scholarly journals Ion Absorption in Atriplex Leaf Tissue II. Secretion of Ions to Epidermal Bladders

1969 ◽  
Vol 22 (4) ◽  
pp. 797 ◽  
Author(s):  
CB Osmond ◽  
U Lüttge ◽  
KR West ◽  
§ CK Pallaghy ◽  
B Shacher-Hill
Keyword(s):  
Concentration Gradient ◽  
Leaf Tissue ◽  
Ion Absorption ◽  
High Concentrations

The epidermal bladders of several Atriplex species contain high concentrations of ions. Chloride was secreted from the solution or the lamina to the bladders, against a concentration gradient. Transfer of 36CI to the bladders was strongly light stimulated, but uptake to the lamina was much less sensitive.

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

scholarly journals Application of DNA Shuffling as a Tool for Hydrolase Activity Improvement of Pseudomonas Strain

2020 ◽  
Vol 11 (1) ◽  
pp. 7735-7745
Keyword(s):  
Protein Engineering ◽  
Protoplast Fusion ◽  
Concentration Gradient ◽  
First Generation ◽  
Human Life ◽  
Genome Shuffling ◽  
Dna Shuffling ◽  
High Concentration ◽  
Mutant Strains ◽  
High Concentrations

Biotechnology is considered one of the most influential technologies in various areas of human life, including health, economics, and the environment. Protein engineering is one of the major biotechnology tools in the field of modification and advancement of biocatalysts capabilities. Among the most effective protein engineering methods, in particular, to improve the industrial strain capabilities, is the shuffling genome method. This study aimed to follow knowledge and biocatalysts engineering techniques based on DNA shuffling methods. In the first step, two procedures were followed (DES method and compatibility according to the concentration gradient of Diazinon) to obtain mutant strains. Acquired mutant strains from both methods were resistant to high concentrations of poison up to 3000 mg/L. The activity of these strains also demonstrated their elevated activity compared to parent samples. The highest activity was related to four strains IR1.G1, IR1.D8, IR1.D4, and IR1.D5, which were 0.234 U/ml, 0.1 U/ml, 0.098 U/ml, and 0.066 U/ml, respectively. The improved strain was obtained via the concentration gradient of the diazinon method (IRL1.G1 strain) in comparison with IRL1.D8 strain (owning highest activity through DES method) possesses excessive activity in 3000 mg/L concentration of Diazinon. The evaluated results of first-generation genome shuffling of strains (the first round of protoplast fusion) also indicated that those shuffled strains with the ability to grow in the vicinity of the toxin (3000 mg/L concentration of Diazinon) showed better activity than obtained mutated strains by both methods (concentration gradient of the toxin and the DES method). In the final stage, the best results were related to IRL1.F2, IRL1.F3, and IRL1.F1 shuffled strains with 0.541 mg/L, 0.523 mg/L, and 0.509 mg/L, respectively. The highest activity belonged to the IRL1.F2 genome shuffled strain (first round of protoplast fusion). This strain could grow in a high concentration of toxin, and also, the activity was increased 30, 3.6, and 2.3 times in comparison with the parent strain (IRL1), IRL.D8 mutant, and IRL1.G1, respectively.

scholarly journals POSSIBILITIES FOR INTER- AND INTRACELLULAR TRANSLOCATION OF SOME ICOSAHEDRAL PLANT VIRUSES

1969 ◽  
Vol 40 (3) ◽  
pp. 814-823 ◽  
Author(s):  
G. A. de Zoeten ◽  
G. Gaard
Keyword(s):  
Leaf Tissue ◽  
Plant Viruses ◽  
Infected Leaf ◽  
Mesophyll Cells ◽  
Low Concentrations ◽  
Infected Cells ◽  
Virus Research ◽  
High Concentrations ◽  
Pore Complexes ◽  
Intracellular Translocation

Southern bean mosaic virus (SBMV) and Tomato ringspot virus (TomRV) were compared with regard to possible ways of inter- and intracellular translocation. The pore complexes in the nuclear membranes of nuclei in leaf palisade and mesophyll cells of several plant species commonly used in plant virus research were studied. The pore structure resembled that earlier described. The diameter of the pores was great enough to allow icosahedral plant viruses between 25 and 30 mµ wide to move through. SBMV occurred in noncrystalline form in nuclei of infected cells. Although this virus forms paracrystalline structures when partially purified, no virus crystals were seen in the cytoplasm of cells containing high concentrations of SBMV. It was established that this virus could move through nuclear pores. TomRV was found in infected leaf tissue in low concentrations. This virus showed a tendency to crystallize even when present in low concentrations. TomRV was observed only in the cytoplasm, not in nuclei. This virus was present in plasmodesmata, indicating the possibility of cell to cell translocation of whole particles through these structures.

scholarly journals Amino acid transport by resealed ghosts from pigeon erythrocytes

1982 ◽  
Vol 202 (3) ◽  
pp. 613-621
Author(s):  
K P Wheeler
Keyword(s):  
Amino Acids ◽  
Concentration Gradient ◽  
Acid Transport ◽  
Ph Values ◽  
Intracellular Amino Acids ◽  
Net Flux ◽  
High Concentrations ◽  
Dependent Transport ◽  
Resealed Ghosts ◽  
Net Fluxes

