scholarly journals The Relationship between Turgor Pressure Change and Cell Hydraulics of Midrib Parenchyma Cells in the Leaves of Zea mays

Cells ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 180 ◽  
Author(s):  
Yangmin X. Kim ◽  
Burkhard Stumpf ◽  
Jwakyung Sung ◽  
Sang Joon Lee
Keyword(s):  
Zea Mays ◽  
Water Potential ◽  
Turgor Pressure ◽  
Root Systems ◽  
Large Degree ◽  
Pressure Change ◽  
Pressure Chamber ◽  
Pressure Probe ◽  
Parenchyma Cells ◽  
Cell Turgor

Leaf dehydration decreases water potential and cell turgor pressure. Therefore, changes in cell turgor pressure may regulate water transport across plant cell membranes. Using a cell pressure probe, the hydraulic properties of parenchyma cells in the midrib of maize (Zea mays L.) leaves were measured (half time of water exchange in cells as a measure of hydraulic conductivity Lp). Using intact plants with root systems encased in a pressure chamber, the root systems were pressurized and the turgor pressure in leaf cells increased by increments up to 0.3 MPa. However, the increase in the cell turgor did not increase but stabilized values. Increased water potential in leaf cells seemed to have stabilizing effects on the probably due to enhanced water availability. When the cell turgor decreased by 0.1 MPa to 0.3 MPa with releasing the pressure in the pressure chamber, was temporarily increased to a large degree,a factor of up to 13 within 30 min.

Viewpoint: Consideration of apoplastic water in plant organs: a reminder

2005 ◽  
Vol 32 (6) ◽  
pp. 561 ◽  
Author(s):  
Ian F. Wardlaw
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Solute Concentration ◽  
Pressure Chamber ◽  
Dilution Method ◽  
Water Fraction ◽  
Thermocouple Psychrometer ◽  
Relative Water ◽  
Cell Turgor ◽  
The Difference

The importance of apoplastic water was confirmed for the leaves of a range of species by a comparison of tissue solute concentrations determined by the extrapolation of water potential isotherms to 100% relative water content (symplastic solute concentration at full turgor) and concentrations derived more directly from frozen / thawed tissue, where there is dilution of the symplastic water fraction by the apoplastic water fraction. A thermocouple psychrometer was used for both water potential and solute potential measurements. Parallel measurements of the apoplastic water content, estimated by the extrapolation of pressure–volume curves to zero (1 / water potential) with a pressure chamber and measurements based on the dilution method, with a thermocouple psychrometer, showed that the two methods gave similar results. This lends support to the conclusion that water is lost from the symplast and not from the apoplast of leaves when these are subjected to increasing pressure in a pressure chamber. However, where tissues or organs are air-dried the loss of water occurs from both the symplast and apoplast. The overall data support the conclusion that the apoplastic water should not be ignored in plant water relations studies, particularly when estimating cell turgor indirectly from the difference between water potential and cell solute concentration based on the analysis of frozen / thawed tissue.

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.

Comparison of plant cell turgor pressure measurement by pressure probe and micromanipulation

2006 ◽  
Vol 28 (15) ◽  
pp. 1147-1150 ◽  
Author(s):  
Lan Wang ◽  
David Hukin ◽  
Jeremy Pritchard ◽  
Colin Thomas
Keyword(s):  
Plant Cell ◽  
Pressure Measurement ◽  
Turgor Pressure ◽  
Pressure Probe ◽  
Cell Turgor

Alternate methods of analysing water potential isotherms: some cautions and clarifications. II. Curvilinearity in water potential isotherms

1982 ◽  
Vol 60 (6) ◽  
pp. 911-916 ◽  
Author(s):  
Melvin T. Tyree ◽  
Hanno Richter
Keyword(s):  
Linear Regression ◽  
Water Potential ◽  
Turgor Pressure ◽  
Living Cells ◽  
Tissue Water ◽  
Relative Water ◽  
Cell Turgor ◽  
Pressure Bomb ◽  
Linear Regressions ◽  
Populus Spp

The Hammel pressure bomb technique has been used to obtain measurements of water potential, Ψ, and relative water content, R*, on single leaves of Populus spp., Helianthus annuus, and Fraxinus ornus. The data were plotted either as Ψ versus 1/R* or as 1/Ψ versus R* and analysed by linear regression in the region where cell turgor was thought to be zero. In some cases the Ψ versus 1/R* transformation showed curvature in the zero turgor region whereas less curvature was found in the same region of R* in the 1/Ψ versus R* transformation. In theory, curvature can appear in the Ψ versus 1/R* transformation whenever a significant fraction of tissue water is contained in the apoplast, and this theoretical prediction can be demonstrated by some of the data in this paper. The presence or absence of curvature in the two transformations can also be due to (1) apoplast compressibility, (2) the development of negative turgor pressure in living cells, and (3) the nonideality of the osmotic solutions in living cells. Linear regressions performed on curved data plots will lead to errors in the estimation of π0, the osmotic pressure at full hydration, and of other parameters derived from the analysis.

