Search results
Results from the WOW.Com Content Network
Since guard cells control water loss of plants, the investigation on how stomatal opening and closure is regulated could lead to the development of plants with improved avoidance or slowing of desiccation and better water use efficiency. [1] ABA is the trigger for the closure of the stomatal opening.
Drought inhibits stomatal opening, but research on soybeans suggests moderate drought does not have a significant effect on stomatal closure of its leaves. There are different mechanisms of stomatal closure. Low humidity stresses guard cells causing turgor loss, termed hydropassive closure.
Stomatal conductance, usually measured in mmol m −2 s −1 by a porometer, estimates the rate of gas exchange (i.e., carbon dioxide uptake) and transpiration (i.e., water loss as water vapor) through the leaf stomata as determined by the degree of stomatal aperture (and therefore the physical resistances to the movement of gases between the air and the interior of the leaf).
ABA then translocates to the leaves, where it rapidly alters the osmotic potential of stomatal guard cells, causing them to shrink and stomata to close. The ABA-induced stomatal closure reduces transpiration (evaporation of water out of the stomata), thus preventing further water loss from the leaves in times of low water availability. A close ...
Furthermore, the unstressed plants were able to send additional stress cues to other neighboring unstressed plants in order to relay the signal. A cascade effect of stomatal closure was observed in neighboring unstressed plants that shared their rooting system but was not observed in the unstressed plants that did not share their rooting system ...
Moisture stress has an effect on stomatal opening, mainly causing a closure in stomata as to reduce the amount of carbon dioxide assimilation. [4] Closing of the stomata also slows the rate of transpiration, which limits water loss and helps to prevent the wilting effects of moisture stress. [ 5 ]
Due to presence of carbon dioxide, a rapid acidification of cytoplasm takes place leading to stomatal closure. Milbarrow (1974) has described the formation of these chemicals in the chloroplast. It moves to the stomata, where it is responsible for checking the intake of Potassium ion or induces loss of potassium ion from the guard cells.
Size of stomatal aperture. The somatal pore controls the diffusion of CO 2 into the leaves to be utilized for photosynthesis. The pore is formed by two guard cells, which control the size of the pore by swelling in response to the activity of the H +-ATPase. Opening and closure of the pore is partly controlled by regulation of the H +-ATPase.