Resealed ghosts from pigeon erythrocytes were shown to haemolyse during incubation in isotonic media with pH values greater than about 7 and high concentrations of Na+ inside the ghosts seemed to enhance this effect. At lower pH values the ghosts were stable but still highly permeable to Na+ and K+, and moderately permeable to sucrose. Under the latter conditions the ghosts transported amino acids in a way qualitatively but not quantitatively similar to intact erythrocytes. The Na+-dependent transport of serine and alanine by the ghosts consisted essentially of an exchange of extracellular for intracellular amino acids, with no significant net flux. In contrast, net fluxes of glycine in the direction of the Na+-concentration gradient across the ghost membrane were demonstrated. However, under one condition a small net influx of glycine occurred against the prevailing Na+-concentration gradient. Unlike Na+-dependent glycine uptake, the uptake of six other amino acids by intact pigeon erythrocytes was not influenced by the nature of the anion present. The significance of these findings in relation to previous work on the Na+-gradient hypothesis of membrane transport is discussed.

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 Selenization of Basil and Cilantro Through Foliar Applications of Selenate-selenium and Selenite-selenium

HortScience ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 438-442 ◽  
Author(s):  
Dean A. Kopsell ◽  
Carl E. Sams ◽  
T. Casey Barickman ◽  
Dennis E. Deyton ◽  
David E. Kopsell
Keyword(s):  
Leaf Tissue ◽  
Dry Weight ◽  
Growth Chamber ◽  
Crop Species ◽  
Field Environment ◽  
Leaf Tissues ◽  
Edible Tissues ◽  
High Concentrations ◽  
Daily Intakes ◽  
Alternative Delivery

Selenium (Se) is an essential mammalian micronutrient. Adult humans have a daily requirement of 55 to 70 μg/day Se depending on sex and pregnancy/lactation for females. In addition, recent studies have shown health benefits with dietary Se supplementation of 100 to 200 μg/day Se. However, daily intakes in humans greater than 900 μg Se will result in toxicity called selenosis. Although not essential in plant nutrition, some species can bioaccumulate Se. Brassica and Allium species became prime candidates for Se enrichment because of their ability to accumulate and tolerate high concentrations of Se in edible tissues; however, there is now concern that these species are too efficient at selenization and overconsumption of their selenized tissues could result in selenosis. Herbal crop species are consumed regularly in the diet for their culinary flavor attributes. Basil (Ocimum basilicum L.) and cilantro (Coridandrum sativum L.) are not classified as Se accumulators. Therefore, a study was undertaken to determine the potential to selenize basil and cilantro through foliar Se applications to consistently supplement diets with nutritionally beneficial levels of Se. Plants of each species were grown in both growth chamber and field environments and treated with foliar applications (5 mL per plant) of selenate-Se and selenite-Se at concentrations of 0, 2, 4, 8, 16, and 32 mg·L−1 Se. Crops received three separate foliar applications at ≈5-day intervals beginning 24 to 28 days after planting for the growth chamber plants and 50 days after planning for the field environment. Selenium accumulation in both basil and cilantro leaf tissues increased linearly under both selenate-Se (P ≤ 0.001) and selenite-Se (P ≤ 0.001) foliar treatments in growth chamber and field evaluations. Maximum Se leaf tissue concentrations for basil and cilantro ranged from 13 to 55 μg·g−1 Se dry weight. Selenization of basil and cilantro is possible through foliar Se applications, and Se fortification of herbal crops may provide alternative delivery systems in human diets.

Carrier-mediated mechanism for biotin transport in rabbit intestine: studies with brush-border membrane vesicles

1991 ◽  
Vol 261 (1) ◽  
pp. R94-R97 ◽  
Author(s):  
H. M. Said ◽  
I. Derweesh
Keyword(s):  
Brush Border ◽  
Concentration Gradient ◽  
Brush Border Membrane ◽  
Maximum Velocity ◽  
Membrane Vesicles ◽  
Brush Border Membrane Vesicles ◽  
Experimental Conditions ◽  
Simple Diffusion ◽  
Rabbit Intestine ◽  
High Concentrations

Simple diffusion has been reported as the mechanism of biotin transport in rabbit intestine. In this study, we reevaluated this concept by examining biotin transport in rabbit intestine using optimal experimental conditions and a well-established brush-border membrane vesicles (BBMV) technique. Uptake of biotin by rabbit intestinal BBMV was found by an osmolarity study to be mostly the result of transport of the vitamin into an osmotically sensitive intravesicular space with little binding to membrane surfaces. Biotin transport in rabbit intestinal BBMV was 1) Na+ gradient dependent (out greater than in) with a clear “overshoot” phenomenon, indicating the accumulation of the substrate against a concentration gradient; 2) initial rate of biotin transport by the Na+ gradient-dependent component was saturable as a function of substrate concentration with apparent Km and maximum velocity (Vmax) values of 6.7 microM and 10.7 pmol.mg protein-1 x 10 s-1, respectively; 3) inhibited by high concentrations of unlabeled biotin and its related compounds desthiobiotin and thioctic acid in the presence, but not absence, of a Na+ gradient; and 4) not affected by inducing a relatively positive or negative intravesicular space with the use of valinomycin-induced K+ diffusion potential. These findings indicate that the biotin transport mechanism in rabbit intestine is carrier mediated in nature. Furthermore, this mechanism is Na+ gradient dependent, capable of accumulating the substrate against a concentration gradient and transport the vitamin via an electroneutral process.

