Plant adaptation to fluctuating environment and biomass production are strongly dependent on guard cell potassium channels.
PNAS. 2008-03-26; 105(13): 5271-5276
DOI: 10.1073/pnas.0709732105
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1. Proc Natl Acad Sci U S A. 2008 Apr 1;105(13):5271-6. doi:
10.1073/pnas.0709732105. Epub 2008 Mar 26.
Plant adaptation to fluctuating environment and biomass production are strongly
dependent on guard cell potassium channels.
Lebaudy A(1), Vavasseur A, Hosy E, Dreyer I, Leonhardt N, Thibaud JB, Véry AA,
Simonneau T, Sentenac H.
Author information:
(1)Biochimie et Physiologie Moléculaire des Plantes, Unité Mixte de Recherche
5004, Centre National de la Recherche Scientifique/Institut National de la
Recherche Agronomique (U.386)/Montpellier SupAgro/Université Montpellier 2,
Montpellier, France.
At least four genes encoding plasma membrane inward K+ channels (K(in) channels)
are expressed in Arabidopsis guard cells. A double mutant plant was engineered by
disruption of a major K(in) channel gene and expression of a dominant negative
channel construct. Using the patch-clamp technique revealed that this mutant was
totally deprived of guard cell K(in) channel (GCK(in)) activity, providing a
model to investigate the roles of this activity in the plant. GCK(in) activity
was found to be an essential effector of stomatal opening triggered by membrane
hyperpolarization and thereby of blue light-induced stomatal opening at dawn. It
improved stomatal reactivity to external or internal signals (light, CO2
availability, and evaporative demand). It protected stomatal function against
detrimental effects of Na+ when plants were grown in the presence of
physiological concentrations of this cation, probably by enabling guard cells to
selectively and rapidly take up K+ instead of Na+ during stomatal opening,
thereby preventing deleterious effects of Na+ on stomatal closure. It was also
shown to be a key component of the mechanisms that underlie the circadian rhythm
of stomatal opening, which is known to gate stomatal responses to extracellular
and intracellular signals. Finally, in a meteorological scenario with higher
light intensity during the first hours of the photophase, GCK(in) activity was
found to allow a strong increase (35%) in plant biomass production. Thus, a large
diversity of approaches indicates that GCK(in) activity plays pleiotropic roles
that crucially contribute to plant adaptation to fluctuating and stressing
natural environments.
DOI: 10.1073/pnas.0709732105
PMCID: PMC2278230
PMID: 18367672 [Indexed for MEDLINE]