Stomatal aperture and the sensing of the environment by guard cells

1979 ◽  
Vol 2 (1) ◽  
pp. 15-22 ◽  
Author(s):  
D. W. SHERIFF
Keyword(s):  
Guard Cells ◽  
Stomatal Aperture

Array and distribution of actin filaments in guard cells contribute to the determination of stomatal aperture

2008 ◽  
Vol 27 (10) ◽  
pp. 1655-1665 ◽  
Author(s):  
Xin-Qi Gao ◽  
Jing Chen ◽  
Peng-Cheng Wei ◽  
Fei Ren ◽  
Jia Chen ◽  
...  
Keyword(s):  
Actin Filaments ◽  
Guard Cells ◽  
Stomatal Aperture

scholarly journals The Regulation of Stomatal Aperture in Tobacco Leaf Epidermal Strips III. The Effect of Atp

1971 ◽  
Vol 24 (3) ◽  
pp. 689 ◽  
Author(s):  
DA Thomas
Keyword(s):  
Guard Cells ◽  
Stomatal Opening ◽  
Stomatal Aperture ◽  
Osmotic Swelling ◽  
Tobacco Leaf

The addition of ATP in the light and dark and ADP in the light to bathing solutions containing K+ can stimulate stomatal opening in tobacco leaf epidermal strips. UTP or AMP do not stimulate opening in the light or dark. The presence of ouabain prevents ATP or ADP stimulating stomatal opening. The additions of Ca2+ and Mg2+, though they reduce stomatal aperture, do not prevent ATP stimulating stomatal opening. Increasing the concentration of ATP presented to the stomata in the dark increases the aperture. The rate of stomatal opening in the presence of ATP is increased in the light. In bathing solutions which contain Na+ as the only cation ATP neither initiates nor maintains stomatal opening. The results are discussed in relation to a postulated light-stimulated, ATPase-mediated accumulation ofK+ in the guard cells which is followed by an influx of water, osmotic swelling, and stomatal opening

Calcium in the xylem and its influence on the behaviour of stomata

1993 ◽  
Vol 341 (1295) ◽  
pp. 67-74 ◽  
Keyword(s):  
Calcium Ions ◽  
Stomatal Closure ◽  
Xylem Sap ◽  
Guard Cells ◽  
Stomatal Aperture ◽  
Lupinus Luteus ◽  
Major Influence ◽  
Free Calcium ◽  
Stomatal Behaviour ◽  
High Calcium

Calcium is known to play an important role in regulating guard cell turgor and the movements of stomata. The concentrations of calcium ions in xylem sap are often higher than 1 mol m -3 , which would be sufficient to influence, or interfere with, stomatal function if such concentrations were delivered to points of evaporation in the vicinity of the guard cells. This paper presents some recent experimental evidence concerning the way in which a plant’s calcium status affects the amount of free calcium in the xylem, and the effect this may have on the diurnal pattern of stomatal behaviour. Changes in the rhizospheric supply of calcium have a major influence on the concentrations in the xylem. In Commelina communis an eightfold increase in rhizospheric calcium led to an increase in the xylem sap in the shoot of approximately sixfold. Very high concentrations of xylem calcium were associated with reduced stomatal opening, and injection of a pulse of calcium ions into the xylem via a catheter caused stomatal closure. Calcium-induced suppression of stomatal aperture does not inflict permanent damage upon the guard cells, because stomatal aperture recovered quickly when the calcium concentration in the xylem was reduced. The experimental data presented suggest that the amount of calcium delivered by the transpiration stream to points of evaporation needs to be regulated if interference with stomatal behaviour is to be avoided. This regulation is likely to occur in tissues such as the mesophyll. The roots may also play an important part in controlling the delivery of calcium into the xylem and evidence is presented of malfunctioning of the regulatory mechanism in roots when plants are exposed to high calcium in the rhizosphere. Some of the data presented are for a calcifuge, Lupinus luteus , and the possibility is discussed that disturbances in stomatal behaviour contribute to the physiological problems of such plants in the presence of high rhizospheric calcium.

Potassium involvement not demonstrated in stomatal movements of Paphiopedilum. Qualified confirmation of the Nelson–Mayo report

1982 ◽  
Vol 60 (3) ◽  
pp. 240-244 ◽  
Author(s):  
William H. Outlaw Jr. ◽  
Jill Manchester ◽  
Vincent E. Zenger
Keyword(s):  
Chlorophyll A ◽  
Guard Cell ◽  
Guard Cells ◽  
Stomatal Aperture ◽  
Potassium Content ◽  
Aperture Size ◽  
Stomatal Movements ◽  
Unique Condition

Guard cells of Paphiopedilum leaves lack chlorophyll, a unique condition. Whether potassium fluxes are involved in stomatal movements is controversial. In attempting to resolve this controversy, we have dissected individual guard cell pairs from frozen-dried epidermal peels of three species. These samples were assayed for potassium using quantitative histochemical methodology. We were unable to detect a correlation between guard cell potassium content and stomatal aperture size. With certain reservations, these results indicate potassium is not the major osmoticum causing stomata of these species to open.

