author={Eduardo Zeiger and Sarah M. Assmann and H. Meioner},
  journal={Photochemistry and Photobiology},
Abstract— The responses of stomata from Paphiopedilum harrisianum, Orchidaceae, to light and CO2 were studied in epidermal peels. Stomatal opening under red light was indistinguishable from that in darkness, whereas blue light promoted opening above dark levels. The ineffectiveness of red light in causing stomatal opening was confirmed in the presence of 100 μM KCN; average apertures in both darkness and red light were 53% of those measured in the absence of the inhibitor, whereas under blue… 

Phytochrome and blue light-mediated stomatal opening in the orchid, paphiopedilum.

It is found that low fluence rate green and red light elicited stomatal opening in Paphiopedilum and this opening was reversed by far red light, indicating the presence of a phytochrome-mediated opening response.

Stomatal Limitation to Carbon Gain in Paphiopedilum sp. (Orchidaceae) and Its Reversal by Blue Light.

Blue light enrichment resulted in significantly higher growth rates-of up to 77%-over a 3 to 4 week growing period, with all evidence indicating that the blue light effect was a stomatal response.

Metabolic energy for stomatal opening. Roles of photophosphorylation and oxidative phosphorylation

Light-dependent stomatal opening appears to require photophosphorylation from guard-cell chloroplasts and the activation of the blue-light photosystem which could rely either on oxidative phosphorylation or a specific, membrane-bound electron-transport carrier.

Induction of CAM in Mesembryanthemum crystallinum Abolishes the Stomatal Response to Blue Light and Light-Dependent Zeaxanthin Formation in Guard Cell Chloroplasts

Light-dependent stomatal opening and the operation of the xanthophyll cycle were characterized in guard cells isolated from ice plants shifting from C3 metabolism to CAM, suggesting that inhibition of light-dependent zeaxanthin formation inguard cells might be one of the regulatory steps mediating the shift from diurnal to nocturnal stomatic opening typical of plants with CAM.

Stomatal Responses to Light and Drought Stress in Variegated Leaves of Hedera helix.

Leaf conductance was found to be more sensitive to drought stress and showed a more persistent aftereffect in the white portions of the leaves.

Absence of Variable Fluorescence from Guard Cell Chloroplasts of Stenotaphrum secundatum.

Results provide evidence that stomatal regulation in this variety of S. secundatum does not rely on photosystem II electron transport in guard cell chloroplasts, and indicate that guard cellchloroplasts in this species do not conduct normal photosystem I electron transport.

Stomatal Responses to CO(2) in Paphiopedilum and Phragmipedium: Role of the Guard Cell Chloroplast.

Investigation of the leaf gas exchange characteristics of two closely related orchids suggests involvement of guard cell chloroplasts in the stomatal response to CO(2) and in the coupling of assimilation and conductance in the intact leaf.

Effects of light quantity and quality during development on the morphology and stomatal physiology of Commelina communis

The results indicate that the specific stomatal response to blue light is plastic, and is modulated by the light environment prevailing during leaf development.

The photobiology of stomatal movements.

Stomata, from the Greek for mouth, are pores in the epidermis of aerial organs of plants that help maintain a closed organization of the organ while allowing a selective interchange between the plant and its environment.



The occurrence of functional non-chlorophyllous guard cells in Paphiopedilum spp.

Hypostomatous lady slipper orchids, Paphiopedilum spp., were found to have non-chlorophyllous epidermal cells, including guard cells. The lack of chlorophyll within the guard cells was demonstrated

Gas exchange in paphiopedilum: lack of chloroplasts in guard cells correlates with low stomatal conductance.

The genetic changes leading to the loss of chloroplast differentiation in Paphiopedilum guard cells were not deleterious because of the low conductance rates characteristic of this genus, singles them out as an exceptional biological system, exhibiting basic differences from typical stomata in higher plants.

Effect of Light Quality on Stomatal Opening in Leaves of Xanthium strumarium L.

Determination of flux response curves on leaves in the normal position or in the inverted position led to the conclusion that the photoreceptors for blue as well as for red light are located on or near the surfaces of the leaves; presumably they are in the guard cells themselves.

The Comparative Effects of Blue and Red Light on the Stomata of Allium cepa L. and Xanthium pennsylvanicum

It is concluded that blue light may promote stomatal opening by its effect on enzymes controlling the starch and soluble polysaccharide content of guard cells.

Action Spectra for Guard Cell Rb Uptake and Stomatal Opening in Vivia faba.

In the abaxial surface of leaf discs under air of normal CO(2) concentration, stomatal opening in white light approached its maximum at an intensity similar to that for epidermal strips, and at both quantum flux densities, the action spectra for opening in leaf discs were very similar to those for epidersmal strips.

Low K+ in Paphiopedilum leeanum leaf epidermis: implications for stomatal functioning

Abaxial epidermal strips from leaves of Paphiopedilum leeanum were analyzed via sodium cobaltinitrite staining and atomic absorption spectrophotometry for the presence and location of potassium, finding K content to be 103 times less than has been reported in other species and no localization of K+ in guard cells of open stomata could be detected.

Photocontrol of the Functional Coupling between Photosynthesis and Stomatal Conductance in the Intact Leaf : Blue Light and Par-Dependent Photosystems in Guard Cells.

The photocontrol of the functional coupling between photosynthesis and stomatal conductance in the leaf was investigated in gas exchange experiments using monochromatic light provided by lasers and indicates that under conditions where the PAR-dependent system is driven by high intensity red light, the blue light- dependent system has an additive effect on stomatic conductance.

Light Saturation of Stomatal Opening on the Adaxial and Abaxial Epidermis of Commelina communis

The quantum flux received by a pair of guard cells appears to be sufficient to support a direct effect of blue light on ion transport into the guard cells, but there is no evidence to suggest that blue light is essential for stomatal opening.