scholarly journals Ion Absorption by Shoot Tissue: Kinetics of Potassium and Rubidium Absorption by Corn Leaf Tissue

1964 ◽  
Vol 39 (6) ◽  
pp. 992-996 ◽  
Author(s):  
Richard C. Smith ◽  
Emanuel Epstein
Keyword(s):  
Leaf Tissue ◽  
Shoot Tissue ◽  
Ion Absorption ◽  
Kinetics Of ◽  
Tissue Kinetics

scholarly journals Ion Absorption by Shoot Tissue: Technique and First Findings with Excised Leaf Tissue of Corn

1964 ◽  
Vol 39 (3) ◽  
pp. 338-341 ◽  
Author(s):  
Richard C. Smith ◽  
Emanuel Epstein
Keyword(s):  
Leaf Tissue ◽  
Shoot Tissue ◽  
Ion Absorption

Size-dependent tissue kinetics of PEG-coated gold nanoparticles

2010 ◽  
Vol 245 (1) ◽  
pp. 116-123 ◽  
Author(s):  
Wan-Seob Cho ◽  
Minjung Cho ◽  
Jinyoung Jeong ◽  
Mina Choi ◽  
Beom Seok Han ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Size Dependent ◽  
Kinetics Of ◽  
Tissue Kinetics

Depolarization of cell membranes in leaves of Lycopersicon by extract containing Ricca's factor

1977 ◽  
Vol 55 (5) ◽  
pp. 511-519 ◽  
Author(s):  
John M. Cheeseman ◽  
Barbara G. Pickard
Keyword(s):  
Membrane Potential ◽  
Maximum Rate ◽  
Electrical Coupling ◽  
Leaf Tissue ◽  
Saturation Level ◽  
Free Medium ◽  
Fresh Leaf ◽  
Stable Level ◽  
Shoot Tissue ◽  
Electrophysiological Studies

Extract containing Ricca's factor depolarizes the membrane potential of at least three types of cells in Lycopersicon leaves : mesophyll, midrib parenchyma, and midrib epidermis. The depolarization has been studied in some detail for the epidermal cells, in which depolarization appears to begin without a lag and is completed within 60–90 s. The maximum rate of depolarization is typically about 3 mV s−1. No changes in resistivity, capacivity, or intercellular electrical coupling have been detected during the depolarization.Extract from 0.5 mg fresh leaf tissue in 1 ml of water at pH 6.6 causes threshold depolarization in many experiments, and a concentration only 40 times greater is usually saturating. Raising the pH increases the concentration of factor required for saturation.With subsaturating concentrations of factor, the potential recovers somewhat after depolarization, and when factor-free medium is washed over the tissue the potential depolarizes briefly before returning to its baseline value. With saturating concentrations of factor, the potential depolarizes to an essentially stable level and no transient depolarization occurs when the factor is washed out.The potential remaining after application of a saturating concentration of factor is independent of the initial baseline potential but depends on the concentration of K+ in the equilibration medium and in the extract. The saturation level of depolarization is in the range of the Nernstian potential for K+, but whether it is precisely equal to the Nernstian potential for K+ has not been established.Evidently, the occurrence and influence of Ricca's factor should be taken into account in all electrophysiological studies of shoot tissue since the factor appears to be released whenever cells are wounded and may be released during other kinds of stress as well.

scholarly journals EFFICACY OF PACLOBUTRAZOL UPTAKE THROUGH PECAN LEAVES, YOUNG SHOOTS, AND BARK

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 862c-862
Author(s):  
Gregory L. Reighard ◽  
Harvey M. Jessup
Keyword(s):  
Biological Activity ◽  
Growth Regulator ◽  
Shoot Growth ◽  
Leaf Surface ◽  
Leaf Tissue ◽  
Distilled Water ◽  
Green Wood ◽  
Shoot Tissue ◽  
Abaxial Leaf Surface ◽  
Leaf Flush

Paclobutrazol, a triazole growth regulator, effectively regulates pecan vegetative growth when applied as a soil or trunk drench. However, its absorption and subsequent biological activity in leaves and shoot tissue is not well understood. Terminal shoots from scaffolds of 8-yr-old `Chickasaw' pecan trees were treated with paclobutrazol after leaf flush in mid-May of 1988. Treatments included painting a mixture of 10 mg a.i. paclobutrazol and 1 ml distilled water onto either 1-yr-old wood, green wood, or the abaxial leaf surface. Shoot growth measurements and nut counts were taken in October of 1988 and 1989 on the treated shoots and all shoots arising from them. Paclobutrazol significantly increased the number of nuts per shoot in 1988, but did not affect shoot growth. More nuts were found on shoots from the 1-yr-old wood and leaf treatments than from the control and green wood treatments. In 1989, shoot growth was significantly less in the 2 former than the 2 latter treatments. These data indicate that paclobutrazol was absorbed through the bark of 1-yr-old wood and abaxial leaf tissue and sub-sequently translocated to areas of shoot growth.

scholarly journals Ion Absorption in Atriplex Leaf Tissue I. Absorption by Mesophyll Cells

1968 ◽  
Vol 21 (6) ◽  
pp. 1119 ◽  
Author(s):  
CB Osmond
Keyword(s):  
Diffusion Coefficient ◽  
Leaf Tissue ◽  
External Solution ◽  
Monovalent Cations ◽  
Mesophyll Cells ◽  
Ion Absorption ◽  
Absorption Studies ◽  
Apparent Diffusion ◽  
And Diffusion ◽  
Cut Surface

