The Effect of a Genetically Reduced Plasma Membrane Protonmotive Force on Vegetative Growth of Arabidopsis
Open Access
- 3 January 2012
- journal article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 158 (3), 1158-1171
- https://doi.org/10.1104/pp.111.189167
Abstract
The plasma membrane proton gradient is an essential feature of plant cells. In Arabidopsis (Arabidopsis thaliana), this gradient is generated by the plasma membrane proton pump encoded by a family of 11 genes (abbreviated as AHA, for Arabidopsis H+-ATPase), of which AHA1 and AHA2 are the two most predominantly expressed in seedlings and adult plants. Although double knockdown mutant plants containing T-DNA insertions in both genes are embryonic lethal, under ideal laboratory growth conditions, single knockdown mutant plants with a 50% reduction in proton pump concentration complete their life cycle without any observable growth alteration. However, when grown under conditions that induce stress on the plasma membrane protonmotive force (PMF), such as high external potassium to reduce the electrical gradient or high external pH to reduce the proton chemical gradient, aha2 mutant plants show a growth retardation compared with wild-type plants. In this report, we describe the results of studies that examine in greater detail AHA2’s specific role in maintaining the PMF during seedling growth. By comparing the wild type and aha2 mutants, we have measured the effects of a reduced PMF on root and hypocotyl growth, ATP-induced skewed root growth, and rapid cytoplasmic calcium spiking. In addition, genome-wide gene expression profiling revealed the up-regulation of potassium transporters in aha2 mutants, indicating, as predicted, a close link between the PMF and potassium uptake at the plasma membrane. Overall, this characterization of aha2 mutants provides an experimental and theoretical framework for investigating growth and signaling processes that are mediated by PMF-coupled energetics at the cell membrane.Keywords
This publication has 83 references indexed in Scilit:
- Caesium and strontium accumulation in shoots of Arabidopsis thaliana: genetic and physiological aspectsJournal of Experimental Botany, 2010
- Molecular Characterization of Mutant Arabidopsis Plants with Reduced Plasma Membrane Proton Pump ActivityJournal of Biological Chemistry, 2010
- Rapid Auxin-Induced Cell Expansion and Gene Expression: A Four-Decade-Old Question RevisitedPlant Physiology, 2010
- Touch induces ATP release in Arabidopsis roots that is modulated by the heterotrimeric G‐protein complexFEBS Letters, 2009
- Facing the challenges of Cu, Fe and Zn homeostasis in plantsNature Chemical Biology, 2009
- Expression of a Constitutively Activated Plasma Membrane H+-ATPase Alters Plant Development and Increases Salt TolerancePlant Physiology, 2007
- Constitutive activation of a plasma membrane H+-ATPase prevents abscisic acid-mediated stomatal closureThe EMBO Journal, 2007
- Arabidopsis Protein Kinase PKS5 Inhibits the Plasma Membrane H+-ATPase by Preventing Interaction with 14-3-3 ProteinPlant Cell, 2007
- Analysis of Relative Gene Expression Data Using Real-Time Quantitative PCR and the 2−ΔΔCT MethodMethods, 2001
- Transgenic plant aequorin reports the effects of touch and cold-shock and elicitors on cytoplasmic calciumNature, 1991