Temporal water use by two maize lines differing in leaf osmotic potential

Crop Science ◽  
2020 ◽  
Vol 60 (2) ◽  
pp. 945-953 ◽  
Author(s):  
Amber L. Beseli ◽  
Avat Shekoofa ◽  
Mujahid Ali ◽  
Thomas R. Sinclair
Keyword(s):  
Water Use ◽  
Osmotic Potential ◽  
Leaf Osmotic Potential

Effect of drought stress on residual transpiration and its relationship with water use of wheat

1991 ◽  
Vol 71 (3) ◽  
pp. 695-702 ◽  
Author(s):  
J. M. Clarke ◽  
R. A. Richards ◽  
A. G. Condon
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Transpiration Rate ◽  
Osmotic Potential ◽  
Water Status ◽  
Yield Potential ◽  
Cuticular Transpiration ◽  
Stress Treatment ◽  
Use Efficiency ◽  
Residual Transpiration

Increasing the water use efficiency (WUE) of wheat (Triticum spp.) has long been a goal in semiarid areas. Low rates of residual (cuticular) transpiration are thought to improve yield potential of wheat under dry conditions, although the linkage is tenuous. The objective of this work was to investigate the association of residual transpiration with water use, WUE, and leaf water status in hexaploid (T. aestivum L.) and tetraploid (T. turgidum L. var. durum) genotypes grown under two watering regimes in two glasshouse experiments. Single plants were grown in 0.1-m × 1-m (0.1-m × 0.5-m in exp. 2 low-stress treatment) PVC tubes filled with soil. The watering regimes consisted of weekly replenishment of water used (low stress), or addition of sufficient water to ensure plant survival (high stress). At anthesis, flag leaf residual transpiration (rate of water loss from excised leaves), stomatal conductance, relative water content (RWC), and osmotic potential (exp. 1 only) were measured. Water use was not correlated with residual transpiration rate in either experiment. Residual transpiration rate did not differ for the two stress treatments in exp. 1, but there were significant (P < 0.01) genotype by stress treatment interactions. Residual transpiration rate was not related to plant water status (leaf RWC or osmotic potential) as had been reported in other studies. Key words: Cuticular transpiration, water use efficiency, Triticum aestivum L., Triticum turgidum L. var. durum

Root osmotic potential and length for two maize lines differing in leaf osmotic potential

2019 ◽  
Vol 33 (4) ◽  
pp. 429-444 ◽  
Author(s):  
Amber Beseli ◽  
Antonio J. Hall ◽  
Anju Manandhar ◽  
Thomas R. Sinclair
Keyword(s):  
Osmotic Potential ◽  
Leaf Osmotic Potential

Accumulation of Glycinebetaine in Chloroplasts Provides Osmotic Adjustment During Salt Stress

1986 ◽  
Vol 13 (5) ◽  
pp. 659 ◽  
Author(s):  
SP Robinson ◽  
GP Jones
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Salt Stress ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Spinacia Oleracea ◽  
Resonance Spectroscopy ◽  
Leaf Osmotic Potential ◽  
Cellular Compartments ◽  
Isolated Chloroplasts

Glycinebetaine was determined in leaves and in isolated chloroplasts of spinach (Spinacia oleracea) by nuclear magnetic resonance spectroscopy. Some leakage of glycinebetaine from the chloroplasts occurred during the isolation so the concentration in chloroplasts in vivo could be up to 1.5 times higher than that measured in isolated chloroplasts. It was demonstrated that any contamination of the chloroplast preparations by glycinebetaine originating from other cellular compartments or from broken chloroplasts would have amounted to less than 10% of the measured values. Leaf osmotic potential of salt-stressed plants was -2.09 MPa compared to -0.91 MPa in non-stressed controls. This was accompanied by a sixfold increase in glycinebetaine content in the leaf but the levels of choline and proline were not increased. In chloroplasts isolated from control leaves the calculated glycinebetaine concentration was 26 mM which was 10-fold higher than the concentration in the leaf as a whole but only contributed 7% of the osmotic potential of the chloroplast. Chloroplasts from salt-stressed plants contained up to 300 mM glycinebetaine which was 20 times the concentration in the leaf as a whole. The glycinebetaine concentration in chloroplasts from salt-stressed leaves was equivalent to an osmotic potential of -0.75 MPa and this contributed 36% of the osmotic potential of the chloroplast and 64% of the decrease in osmotic potential induced by salt stress. At least 30-40% of the total leaf glycinebetaine was localized in the chloroplast. The results demonstrate that glycinebetaine accumulates in chloroplasts to provide osmotic adjustment during salt stress and provide support for the hypothesis that glycinebetaine is a compatible cytoplasmic solute which may be preferentially located in the cytoplasm of cells.

