Premium
Transcription factor WRKY 46 regulates osmotic stress responses and stomatal movement independently in A rabidopsis
Author(s) -
Ding Zhong Jie,
Yan Jing Ying,
Xu Xiao Yan,
Yu Di Qiu,
Li Gui Xin,
Zhang Shu Qun,
Zheng Shao Jian
Publication year - 2014
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12538
Subject(s) - wrky protein domain , guard cell , malondialdehyde , biology , microbiology and biotechnology , abscisic acid , arabidopsis , reactive oxygen species , turgor pressure , transcription factor , osmotic shock , botany , biochemistry , oxidative stress , gene , mutant
Summary Drought and salt stress severely inhibit plant growth and development; however, the regulatory mechanisms of plants in response to these stresses are not fully understood. Here we report that the expression of a WRKY transcription factor WRKY 46 is rapidly induced by drought, salt and oxidative stresses. T– DNA insertion of WRKY 46 leads to more sensitivity to drought and salt stress, whereas overexpression of WRKY 46 ( OV 46) results in hypersensitivity in soil‐grown plants, with a higher water loss rate, but with increased tolerance on the sealed agar plates. Stomatal closing in the OV 46 line is insensitive to ABA because of a reduced accumulation of reactive oxygen species ( ROS ) in the guard cells. We further find that WRKY 46 is expressed in guard cells, where its expression is not affected by dehydration, and is involved in light‐dependent stomatal opening. Microarray analysis reveals that WRKY 46 regulates a set of genes involved in cellular osmoprotection and redox homeostasis under dehydration stress, which is confirmed by ROS and malondialdehyde ( MDA ) levels in stressed seedlings. Moreover, WRKY 46 modulates light‐dependent starch metabolism in guard cells via regulating QUA ‐ QUINE STARCH ( QQS ) gene expression. Taken together, we demonstrate that WRKY 46 plays dual roles in regulating plant responses to drought and salt stress and light‐dependent stomatal opening in guard cells.