Leaf tissue cut into disks was unsuitable for quantitative ion-absorption studies because cells in the interior did not equilibrate with the external solution. Ion entry was restricted to the cut surface and diffusion was too slow to permit equilibration of the whole disk (apparent diffusion coefficient for sodium at O� 5�C was 1 X IO-L 3 X 10-7 cm2 sec-I). However, leaf slices 0�5 mm in width permitted rapid access of electrolyte to all cells and were used to study uptake of monovalent cations and oxalate

scholarly journals 095 Vase Life of Cut Roses Grown in Coal Bottom Ash-amended Media: A Correlation with Tissue Calcium

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 405B-405
Author(s):  
Marlene Cross ◽  
Bradford Bearce ◽  
Rajeev Arora
Keyword(s):  
Bottom Ash ◽  
Leaf Tissue ◽  
Vase Life ◽  
Dolomitic Lime ◽  
Coal Bottom Ash ◽  
Low Calcium ◽  
High Calcium ◽  
Tissue Calcium ◽  
Calcium And Magnesium ◽  
Kinetics Of

The vase life of roses grown in coal bottom ash (CBA)-amended media was evaluated. CBA is enriched in calcium, a nutrient implicated in delaying senescence. Two rose cultivars, Cara Mia and Dakota, were grown (from started eye plants) in four media: a 50% CBA medium and a peat:vermiculite medium amended with calcitic and dolomitic lime (1:1) were used as “high calcium” media, whereas a 25% CBA medium and a peat:vermiculite medium amended with dolomitic lime only were used as “low calcium” media. Vase life of the freshly harvested roses was evaluated. Elemental analysis of the leaves showed that roses grown in the “high calcium” media had greater calcium in the leaf tissue as well as longer vase lives (12.6 and 13.5 days) when compared to those grown in the “low calcium” media (12.1 and 10.9 days). However, petal tissue Ca was not affected by media and was not correlated with vase life. Petal tissue calcium was ≈15 times lower than leaf tissue calcium. Calcium and magnesium increased in the petal tissue over the vase life of the senescing petals. A comparison of `Cara Mia' roses (vase life of 14 days) and `Dakota' roses (vase life of 8.5 days) showed that the longer-lived `Cara Mia' had lower leaf and petal calcium levels. Both varieties followed a similar kinetics of electrolyte leakage (total E.C. and K) during their respective vase lives.

scholarly journals Adenosine diphosphate sulphurylase activity in leaf tissue

1973 ◽  
Vol 133 (3) ◽  
pp. 417-428 ◽  
Author(s):  
Jim N. Burnell ◽  
John W. Anderson
Keyword(s):  
Leaf Tissue ◽  
Thiol Group ◽  
Adenosine Diphosphate ◽  
Ph Optimum ◽  
Elementary Kinetics ◽  
Crude Extracts ◽  
Standard Assay ◽  
Spinach Leaf ◽  
Kinetics Of ◽  
Assay Conditions

1. A new method is described for the assay of ADP sulphurylase. The method involves sulphate-dependent [32P]Pi–ADP exchange; the method is simpler, more sensitive and more direct than the method involving adenosine 5′-sulphatophosphate-dependent uptake of Pi. 2. ADP sulphurylase activity was demonstrated in crude extracts of leaf tissue from a range of plants. Crude spinach extract catalysed the sulphate-dependent synthesis of [32P]ADP from [32P]Pi; spinach extracts did not catalyse sulphate-dependent AMP–Pi, ADP–PPi or ATP–Pi exchange under standard assay conditions. ADP sulphurylase activity in spinach leaf tissue was associated with chloroplasts and was liberated by sonication. 3. Some elementary kinetics of crude spinach leaf and purified yeast ADP sulphurylases in the standard assay are described; addition of Ba2+ was necessary to minimize endogenous Pi–ADP exchange of the yeast enzyme and crude extracts of winter-grown spinach. 4. Spinach leaf ADP sulphurylase was activated by Ba2+ and Ca2+; Mg2+ was ineffective. The yeast enzyme was also activated by Ba2+. The activity of both enzymes decreased with increasing ionic strength. 5. Purified yeast and spinach leaf ADP sulphurylases were sensitive to thiol-group reagents and fluoride. The pH optimum was 8. ATP inhibited sulphate-dependent Pi–ADP exchange. Neither selenate nor molybdate inhibited sulphate-dependent Pi–ADP exchange and crude spinach extracts did not catalyse selenate-dependent Pi–ADP exchange. 6. The presence of ADP sulphurylase activity jeopardizes the enzymic synthesis of adenosine 5′-sulphatophosphate from ATP and sulphate with purified ATP sulphurylase and pyrophosphatase.

Comparative adipose tissue kinetics of thiopental, DDE and 2,4,5,2′,4′,5′-hexachlorobiphenyl in the rat

Xenobiotica ◽  
1985 ◽  
Vol 15 (6) ◽  
pp. 485-491 ◽  
Author(s):  
S. Mühlebach ◽  
P. A. Wyss ◽  
M. H. Bickel
Keyword(s):  
Adipose Tissue ◽  
Kinetics Of ◽  
Tissue Kinetics
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