scholarly journals Sugar/osmoticum levels modulate differential abscisic acid-independent expression of two stress-responsive sucrose synthase genes in Arabidopsis

1999 ◽  
Vol 344 (2) ◽  
pp. 503-509 ◽  
Author(s):  
Annabelle DÉJARDIN ◽  
Lubomir N. SOKOLOV ◽  
Leszek A. KLECZKOWSKI
Keyword(s):  
Signal Transduction ◽  
Abscisic Acid ◽  
Cold Stress ◽  
Osmotic Potential ◽  
Sucrose Synthase ◽  
Cellular Response ◽  
Expression Profiles ◽  
Soluble Sugars ◽  
Leaf Osmotic Potential ◽  
Detached Leaves

Sucrose synthase (Sus) is a key enzyme of sucrose metabolism. Two Sus-encoding genes (Sus1 and Sus2) from Arabidopsis thaliana were found to be profoundly and differentially regulated in leaves exposed to environmental stresses (cold stress, drought or O2 deficiency). Transcript levels of Sus1 increased on exposure to cold and drought, whereas Sus2 mRNA was induced specifically by O2 deficiency. Both cold and drought exposures induced the accumulation of soluble sugars and caused a decrease in leaf osmotic potential, whereas O2 deficiency was characterized by a nearly complete depletion in sugars. Feeding abscisic acid (ABA) to detached leaves or subjecting Arabidopsis ABA-deficient mutants to cold stress conditions had no effect on the expression profiles of Sus1 or Sus2, whereas feeding metabolizable sugars (sucrose or glucose) or non-metabolizable osmotica [poly(ethylene glycol), sorbitol or mannitol] mimicked the effects of osmotic stress on Sus1 expression in detached leaves. By using various sucrose/mannitol solutions, we demonstrated that Sus1 was up-regulated by a decrease in leaf osmotic potential rather than an increase in sucrose concentration itself. We suggest that Sus1 expression is regulated via an ABA-independent signal transduction pathway that is related to the perception of a decrease in leaf osmotic potential during stresses. In contrast, the expression of Sus2 was independent of sugar/osmoticum effects, suggesting the involvement of a signal transduction mechanism distinct from that regulating Sus1 expression. The differential stress-responsive regulation of Sus genes in leaves might represent part of a general cellular response to the allocation of carbohydrates during acclimation processes.

Osmotic Adjustment in Expanding and Fully Expanded Leaves of Sunflower in Response to Water Deficits

1980 ◽  
Vol 7 (2) ◽  
pp. 181 ◽  
Author(s):  
MM Jones ◽  
NC Turner
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Leaf Water ◽  
Similar Degree ◽  
Tissue Water ◽  
Predawn Leaf Water Potential ◽  
Leaf Osmotic Potential ◽  
Osmotic Potentials

Sunflower plants were grown in large volumes of soil and slowly water-stressed by withholding water. The tissue water relationships of leaves at various stages of stress and of leaves of equivalent well watered controls were studied by the pressure chamber technique. Plants were stressed either when leaf 17 was expanding or when it was fully expanded. When expanding leaves reached a moderate level of stress (predawn leaf water potential of -0.9 MPa), the osmotic potentials at full turgor and zero turgor were lower than the control values by 0.1 MPa and 0.2 MPa, respectively. When fully expanded leaves were stressed to a similar degree (predawn leaf water potential of - 1.1 MPa), the osmotic potentials at full turgor and zero turgor were lower than the control values by 0.2 MPa and 0.3 MPa, respectively. The development of more severe stress in the fully expanded leaves was not accompanied by any further osmotic adjustment. However, when the expanding leaves reached a predawn leaf water potential of -2.3 MPa, the values of leaf osmotic potential at full turgor and zero turgor were lower than the values for the well watered plants by 0.4 MPa and 0.6 MPa, respectively. In expanding leaves prestressed to a predawn leaf water potential of -2.3 MPa, the osmotic potential at full turgor was significantly less than the control values for at least 7 days after rewatering. Stress had no effect on the bulk modulus of elasticity. It is concluded that both expanding and fully expanded sunflower leaves show osmotic adjustment.

scholarly journals The Influence of Deficit Irrigation on Growth, Ornamental Quality, and Water Use Efficiency of Three Potted Bougainvillea Genotypes Grown in Two Shapes

