Stomata provide temporal control over the diffusion of essential gases

The photobiology of stomatal movements

Zeiger E. (1994)

Eduardo Zeiger, Department of Biology, University of California at Los Angeles – Los Angeles – USA

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In : Photomorphogenesis in Plants (eds R.E. Kendrick & G.H.M.
Kronenberg), 683–706. Kluwer Academic Publishers, Dordrecht – https://doi.org/10.1007/978-94-011-1884-2_24 –

https://link.springer.com/chapter/10.1007/978-94-011-1884-2_24#citeas

Abstract

Stomata, from the Greek for mouth, are pores in the epidermis of aerial organs of plants. In the broadest sense, stomata are to leaves what membranes are to cells; that is, they help maintain a closed organization of the organ while allowing a selective interchange between the plant and its environment. Stomata are a crucial adaptation to terrestrial habitats. Plants living in dry land have developed an impermeable cuticle that helps prevent excessive water loss. This cuticle, however, is also impermeable to carbon dioxide (CO₂), which is required for photosynthesis. In the absence of differential permeability to water and CO₂, stomata provide temporal control over the diffusion of these essential gases. The stomata open at times of high photosynthetic activity and abundant water and close when water is limiting or photosynthesis is not occurring, such as at night.