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Reactive oxygen species in signalling the transcriptional activation of WIPK expression in tobacco
Author(s) -
XU JUAN,
YANG KWANGYEOL,
YOO SEUNG JIN,
LIU YIDONG,
REN DONGTAO,
ZHANG SHUQUN
Publication year - 2014
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12271
Subject(s) - biology , nadph oxidase , reactive oxygen species , microbiology and biotechnology , gene expression , chloroplast , regulation of gene expression , signal transduction , hypersensitive response , protein kinase a , kinase , biochemistry , gene , plant disease resistance
Plant mitogen‐activated protein kinases represented by tobacco WIPK (wounding‐induced protein kinase) and its orthologs in other species are unique in their regulation at transcriptional level in response to stress and pathogen infection. We previously demonstrated that transcriptional activation of WIPK is essential for induced WIPK activity, and activation of salicylic acid‐induced protein kinase ( SIPK ) by the constitutively active N t MEK 2 DD is sufficient to induce WIPK gene expression. Here, we report that the effect of SIPK on WIPK gene expression is mediated by reactive oxygen species ( ROS ). Using a combination of pharmacological and gain‐of‐function transgenic approaches, we studied the relationship among SIPK activation, WIPK gene activation in response to fungal cryptogein, light‐dependent ROS generation in chloroplasts, and ROS generated via NADPH oxidase. In the conditional gain‐of‐function GVG‐NtMEK2 DD transgenic tobacco, induction of WIPK expression is dependent on the ROS generation in chloroplasts. Consistently, methyl viologen, an inducer of ROS generation in chloroplasts, highly activated WIPK expression. In addition to chloroplast‐originated ROS , H 2 O 2 generated from the cell‐surface NADPH oxidase could also activate WIPK gene expression, and inhibition of cryptogein‐induced ROS generation also abolished WIPK gene activation. Our data demonstrate that WIPK gene activation is mediated by ROS , which provides a mechanism by which ROS influence cellular signalling processes in plant stress/defence response.