Direct turgor pressure measurements in individual leaf cells of Tradescantia virginiana

Planta ◽  
1980 ◽  
Vol 149 (5) ◽  
pp. 445-453 ◽  
Author(s):  
U. Zimmermann ◽  
D. H�sken ◽  
E.-D. Schulze
Keyword(s):  
Turgor Pressure ◽  
Pressure Measurements ◽  
Tradescantia Virginiana ◽  
Individual Leaf

scholarly journals Evaluating the usefulness of continuous leaf turgor pressure measurements for the assessment of Persimmon tree water status

2016 ◽  
Vol 35 (2) ◽  
pp. 159-167 ◽  
Author(s):  
M. A. Martínez-Gimeno ◽  
M. Castiella ◽  
S. Rüger ◽  
D. S. Intrigliolo ◽  
C. Ballester
Keyword(s):  
Water Status ◽  
Turgor Pressure ◽  
Pressure Measurements

Comparison Between Osmotic and Hydrostatic Water Flows in a Higher Plant Cell: Determination of Hydraulic Conductivities and Reflection Coefficients in Isolated Epidermis of Tradescantia virginiana

1982 ◽  
Vol 9 (4) ◽  
pp. 461 ◽  
Author(s):  
SD Tyerman ◽  
E Steudle
Keyword(s):  
Osmotic Pressure ◽  
Turgor Pressure ◽  
Water Volume ◽  
Pressure Probe ◽  
Reflection Coefficients ◽  
Higher Plant ◽  
Bathing Medium ◽  
Tradescantia Virginiana ◽  
Cell Turgor

Hydraulic conductivity (Lp), volumetric elastic modulus (ε) and reflection coefficients (δ) have been determined for cells from isolated strips of the lower epidermis of leaves of Tradescantia virginiana using the pressure probe. Lp was (6.4 � 4.5) × 10-8 ms-1 Mpa-1 [(6.4 � 4.5) × 10-7 cm s-1 bar-1; mean � s.d., n = 15 cells] and was independent of the cell turgor pressure (P) and of osmotic pressure of the bathing medium. P in Johnson's solution (π° = 0.09 MPa) was 0.42-0.67 MPa (4.2-6.7 bar), which was somewhat larger than in the intact tissue. ε increased linearly with increasing P in the pressure range from zero to full turgor. Reflection coefficients of some non-electrolytes were determined by measuring the ΔP in response to a change in external osmotic pressure (Δπ°) after the addition of the solutes. The data were corrected for solute flow. For sucrose, mannitol, urea, acetamide, formamide, glycerol and ethylene glycol, δ was close to unity and the cells behaved like ideal osmometers. For the monohydroxyalcohols n-propanol ( δ = -0.58), isopropanol (δ = 0.26), ethanol (δ = 0.25) and methanol (δ = 0.15), rather low reflection coefficients were found which were even negative for some solutes and cells. Values of δ obtained from measuring the inital water (volume) flow were in agreement with those determined from the ΔP/Δπ° ratios. For the rapidly permeating substances, the changes in turgor after the addition of solute were transient and the equilibration of solutes between cell and medium could be measured using the probe. Although unstirred layers may affect the equilibration of solute it should, in principle, be possible to use the technique for the determination of permeability coefficients of membranes of higher plant cells.

THE EFFECT OF LEAF WATER BALANCE ON THE SUSCEPTIBILITY OF FRENCH BEAN TO TOBACCO NECROSIS VIRUS

1967 ◽  
Vol 45 (11) ◽  
pp. 2115-2118 ◽  
Author(s):  
W. C. Kimmins ◽  
R. E. Litz
Keyword(s):  
Relative Humidity ◽  
Turgor Pressure ◽  
Continuous Light ◽  
French Bean ◽  
Tobacco Necrosis Virus ◽  
Culture Solution ◽  
Pressure Measurements ◽  
Necrosis Virus ◽  
Continuous Darkness ◽  
High Suction

French beans were germinated under constant temperature, relative humidity, and day period, and were transferred to Hoagland's culture solution. Variations of the preinoculation treatment were begun at an age of 10 days for a period of 24 h. Treatments were selected which would induce turgor changes in the primary leaves.It was observed that susceptibility to tobacco necrosis virus infection was increased by preinoculation conditions of continuous darkness, high relative humidity, and low suction tension of the culture solution. Susceptibility was lowered by preinoculation conditions of continuous light, low relative humidity, and high suction tension of the culture solution.Diffusion pressure deficit, osmotic pressure, and turgor pressure measurements were made with the primary leaves at time of inoculation. Considerable agreement was noted between turgor changes and susceptibility.Preinoculation treatments such as darkening will alter susceptibility through changes in turgor pressure. It is suggested that there may be a direct effect of leaf turgor on the number of infectible sites.

Signal Interpretation Considerations When Estimating Subglottal Pressure From Oral Air Pressure

2019 ◽  
Vol 62 (5) ◽  
pp. 1326-1337 ◽  
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer ◽  
Jason A. Whitfield
Keyword(s):  
Standard Condition ◽  
Word Production ◽  
Air Pressure ◽  
Pressure Waveform ◽  
Pressure Measurements ◽  
Air Leak ◽  
Pressure Signal ◽  
Adult Participants ◽  
Syllable Repetition ◽  
Subglottal Pressure

Purpose Oral air pressure measurements during lip occlusion for /pVpV/ syllable strings are used to estimate subglottal pressure during the vowel. Accuracy of this method relies on smoothly produced syllable repetitions. The purpose of this study was to investigate the oral air pressure waveform during the /p/ lip occlusions and propose physiological explanations for nonflat shapes. Method Ten adult participants were trained to produce the “standard condition” and were instructed to produce nonstandard tasks. Results from 8 participants are included. The standard condition required participants to produce /pːiːpːiː.../ syllables smoothly at approximately 1.5 syllables/s. The nonstandard tasks included an air leak between the lips, faster syllable repetition rates, an initial voiced consonant, and 2-syllable word productions. Results Eleven oral air pressure waveform shapes were identified during the lip occlusions, and plausible physiological explanations for each shape are provided based on the tasks in which they occurred. Training the use of the standard condition, the initial voice consonant condition, and the 2-syllable word production increased the likelihood of rectangular oral air pressure waveform shapes. Increasing the rate beyond 1.5 syllables/s improved the probability of producing rectangular oral air pressure signal shapes in some participants. Conclusions Visual and verbal feedback improved the likelihood of producing rectangular oral air pressure signal shapes. The physiological explanations of variations in the oral air pressure waveform shape may provide direction to the clinician or researcher when providing feedback to increase the accuracy of estimating subglottal pressure from oral air pressure.

Abscisic acid levels of individual leaf cells

1990 ◽  
Vol 80 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Enno Brinckmann ◽  
Wolfram Hartung ◽  
Margarete Wartinger
Keyword(s):  
Abscisic Acid ◽  
Individual Leaf

Assessment of Driver Movements during Prolonged Driving Using Seat Pressure Measurements

2011 ◽  
Author(s):  
Bo Wang ◽  
Xiaoping Jin ◽  
Bo Cheng ◽  
Xin Tao
Keyword(s):  
Pressure Measurements
Sign in / Sign up

Export Citation Format

Share Document