title: AtWNK9 is regulated by ABA and dehydration and is involved in drought tolerance in Arabidopsis.
abstract: WNK (with no lysine [K]) kinases play important regulatory roles in flowering, as well as salt and osmotic stress tolerance in plants. Here, we report that AtWNK9, a member of the Arabidopsis WNK gene family, was induced by exogenous abscisic acid (ABA) treatment and dehydration stress. Overexpression of AtWNK9 from the cauliflower mosaic virus 35S promoter in Arabidopsis resulted in increased sensitivity to ABA, strong inhibition of primary root elongation, increased proline accumulation, reduced stomatal aperture, and a reduced rate of water loss. In addition, plant survival under drought stress was improved compared to wild type. In contrast, a mutant with a T-DNA insertion in AtWNK9 showed reduced ABA sensitivity and an increased rate of water loss; further, it showed increased susceptibility to drought stress. The transcription of a number of ABA signaling components, including ABI1, ERA1, ABI3, and ABF3, was up-regulated in AtWNK9 transgenic plants and down-regulated in the wnk9 mutant in response to ABA. Some ABA-responsive and biosynthetic genes, as well as other drought-related genes, were altered at various levels in AtWNK9 transgenic plants and wnk9 mutants under dehydration stress. Overall, these findings suggest that AtWNK9 plays a positive role in ABA signaling and improves drought tolerance in transgenic Arabidopsis.
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China.
authors.forename: Minmin
authors.initials: M
authors.lastname: Xie
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China.
authors.forename: Guifang
authors.initials: G
authors.lastname: Duan
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China.
authors.forename: Liqun
authors.initials: L
authors.lastname: Wang
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China.
authors.forename: Reqing
authors.initials: R
authors.lastname: He
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China.
authors.forename: Xiushan
authors.initials: X
authors.lastname: Li
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China.
authors.forename: Dongying
authors.initials: D
authors.lastname: Tang
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China. Electronic address: zxy_mm@163.com.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China; State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, China. Electronic address: xmL05@hnu.edu.cn.
authors.forename: Xuanming
authors.initials: X
authors.lastname: Liu
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism* / Q000494:pharmacology; D000222:Adaptation, Physiological / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial; D055864:Droughts; D015870:Gene Expression; D017343:Genes, Plant; D016254:Mutagenesis, Insertional; D030821:Plants, Genetically Modified; D015398:Signal Transduction; D013312:Stress, Physiological / Q000235:genetics; D014867:Water
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; C036483:T-DNA; D014867:Water; D000040:Abscisic Acid
keywords: ABA; Arabidopsis; AtWNK9; Drought tolerance