scholarly journals Response of Leaf Water Potential, Stomatal Resistance, and Leaf Rolling to Water Stress

1980 ◽  
Vol 65 (3) ◽  
pp. 428-432 ◽  
Author(s):  
John C. O'Toole ◽  
Rolando T. Cruz
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Stomatal Resistance ◽  
Leaf Water ◽  
Leaf Rolling

COMPARATIVE WATER STRESS STUDIES ON DROUGHT RESISTANT AND SUSCEPTIBLE CORN GROWN IN CHAMBER AND FIELD ENVIRONMENTS

1983 ◽  
Vol 63 (4) ◽  
pp. 775-787 ◽  
Author(s):  
A. L. SKRETKOWICZ ◽  
G. W. THURTELL
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Extended Period ◽  
Stomatal Resistance ◽  
Leaf Water ◽  
Stress Studies ◽  
Controlled Environments ◽  
Drought Resistant ◽  
Corn Plants

Drought resistant and drought susceptible corn plants were grown in both field and growth room environments in order to study differences in response to water stress attributable to their growth environments, including their prestress history.After 40–56 days of growth, field- and chamber-grown drought resistant and susceptible plants were placed in a growth cabinet for the drought stress experiments. There they underwent two stress cycles, during which time water was witheld. During the cycles, leaf water potential, transpiration, stomatal resistance and soil moisture content were monitored. The response differences due to water stress between the drought resistant and susceptible plants were first examined. Response differences due to their prestress growth environments were then considered.The responses of the field- and chamber-grown drought resistant plants to stress were found to be similar although there were differences in the absolute value of the responses measured. This was also true of the drought susceptible plants. The drought resistant plants were able to maintain their ability to extract water for a longer period of time than the susceptible plants. They maintained low stomatal resistance values for a large part of the drying cycle. The values of leaf water potential at which the stomatal resistances increased were lower than those of the drought susceptible plants. This enabled the drought resistant plants to extend their period of water utilization.During the drying cycles, the field-grown drought resistant and susceptible plants maintained low stomatal resistances and high transpiration rates for a longer period of time than their chamber counterparts. The values of leaf water potential at which stomatal resistance increased and transpiration decreased were lower than those of the chamber-grown plants, allowing the field-grown plants a slightly extended period of water utilization.The knowledge of prestress history of plants grown in different environments is shown to be of importance when comparative studies between field and controlled environments are undertaken. The similarity in response found between field- and chamber- grown plants is a useful factor as the chamber work with these particular cultivars is shown to be representative of field response at this location.Key words: Water stress, drought resistance, Zea mays L.

scholarly journals Tolerance to Drought and Water Stress Resistance Mechanism of Castor Bean

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1580
Author(s):  
Eleni G. Papazoglou ◽  
Efthymia Alexopoulou ◽  
George K. Papadopoulos ◽  
Garifalia Economou-Antonaka
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Stress Resistance ◽  
Water Scarcity ◽  
Castor Bean ◽  
Resistance Mechanism ◽  
Stomatal Resistance ◽  
Leaf Water ◽  
Leaf Number

Castor bean (Ricinus communis L.) is a multipurpose crop; its oil has numerous applications worldwide and the last decade demonstrated a growing international demand. The aim of this work was to investigate the level of castor bean tolerance to drought and its possession of a water stress resistance mechanism by applying three different water regimes in a glasshouse pot experiment conducted for two years. The treatments applied were 70% (T70-control), 55% (T55) and 40% (T40) of the available soil moisture. The results showed that the growth parameters height, trunk diameter, and fresh and dry weights of leaves and stems were not affected by the moderate water scarcity (T55), while they were significantly decreased by T40. Significant decrease in leaf number was observed in both T55 (17%) and T40 (27%) plants, with a delay of 4 weeks in the lower treated plants. Leaf area was decreased by 54% and 20% in T55 and T40 respectively, indicating that its reduction was mainly due to a reduction of leaf size than of leaf number. The leaf water potential was increased negatively with increasing stress, showing a water loss and decrease of turgidity in cells. Stomatal resistance was significantly higher at the higher water scarcity and this response indicates a water stress resistance mechanism. This result was also confirmed by the regression analysis performed between stomatal resistance and leaf water potential. In conclusion, castor bean showed a tolerance ability under water stress conditions and its early physiological reaction allows its acclimatization to drought conditions.

INDICATORS OF WATER STRESS IN CORN (Zea mays L.)

