The mystery of the evolution of stomata


The mystery of the evolution of stomata – Success of vascular plants through stomata

VIDEO:Duration: 56 mins 29 secs


The Gatsby Plant Science Summer School Lecture Collection

University of Cambridge

Prof Alistair Hetherington – Stomata: key elements essential for the success of the vascular plants. Prof Alistair Hetherington, University of Bristol, shares his research on stomata, and explains why fundamental research is important to tackling the world’s biggest problems. This research lecture was recorded at the Gatsby Summer School, 2015.



Evolution, structure and functioning of stomata.



The evolution, structure and functioning of stomata.

by Willmer C. M. (1993)

in Bot. J. Scotl. 46. 433-445. – DOI: 10.1080/03746609308684805 –


The anatomy and ultrastructure of guard cells from a range of species varying from the primitive types, such as mosses, to the advanced grasses and orchids are described.

An attempt is made to trace the lines along which stomata developed and to define what might be considered advanced stomata.

Additionally, the differentiation of guard cells from guard mother cells is discussed.

Of particular note is the preprophase band of microtubules which marks the zone where the future cell wall will form and the movement of the spindle and developing cell plate through 45 degrees. The structure and function of guard cells are intimately linked.

Stomata are turgor regulated valves; the osmotica for absorbing water during opening are K+, Cl and malate anions which accumulate in the guard cell vacuoles.

Upon stomatal closure, K+ and Cl exit from the guard cells while at least some of the carbon from malate is channelled into starch and there is a resultant loss of guard cell turgor.

The Calvin cycle may be absent or of low activity in guard cell chloroplasts and under those circumstances a source of carbon and energy to sustain the guard cells is needed. Hence it is believed that sucrose is transported into the guard cells from mesophyll cells.

A brief consideration of the mechanism by which the ions are transported across the plasma membrane and tonoplast is made: the driving force for the K+, Cl and malate movement across the membranes is the proton motive force set up by proton-pumping ATPases.

Stomatal cells as idioblasts (in German)

Photo credit: Google

Scutellaria altissima (Tall skullcap)


Stomata-zellen als Idioblasten

by Weber F. (1955)

Friedl Weber, Pflanzenphysiologischen Institut der Universität Graz, Österreich

in Österr. bot. Z. 102: 436-443 –


Den Schließzellen des Spaltöffnungsapparates als Idioblasten, Sonderlinge, der Epidermis fehlen bei verschiedenen Pflanzen eine Reihe von Inhaltskörpern, die in den anderen Epidermiszellen vorkommen.

Ein neues Beispiel für diese Regel bildet das Auftreten langer stab-, nadel-, oder spindelförmiger Inhaltskörper in den gewöhnlichen Oberhautzellen der Blattunterseite von Scutellaria altissima und das Fehlen dieser Körper in den Schließzellen dieser Pflanze. Diese Gebilde haben eine Ähnlichkeit mit den Eiweißspindeln der Kakteen, doch ist die Eiweißnatur der Scutellaria-Spindeln noch fraglich.

Die Schließzellen machen in der Regel die in anderen Blattzellen vorsichgehende Umwandlung der Chloroplasten in Chromoplasten nicht mit. Eine Ausnahme von dieser Regel bilden die Stomazellen von Selaginella helvetica, in denen sich in der kalten Jahreszeit die Chloroplasten in Chromoplasten umwandeln, ebenso wie in den übrigen Epidermiszellen.

No Ca-oxalate crystals in stomata (in German)

Photo credit: Google

A Vanilla planifolia flower. [Taken by Michael Doss.]


Kalziumoxalatkristalle fehlen den Schliesszellen

by Weber F. (1955)

Friedl Weber, Pflanzcnphysiologischen Institut der Universität GrazÖsterreich

in Protoplasma 44: 464-468 –


Die Schließzellen der Stomata enthalten auch dann keine Kalziumoxalatkristalle, wenn die übrigen Epidermiszellen solche Kristalle regelmäßig aufweisen.

Als Beispiel für diese Regel wird die Oberhaut von Blatt und Stengel von Vanilla planifolia angeführt. Es wird erörtert, wodurch das Fehlen der Kalziumoxalatkristalle in den Schließzellen bedingt sein könnte.

Effectiveness of change in upper and lower stomatal openings



Relative effectiveness of change in upper and lower stomatal openings

by Waggoner P. E. (1965)

Paul E. Waggoner, Connecticut Agricultural Experiment Station

in Crop Sci. 5: 291 – Shot 2017-09-16 at 13.50.58


Stomatal types classification



A classification of the stomatal types

by Van Cotthem W. R. J. (1970)

University of Ghent, Belgium

Willem Van Cotthem
Willem Van Cotthem, Ghent University, Belgium

in Bot. J. Linn. Soc. 63: 235-246. –


In 1950 Metcalfe & Chalk showed the need for new technical terms ‘devoid of taxonomic or ontogenetic implications’ to replace those of Vesque.Their new terms and some others, proposed by Metcalfe and Stace, are now generally used. All previous classifications of stomatal types included only those of Angiosperms and Gymnosperms.

The eight new forms described in this and a previous paper (Van Cotthem, 1968) include five known only from the Filices and bring the number of known stomatal types to 15, of which two have been subdivided.