Query (optional)   in Class  All Allele Author Colleague Collection Assembly Gene Gene Class Gene Product Germplasm Image Journal Keyword Library Locus Map Map Data Marker Pathology Polymorphism Probe Protein QTL Rearrangement Reference Sequence Species Trait Trait Study Two Point Data  

---

GrainGenes Reference Report: PCP-35-743

[Submit comment/correction]

Reference	PCP-35-743
Title	Abscisic acid-induced membrane potential changes in barley aleurone protoplasts: a possible relevance for the regulation of rab gene expression
Journal	Plant and Cell Physiology
Year	1994
Volume	35
Pages	743-750
Author	Heimovaara-Dijkstra S Duijn B Libbenga K Heidekamp F Wang M
Abstract	The effect of ABA on the membrane potential of barley (Hordeum vulgare cv Himalaya) aleurone protoplasts was studied by measuring the distribution of the lipophilic cation tetraphenylphosphonium (TPP+) The resting membrane potential (Em) according to our measurements with TPP+ is about -53 mV and is in agreement with membrane potential values as measured with intracellular microelectrodes (about -55 mV). The TPP+-measurements could demonstrate a clear dependence of the resting Em on the internal pH (pHe). Stimulation of the protoplasts with ABA induced a transient hyperpolarization of the membrane to -62 mV as measured with TPP+. The hyperpolarization was ABA-concentration dependent. Inhibition of the H+-ATPases with the specific proton pump inhibitors diethylstilbestrol (DES) or Micanozole effectively prevented hyperpolarization. This indicates that the hyperpolarization is consistent with the activation of plasma membrane H+-ATPases. The K+-inward rectifier inhibitor BaCl2 was able to prolong the hyperpolarization. This result suggests that the hyperpolarization causes the opening of K+-channels. The ABA-induced proton-pump activation may be involved in ABA-induced gene-expression, as DES was able to inhibit this gene expression. BaCl2 did only show a slight inhibitory effect on ABA-induced gene-expression.
Keyword	[ Hide all but 1 of 11 ] abscisic acid aleurone-layer cell-membranes enzyme activity gene expression genetic regulation hordeum vulgare ion-uptake membrane-potential protoplast regulation

GrainGenes is a product of the Agricultural Research Service of the US Department of Agriculture.