A number of recent observations have indicated a role for abscisic acid in maintaining water balance. Treatment with ABA reduces the transpiration rate (3, 5), probably by bringing about stomatal closure (2, 4). Furthermore, water stress leads to a significant increase in ABA concentration in leaves (5, 7). On the other hand, ABA increases the rate of root exudation (6). The present communicati...

The following three models were combined to predict simultaneously photosynthesis, stomatal conductance, transpiration and leaf temperature of a rose leaf: the biochemical model of photosynthesis of Farquhar, von Caemmerer and Berry (1980, Planta 149: 78-90), the stomatal conductance model of Ball, Woodrow and Berry (In: Biggens J, ed. Progress in photosynthesis research. The Netherlands: Marti...

This work aimed to evaluate the physiological behavior and growth of jurema-preta seedlings under salinity conditions. The experiment was conducted at Forestry Nursery Academic Unit Engineering/UFCG, with plants kept in 'Leonard' pots. treatments were distributed a completely randomized design, five levels electrical conductivity (EC) nutrient solution (0.5; 2.0; 3.5; 5.0 6.5 dS m-1) four repet...

extended abstract background and objectives sugarcane (saccharum officinarum l.) is from poaceae trible and perennial native plant of asia continent warm areas. ratio fv/fm estimates the maximum quantum yield of photosystem ii. under conditions of stress fv/fm decreased, this decreasing is due to low activity of reaction of photosynthesis centers and reducing of proteins that are responsible fo...

Leaf abscisic acid concentration ([ABA]) during growth influences morpho-physiological traits associated with the plant's ability to cope with stress. A dose-response curve between [ABA] during growth and the leaf's ability to regulate water loss during desiccation or rehydrate upon re-watering was obtained. Rosa hybrida plants were grown at two relative air humidities (RHs, 60% or 90%) under d...

When sprayed on plant leaves, several compounds, notably phenylmercuric acetate (PMA), can induce stomatal closure (16, 17). Most of these investigations with PMA were carried out on detached leaves with petioles dipping in water; it was found that the stomatal closing markedly reduced transpiration, whereas photosynthesis was reduced to a lesser extent. In these experiments it was demonstrated...

Rapid changes in the transpiration rate from a leaf or leafy shoot as a result of excision of that leaf or shoot have been observed in many plants bv many investigators (1, 2, 5, 7, 10, 11, 12, 13, 16). In banana plants, both photosynthesis and transpiration have been found to change rapidly following excision of the leaf (7). The mechanism underlying such rapid changes in transpiration has bee...