Die stomatäre Transpiration und die Physiologie der Spaltöffnungen

Stålfelt, M. G.

doi:10.1007/978-3-642-94678-3_22

Cited by 38 publications

(15 citation statements)

References 110 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…St'alfelt's hypothesis of "hydroactive" responses in the stomata (36,37) would imply that the water potential in the leaf controls the osmotic pressures in all epidermal cells, including the guard cells. The experimental results reported in this paper, however, do not indicate the functioning of such a "hydroactive" mechanism in maize under the conditions described.…”

Section: Discussionmentioning

confidence: 99%

“…A reduction of the water potential in the xylem will, therefore, also cause a reduction of the turgor in the epidermal cells and thereby ease the pressure exerted by the epidermis on the guard cells of the stomata. Stailfelt called this effect the "hydropassive" response of the stomata (36,37), and von Mohl recognized as early as 1856 that an "antagonism" exists between the guard cells and the epidermal cells (27).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Stomatal Responses to Pressure Changes and Interruptions in the Water Supply of Detached Leaves of Zea mays L.

Raschke¹

1970

Plant Physiol.

151

View full text Add to dashboard Cite

Stomata of Zea mays L. respond to changes in hydrostatic pressure in the water supply of the leaves almost instantaneously and in all leaf parts simultaneously. Therefore, the leaf is a hydraulic unit. The stomata are part of it and their aperture is controlled by the water potential in the water-conducting system. Stomatal aperture is not uniquely related to the relative water content of a leaf. The relation depends also on the humidity in the air and is different for the upper and the lower epidermis.Stomata respond to changes in the chemical potential of water in the water supply system of a leaf, and one component of this potential is the tension produced by transpiration in the water conduits of the plant. This was concluded from experiments with isolated leaf sections of maize which were exposed to C02-free air and subjected to changes in atmospheric humidity and water supply (33). Changes of the water potential in the supply system of a leaf produce two opposing effects on the stomata.One of these effects is direct. It makes the water potential in the guard cells follow the potential changes in the water conduits and causes the stomata to close upon a reduction of the water potential. The second effect is indirect and is due to pressure changes in the epidermis and possibly also the mesophyll (36). It leads to transient stomatal responses in a direction opposite to the direct effect; i.e., a decrease in water potential in the supply system of a leaf produces a temporary opening, and an increase in water supply causes a temporary closure. This indirect effect is caused by the fact that all leaf tissues, including the epidermis, respond to changes in water supply to the leaf. A reduction of the water potential in the xylem will, therefore, also cause a reduction of the turgor in the epidermal cells and thereby ease the pressure exerted by the epidermis on the guard cells of the stomata. Stailfelt called this effect the "hydropassive" response of the stomata (36, 37), and von Mohl recognized as early as 1856 that an "antagonism" exists between the guard cells and the epidermal cells (27).If stomatal aperture is controlled by the water potential in the xylem, it should be possible to cause two-phased stomatal responses not only by the addition of osmotica to the water supply of the leaves but also by a sudden variation of the hydrostatic pressure in the liquid. Changes in hydrostatic pressure can easily be produced by directly applying pressure to the water into which detached leaves are dipping. Since the interest is in stomatal regulation of water loss, this pressure will have to be negative. Pressure changes can also be produced indirectly by allowing the transpiration stream to develop a potential drop along the flow resistances in the leaf. Still larger negative pressure will occur in the xylem if the water supply to the leaf is completely interrupted and tension is determined by the radii of the capillaries into which the air-water interfaces retreat.Stomatal activity follows a pronounced gradie...

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Stomatal Responses to Pressure Changes and Interruptions in the Water Supply of Detached Leaves of Zea mays L.

Raschke¹

1970

Plant Physiol.

