caa a22 4500 463160770 CHVBK 20180406164747.0 cr unu---uuuuu 170326e20070601xx s 000 0 eng 10.1007/s10535-007-0057-1 doi (NATIONALLICENCE)springer-10.1007/s10535-007-0057-1 Cousson A. Laboratoire des Echanges Membranaires et Signalisation, UMR 6191 CNRS-CEA-AIX-Marseille II, F-13108, Saint-Paul-lez-Durance, Cedex, France aut Two calcium mobilizing pathways implicated within abscisic acid-induced stomatal closing in Arabidopsis thaliana [Elektronische Daten] [A. Cousson] The present study investigated whether, depending on the abscisic acid (ABA) concentration, phospholipase C (PLC) would be implicated within a Ca2+ mobilizing pathway that would regulate stomatal aperture under standard watering conditions. Among Al sensitive mutants the als1-1 mutant of Arabidopsis thaliana (L.) Heynh. (Columbia-4 ecotype) was selected for a pharmacological approach of stomatal closing in leaf epidermal peels induced by 3, 20 or 30 µM ABA. Comparison with the wild type (WT) revealed that, exclusively in the als1-1 mutant, the stomatal response to 3 or 20 µM ABA was inhibited by about 40 %, whereas the stomatal response to 30 µM ABA and the wilting response to drought were unaffected. In WT, the Ca2+ buffer EGTA and the PLC inhibitor, 1-[6-[[17β-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U73122), specifically inhibited by about 70 and 40 %, respectively, the response to 3 or 20 µM ABA, while the Ca2+ buffer 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA) inhibited by about 70 % the response to 3, 20 or 30 µM ABA. EGTA, BAPTA and U73122 did not inhibit the part of the response to 3 or 20 µM ABA that was unaffected by the als1-1 mutation. Together, these results showed that ABA closes the stomata through two different Ca2+ mobilizing pathways. Since PLC could be indirectly deactivated in the als1-1 mutant, these results might suggest that, under sufficient water supply, PLC-mediated Ca2+ mobilization is needed for the regulation of stomatal aperture by endogenous ABA resting at concentrations below a drought-specific threshold value. Institute of Experimental Botany, ASCR, 2007 ABA concentration nationallicence als1 -1 mutation nationallicence drought nationallicence phospholipase C nationallicence ABA : abscisic acid nationallicence alr : Al resistant nationallicence als : Al sensitive nationallicence BAPTA : 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid nationallicence DAG : diacylglycerol nationallicence GP Ant-2 : pGlu-Gln-D-Trp-Phe-D-Trp-D-Trp-Met-NH2 nationallicence G protein : GTP-binding protein nationallicence IP3 : inositol triphosphate nationallicence PI : phosphoinositide nationallicence PLC : phospholipase C nationallicence 7TMS : seven-transmembrane-span nationallicence U73122 : 1-[6-[[17β-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione nationallicence U73343 : 1-[6-[[17β-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-2,5-pyrrolidine-dione nationallicence WT : wild type nationallicence Biologia Plantarum Kluwer Academic Publishers-Consultants Bureau 51/2(2007-06-01), 285-291 0006-3134 51:2<285 2007 51 10535 https://doi.org/10.1007/s10535-007-0057-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10535-007-0057-1 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Cousson A. Laboratoire des Echanges Membranaires et Signalisation, UMR 6191 CNRS-CEA-AIX-Marseille II, F-13108, Saint-Paul-lez-Durance, Cedex, France aut NATIONALLICENCE 773 0- Biologia Plantarum Kluwer Academic Publishers-Consultants Bureau 51/2(2007-06-01), 285-291 0006-3134 51:2<285 2007 51 10535 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer