Effect of ozone and aluminum on pitch pine (Pinusrigida) seedlings: needle ultrastructure

1993 ◽  
Vol 23 (7) ◽  
pp. 1375-1387 ◽  
Author(s):  
Carolyn J. McQuattie ◽  
George A. Schier
Keyword(s):  
Light And Electron Microscopy ◽  
Mycorrhizal Fungus ◽  
Membrane System ◽  
High Concentration ◽  
Solution Ph ◽  
Pitch Pine ◽  
Cytological Changes ◽  
Growth Chambers ◽  
Starch Formation ◽  
Cell Collapse

Newly germinated pitch pine (Pinusrigida Mill.) seedlings inoculated with a mycorrhizal fungus (Pisolithustinctorius (Pers.) Coker & Couch) were grown for 13 weeks in sand irrigated with nutrient solution (pH 4.0) containing 0, 12.5, 25, or 50 mg/L aluminum in growth chambers fumigated with 0, 50, 100, or 200 ppb ozone. Cytological changes in needles of seedlings stressed by ozone and aluminum, singly and in combination, were determined by light and electron microscopy. The most pronounced changes in needles exposed to ozone occurred in the outer mesophyll, whereas major changes in the presence of aluminum occurred in the stele and inner mesophyll. At lower levels of either ozone or aluminum, the cytoplasm became more densely stained. Accumulation of dense materials appeared at intermediate treatment concentrations, and at high concentration localized cell collapse and deterioration became evident. Ozone or aluminum caused similar changes in the chloroplasts, for example, increase in number of plastoglobuli, accumulation of starch, formation of electron-dense stroma, and swelling or disruption of thylakoid membrane system. Ozone and aluminum in combination generally caused histological and cytological damage in needles to occur at lower concentrations than either aluminum or ozone alone.

Effect of ozone and aluminum on pitch pine (Pinusrigida) seedlings: anatomy of mycorrhizae

1992 ◽  
Vol 22 (12) ◽  
pp. 1901-1916 ◽  
Author(s):  
Carolyn J. McQuattie ◽  
George A. Schier
Keyword(s):  
Root Meristem ◽  
Light And Electron Microscopy ◽  
Mycorrhizal Fungus ◽  
Solution Ph ◽  
Root Cortex ◽  
Anatomical Changes ◽  
Fungal Hyphae ◽  
Pitch Pine ◽  
Growth Chambers ◽  
Cellular Alterations

Newly germinated pitch pine (Pinusrigida Mill.) seedlings inoculated with a mycorrhizal fungus (Pisolithustinctorius (Pers.) Coker & Couch) were grown for 13 weeks in sand irrigated with nutrient solution (pH 4.0) containing 0, 12.5, 25, or 50 mg/L aluminum (Al) in growth chambers fumigated with 0, 50, 100, or 200 ppb ozone. Anatomical changes in roots stressed by ozone and Al, singly and in combination, were determined by light and electron microscopy. All ozone concentrations reduced the percentage of mycorrhizal colonization. In contrast, Al increased the percentage of colonization at low concentration, reducing it only at the highest level. Aluminum caused more overall deterioration of root cortex than ozone, though both treatments adversely affected the mycorrhizal fungus. Increased vacuolation in the root meristem was caused by both ozone and Al. Additional effects of ozone on cells in the meristem were the swelling of the nuclear membrane and invaginations in the plasmalemma. Intracellular fungal hyphae were observed at the highest level of ozone and (or) Al. The combined effect of ozone and Al on the anatomy of mycorrhizae was greater (possibly synergistic) than the effect of each pollutant alone. Similar cellular alterations have also been observed in forests damaged by pollution.

Effect of ozone and aluminum on pitch pine (Pinusrigida) seedlings: growth and nutrient relations

1990 ◽  
Vol 20 (11) ◽  
pp. 1714-1719 ◽  
Author(s):  
George A. Schier ◽  
Carolyn J. McQuattie ◽  
Keith F. Jensen
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
Mycorrhizal Fungus ◽  
Mineral Elements ◽  
Growth Effect ◽  
Solution Ph ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Pitch Pine ◽  
Nutrient Relations

Newly germimated pitch pine (Pinusrigida Mill.) seedlings inoculated with a mycorrhizal fungus (Pisolithustinctorius (Pers.) Coker & Couch) were grown for 13 weeks in sand irrigated with nutrient solution (pH 4.0) containing 0, 12.5, 25, 50, or 100 mg/L of aluminum (Al) in growth chambers fumigated with 0, 50, 100, or 200 ppb ozone. Increasing the concentration of ozone or Al caused increasing reductions in needle length, seedling height, and biomass of needles, stems, and roots. Significant ozone × Al interactions indicated that ozone and Al were interacting synergistically in reducing growth. Effect of treatments on the root/shoot ratio demonstrated that shoot growth was more sensitive to Al than root growth, whereas root growth was more sensitive to ozone. The concentration of most mineral elements (P, K, Ca, Mg, Mn, Cu, Zn) in needles was reduced by ozone or Al. Iron was the only element that increased with increasing concentrations of ozone or Al.