151

View full text Add to dashboard Cite

show abstract

“…Plant cuticles are biological polymer membranes of heterogeneous composition (12). Their transport properties are of great biological and practical importance and interest, as is evident from an extensive literature dealing with cuticular transpiration (21), leaching, uptake of nutrients, growth regulators, herbicides, fungicides, and insecticides applied to the foliage (9).…”

mentioning

confidence: 99%

Plant Cuticles Are Polyelectrolytes with Isoelectric Points around Three

1977

View full text Add to dashboard Cite

The isoelectric points of isolated cutides from Citrus aurantium L. Transport properties of membranes depend strongly on the nature and density of charges fixed to the membrane matrix (6,11). Plant cuticles are biological polymer membranes of heterogeneous composition (12). Their transport properties are of great biological and practical importance and interest, as is evident from an extensive literature dealing with cuticular transpiration (21), leaching, uptake of nutrients, growth regulators, herbicides, fungicides, and insecticides applied to the foliage (9).Early indirect evidence suggested that cuticles may function as weak acid ion exchangers. Sorption of organic ions such as dyes, 2,4-D, and naphthaleneacetic acid was found to be pH-dependent; sorption of anions decreased while sorption of cations increased with increasing pH (2,5,14,16). When sorption of anionic and cationic dyes was plotted against pH, the curves had a point of inflection between pH 2.8 and 3.2 (2), which was believed to represent the pK of the cuticle. Further, surfaces of intact leaves selectively bound divalent over monovalent ions (10). From studies concerning the effect of pH on cuticular transpiration, Hartel (4) properties of isolated tomato fruit cuticular membranes directly and quantitatively. Three dissociable groups in the pH ranges 3 to 6 (0.2 meq g-'), 6 to 9 (0.3 meq g-'), and 9 to 12 (0.55 meq g-') were observed. The first two groups were tentatively identified as -COOH groups and the third as phenolic -OH group. The cuticles contained 0.65% (w/w) nitrogen, and above pH 9 more OH-ions were consumed in titration than Ca2+ bound, indicating titration of some basic groups, possibly -NH3+. Cuticles of apple fruits had previously been shown to contain small amounts of protein (8).Thus, there is some evidence that cuticles are bipolar polyelectrolytes, but quantitative data are lacking. In this paper, we present quantitative data on the isoelectric point, on permselectivity of cuticles to ions, and on the amounts of positive and negative charges fixed to the matrix of various isolated cuticles. (18); (c) immersion at room temperature in a solution of ZnC12 in concentrated HCI (1 g in 1.7 ml) (7). Cellular debris still adhering to the cuticles after isolation was removed with a jet of water, exchangeable cations were removed by agitating the cuticles at room temperature in 1 N HCI for 10 to 20 min (three changes) followed by washing with deionized H20 to remove sorbed HCI. Cuticular waxes were removed from a portion of the pear and Citrus leaf cuticular membranes by successive extraction at room temperature with methanol (three changes), 1 part methanol and 1 part chloroform (three changes), and chloroform (five changes) for 10 min each. All cuticular membranes were air-dried and stored until used. In the following, the method of isolation (enz., oxalate, ZnCl2/HCI) and the removal of waxes (-wax) will be stated after the name of the species from which the cuticle was isolated. MATERIALS AND METHODSMembrane Potential...

show abstract

“…The results obtained in investigations concerning the effect of temperature on stomatal opening differ widely as appears from a review on this subject presented by STALFELT (1956). The results seem to depend on both the type of crop used and the range in temperature applied.…”

Section: Effect Of Leaf Temperaturementioning

confidence: 73%

“…The aperture of the stomata is under conditions of optimum water supply determined by light intensity (STALFELT, 1956;KUIPER, 1961). This light sensitive reaction seems to be related essentially to photosynthesis.…”

Section: Effect Of Light Intensitymentioning

confidence: 99%

An Analysis of Actual Evapotranspiration

Rijtema¹

1965

Soil Science Soc of Amer J

View full text Add to dashboard Cite

Die stomatäre Transpiration und die Physiologie der Spaltöffnungen

Cited by 38 publications

References 110 publications

Stomatal Responses to Pressure Changes and Interruptions in the Water Supply of Detached Leaves of Zea mays L.

Stomatal Responses to Pressure Changes and Interruptions in the Water Supply of Detached Leaves of Zea mays L.

Plant Cuticles Are Polyelectrolytes with Isoelectric Points around Three

An Analysis of Actual Evapotranspiration

Contact Info

Product

Resources

About