Search results
Results From The WOW.Com Content Network
Photosynthesis, plant water transport and gas exchange are regulated by stomatal function which is important in the functioning of plants. [30] Stomata are responsive to light with blue light being almost 10 times as effective as red light in causing stomatal response.
Photosynthesis depends on the diffusion of carbon dioxide (CO 2) from the air through the stomata into the mesophyll tissues. Oxygen (O 2), produced as a byproduct of photosynthesis, exits the plant via the stomata. When the stomata are open, water is lost by evaporation and must be replaced via the transpiration stream, with water taken up by ...
The plant cuticle is one of a series of innovations, together with stomata, xylem and phloem and intercellular spaces in stem and later leaf mesophyll tissue, that plants evolved more than 450 million years ago during the transition between life in water and life on land. [11]
As a consequence of these important functions, differentiation of cells to form stomata is also subject to environmental conditions to a much greater degree than other epidermal cell types. Stomata are pores in the plant epidermis that are surrounded by two guard cells, which control the opening and closing of the aperture.
When the stomata are closed at night, water pressure can build up in the plant. Excess water is excreted through pores known as hydathodes . [ 23 ] The movement of water out of the leaf stomata sets up transpiration pull or tension in the water column in the xylem vessels or tracheids.
A germination rate experiment. Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. [1]Plant physiologists study fundamental processes of plants, such as photosynthesis, respiration, plant nutrition, plant hormone functions, tropisms, nastic movements, photoperiodism, photomorphogenesis, circadian rhythms, environmental stress physiology, seed ...
In plants under water stress, ABA plays a role in closing the stomata. Soon after plants are water-stressed and the roots are deficient in water, a signal moves up to the leaves, causing the formation of ABA precursors there, which then move to the roots.
However, in woody plants, while the respiratory function of stomata is retained in the living epidermis of leaves and green stems, that function is lost where the epidermis of trunks and branches is displaced by vascular and cork cambial activity and by secondary growth.