Cell wall water dilution: an explanation of apparent negative turgor potentials

1981 ◽  
Vol 59 (9) ◽  
pp. 1722-1725 ◽  
Author(s):  
Albert H. Markhart III ◽  
Nasser Sionit ◽  
James N. Siedow
Keyword(s):  
Cell Wall ◽  
Mathematical Simulation ◽  
Filter Paper ◽  
Plant Tissue ◽  
Osmotic Potential ◽  
Sucrose Solution ◽  
Model Systems ◽  
Significant Problem ◽  
Distilled Water ◽  
Water Dilution

Errors in psychrometric determinations of osmotic potential (Ψs) due to dilution of the cytoplasm by cell wall water are investigated. Model systems using filter paper to represent the cell wall and sucrose solution and distilled water to represent protoplasm and cell wall water, respectively, show significant dilution of the sucrose solution at cell wall to protoplast ratios typical of plant tissue. Mathematical simulation of error in Ψs determination as a function of percent cell wall and cell wall hydration indicate that wall water dilution can be a significant problem and could explain reported apparent negative turgor potentials.

Freeze-fracture, freeze-etch complementary pairs of virus-infected cells reveal value of etching even when relatively high concentrations of cryoprotectants are used

1978 ◽  
Vol 36 (2) ◽  
pp. 136-137
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe
Keyword(s):  
Plant Tissue ◽  
Phosphate Buffer ◽  
Infected Plant ◽  
Freeze Fracture ◽  
Distilled Water ◽  
Virus Infected Plant ◽  
Infected Cells ◽  
High Concentrations

It has been assumed by many involved in freeze-etch or freeze-fracture studies that it would be useless to etch specimens which were cryoprotected by more than 15% glycerol. We presumed that the amount of cryoprotective material exposed at the surface would serve as a contaminating layer and prevent the visualization of fine details. Recent unexpected freeze-etch results indicated that it would be useful to compare complementary replicas in which one-half of the frozen-fractured specimen would be shadowed and replicated immediately after fracturing whereas the complement would be etched at -98°C for 1 to 10 minutes before being shadowed and replicated.Standard complementary replica holders (Steere, 1973) with hinges removed were used for this study. Specimens consisting of unfixed virus-infected plant tissue infiltrated with 0.05 M phosphate buffer or distilled water were used without cryoprotectant. Some were permitted to settle through gradients to the desired concentrations of different cryoprotectants.

scholarly journals Larvicidal potencial of Sapindus saponaria (Sapindaceae) against Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

2007 ◽  
Vol 59 (1) ◽  
pp. 145-149 ◽  
Author(s):  
F.F. Fernandes ◽  
R.N. Leles ◽  
I.G. Silva ◽  
E.P.S. Freitas
Keyword(s):  
Larvicidal Activity ◽  
Filter Paper ◽  
Control Measure ◽  
Larval Mortality ◽  
Rhipicephalus Sanguineus ◽  
Distilled Water ◽  
Alternative Control ◽  
Ethanolic Extracts ◽  
Sapindus Saponaria ◽  
Botanical Acaricide

The larvicidal potential of the crude ethanolic extracts (CEE) of the stem peel of Sapindus saponaria was evaluated against Rhipicephalus sanguineus. Lethal concentrations (LC), were calculated by preparing CEE solutions at different concentrations in distilled water. Larvae fasted for 14-21 days were utilized in the bioassays, after incubation of engorged females collected from infested environments frequented by dogs in several neighborhoods of Goiânia, GO. Bioassays were performed in a specially constructed biological chamber for testing botanical acaricides, acclimatized to 27±1ºC, RH>80%. The larvae were counted on filter paper envelopes impregnated with the solutions or distilled water and larval mortality observed after 48h. S. saponaria showed good larvicidal activity (LC50 and LC99 of 1994 and 3922ppm, respectively) and the results demonstrated its potential as a botanical acaricide and an alternative control measure for R. sanguineus.

scholarly journals Effect of Seed Priming Techniques on Germination Parameters of Safflower (Carthamus tinctorius L.)

2018 ◽  
Vol 67 (2) ◽  
pp. 157-163
Author(s):  
Milan Jocković ◽  
Petar Čanak ◽  
Vladimir Miklič ◽  
Jelena Ovuka ◽  
Velimir Radić ◽  
...  
Keyword(s):  
Filter Paper ◽  
Low Cost ◽  
Seed Priming ◽  
Carthamus Tinctorius ◽  
Distilled Water ◽  
Significant Difference ◽  
Mean Germination Time ◽  
Metabolic Activities ◽  
Germination Parameters ◽  
Priming Technique