1984 ◽  
Vol 64 (3) ◽  
pp. 537-546 ◽  
Author(s):  
L. M. DWYER ◽  
D. W. STEWART
Keyword(s):  
Zea Mays ◽  
Water Stress ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Zea Mays L ◽  
Stomatal Resistance ◽  
Leaf Water ◽  
Predawn Leaf Water Potential ◽  
Diurnal Patterns ◽  
Potential Transpiration

Greenhouse experiments were conducted to monitor the response of corn (Zea mays L.) to water stress conditions during and following tasselling, and to compare several indicators of water stress. Daily measurements of soil water content and of evaporative demand were made. The degree of plant water stress was indicated by estimates of minimum daily stomatal resistance, comparison of estimated actual and potential transpiration rates, diurnal patterns of leaf water potential and predawn leaf water potentials taken on lower leaves. Analysis of the series of measurements necessary to estimate minimum daily stomatal resistance, actual to potential transpiration rate ratios, and diurnal patterns of leaf water potential identified periods of relative water stress. The simpler and less time-consuming measurement of predawn leaf water potential compared favorably with these other indicators of water stress. We therefore suggest that predawn leaf water potential is an appropriate diagnostic measurement of water stress with promise for irrigation scheduling, particularly for crops in which irrigation is important for a short but critical period.Key words: Leaf water potential, stomatal resistance, transpiration, vapor pressure deficit, soil water deficit

scholarly journals Interactions between leaf water potential, stomatal conductance and abscisic acid content of orange trees submitted to drought stress

2004 ◽  
Vol 16 (3) ◽  
pp. 155-161 ◽  
Author(s):  
Mara de Menezes de Assis Gomes ◽  
Ana Maria Magalhães Andrade Lagôa ◽  
Camilo Lázaro Medina ◽  
Eduardo Caruso Machado ◽  
Marcos Antônio Machado
Keyword(s):  
Abscisic Acid ◽  
Water Stress ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Acid Content ◽  
Stomatal Closure ◽  
Leaf Water ◽  
Orange Trees ◽  
Abscisic Acid Content

Thirty-month-old 'Pêra' orange trees grafted on 'Rangpur' lemon trees grown in 100 L pots were submitted to water stress by the suspension of irrigation. CO2 assimilation (A), transpiration (E) and stomatal conductance (g s) values declined from the seventh day of stress, although the leaf water potential at 6:00 a.m. (psipd) and at 2:00 p.m. (psi2) began to decline from the fifth day of water deficiency. The CO2 intercellular concentration (Ci) of water-stressed plants increased from the seventh day, reaching a maximum concentration on the day of most severe stress. The carboxylation efficiency, as revealed by the ratio A/Ci was low on this day and did not show the same values of non-stressed plants even after ten days of rewatering. After five days of rewatering only psi pd and psi2 were similar to control plants while A, E and g s were still different. When psi2 decreases, there was a trend for increasing abscisic acid (ABA) concentration in the leaves. Similarly, stomatal conductance was found to decrease as a function of decreasing psi2. ABA accumulation and stomatal closure occurred when psi2 was lower than -1.0 MPa. Water stress in 'Pera´ orange trees increased abscisic acid content with consequent stomatal closure and decreased psi2 values.

Effects of water stress and soil type on photosynthesis, leaf water potential and yield of olive trees (Olea europaea L. cv. Chemlali Sfax)

2007 ◽  
Vol 47 (12) ◽  
pp. 1484 ◽  
Author(s):  
B. Ben Rouina ◽  
A. Trigui ◽  
R. d'Andria ◽  
M. Boukhris ◽  
M. Chaïeb
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Sandy Soil ◽  
Clay Soil ◽  
Sandy Loam ◽  
Leaf Water ◽  
Severe Drought ◽  
Relative Water ◽  
Olive Trees

In Tunisia, olives are grown under severe rain-fed, arid conditions. To determine the behaviour of olive trees (cv. Chemlali Sfax) during the severe drought affecting Tunisian arid areas in 2002, a range of physiological parameters were investigated in three adjacent orchards. Two olive orchards were rain-fed, one located on a sandy soil, and the other on a sandy-loam clay soil. A third orchard was also located on sandy soil, but received remedial irrigation (415 mm of water per year; ~40% of olive evapotranspiration). Predawn leaf water potential (Ψpd) did not fall below –1.52 MPa for irrigated olive trees. However, a large decrease in Ψpd was observed for rain-fed olive trees in the same period with Ψpd measured at about –3.2 MPa on sandy soil and –3.6 MPa on sandy-loam clay soil. At the same time, the minimal leaf water potential recorded at midday (Ψmin) decreased to –4.15 MPa and –4.71 MPa in the rain-fed trees for sandy and sandy-loam clay soil, respectively. For irrigated trees, the Ψmin was –1.95 MPa. These results were associated with relative water content, which varied from 80% for irrigated trees to 54 and 43.6%, respectively, for rain-fed trees and trees subjected to severe drought. In August, when the relative water content values were less than 50%, a progressive desiccation in the outer layer of canopy and death of terminal shoots were observed in trees, which grew on the sandy-loam clay soil. Furthermore, low soil water availability also affected (negatively) the net photosynthetic rate in rain-fed orchards (10.3 µmol/m2.s for irrigated trees v. 5.3 µmol/m2.s in rain-fed trees on sandy soil) and stomatal conductance (98.5 mmol/m2.s v. 69.3 mmol/m2.s). However, it improved water use efficiency (7.6 v. 4.7 µmol CO2/mmol H2O), which increased by more than 50% in both groups of rain-fed trees compared with the irrigated ones. We can conclude that olive trees respond to drought by showing significant changes in their physiological and biological mechanisms. These results also help our understanding of how olive trees cope with water stress in the field and how marginal soils can restrict growth and lower yields.

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