Aluminum (Al)-induced decrease in leaf hydration has been associated with low gas exchange, especially stomatal conductance (gs). However, the mechanisms explaining these responses are unclear. Citrus limonia was exposed to 0 and 1480 μM Al nutrient solution for 90 days test whether gs plants is increased 9-cis-epoxycarotenoid dioxygenase (NCED) gene expression abscisic acid (ABA) biosynthesis....

Five-year-old olive plants (cvs. Frantoio and Moraiolo) grown in large pots were exposed for seven months to ambient or high atmospheric CO2 concentration ([CO2]) in free-air CO2 enrichment facility. Exposure to elevated [CO2] enhanced net photosynthesis and decreased stomatal conductance, leading to greater water use efficiency. Stomatal density also decreased in elevated [CO2], while the rati...

The effect of temperature on stomatal conductance (gs) and corresponding gas exchange parameters was studied in two tree species with contrasting leaf anatomy and ecophysiology-a broadleaf angiosperm, Populus deltoides x nigra (poplar), and a needle-leaf gymnosperm, Pinus taeda (loblolly pine). Experiments were conducted in growth chambers across a leaf temperature range of 19-48°C. Manipulatio...

We investigated how leaf hydraulic conductance (Kleaf) of loblolly pine trees is influenced by soil nitrogen amendment (N) in stands subjected to ambient or elevated CO2 concentrations (CO2 and CO2, respectively). We also examined how Kleaf varies with changes in reference leaf water potential (Yleaf-ref) and stomatal conductance (gs-ref) calculated at vapour pressure deficit, D of 1 kPa. We de...

BACKGROUND AND AIMS Rice (Oryza sativa) plants lose significant amounts of volatile NH(3) from their leaves, but it has not been shown that this is a consequence of photorespiration. Involvement of photorespiration in NH(3) emission and the role of glutamine synthetase (GS) on NH(3) recycling were investigated using two rice cultivars with different GS activities. METHODS NH(3) emission (AER)...

Silvicultural thinning usually improves the water status of remaining trees in water-limited forests. We evaluated the usefulness of a dual stable isotope approach (d 13C, d 18O) for comparing the physiological performance of remaining trees between forest stands subjected to two different thinning intensities (moderate versus heavy) in a 60-yearold Pinus halepensis Mill. plantation in semiarid...

in order to evaluate the effect of different levels of drought stress on some physiological parameters in grapevine, a potted experiment with iranian grapevine cultivars ‘sahani’, ‘bidane-sefid’ and ‘farkhii’ was conducted in summer of 2008. the experiment was performed while employing four drought stress (water potential of soil, ?s= -0.2, -0.6, -1, -1.5 mpa) treatments each in three replicati...

The role of stomata in regulating photosynthesis and transpiration, hence governing global biogeochemical cycles climate, is well-known. Less well-understood, however, the importance stomatal control to exchange other trace gases between terrestrial vegetation atmosphere. Yet these determine atmospheric composition, air quality on scales ranging from local global, seconds decades. Vegetation a ...

Experimental evidence is presented to show that the O enrichment in the leaf biomass and the mean (timeaveraged) transpiration rate are positively correlated in groundnut and rice genotypes. The relationship between oxygen isotope enrichment and stomatal conductance (gs) was determined by altering gs through ABA and subsequently using contrasting genotypes of cowpea and groundnut. The Peclet mo...