Summary A useful approach for improving seed germination and seedling growth is a seed priming technique. Application of the priming technique enhances water absorption, causing activation of metabolic activities in the seed. The objective of this study was to evaluate the effect of seed priming on germination parameters of safflower and to compare different priming techniques: priming by soaking and priming on filter paper. The priming treatments included hydropriming (distilled water) and osmopriming with 0.1% and 0.5% solutions of KNO3 for 8 and 16 hours. The experiment revealed significant difference between the priming treatments and the control. The highest germination (89.50%) was recorded within the priming treatments by soaking in the solution of 0.1% KNO3 and priming on filter paper moistened with 0.5% KNO3 for 8 hours. Considering germination index, mean germination time and time to 50% germination, the best results were obtained within hydropriming on filter paper for 16 hours. This study has shown that the priming techniques significantly improved germination parameters of safflower. Although priming on filter paper showed better results, the soaking technique – due to its simplicity, low cost and easiness of application – can be successfully used to improve germination parameters of safflower and increase the number of plants per unit of area and thus increase the seed yield per acreage.

scholarly journals Larvicidal potential of Sapindus saponaria to control the cattle tick Boophilus microplus

2005 ◽  
Vol 40 (12) ◽  
pp. 1243-1245 ◽  
Author(s):  
Fernando de Freitas Fernandes ◽  
Edméia de Paula e Souza Freitas ◽  
Anna Carolina da Costa ◽  
Ionizete Garcia da Silva
Keyword(s):  
Filter Paper ◽  
Test Group ◽  
Ethanol Extract ◽  
Boophilus Microplus ◽  
Lethal Concentration ◽  
Cattle Tick ◽  
Control Group ◽  
Distilled Water ◽  
Sapindus Saponaria

The objective of this study was to evaluate the larvicidal potential of a crude ethanol extract (CEE) of soapberry Sapindus saponaria stem peel on the cattle tick Boophilus microplus. Tick larvae obtained by incubating engorged females, collected from naturally infested cattle, were placed in envelopes of filter paper impregnated with different concentrations of CEE in the test group, and distilled water in the control group. Four repetitions were made with each solution (n>120). Mortality was observed after 48 hours. Lethal concentration values of 1,258 ppm (LC50) and 6,360 ppm (LC99) were obtained.

scholarly journals Tribo-electricity and friction. III.—Solid elements and textiles

1928 ◽  
Vol 118 (779) ◽  
pp. 108-113 ◽  
Keyword(s):  
General Practice ◽  
Filter Paper ◽  
Reliable Method ◽  
Preceding Paper ◽  
Systematic Investigation ◽  
The Other ◽  
Textile Material ◽  
Distilled Water ◽  
Initial Surface

1. No systematic investigation on this subject has yet been attempted. The efforts made to group these materials in a series according to the charges generated when they are rubbed two at a time are of uncertain value because of (1) impurities of substance and surface, (2) indeterminate initial surface strains. Moreover, the general practice has been to rub the solids when held, one in each hand. A more reliable method is to mount the bodies in a mechanism which ensures that the same parts of them come into contact at each fresh stroke. In the present research, the elements, mostly metals, are those specified in the preceding paper. The textiles are made and cleansed as described in an earlier paper. Silk, cotton and linen in our experience behave reliably when fully cleaned. The other great textile material, wool, is more oily and cannot be readily cleansed; so is less trustworthy. We therefore at present confine ourselves to one animal and one vegetable textile, choosing the pure samples of silk and cotton specified in the above paper. Also filter paper, another convenient fabric, is used after being boiled in several lots of distilled water. As the silk and cotton are treated with boiling chloroform, we tried exhausting the filter paper in this solvent to see if such treatment affected the cellulose in any way; but no effect on the properties of the paper could be found.

An investigation of angle-meristem development in excised stem segments of Selaginella martensii

1969 ◽  
Vol 47 (5) ◽  
pp. 717-722 ◽  
Author(s):  
T. R. Webster
Keyword(s):  
Early Development ◽  
Filter Paper ◽  
Shoot Tip ◽  
Intact Plant ◽  
Developmental Study ◽  
Distilled Water ◽  
Effective Factor ◽  
Meristem Development ◽  
Stem Segments ◽  
Applied Auxin

The development of dorsal and ventral angle-meristems in excised Y-shaped stem segments of Selaginella martensii grown on filter paper moistened with distilled water has been investigated. Based on the position of the branchings relative to the shoot tip on the intact plant, segments were designated as young, intermediate, or old. In most segments, with no auxin treatment, ventral angle-meristems formed shoots. In most young segments the dorsal angle-meristem formed a root, whereas most old segments formed a dorsal shoot. A developmental study suggests that (1) in young segments early development of a ventral shoot, controls development of the dorsal angle-meristem as a root, and (2) in old segments where both angle-meristems develop at approximately the same time, there is no ventral control over dorsal development, and a dorsal shoot results. Experiments with externally applied auxin suggest that auxin is an effective factor in controlling ventral angle-meristem development as a root.

