title: Two spatially and temporally distinct Ca2+signals convey Arabidopsis thaliana responses to K+deficiency.
abstract: In plants, potassium (K+) homeostasis is tightly regulated and established against a concentration gradient to the environment. Despite the identification of Ca2+-regulated kinases as modulators of K+channels, the immediate signaling and adaptation mechanisms of plants to low-K+conditions are only partially understood. To assess the occurrence and role of Ca2+signals in Arabidopsis thaliana roots, we employed ratiometric analyses of Ca2+dynamics in plants expressing the Ca2+reporter YC3.6 in combination with patch-clamp analyses of root cells and two-electrode voltage clamp (TEVC) analyses in Xenopus laevis oocytes. K+deficiency triggers two successive and distinct Ca2+signals in roots exhibiting spatial and temporal specificity. A transient primary Ca2+signature arose within 1 min in the postmeristematic stelar tissue of the elongation zone, while a secondary Ca2+response occurred after several hours as sustained Ca2+elevation in defined tissues of the elongation and root hair differentiation zones. Patch-clamp and TEVC analyses revealed Ca2+dependence of the activation of the K+channel AKT1 by the CBL1-CIPK23 Ca2+sensor-kinase complex. Together, these findings identify a critical role of cell group-specific Ca2+signaling in low K+responses and indicate an essential and direct role of Ca2+signals for AKT1 K+channel activation in roots.
authors: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, Münster, 48149, Germany.
authors: Smrutisanjita
authors: S
authors: Behera
authors: State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing, 100193, China.
authors: Yu
authors: Y
authors: Long
authors: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, Münster, 48149, Germany.
authors: Ina
authors: I
authors: Schmitz-Thom
authors: State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing, 100193, China.
authors: Xue-Ping
authors: XP
authors: Wang
authors: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, Münster, 48149, Germany.
authors: Chunxia
authors: C
authors: Zhang
authors: State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing, 100193, China.
authors: Hong
authors: H
authors: Li
authors: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, Münster, 48149, Germany.
authors: Leonie
authors: L
authors: Steinhorst
authors: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, Münster, 48149, Germany.
authors: Prabha
authors: P
authors: Manishankar
authors: State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing, 100193, China.
authors: Xiao-Ling
authors: XL
authors: Ren
authors: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, Münster, 48149, Germany.
authors: Jan Niklas
authors: JN
authors: Offenborn
authors: State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing, 100193, China.
authors: Wei-Hua
authors: WH
authors: Wu
authors: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, Münster, 48149, Germany.|State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing, 100193, China.
authors: Jörg
authors: J
authors: Kudla
authors: State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing, 100193, China.
authors: Yi
authors: Y
authors: Wang
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000818:Animals; D017360:Arabidopsis / Q000187:drug effects / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004566:Electrodes; D015640:Ion Channel Gating / Q000187:drug effects; D007811:Lanthanum / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D018408:Patch-Clamp Techniques; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D000072417:Protein Domains; D011523:Protoplasts / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D014981:Xenopus
chemical_list: D029681:Arabidopsis Proteins; C028521:lanthanum chloride; D007811:Lanthanum; D011188:Potassium; D002118:Calcium
keywords: 
  Arabidopsis thaliana
  ; K+ channel; calcium; cameleon YC3.6; high-resolution calcium imaging; nutrient starvation; potassium; signaling