Abscisic acid plasmalemma perception triggers a calcium influx essential for RAB18 gene expression in Arabidopsis thaliana suspension cells.
Pretreatment of Arabidopsis thaliana suspension cells with impermeant calcium chelator EGTA inhibited the ABA-induced RAB18 gene expression. However, extracellular calcium alone, up to 10 mM, did not trigger RAB18 expression. Spectrofluorimetric extracellular Ca(2+) measurement with Fluo-3 showed a fast, within 1 min, Ca(2+) influx associated with outer plasmalemma ABA perception. In the presence of the Ca(2+) blockers Cd(2+) and Ni(2+), RAB18 expression was suppressed. Pimozide and fluspirilene inhibited Ca(2+) influx and ABA-induced RAB18 expression. Thus we demonstrated the involvement of specific Ca(2+) influx in the ABA signaling sequence leading to RAB18 expression.
Ghelis
T
T
Physiologie Cellulaire et Moléculaire des Plantes, UMR CNRS 7632, case 156, Université Pierre et Marie Curie (Paris VI), 4 place Jussieu, 75252 Cedex 05, Paris, France.
Dellis
O
O
Jeannette
E
E
Bardat
F
F
Miginiac
E
E
Sotta
B
B
D000040:Abscisic Acid / Q000494:pharmacology*; D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects* / Q000235:genetics; D029681:Arabidopsis Proteins; D001692:Biological Transport / Q000187:drug effects; D015152:Blotting, Northern; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D010940:Plant Proteins / Q000235:genetics*; D018749:RNA, Plant / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D020691:rab GTP-Binding Proteins
D029681:Arabidopsis Proteins; D010940:Plant Proteins; D018749:RNA, Plant; C078703:rab18 protein, Arabidopsis; D000040:Abscisic Acid; D020691:rab GTP-Binding Proteins; D002118:Calcium