title: NaCl-elicited, vacuolar Ca(2+) release facilitates prolonged cytosolic Ca(2+) signaling in the salt response of Populus euphratica cells.
abstract: High environmental salt elicits an increase in cytosolic Ca(2+) ([Ca(2+)]cyt) in plants, which is generated by extracellular Ca(2+) influx and Ca(2+) release from intracellular stores, such as vacuole and endoplasmic reticulum. This study aimed to determine the physiological mechanisms underlying Ca(2+) release from vacuoles and its role in ionic homeostasis in Populus euphratica. In vivo Ca(2+) imaging showed that NaCl treatment induced a rapid elevation in [Ca(2+)]cyt, which was accompanied by a subsequent release of vacuolar Ca(2+). In cell cultures, NaCl-altered intracellular Ca(2+) mobilization was abolished by antagonists of inositol (1, 4, 5) trisphosphate (IP3) and cyclic adenosine diphosphate ribose (cADPR) signaling pathways, but not by slow vacuolar (SV) channel blockers. Furthermore, the NaCl-induced vacuolar Ca(2+) release was dependent on extracellular ATP, extracellular Ca(2+) influx, H2O2, and NO. In vitro Ca(2+) flux recordings confirmed that IP3, cADPR, and Ca(2+) induced substantial Ca(2+) efflux from intact vacuoles, but this vacuolar Ca(2+) flux did not directly respond to ATP, H2O2, or NO. Moreover, the IP3/cADPR-mediated vacuolar Ca(2+) release enhanced the expression of salt-responsive genes that regulated a wide range of cellular processes required for ion homeostasis, including cytosolic K(+) maintenance, Na(+) and Cl(-) exclusion across the plasma membrane, and Na(+)/H(+) and Cl(-)/H(+) exchanges across the vacuolar membrane.
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University (Box 162), Beijing 100083, People's Republic of China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University (Box 162), Beijing 100083, People's Republic of China.
authors.forename: Zedan
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Institute of Integrative Plant Biology, School of Life Science, Jiangsu Normal University, Xuzhou 221116, Jiangsu Province, People's Republic of China. Electronic address: Sunjian@jsnu.edu.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.affiliation: Institute of Integrative Plant Biology, School of Life Science, Jiangsu Normal University, Xuzhou 221116, Jiangsu Province, People's Republic of China.
authors.forename: Yicheng
authors.initials: Y
authors.lastname: Yu
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University (Box 162), Beijing 100083, People's Republic of China.
authors.forename: Shurong
authors.initials: S
authors.lastname: Deng
authors.affiliation: Institute of Integrative Plant Biology, School of Life Science, Jiangsu Normal University, Xuzhou 221116, Jiangsu Province, People's Republic of China.
authors.forename: Zongyun
authors.initials: Z
authors.lastname: Li
authors.affiliation: Institute of Integrative Plant Biology, School of Life Science, Jiangsu Normal University, Xuzhou 221116, Jiangsu Province, People's Republic of China.
authors.forename: Cunhua
authors.initials: C
authors.lastname: Sun
authors.affiliation: Institute of Integrative Plant Biology, School of Life Science, Jiangsu Normal University, Xuzhou 221116, Jiangsu Province, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University (Box 162), Beijing 100083, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhao
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University (Box 162), Beijing 100083, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Shen
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University (Box 162), Beijing 100083, People's Republic of China. Electronic address: Lschen@bjfu.edu.cn.
authors.forename: Shaoliang
authors.initials: S
authors.lastname: Chen
mesh_terms: D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006706:Homeostasis / Q000187:drug effects / Q000502:physiology; D007425:Intracellular Membranes / Q000187:drug effects; D008954:Models, Biological; D032107:Populus / Q000166:cytology / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D012965:Sodium Chloride / Q000494:pharmacology*; D014617:Vacuoles / Q000378:metabolism*
chemical_list: D012965:Sodium Chloride; D002118:Calcium
keywords: IP(3); Ion flux; Poplar; SV channel; Salinity; Vacuolar Ca(2+) signaling; cADPR