Modification of the pressure-probe technique permits controlled intracellular microinjection of fluorescent probes

1991 ◽  
Vol 98 (4) ◽  
pp. 539-544
Author(s):  
K. J. OPARKA ◽  
R. MURPHY ◽  
P. M. DERRICK ◽  
D. A. M. PRIOR ◽  
J. A. C. SMITH
Keyword(s):  
Fluorescent Probes ◽  
Lucifer Yellow ◽  
Turgor Pressure ◽  
Plant Cells ◽  
Pressure Probe ◽  
Simple Modification ◽  
Symplastic Transport ◽  
Probe Technique ◽  
Cell Turgor ◽  
Leaf Trichome

The pressure probe has been widely used to study the water relations of plant cells. Here we describe a simple modification of the pressure-probe technique that permits the controlled microinjection of fluorescent probes into plant cells while simultaneously measuring cell turgor pressure. Using the pressure probe, less than 1 nl of the membrane-impermeant fluorescent dye Lucifer Yellow CH was introduced into micropipettes and subsequently injected into leaf trichome cells of Nicotiana clevelandii. Disruption of cell contents could be minimized by raising the hydrostatic pressure in the probe prior to impalement to a value approaching the anticipated cell turgor pressure. Injections to the cytosol resulted in intercellular symplastic transport of the dye in both acropetal and basipetal directions. In contrast, no symplastic transport was observed following an injection of dye into the vacuole. As measured with the pressure probe, cell turgor pressures were in the range 0.18 to 0.36 MPa; the half-time for water exchange across the cell boundary was approximately 10 s. The potential of this technique for the study of turgor-pressure-dependent intercellular transport and the hydraulic conductivities of the tonoplast, plasmalemma and plasmodesmata is discussed.

Turgor, solute import and growth in maize roots treated with galactose

2004 ◽  
Vol 31 (11) ◽  
pp. 1095 ◽  
Author(s):  
Jeremy Pritchard ◽  
A. Deri Tomos ◽  
John F. Farrar ◽  
Peter E. H. Minchin ◽  
Nick Gould ◽  
...  
Keyword(s):  
Turgor Pressure ◽  
Cortical Cell ◽  
Root Tip ◽  
Pressure Probe ◽  
Similar Response ◽  
Fixed Carbon ◽  
Cortical Cells ◽  
Maize Roots ◽  
Before And After ◽  
Cell Turgor

It has been observed that extension growth in maize roots is almost stopped by exposure to 5 mm d-galactose in the root medium, while the import of recent photoassimilate into the entire root system is temporarily promoted by the same treatment. The aim of this study was to reconcile these two apparently incompatible observations. We examined events near the root tip before and after galactose treatment since the tip region is the site of elongation and of high carbon deposition in the root. The treatment rapidly decreased root extension along the whole growing zone. In contrast, turgor pressure, measured directly with the pressure probe in the cortical cells of the growing zone, rapidly increased by 0.15 MPa within the first hour following treatment, and the increase was maintained over the following 24 h. Both tensiometric measurements and a comparison of turgor pressure with local growth rate demonstrated that a rapid tightening of the cell wall caused the reduction in growth. Single cell sampling showed cell osmotic pressure increased by 0.3 MPa owing to accumulation of both organic and inorganic solutes. The corresponding change in cell water potential was a rise from –0.18 MPa to approximately zero. More mature cells at 14 mm from the root tip (just outside the growing region) showed a qualitatively similar response. Galactose treatment rapidly increased the import of recently fixed carbon (RFC) into the whole root as deduced by 11C labelling of photoassimilate. In contrast, there was a significant decrease in import of recently fixed carbon into the apical 5mm concomitant with the increase in turgor in this region. No decrease in import of recently fixed carbon was observed 5–15 mm from the root tip despite the increase in cortical cell turgor. These data are consistent with direct symplastic connections between the growing cells and the phloem supplying the solutes in the apical, but not the basal, regions of the growing zone. Hence, the inhibition of growth and the elevation of solute import induced by galactose are spatially separated within the root.

scholarly journals A Leaf Lamina Compression Method for Estimating Turgor Pressure

HortScience ◽  
2010 ◽  
Vol 45 (3) ◽  
pp. 418-423 ◽  
Author(s):  
Adonai Gimenez Calbo ◽  
Marcos David Ferreira ◽  
José Dalton Cruz Pessoa
Keyword(s):  
Air Flow ◽  
Turgor Pressure ◽  
Regression Coefficients ◽  
Pressure Probe ◽  
Compression Method ◽  
Cell Turgor ◽  
Detached Leaves ◽  
Air Passage ◽  
Quantitative Procedure ◽  
Probe Measurements

A portable wiltmeter instrument to estimate leaf turgor pressure according to an adaptation of the flattening method was developed. In the instrument, a flexible inflating membrane presses the leaf against a flattening plate having small orifices surrounded by a finely engraved network of obtuse indentations through which air flow is delivered. During a measurement, as the compression builds up, the leaf is progressively molded against the flattening plate, and as a consequence, the air flow (x) crossing the plate is reduced toward zero. The smallest leaf compression (p0) that blocks the air passage is an estimate of the leaf turgor. Wiltmeter measurements were compared with pressure probe measurements of cell turgor pressure in detached leaves of lettuce (Lactuca sativa L.), kale (Brassica oleracea L. var. Acephala), and chicory (Chichorium endivia L.), which were allowed to suffer diverse levels of wilting caused by transpiration. Such observed wiltmeter readings were a little lower than the cell turgor pressure measured with a pressure probe; the regression coefficients between these methods were: 1.156 for lettuce, 1.13 for kale, and 1.036 for chicory. This portable quantitative procedure to measure leaf firmness has potentially valuable applications related to postharvest and field plant physiology studies.

Discrimination of water stress in pepper using thermography and leaf turgor pressure probe techniques

2021 ◽  
Vol 254 ◽  
pp. 106942
Author(s):  
Gokhan Camoglu ◽  
Kursad Demirel ◽  
Fatih Kahriman ◽  
Arda Akcal ◽  
Hakan Nar ◽  
...  
Keyword(s):  
Water Stress ◽  
Turgor Pressure ◽  
Pressure Probe
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