The coordination of veins and stomata during leaf acclimation to sun and shade can be facilitated by differential epidermal cell expansion so large leaves with low vein and stomatal densities grow in shade, effectively balancing liquid- and vapour-phase conductances. As the difference in vapour pressure between leaf and atmosphere (VPD) determines transpiration at any given stomatal density, we...

mungbean (vigna radiata (l.) wilczek) or green gram as a dryland grain legume is exposed to varied timings and severity of drought stress, resulting in variability in photoassimilate production. in order to evaluate some physiological responses in one mungbean cultivar to timing and severity of drought stress, a 3-replicate rcbd (randomized complete block design) field experiment was carried ou...

A combined model to simulate CO₂ and H₂O gas exchange at the leaf scale was parameterized using data obtained from in situ leaf-scale observations of diurnal and seasonal changes in CO₂ and H₂O gas exchange. The Farquhar et al.-type model of photosynthesis was parameterized by using the Bayesian approach and the Ball et al.-type stomatal conductance model was optimized using the linear least-sq...

Plant physiological adaptation to the global rise in atmospheric CO(2) concentration (CO(2)) is identified as a crucial climatic forcing. To optimize functioning under rising CO(2), plants reduce the diffusive stomatal conductance of their leaves (g(s)) dynamically by closing stomata and structurally by growing leaves with altered stomatal densities and pore sizes. The structural adaptations re...

The AP2 domain class of transcription factors is a large family of genes with various roles in plant development and adaptation but with very little functional information in plants other than Arabidopsis. Here, the characterization of an EAR motif-containing transcription factor, SlERF36, from tomato that affects stomatal density, conductance, and photosynthesis is described. Heterologous expr...

A growth regulator (G; 4-ethyl-1-hydroxy-4,8,8,10,10 pentamethyl-7,9-dioxo-2,3 dioxyabicyclo (4.4.0) decene-5) from Eucalyptus grandis (Maiden) reduced stomatal conductance and also photosynthetic capacity when fed through the transpiration stream of detached leaves. The concentration of G required for this effect was high (10(-4) molar), but the amount of G taken up (dose) was below the level ...

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...

this study was conducted to determine the effects of stomatal size and frequency on stomatal conductance, photosynthesis rate and yield, and to locate the genes controlling these traits. therefore, substitution lines series of ‘timstein’ (tim) into genetic background of ‘chinese spring’ (cs) were tested in a completely randomized block design with three replications under two normal and water s...

Soil and plant hydraulics constrain ecosystem productivity by setting physical limits to water transport and hence carbon uptake by leaves. While more negative xylem water potentials provide a larger driving force for water transport, they also cause cavitation that limits hydraulic conductivity. An optimum balance between driving force and cavitation occurs at intermediate water potentials, th...

This study determined whether the field level concentration of root zone CO2 affects transpiration rate and root water transport in soybean (Glycine max L. Merr.). In an upland field converted from a paddy field, topsoil CO2 during the cropping season rose to 8 kPa of partial pressure after rainfall, whereas O2 dropped only to a minimum of 7 kPa. An elevated root zone CO2 pressure of 6 kPa sign...