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Systems dynamic modeling of a guard cell Cl- channel mutant uncovers an emergent homeostatic network regulating stomatal transpiration.
- Source :
-
Plant physiology [Plant Physiol] 2012 Dec; Vol. 160 (4), pp. 1956-67. Date of Electronic Publication: 2012 Oct 22. - Publication Year :
- 2012
-
Abstract
- Stomata account for much of the 70% of global water usage associated with agriculture and have a profound impact on the water and carbon cycles of the world. Stomata have long been modeled mathematically, but until now, no systems analysis of a plant cell has yielded detail sufficient to guide phenotypic and mutational analysis. Here, we demonstrate the predictive power of a systems dynamic model in Arabidopsis (Arabidopsis thaliana) to explain the paradoxical suppression of channels that facilitate K(+) uptake, slowing stomatal opening, by mutation of the SLAC1 anion channel, which mediates solute loss for closure. The model showed how anion accumulation in the mutant suppressed the H(+) load on the cytosol and promoted Ca(2+) influx to elevate cytosolic pH (pH(i)) and free cytosolic Ca(2+) concentration ([Ca(2+)](i)), in turn regulating the K(+) channels. We have confirmed these predictions, measuring pH(i) and [Ca(2+)](i) in vivo, and report that experimental manipulation of pH(i) and [Ca(2+)](i) is sufficient to recover K(+) channel activities and accelerate stomatal opening in the slac1 mutant. Thus, we uncover a previously unrecognized signaling network that ameliorates the effects of the slac1 mutant on transpiration by regulating the K(+) channels. Additionally, these findings underscore the importance of H(+)-coupled anion transport for pH(i) homeostasis.
- Subjects :
- Arabidopsis genetics
Arabidopsis physiology
Arabidopsis radiation effects
Calcium metabolism
Cell Membrane metabolism
Cell Membrane radiation effects
Chloride Channels genetics
Gene Expression Regulation, Plant radiation effects
Hydrogen-Ion Concentration
Ion Channel Gating radiation effects
Light
Plant Stomata genetics
Plant Stomata radiation effects
Plant Transpiration genetics
Plant Transpiration radiation effects
Potassium Channels metabolism
RNA, Messenger genetics
RNA, Messenger metabolism
Reproducibility of Results
Signal Transduction genetics
Signal Transduction radiation effects
Systems Biology
Transcription, Genetic radiation effects
Arabidopsis Proteins genetics
Homeostasis radiation effects
Membrane Proteins genetics
Models, Biological
Mutation genetics
Plant Stomata cytology
Plant Stomata physiology
Plant Transpiration physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1532-2548
- Volume :
- 160
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Plant physiology
- Publication Type :
- Academic Journal
- Accession number :
- 23090586
- Full Text :
- https://doi.org/10.1104/pp.112.207704