PathoPlant TU-Logo
Reference RF000169
General Information
Acc No RF000169
Journal EMBO J
Authors Ouaked F, Rozhon W, Lecourieux D, Hirt H.
Title A MAPK pathway mediates ethylene signaling in plants.
Volume 22
Issue 6
Page 1282-8
Year 2003
Abstract Ethylene signal transduction involves ETR1, a two-component histidine protein kinase receptor. ETR1 functions upstream of the negative regulator CTR1. The similarity of CTR1 to members of the Raf family of mitogen-activated protein kinase kinase kinases (MAPKKKs) suggested that ethylene signaling in plants involves a MAPK pathway, but no direct evidence for this has been provided. Here we show that distinct MAPKs are activated by the ethylene precursor aminocyclopropane-1-carboxylic acid (ACC) in Medicago and ARABIDOPSIS: In Medicago, the ACC-activated MAPKs were SIMK and MMK3, while in Arabidopsis MPK6 and another MAPK were identified. Medicago SIMKK specifically mediated ACC-induced activation of SIMK and MMK3. Transgenic Arabidopsis plants overexpressing SIMKK have constitutive MPK6 activation and ethylene-induced target gene expression. SIMKK overexpressor lines resemble ctr1 mutants in showing a triple response phenotype in the absence of ACC. Whereas MPK6 was not activated by ACC in etr1 mutants, ein2 and ein3 mutants showed normal activation profiles. In contrast, ctr1 mutants showed constitutive activation of MPK6. These data indicate that a MAPK cascade is part of the ethylene signal transduction pathway in plants.
PMID 12628921
Corresp Author Hirt H
Corresp Email
Creation Sep 17 2003 10:07:52:810AM
Creator lb
Last Update Sep 17 2003 11:01:12:000AM
Last Updater lb
Database  Link 
PubMed  12628921

    printer-friendly version