Stomata are the most important valves by which plants can regulate transpiration in an otherwise physically determined process. Stomatal aperture is referred to as "conductance" in analogy to Ohms law. Stomata respond to the physiological activity of leaves measured as photosynthesis. Stomata determine the maximum conductance which is related to the specific leaf area for different types of plants.
Stomata respond to root signals, during drought (abscisic acid, ABA) and also under favourable conditions of water and nutrition (cytokinin, CK). Stomata respond to conditions within the leaf, particularly C02 within the mesophyll, which in turn depends on photosynthesis and on the water status of the epidermis. Stomata respond to environmental factors, particularly light, temperature and atmospheric humidity.
Was this article helpful?