scholarly journals A MORPHOLOGICAL STUDY OF HALOBACTERIUM HALOBIUM AND ITS LYSIS IN MEDIA OF LOW SALT CONCENTRATION

1967 ◽  
Vol 34 (1) ◽  
pp. 365-393 ◽  
Author(s):  
Walther Stoeckenius ◽  
Robert Rowen
Keyword(s):  
Cell Wall ◽  
Cell Membrane ◽  
Salt Concentration ◽  
Prolonged Exposure ◽  
Structural Characteristics ◽  
Wall Material ◽  
Breakdown Product ◽  
Distilled Water ◽  
Fixation Techniques ◽  
A Cell

The reported absence of a cell wall in halobacteria cannot be confirmed. Improved fixation techniques clearly show a cell wall-like structure on the surface of these cells. A stepwise reduction of the salt concentration causes the release of cell wall material before the cell membrane begins to disintegrate. The cell membrane breaks up into fragments of variable but rather small size, which are clearly different from a 4S component reported by others to be the major breakdown product of the cell membrane. It appears more likely that the 4S component arises from the dissolution of the cell wall. A residue of large membranous sheets remains even after prolonged exposure of halobacteria envelopes to distilled water. The lipids in these sheets do not differ significantly from the lipids in the lysed part of the cell membrane. The sheets, however, contain a purple-colored substance, which is not present in the lysed part. The easily sedimentable residue that remains after lysis of the cells or envelopes in distilled water also contains "intracytoplasmic membranes" with unusual structural characteristics. They can also be identified in sections through intact bacteria or envelope preparations. Their function is at present unknown but seems to be related to the formation of gas vacuoles in these organisms.

Response of red-osier dogwood (Cornus sericea) seedlings to NaCl during the onset of bud break

2006 ◽  
Vol 84 (5) ◽  
pp. 844-851 ◽  
Author(s):  
Jennifer Mustard ◽  
Sylvie Renault
Keyword(s):  
Cell Wall ◽  
Osmotic Potential ◽  
Dry Mass ◽  
Bud Break ◽  
Pressure Potential ◽  
Shoot Height ◽  
Cell Wall Elasticity ◽  
Greenhouse Study ◽  
Cornus Sericea ◽  
Bud Breaking

A greenhouse study was designed to test the response of red-osier dogwood (Cornus sericea L.) to NaCl during the onset of bud break. Seedlings treated with 50 mmol·L–1 NaCl for 32 d had lower shoot dry mass and shoot height than untreated seedlings. Transpiration and photosynthetic rates, chlorophyll b and carotenoid concentrations of red-osier dogwood seedlings were significantly reduced by NaCl treatment. The shoots of seedlings treated with 50 mmol·L–1 NaCl had a higher bulk modulus of cell wall elasticity than those of untreated seedlings, but the water potential components determined from the pressure-volume curves, osmotic potential and pressure potential at full turgor and osmotic potential at pressure loss, suggest that this change did not contribute to salt tolerance. Minor changes, including a small increase in arabinose of the hemicellulose fraction and a decrease in both galactose and rhamnose of the pectin fraction, also occurred in response to NaCl treatment. These changes in cell wall composition and elasticity could be partly attributed to differences in the developmental stage of the shoot tissues resulting from the delay in bud breaking in salt treated plants.

scholarly journals Effects of Osmopriming on Germination and Vigour Traits of Bersim Clover (Trifolium alexandrinum L.)

2010 ◽  
Vol 2 (4) ◽  
pp. 59-63 ◽  
Author(s):  
Hossein Reza ROUHI ◽  
Reza Tavakkol AFSHARI ◽  
Seyed Amir MOOSAVI ◽  
Mohammad Hossain GHARINEH
Keyword(s):  
Polyethylene Glycol ◽  
Osmotic Potential ◽  
Seed Priming ◽  
Control Group ◽  
Trifolium Alexandrinum ◽  
Distilled Water ◽  
Peg 6000 ◽  
Crop Establishment ◽  
Germination Characteristics ◽  
Polyethylene Glycol 6000

Previous studies suggested that fast and uniform germination is important for good crop establishment. The present study was conducted to investigate the possibility of increasing germination characteristics by seed priming techniques. An experiment was conducted with three replicates and two treatments including: 2 different priming duration (8 and 12 hours) and 6 osmotic potential of PEG 6000 solutions (-0.8, -1,-1.2,-1.4,-1.6 Mpa) and distilled water as a control group). The priming solutions were prepared using polyethylene glycol 6000 (PEG). Our results showed that the most effective osmotic potential in improving germination characteristics of Trifolium alexandrium is -0.8 MPa for 16 hours.

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