Cell sizes are linked across multiple tissues, including stomata, and this variation is closely correlated with genome size. These associations raise the question of whether generic changes in cell size cause suboptimal changes in stomata, requiring subsequent evolution under selection for stomatal size. We tested the relationships among guard cell length, genome size and vegetation type using ...

Cyclin-dependent kinases (CDKs) are key regulators of the cell cycle. In yeasts, only one CDK is sufficient to drive cells through the cell cycle, whereas higher eukaryotes developed a family of related CDKs. Curiously, plants contain a unique class of CDKs (B-type CDKs), whose function is still unclear. We show that the CDKB1;1 gene of Arabidopsis (Arabidopsis thaliana) is highly expressed in ...

We used local microclimatic conditions and twig sap flow rates to interpret midday stomatal closure in the canopies of two 250-year-old Norway spruce (Picea abies (L.) Karst.) trees at a subalpine site in the Swiss Alps (1,650 m a.s.l.). Both trees showed midday stomatal closure on most clear summer days, despite the permanently wet soil. We used a modified Penman-Monteith formula to simulate p...

Stomatal conductance links plant water use and carbon uptake, and is a critical process for the land surface component of climate models. However, stomatal conductance schemes commonly assume that all vegetation with the same photosynthetic pathway use identical plant water use strategies whereas observations indicate otherwise. Here, we implement a new stomatal scheme derived from optimal stom...

this study was conducted to determine the effects of stomatal size and frequency on stomatal conductance, photosynthesis rate and yield, and to locate the genes controlling these traits. therefore, substitution lines series of ‘timstein’ (tim) into genetic background of ‘chinese spring’ (cs) were tested in a completely randomized block design with three replications under two normal and water s...

BACKGROUND AND AIMS The inverse relationship between the number of stomata and atmospheric CO2 levels observed in different plant species is increasingly used for reconstructions of past CO2 concentrations. To validate this relationship, the potential influence of other environmental conditions and ontogenetical development stage on stomatal densities must be investigated as well. Quantitative ...

Suboptimal N nutrition increased the water potential for stomatal closure in water stressed cotton (Gossypium hirsutum L.) leaves. This increased sensitivity to water stress had two components, increased accumulation of abscisic acid (ABA) and increased apparent stomatal sensitivity to ABA. Low N increased the threshold water potentials for stomatal closure and ABA accumulation by about 4 bars ...

The spatial distribution of plant stomata is a model system to study epidermal cell pattern formation. Molecular genetic approaches have identified several key genes required for stomatal distribution patterning, but environmental conditions that perturb the stomatal spacing distribution have not yet been identified. We found that immersing hydroponic cultures in 1-5% sucrose solution induced a...

Recent work shows that transcription factors are necessary for stomatal movements in plants. Different members of the plant-specific R2R3-MYB transcription factor family are required for mediating stomatal opening in response to light and stomatal closure in response to darkness.

In mammals, basal currents through G protein-coupled inwardly rectifying K(+) (GIRK) channels are repressed by Galpha(i/o)GDP, and the channels are activated by direct binding of free Gbetagamma subunits released upon stimulation of Galpha(i/o)-coupled receptors. However, essentially all information on G protein regulation of GIRK electrophysiology has been gained on the basis of coexpression s...