Ghelis T, Dellis O, Jeannette E, Bardat F, Miginiac E, Sotta B
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.
FEBS Lett. 2000 Oct 13;483(1):67-70. doi: 10.1016/s0014-5793(00)02088-3.
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.
用不可渗透的钙螯合剂乙二醇双（2-氨基乙基醚）四乙酸（EGTA）预处理拟南芥悬浮细胞，可抑制脱落酸（ABA）诱导的RAB18基因表达。然而，单独的细胞外钙，浓度高达10 mM时，并不会触发RAB18表达。用Fluo-3进行的细胞外钙离子荧光光谱测量显示，与质膜外表面ABA感知相关的钙离子内流迅速，在1分钟内即可完成。在存在钙离子阻滞剂镉离子（Cd2+）和镍离子（Ni2+）的情况下，RAB18表达受到抑制。匹莫齐特和氟司必林抑制钙离子内流以及ABA诱导的RAB18表达。因此，我们证明了特定的钙离子内流参与了导致RAB18表达的ABA信号序列。
