title: PYR/PYL/RCAR abscisic acid receptors regulate K+ and Cl- channels through reactive oxygen species-mediated activation of Ca2+ channels at the plasma membrane of intact Arabidopsis guard cells.
abstract: The discovery of the START family of abscisic acid (ABA) receptors places these proteins at the front of a protein kinase/phosphatase signal cascade that promotes stomatal closure. The connection of these receptors to Ca(2+) signals evoked by ABA has proven more difficult to resolve, although it has been implicated by studies of the pyrbactin-insensitive pyr1/pyl1/pyl2/pyl4 quadruple mutant. One difficulty is that flux through plasma membrane Ca(2+) channels and Ca(2+) release from endomembrane stores coordinately elevate cytosolic free Ca(2+) concentration ([Ca(2+)]i) in guard cells, and both processes are facilitated by ABA. Here, we describe a method for recording Ca(2+) channels at the plasma membrane of intact guard cells of Arabidopsis (Arabidopsis thaliana). We have used this method to resolve the loss of ABA-evoked Ca(2+) channel activity at the plasma membrane in the pyr1/pyl1/pyl2/pyl4 mutant and show the consequent suppression of [Ca(2+)]i increases in vivo. The basal activity of Ca(2+) channels was not affected in the mutant; raising the concentration of Ca(2+) outside was sufficient to promote Ca(2+) entry, to inactivate current carried by inward-rectifying K(+) channels and to activate current carried by the anion channels, both of which are sensitive to [Ca(2+)]i elevations. However, the ABA-dependent increase in reactive oxygen species (ROS) was impaired. Adding the ROS hydrogen peroxide was sufficient to activate the Ca(2+) channels and trigger stomatal closure in the mutant. These results offer direct evidence of PYR/PYL/RCAR receptor coupling to the activation by ABA of plasma membrane Ca(2+) channels through ROS, thus affecting [Ca(2+)]i and its regulation of stomatal closure.
authors.affiliation: Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors.forename: Yizhou
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhong-Hua
authors.initials: ZH
authors.lastname: Chen
authors.forename: Ben
authors.initials: B
authors.lastname: Zhang
authors.forename: Adrian
authors.initials: A
authors.lastname: Hills
authors.forename: Michael R
authors.initials: MR
authors.lastname: Blatt
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism* / Q000494:pharmacology; D000838:Anions / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D015220:Calcium Channels / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D018118:Chloride Channels / Q000378:metabolism; D015640:Ion Channel Gating / Q000187:drug effects; D007473:Ion Channels / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D054046:Plant Stomata / Q000166:cytology*; D015221:Potassium Channels / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*
chemical_list: D000838:Anions; D029681:Arabidopsis Proteins; D015220:Calcium Channels; D018118:Chloride Channels; D007473:Ion Channels; D015221:Potassium Channels; D017382:Reactive Oxygen Species; D011956:Receptors, Cell Surface; D000040:Abscisic Acid; D002118:Calcium
references.citation: Mol Plant. 2008 Mar;1(2):347-58
references.pmid: 19825544
references.citation: Plant J. 2010 Mar;61(5):816-25
references.pmid: 20015065
references.citation: J Exp Bot. 2004 Jan;55(395):205-12
references.pmid: 14673026
references.citation: Antioxid Redox Signal. 2006 Mar-Apr;8(3-4):243-70
references.pmid: 16677071
references.citation: Plant Physiol. 2012 Jul;159(3):1026-42
references.pmid: 22635116
references.citation: Nature. 2001 Jun 28;411(6841):1053-7
references.pmid: 11429606
references.citation: Proc Natl Acad Sci U S A. 2000 Apr 25;97(9):4967-72
