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NADPH oxidase AtrbohD and AtrbohF genes function in ROS‐dependent ABA signaling in Arabidopsis
Author(s) -
Kwak June M.,
Mori Izumi C.,
Pei ZhenMing,
Leonhardt Nathalie,
Torres Miguel Angel,
Dangl Jeffery L.,
Bloom Rachel E.,
Bodde Sara,
Jones Jonathan D.G.,
Schroeder Julian I.
Publication year - 2003
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdg277
Subject(s) - biology , arabidopsis , gene , nadph oxidase , function (biology) , signal transduction , microbiology and biotechnology , reactive oxygen species , genetics , mutant
Reactive oxygen species (ROS) have been proposed to function as second messengers in abscisic acid (ABA) signaling in guard cells. However, the question whether ROS production is indeed required for ABA signal transduction in vivo has not yet been addressed, and the molecular mechanisms mediating ROS production during ABA signaling remain unknown. Here, we report identification of two partially redundant Arabidopsis guard cell‐expressed NADPH oxidase catalytic subunit genes, AtrbohD and AtrbohF , in which gene disruption impairs ABA signaling. atrbohD/F double mutations impair ABA‐induced stomatal closing, ABA promotion of ROS production, ABA‐induced cytosolic Ca 2+ increases and ABA‐ activation of plasma membrane Ca 2+ ‐permeable channels in guard cells. Exogenous H 2 O 2 rescues both Ca 2+ channel activation and stomatal closing in atrbohD/F . ABA inhibition of seed germination and root elongation are impaired in atrbohD/F , suggesting more general roles for ROS and NADPH oxidases in ABA signaling. These data provide direct molecular genetic and cell biological evidence that ROS are rate‐limiting second messengers in ABA signaling, and that the AtrbohD and AtrbohF NADPH oxidases function in guard cell ABA signal transduction.