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

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 Ion Absorption in Atriplex Leaf Tissue III. Site of Metabolic Control of Light-Dependent Chloride Secretion to Epidermal Bladders

1970 ◽  
Vol 23 (1) ◽  
pp. 17 ◽  
Author(s):  
U Lüttge ◽  
CB Osmond
Keyword(s):  
Metabolic Control ◽  
Active Transport ◽  
Chloride Transport ◽  
Leaf Tissue ◽  
Chloride Secretion ◽  
Ion Absorption

The nature and location of the light-stimulated active transport of chloride to the epidermal bladders of A. 8pongio8a leaves was examined. Chloride transport to the bladder vacuole was found to have properties similar to those for light-dependent

Physiological Changes Accompanying the Death of Cocklebur Plants Treated with 2,4-D

Weed Science ◽  
1968 ◽  
Vol 16 (1) ◽  
pp. 96-100 ◽  
Author(s):  
J. Cardenas ◽  
F. W. Slife ◽  
J. B. Hanson ◽  
H. Butler
Keyword(s):  
Nucleic Acid ◽  
Leaf Growth ◽  
Growth Failure ◽  
Leaf Tissue ◽  
Nucleic Acid Metabolism ◽  
Dichlorophenoxyacetic Acid ◽  
Biochemical Basis ◽  
Abnormal Growth ◽  
Ion Absorption ◽  
2,4 Dichlorophenoxyacetic Acid

The hypothesis that plants treated with 2,4-dichlorophenoxyacetic acid (2,4-D) die as a consequence of abnormal growth has been examined. Cocklebur (Xanthium sp) plants spot treated on one leaf with 2,4-D show three phases of growth toward death. For the first 2 days after treatment, there is a net weight increase, largely due to abnormal growth of the axis (apex, stem, and tap root). Root and leaf growth are drastically curtailed. Between 2 and 7 days, axis growth continues primarily at the expense of leaf tissue which is induced to senesce, especially the cotyledons. The last phase between 7 and 10 days leads to collapse and withering of plants, and was not examined in detail.Analyses for nitrogenous constituents show the usual mobilization to the axis, with early and large increases in nucleic acid. Both photosynthesis and ion absorption are initially stimulated but decline sharply after the first day. Translocation to leaves and roots is drastically reduced in favor of the proliferating axis.The death of the plant appears to be due to suppression of normal apical growth coupled with induction of abnormal axis growth. Failure to produce new root and leaf tissue plus inadequate nutritional maintenance of existing roots and leaves lead to lack of autotrophism and eventual death. The biochemical basis for these responses appears to be with aberrant nucleic acid metabolism.

scholarly journals Elevated Relative Humidity Increases the Incidence of Distorted Growth and Boron Deficiency in Bedding Plant Plugs

HortScience ◽  
2013 ◽  
Vol 48 (3) ◽  
pp. 311-313 ◽  
Author(s):  
Brian A. Krug ◽  
Brian E. Whipker ◽  
Ingram McCall ◽  
Jonathan Frantz
Keyword(s):  
Relative Humidity ◽  
Leaf Tissue ◽  
High Heat ◽  
Convincing Evidence ◽  
Boron Deficiency ◽  
Shoot Tissue ◽  
Bedding Plant ◽  
The Common ◽  
B Uptake ◽  
Leaf Distortion

High relative humidity (RH) can cause lower concentrations of boron (B) accumulating in plants. The common greenhouse practice of controlling excess temperatures by applying mist irrigation to young plants (plugs) can result in elevated RH levels, especially with plugs grown in high heat and humidity conditions of summer. ‘Dynamite Yellow’ pansy (Viola ×wittrockiana Gams.), ‘White Storm’ petunia (Petunia ×hybrida Vilm.), and ‘Festival Apricot’ gerbera (Gerbera jamesonii Bolus) plugs were grown in high or ambient RH conditions to determine the effect RH had on B uptake. Results indicate that an increase in RH decreased the amount of water the plant lost as a result of transpiration resulting in lower concentrations of B in shoot tissue. Boron concentrations in leaf tissue were 9.43, 10.56, and 17.81 mg·L−1 in pansy, petunia, and gerbera plants, respectively, grown in high RH conditions. These values were significantly lower than pansy, petunia, and gerbera plants grown in ambient RH conditions (19.94, 25.49, and 42.71 mg·L−1, respectively). Leaf distortion, consistent with B deficiency symptoms, was present in petunia and gerbera plants. Similar trends were observed when the experiment was repeated and leaf distortion was present in all species. This provides convincing evidence that the distorted growth observed in pansy, petunia, and gerbera plug production is the result of limited B caused by excessive humidity.

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.

Ultrastructure of Plant Leaf Tissue Infected with Mite-Borne Viral-Like Pathogens

1970 ◽  
Vol 28 ◽  
pp. 178-179 ◽  
Author(s):  
O. E. Bradfute ◽  
R. E. Whitmoyer ◽  
L. R. Nault
Keyword(s):  
Triticum Aestivum ◽  
Zea Mays ◽  
Electron Microscope ◽  
Hordeum Vulgare ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Leaf Tissue ◽  
Leaf Ultrastructure ◽  
Double Membrane ◽  
Aceria Tulipae

A pathogen transmitted by the eriophyid mite, Aceria tulipae, infects a number of Gramineae producing symptoms similar to wheat spot mosaic virus (1). An electron microscope study of leaf ultrastructure from systemically infected Zea mays, Hordeum vulgare, and Triticum aestivum showed the presence of ovoid, double membrane bodies (0.1 - 0.2 microns) in the cytoplasm of parenchyma, phloem and epidermis cells (Fig. 1 ).

Use of TEM in Plant Disease Diagnosis: A Xylem-Limited Bacterium Associated with Diseased ‘Toronto’ Creeping Bentgrass

1981 ◽  
Vol 39 ◽  
pp. 414-415
Author(s):  
Karen K. Baker ◽  
David L. Roberts
Keyword(s):  
Osmium Tetroxide ◽  
Plant Disease ◽  
Leaf Tissue ◽  
Infectious Agent ◽  
Creeping Bentgrass ◽  
Disease Diagnosis ◽  
Unknown Etiology ◽  
Agrostis Palustris ◽  
Putting Greens ◽  
Plant Disease Diagnosis

Plant disease diagnosis is most often accomplished by examination of symptoms and observation or isolation of causal organisms. Occasionally, diseases of unknown etiology occur and are difficult or impossible to accurately diagnose by the usual means. In 1980, such a disease was observed on Agrostis palustris Huds. c.v. Toronto (creeping bentgrass) putting greens at the Butler National Golf Course in Oak Brook, IL.The wilting symptoms of the disease and the irregular nature of its spread through affected areas suggested that an infectious agent was involved. However, normal isolation procedures did not yield any organism known to infect turf grass. TEM was employed in order to aid in the possible diagnosis of the disease.Crown, root and leaf tissue of both infected and symptomless plants were fixed in cold 5% glutaraldehyde in 0.1 M phosphate buffer, post-fixed in buffered 1% osmium tetroxide, dehydrated in ethanol and embedded in a 1:1 mixture of Spurrs and epon-araldite epoxy resins.

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