Artigos científicos, teses e dissertações
Publicados nas melhores instituições de ensino

Young barley seedlings were stressed using nutrient solutions containing NaCl or polyethylene glycol and measurements were made of leaf growth, water potential, osmotic potential and turgor values of both growing (basal) and nongrowing (blade) tissues. Rapid growth responses simi...

Concurrent measurements of abaxial and adaxial stomatal resistance and leaf-water potentials of snap beans (Phaseolus vulgaris L.) in the field and growth chamber show that the stomata on the 2 surfaces of the leaflet react differently to water deficit. The stomata on the abaxial...

The effect of water potential on the growth of two strains of Thiobacillus ferroxidans was determined by adding defined amounts of sodium chloride or glycerol to the culture medium. The two strains differed slightly, and the most tolerant strain had a minimum water potential for ...

Photosynthesis was studied in sunflower plants subjected to 1 to 2 days of desiccation and then permitted to recover. The leaf water potential to which leaves returned after rewatering was dependent on the severity of desiccation and the evaporative conditions. Under moderately e...

Water potential was monitored at nine locations along single maize (Zea mays L.) leaf blades with aluminum block in situ thermocouple hygrometers. Water potential showed a continuous decrease toward the tip, with a 2- to 4-bar difference between leaf base and tip under both moist...

Gradients in water potential form the driving force for the movement of water for cell enlargement. In stems, they are oriented radially around the vascular system but should also be present along the stem. To test this possibility, growth, water potential, osmotic potential, and...

Soybean (Glycine max) was grown with root systems divided between adjacent cartons containing nutrient solution or soil. By adding polyethylene glycol (Carbowax 6000) to reduce solute potential or withholding water to reduce soil matric potential until water absorption from that ...

A relationship between abscisic acid concentration and leaf water status is reported. Water potentials were measured in leaves of Ambrosia artemisiifolia L. and Ambrosia trifida L. throughout a period of dehydration of intact plants. Tissues from the same leaves were analyzed for...

Cell enlargement depends on a growth-induced difference in water potential to move water into the cells. Water deficits decrease this potential difference and inhibit growth. To investigate whether the decrease causes the growth inhibition, pressure was applied to the roots of so...

Earlier reports that the water potential of sliced leaf tissue is higher than that of unsliced control tissue are confirmed. The effect is shown to increase as damage to the tissue due to slicing is increased. However, there is some evidence that increase in damage beyond a certa...

The pressure probe, which is routinely used to measure the turgor potential (Ψp) of individual epidermal cells in Tradescantia virginiana (L.), has also been used to sample small volumes of vacuolar fluid from these same cells (as low as 0.02 nl) for measurement of cellular solut...

Corn (Zea mays L.) and sorghum (Sorghum vulgare, Pers.) plants were grown in a vermiculite-gravel mixture in controlled environment chambers until they were 40 days old. Water was withheld until they were severely wilted, and they were then rewatered. During drying and after rewa...

An equation is derived from transport theory to relate local growth rate to local water potential in an expanding tissue. For a noncompartmented continuum model, the relative elemental growth rate (L) equals the divergence of the tensor product of hydraulic conductivity (K̰) and ...

With the goal of identifying molecular components of the low-water-potential response, we have carried out a two-part selection and screening strategy to identify new Arabidopsis mutants. Using a system of polyethylene glycol-infused agar plates to impose a constant low-water-pot...

Concurrent measurements of evaporation, leaf conductance, irradiance, leaf water potential, and osmotic potential of maize (Zea mays L. cv. Pa602A) in soil at either high or low soil water potential were compared at several hours on two consecutive days in July. Hourly evaporatio...

Individual groups of peach (Prunus persica [L.] Batsch) seedlings stressed to −17, −26 and −36 bars recovered to control levels within 1, 3, and 4 days, respectively. Stomatal resistance was significantly correlated with both leaf water potential and net photosynthesis. In seedli...

Malate efflux from leaf cells of the Crassulacean acid metabolism plant Kalanchoë daigremontiana Hamet et Perrier was studied using leaf slices submerged in experimental solutions. Leaves were harvested at the end of the dark phase and therefore contained high malate levels. Wate...

Numerous studies have associated increased stomatal resistance with response to water deficit in cereals. However, consideration of change in leaf form seems to have been neglected. The response of adaxial and abaxial stomatal resistance and leaf rolling in rice to decreasing lea...

The objective of this study was to compare the gas exchange, photosynthetic capacity and water potential of sugarcane genotypes cultivated under water deficit conditions imposed during the initial growth phase. Experiments were performed in a greenhouse using two sugarcane genoty...

Ultrastructural changes were correlated with leaf water potential, relative water content, and abscisic acid levels in the leaf. Mesophyll cells were more prone to damage than bundle sheath cells at a leaf water potential of -18.5 bars. Tonoplast breakdown and cell disruption occ...

When transpiration is negligible, water potentials in growing tissues are less than those in mature tissues and have been predicted to form gradients that move water into the enlarging cells. To determine directly whether the gradients exist, we measured water potentials along th...