Record Details

Regulation of WRKY46 transcription factor function by mitogen-activated protein kinases in Arabidopsis thaliana

NIPGR Digital Knowledge Repository (NDKR)

View Archive Info
 
 
Field Value
 
Title Regulation of WRKY46 transcription factor function by mitogen-activated protein kinases in Arabidopsis thaliana
 
Creator Sheikh, Arsheed H.
Eschen-Lippold, Lennart
Pecher, Pascal
Hoehenwarter, Wolfgang
Sinha, Alok Krishna
Scheel, Dierk
Lee, Justin
 
Subject WRKY transcription factors
defense
mitogen-activated protein kinase
pathogen-associated molecular patterns (PAMPs)
phosphorylation
protein stability
 
Description Accepted date: 14 January 2016
Mitogen-activated protein kinase (MAPK) cascades are central signaling pathways activated in plants after sensing internal developmental and external stress cues. Knowledge about the downstream substrate proteins of MAPKs is still limited in plants. We screened Arabidopsis WRKY transcription factors as potential targets downstream of MAPKs, and concentrated on characterizing WRKY46 as a substrate of the MAPK, MPK3. Mass spectrometry revealed in vitro phosphorylation of WRKY46 at amino acid position S168 by MPK3. However, mutagenesis studies showed that a second phosphosite, S250, can also be phosphorylated. Elicitation with pathogen-associated molecular patterns (PAMPs), such as the bacterial flagellin-derived flg22 peptide led to in vivo destabilization of WRKY46 in Arabidopsis protoplasts. Mutation of either phosphorylation site reduced the PAMP-induced degradation of WRKY46. Furthermore, the protein for the double phosphosite mutant is expressed at higher levels compared to wild-type proteins or single phosphosite mutants. In line with its nuclear localization and predicted function as a transcriptional activator, overexpression of WRKY46 in protoplasts raised basal plant defense as reflected by the increase in promoter activity of the PAMP-responsive gene, NHL10, in a MAPK-dependent manner. Thus, MAPK-mediated regulation of WRKY46 is a mechanism to control plant defense.
AS is supported by a German Academic Exchange (DAAD) fellowship (A/11/75070). Research in our laboratory is financed by the German Research Foundation through the Collaborative Research Centre SFB648/TP-B1 “Molecular mechanisms of information processing in plants.” The BMBF project ProNET-T3 (03ISO2211B) supported LE.
 
Date 2016-02-15T06:11:46Z
2016-02-15T06:11:46Z
2016
 
Type Article
 
Identifier Front. Plant Sc., 7: 61
1664-462X
http://172.16.0.77:8080/jspui/handle/123456789/623
http://journal.frontiersin.org/article/10.3389/fpls.2016.00061/full
10.3389/fpls.2016.00061
 
Language en_US
 
Publisher Frontiers Media S.A.