Abscisic acid plasmalemma perception triggers a calcium influx essential for RAB18 gene expression in Arabidopsis thaliana suspension cells

[摘要]

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 Ca²⁺ measurement with Fluo-3 showed a fast, within 1 min, Ca²⁺ influx associated with outer plasmalemma ABA perception. In the presence of the Ca²⁺ blockers Cd²⁺ and Ni²⁺, RAB18 expression was suppressed. Pimozide and fluspirilene inhibited Ca²⁺ influx and ABA-induced RAB18 expression. Thus we demonstrated the involvement of specific Ca²⁺ influx in the ABA signaling sequence leading to RAB18 expression.

[学科分类] 生物化学/生物物理

[关键词] Abscisic acid transduction;Calcium channel inhibitor;Arabidopsis thaliana suspension cells