
Tanaka
Yasushi
Y
Sakakibara
Hitoshi
H
Kakimoto
Tatsuo
T
Sato
Shusei
S
Kato
Tomohiko
T
Tabata
Satoshi
S
Nagatani
Akira
A
Mizuno
Takeshi
T
D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D005030:Ethylenes / Q000378:metabolism*; D000071677:Histidine Kinase; D018517:Plant Roots / Q000254:growth & development*; D011494:Protein Kinases / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction
D005030:Ethylenes; D000040:Abscisic Acid; C036216:ethylene; D011494:Protein Kinases; D000071677:Histidine Kinase