3-O-methyl-D-glucose transport in tumoral insulin-producing cells

1986 ◽  
Vol 251 (6) ◽  
pp. C841-C846 ◽  
Author(s):  
W. J. Malaisse ◽  
M. H. Giroix ◽  
F. Malaisse-Lagae ◽  
A. Sener
Keyword(s):  
Plasma Membrane ◽  
Low Temperature ◽  
Glucose Transport ◽  
Concentration Gradient ◽  
Glucose Oxidation ◽  
Temperature Sensitive ◽  
Insulin Producing Cells ◽  
Different Temperatures ◽  
High Concentrations ◽  
Tumoral Cells

Tumoral insulin-producing cells of the RINm5F line were exposed at different temperatures, and for various lengths of time to increasing concentrations of 3-O-methyl-D-[U-14C]glucose. The uptake of the hexose represented a temperature-sensitive and saturable process, so that no rapid equilibration of hexose concentrations across the plasma membrane was reached, especially at low temperature and/or high concentrations of 3-O-methyl-D-glucose. The uptake of 3-O-methyl-D-[U-14C]glucose was not affected by a prior loading of the cells with the unlabeled hexose and its release from prelabeled cells was observed in the absence of any concentration gradient across the plasma membrane. The uptake of D-[U-14C]glucose and utilization of D-[5-3H]glucose was inhibited by 3-O-methyl-D-glucose, which failed, however, to affect D-[U-14C]glucose oxidation. At variance with the situation found in normal insulin-producing cells, the transport of D-glucose into the tumoral cells may thus play a regulatory role in its metabolism.

scholarly journals Sampling Tissue for DNA Analysis of Trees: Trunk Cambium as an Alternative to Canopy Leaves

2005 ◽  
Vol 54 (1-6) ◽  
pp. 265-269 ◽  
Author(s):  
N. Colpaert ◽  
S. Cavers ◽  
E. Bandou ◽  
H. Caron ◽  
G. Gheysen ◽  
...  
Keyword(s):  
Dna Extraction ◽  
Tree Species ◽  
Dna Analysis ◽  
Leaf Tissue ◽  
Ground Level ◽  
Tropical Tree ◽  
Aflp Analysis ◽  
Simple Method ◽  
Tropical Tree Species ◽  
High Concentrations

Abstract The number of studies of tropical tree species that use molecular tools is increasing, most of which collect leaf tissue for genomic DNA extraction. In tropical trees the canopy is not only frequently inaccessible, but also, once reached, the leaf tissue is often heavily defended against herbivory by high concentrations of anti-predation compounds, which may inhibit downstream applications, particularly PCR. Cambium tissue, accessed directly from the tree trunk at ground level, offers a readily accessible resource that is less hampered by the presence of defensive chemicals than leaf tissue. Here we describe a simple method for obtaining tissue from the cambial zone for DNA extraction and test the applicability of the method in a range of tropical tree species. The method was used successfully to extract DNA from 11 species in nine families. A subset of the DNA extracts was tested in more detail and proved to be highly suitable for AFLP analysis.

Characteristics of accumulation of ephedrine in rabbit atria

1976 ◽  
Vol 54 (2) ◽  
pp. 93-100 ◽  
Author(s):  
D. S. Golko ◽  
D. M. Paton
Keyword(s):  
Concentration Gradient ◽  
Initial Rate ◽  
Passive Diffusion ◽  
Extraneuronal Uptake ◽  
Metabolic Inhibitors ◽  
High Concentrations ◽  
6 Hydroxydopamine ◽  
Rabbit Atria

The characteristics of uptake of (±)-[β-14C]ephedrine were studied in isolated rabbit atria. Ephedrine was rapidly accumulated against the concentration gradient. From 5 × 10−7 to 10−2 M, uptake occurred at a uniform initial rate. Uptake was slightly inhibited by high concentrations of ouabain, cocaine, desipramine, lidocaine and phenethylamines, and by a reduction in the external Na+ concentration. Uptake was not, however, reduced by omission of K+ from the medium, by metabolic inhibitors or by a variety of drugs known to inhibit the extraneuronal uptake and binding of noradrenaline. Pretreatment of animals with 6-hydroxydopamine very significantly reduced the uptake of (±)-[3H]metaraminol, but did not alter the uptake of ephedrine. It was concluded that the uptake of ephedrine in rabbit atria occurred predominantly in extraneuronal tissues possibly as a result of passive diffusion followed by binding.

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