Plasma membrane depolarization induced by abscisic acid in Arabidopsis suspension cells involves reduction of proton pumping in addition to anion channel activation, which are both Ca2+ dependent
Plasma membrane depolarization induced by abscisic acid in Arabidopsis suspension cells involves reduction of proton pumping in addition to anion channel activation, which are both Ca2+ dependent
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DOI：
10.1104/pp.104.039255
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发表时间：
2004-05-01
期刊：
影响因子：
7.4
通讯作者：
Rona, JP
中科院分区：
文献类型：
--
作者：
Brault, M;Amiar, Z;Rona, JP
在拟南芥悬浮细胞中，脱落酸（阿坝）可引起质膜快速去极化。阴离子通道的激活被证明是导致ABA诱导的质膜去极化的一个组成部分。采用联合电压钳位，连续测量细胞外pH值的实验，我们研究了质膜H+-ATP酶是否也可以参与去极化。我们发现，阿坝同时引起细胞去极化和介质碱化，当在H存在下加入阿坝时，第二种效应被消除。泵抑制剂。因此，阿坝对质子泵的抑制是导致质膜去极化的第二个因素。因此，ABA诱导的去极化是两个不同过程的结果：阴离子通道的激活和H+-ATP酶的抑制。这两个过程是独立的，因为削弱一个不抑制去极化。然而，这两个过程都依赖于阿坝诱导的[Ca ~（2+）]（cyt）的增加，因为[Ca ~（2+）]（cyt）的增加增强了阴离子通道，损害了H-ATP酶。
In Arabidopsis suspension cells a rapid plasma membrane depolarization is triggered by abscisic acid (ABA). Activation of anion channels was shown to be a component leading to this ABA-induced plasma membrane depolarization. Using experiments employing combined voltage clamping, continuous measurement of extracellular pH, we examined whether plasma membrane H+-ATPases could also be involved in the depolarization. We found that ABA causes simultaneously cell depolarization and medium alkalinization, the second effect being abolished when ABA is added in the presence of H. Pump inhibitors. Inhibition of the proton pump by ABA is thus a second component leading to the plasma membrane depolarization. The ABA-induced depolarization is therefore the result of two different processes: activation of anion channels and inhibition of H+-ATPases. These two processes are independent because impairing one did not suppress the depolarization. Both processes are however dependent on the [Ca2+](cyt) increase induced by ABA since increase in [Ca2+](cyt) enhanced anion channels and impaired H-ATPases.