references.pmid: 10781106
references.citation: EMBO J. 1990 Dec;9(12):3889-92
references.pmid: 1701140
references.citation: Plant J. 2010 Jan;61(2):290-9
references.pmid: 19874541
references.citation: J Gen Physiol. 1992 Apr;99(4):615-44
references.pmid: 1534573
references.citation: Plant Physiol. 2012 Jul;159(3):1235-51
references.pmid: 22635112
references.citation: Plant Physiol. 2012 Dec;160(4):1956-67
references.pmid: 23090586
references.citation: Proc Natl Acad Sci U S A. 1995 Oct 10;92(21):9520-4
references.pmid: 7568166
references.citation: Proc Natl Acad Sci U S A. 2009 Oct 13;106(41):17588-93
references.pmid: 19805022
references.citation: Plant J. 2002 Oct;32(2):185-94
references.pmid: 12383084
references.citation: Science. 2009 May 22;324(5930):1068-71
references.pmid: 19407142
references.citation: Plant Physiol. 2007 Jan;143(1):28-37
references.pmid: 17142476
references.citation: Plant J. 2012 Jan;69(2):241-51
references.pmid: 21914010
references.citation: Plant Cell. 2001 Nov;13(11):2513-23
references.pmid: 11701885
references.citation: Plant Cell. 1996 Dec;8(12):2359-2368
references.pmid: 12239380
references.citation: J Membr Biol. 1983;72(3):223-34
references.pmid: 6222189
references.citation: PLoS Biol. 2006 Oct;4(10):e327
references.pmid: 17032064
references.citation: Plant J. 1997 Jul;12(1):203-13
references.pmid: 9263461
references.citation: Plant J. 2005 Aug;43(4):520-9
references.pmid: 16098106
references.citation: Plant Cell. 1997 Mar;9(3):409-23
references.pmid: 9090884
references.citation: Proc Natl Acad Sci U S A. 2003 Sep 16;100(19):11116-21
references.pmid: 12949257
references.citation: Nature. 2000 Aug 17;406(6797):731-4
references.pmid: 10963598
references.citation: Plant Physiol. 2002 Jan;128(1):13-6
references.pmid: 11788747
references.citation: Proc Natl Acad Sci U S A. 1998 Dec 22;95(26):15837-42
references.pmid: 9861057
references.citation: Biophys J. 1991 Nov;60(5):1156-63
references.pmid: 1722116
references.citation: Planta. 1997;202(1):18-27
references.pmid: 9177048
references.citation: J Membr Biol. 1992 Feb;126(1):1-18
references.pmid: 1534380
references.citation: Biochem J. 2009 Dec 10;424(3):439-48
references.pmid: 19785574
references.citation: Annu Rev Cell Dev Biol. 2000;16:221-41
references.pmid: 11031236
references.citation: Plant Cell. 1999 Sep;11(9):1785-98
references.pmid: 10488243
references.citation: J Biol Chem. 2009 Aug 7;284(32):21288-95
references.pmid: 19509299
references.citation: Plant J. 2003 Jul;35(1):116-28
references.pmid: 12834407
references.citation: Proc Natl Acad Sci U S A. 2009 Dec 15;106(50):21425-30
references.pmid: 19955405
references.citation: Plant Physiol. 2006 Dec;142(4):1460-8
references.pmid: 17041030
references.citation: FEBS Lett. 2001 Feb 23;491(1-2):99-103
references.pmid: 11226428
references.citation: Proc Natl Acad Sci U S A. 1998 Apr 14;95(8):4778-83
references.pmid: 9539815
references.citation: Plant Cell. 2002 Dec;14(12):3089-99
references.pmid: 12468729
references.citation: EMBO J. 2003 Jun 2;22(11):2623-33
references.pmid: 12773379
references.citation: Nature. 1990 Aug 23;346(6286):766-9
references.pmid: 2388696
references.citation: Plant Methods. 2012 May 06;8(1):15
references.pmid: 22559714
references.citation: Annu Rev Plant Biol. 2010;61:561-91
references.pmid: 20192751
references.citation: Plant J. 2004 Feb;37(3):391-7
references.pmid: 14731259
references.citation: Trends Plant Sci. 2003 Jan;8(1):20-6
references.pmid: 12523996
references.citation: Plant Physiol. 1999 Jan;119(1):277-88
references.pmid: 9880370
references.citation: J Membr Biol. 1994 Jan;137(2):99-107
references.pmid: 8006956
references.citation: Biochem J. 2011 Oct 1;439(1):161-70
references.pmid: 21745184