HortScience ◽  
2014 ◽  
Vol 49 (10) ◽  
pp. 1284-1291 ◽  
Author(s):  
Chiara Cirillo ◽  
Youssef Rouphael ◽  
Rosanna Caputo ◽  
Giampaolo Raimondi ◽  
Stefania De Pascale
Keyword(s):  
Water Stress ◽  
Water Use Efficiency ◽  
Water Use ◽  
Deficit Irrigation ◽  
Water Productivity ◽  
Plant Production ◽  
Irrigation Level ◽  
Leaf Osmotic Potential ◽  
Dry Biomass ◽  
Use Efficiency

Bougainvillea is widely used as flowering shrub in gardening and landscaping in the Mediterranean region characterized by limited water supply. The evaluation of deficit irrigation as a possible technique to improve water productivity and selection of genotypes that can better withstand soil water deficits are essential for sustainable production. A greenhouse experiment was conducted to determine the effects of deficit irrigation on three potted Bougainvillea genotypes [B. glabra var. Sanderiana, B. ×buttiana ‘Rosenka’, B. ‘Lindleyana’ (=B. ‘Aurantiaca’)] grown in two shapes, globe and pyramid, on agronomical and physiological parameters. Irrigation treatments were based on the daily water use (100%, 50%, or 25%). The shoot, total dry biomass, leaf number, leaf area, and macronutrient [nitrogen (N), phosphorus (P), and potassium (K)] concentration decreased in response to an increase in water stress with the lowest values recorded in the severe deficit irrigation (SDI) treatment. At 160 days after transplanting (DAT), the percentage of total dry biomass reduction caused by irrigation level was lower in B. ×buttiana ‘Rosenka’ compared with B. glabra var. Sanderiana and B. ‘Lindleyana’ (=B. ‘Aurantiaca’). At 160 DAT, the flower index increased in response to an increase in water stress with the highest values recorded under both moderate deficit irrigation (MDI) and SDI for B. ×buttiana ‘Rosenka’. The biomass water use efficiency (WUE) increased under water stress conditions with the highest values recorded in B. glabra var. Sanderiana and B. ×buttiana ‘Rosenka’ grown under MDI (average 1.43 and 1.25 g·L−1, respectively) and especially with SDI (average 1.68 and 1.36 g·L−1, respectively). A number of tolerance mechanisms such as increase in stomatal resistance, decrease in leaf water potential, and decrease in leaf osmotic potential have been observed, especially under SDI. The MDI treatment can be used successfully in Bougainvillea to reduce water consumption while improving the overall quality and WUE, whereas the genotypes B. glabra var. Sanderiana and B. ×buttiana ‘Rosenka’ could be considered suitable for pot plant production.

scholarly journals Variation among Red and Freeman Maples in Response to Drought and Flooding

HortScience ◽  
1999 ◽  
Vol 34 (4) ◽  
pp. 664-668 ◽  
Author(s):  
James A. Zwack ◽  
William R. Graves ◽  
Alden M. Townsend
Keyword(s):  
Stomatal Conductance ◽  
Osmotic Potential ◽  
Root Zone ◽  
Acer Rubrum ◽  
Weight Ratio ◽  
Control Treatment ◽  
Leaf Osmotic Potential ◽  
Leaf Surface Area ◽  
Shoot Weight ◽  
As Stress

Freeman maples (Ace×freemanii E. Murray) are marketed as stress-resistant alternatives to red maples (Acer rubrum L.). Our objective was to compare two cultivars of Freeman maple [`Jeffersred' (Autumn Blaze®) and `Indian Summer'] and five red maples [`Franksred' (Red Sunset®), `Autumn Flame', `PNI 0268' (October Glory®), `Fairview Flame', and unnamed selection 59904] for effects of flooding and water deficit on plant growth, biomass partitioning, stomatal conductance, and leaf osmotic potential. Plants grown from rooted cuttings in containers were subjected to three consecutive cycles during which root-zone water content decreased to 0.12, 0.08, and 0.02 m3·m–3, respectively. Additional plants were flooded for 75 days, while plants in a control treatment were irrigated frequently. Stomatal conductance immediately before imposing drought and after three drought cycles did not differ among genotypes and averaged 220 and 26 mmol·s–1·m–2, respectively. Differences in stomatal conductance after recovery from the first drought cycle and at the end of the second drought cycle did not vary with species. Drought reduced estimated leaf osmotic potential similarly for all genotypes; means for drought-stressed and control plants were –1.92 and –1.16 MPa, respectively. Freeman maples had a higher mean root: shoot weight ratio and a lower leaf surface area: root dryweight ratio than did red maples. Across genotypes, stomatal conductance of flooded plants initially increased by ≈20% and then fell to and remained below 50 mmol·s–1·m–2. Stomatal conductance of `Indian Summer' decreased to ≈20 mmol·s–1·m–2 after 8 days of flooding, indicating that this cultivar may be particularly sensitive to root-zone saturation.

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