scholarly journals Relationship of Temperature to Stomatal Aperture and Potassium Accumulation in Guard Cells of Vicia faba

1979 ◽  
Vol 63 (2) ◽  
pp. 388-391 ◽  
Author(s):  
Cynthia A. Rogers ◽  
Robert D. Powell ◽  
Peter J. H. Sharpe
Keyword(s):  
Vicia Faba ◽  
Guard Cells ◽  
Stomatal Aperture ◽  
Potassium Accumulation ◽  
Relationship Of

scholarly journals The Regulation of Stomatal Aperture in Tobacco Leaf Epidermal Strips

1972 ◽  
Vol 25 (5) ◽  
pp. 877 ◽  
Author(s):  
DA Thomas
Keyword(s):  
Guard Cell ◽  
Cell Membranes ◽  
Guard Cells ◽  
Stomatal Opening ◽  
Stomatal Aperture ◽  
Bathing Solution ◽  
Bathing Medium ◽  
Tobacco Leaf ◽  
Phosphoenol Pyruvate

Stepwise decreases in the stomatal aperture of tobacco leaf epidermal strips followed stepwise increases in the concentration of KHCOa added to bathing solutions. Removal of KHCOa from the bathing solution resulted in a rapid increase in aperture. The reduction in aperture caused by KHCO., both in the light and dark, can be reversed by the addition of ATP or phosphoenol pyruvate to the bathing solution. The stomatal opening, supported by a NaCl bathing medium, is reduced by the addition of NaHCOa? From the results it is suggested that HCO;/C02t increases the permeability of guard cell membranes causing a net efflux of water or ions or both from the guard cells.

Role and interrelationship of PTPases and H2O2 in light/dark-regulated stomatal movement in Vicia faba

2009 ◽  
Vol 57 (6) ◽  
pp. 486 ◽  
Author(s):  
Yuanhua Zhang ◽  
Xiaoping She ◽  
Guangbin Zhang
Keyword(s):  
Vicia Faba ◽  
Laser Scanning ◽  
Stomatal Closure ◽  
Specific Inhibitor ◽  
Guard Cells ◽  
Stomatal Aperture ◽  
Stomatal Movement ◽  
Obvious Effect ◽  
Exogenous H2o2 ◽  
Ptpase Activity

Role and interrelationship of protein tyrosine phosphatases (PTPases) and H2O2 in light/dark-regulated stomatal movement in Vicia faba were investigated by epidermal strip bioassay, laser-scanning confocal microscopy and assays of PTPase activity. Our results indicate that phenylarsine oxide (PAO), a specific inhibitor of PTPases, ascorbic acid (ASA), an important reducing substrate for H2O2 removal, and catalase (CAT), one of the H2O2 scavenging enzymes, did not cause any change of stomatal aperture in light, but remarkably prevented dark-induced stomatal closure. Exogenous H2O2 had no obvious effect on stomatal aperture in the dark, but significantly induced stomatal closure in light. Both PTPase activity in epidermal strips and endogenous H2O2 level in guard cells in the dark were higher than those in light. The results showed that both PTPases and H2O2 mediate light/dark-regulated stomatal movement, that dark-induced stomatal closure requires the activation of PTPases and the enhancement of H2O2 levels in guard cells, and stomatal opening caused by light is associated with the inactivation of PTPases and the reduction of H2O2 levels in guard cells. Additionally, like ASA and CAT, PAO abolished dark-, exogenous H2O2-induced stomatal closure and dichlorofluorescein fluorescence in guard cells, indicating that activation of PTPases can enhance H2O2 levels probably via suppressing the decrease of H2O2 levels in guard cells. On the other hand, similar to PAO, ASA and CAT evidently prevented dark-, exogenous H2O2-induced stomatal closure and obviously inactivated PTPases in the dark. However, exogenous H2O2 significantly activated PTPases in light. The results show that H2O2 can induce activation of PTPases. Taken together, the present results provide evidence that both H2O2 and PTPases are involved in light/dark-regulated stomatal movement, and the interaction between H2O2 and PTPases plays a pivotal role in light/dark signal transduction process in guard cells.

Fluxes of Potassium and Changes in Malate within Epidermis of Commelina cyanea and their Relationships with Stomatal Aperture

1975 ◽  
Vol 2 (1) ◽  
pp. 85
Author(s):  
C.J Pearson
Keyword(s):  
Positive Relationship ◽  
Guard Cells ◽  
Stomatal Opening ◽  
Stomatal Aperture ◽  
Degree Of Isolation

Stomatal apertures and concentrations of potassium, malate and sugars within the epidermis were measured during stomatal opening and closure; the location of K+ was also estimated by cobaltinitrite staining. The concentration of K+ in the epidermis as a whole did not change during stomatal opening and closure, but K+ migrated between epidermal and guard cells. Concentrations of sugars also remained constant. By contrast, there was a positive relationship between concentration of malate and aperture. These and other results emphasize an appreciable degree of isolation of the epidermis.

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