Ultrastructure of Melosira resting cell rejuvenation

1984 ◽  
Vol 42 ◽  
pp. 734-735
Author(s):  
C. E. M. Bourne ◽  
L. Sicko-Goad
Keyword(s):  
Electron Microscopy ◽  
Lake Michigan ◽  
Light And Electron Microscopy ◽  
Resting Cells ◽  
Planktonic Diatoms ◽  
Resting Cell ◽  
Vegetative Survival ◽  
Cytological Changes ◽  
Recent Attention ◽  
Freshwater Diatom

Much recent attention has been focused on vegetative survival forms of planktonic diatoms and other algae. There are several reports of extended vegetative survival of the freshwater diatom Melosira in lake sediments. In contrast to those diatoms which form a morphologically distinct resistant spore, Melosira is known to produce physiological resting cells that are indistinguishable in outward morphology from actively growing cells.We used both light and electron microscopy to document and elucidate the sequence of cytological changes during the transition from resting cells to actively growing cells in a population of Melosira granulata from Douglas Lake, Michigan sediments collected in mid-July of 1983.

scholarly journals STUDIES ON MICROPEROXISOMES II. A CYTOCHEMICAL METHOD FOR LIGHT AND ELECTRON MICROSCOPY

1972 ◽  
Vol 20 (12) ◽  
pp. 1006-1023 ◽  
Author(s):  
ALEX B. NOVIKOFF ◽  
PHYLLIS M. NOVIKOFF ◽  
CLEVELAND DAVIS ◽  
NELSON QUINTANA
Keyword(s):  
Endoplasmic Reticulum ◽  
Guinea Pig ◽  
Lipid Droplets ◽  
Smooth Endoplasmic Reticulum ◽  
Light And Electron Microscopy ◽  
Distal Tubule ◽  
Striking Difference ◽  
High Concentration ◽  
Electron Microscopic ◽  
Pig Kidney

A modification of the Novikoff-Goldfischer alkaline 3,3'-diaminobenzidine medium for visualizing peroxisomes is described. It makes possible light microscopic as well as electron microscopic studies of a recently described class of peroxisomes, the microperoxisomes. Potassium cyanide (5 x 10–3 M) is included in the medium to inhibit mitochondrial staining, the pH is 9.7 and there is a high concentration of H2O2 (0.05%). Two cell types have been chosen to illustrate the advantages of the new procedure for demonstrating the microperoxisomes: the absorptive cells in the human jejunum and the distal tubule cells in the guinea pig kidney. Suggestive relations of microperoxisomes and lipid are described in the human jejunum. The microperoxisomes are strategically located between smooth endoplasmic reticulum that radiates toward the organelles and contains lipid droplets and "central domains" of highly specialized endoplasmic reticulum which do not show the lipid droplets. The microperoxisomes are also present at the periphery of large lipid-like drops. In the guinea pig kidney tubule there is a striking difference between the thick limb of Henle and distal tubule. The distal tubule has a population of cells with large numbers of microperoxisomes readily visible by light microscopy; these cells are not present in the thick limb of Henle. Other differences between the two are also described.

POTASSIUM-SODIUM SELECTIVITY OF SUNFLOWER AS INFLUENCED BY CALCIUM SUPPLY UNDER SALINE CONDITIONS / SELECTIVIDAD DEL GIRASOL RESPECTO AL POTASIO Y SODIO BAJO LA INFLUENCIA DE LA PROVISION DEL POTASIO Y LAS CONDITIONES DE SALINIDAD / SÉLECTIVITÉ DU TOURNESOL EN CE QUI CONCERNE LE POTASSIUM ET LE SODIUM SOUS L’EFFET DE L’APPPORT DE CALCIUM DANS DES CONDITIONS SALINES

Helia ◽  
2001 ◽  
Vol 24 (34) ◽  
pp. 121-130
Author(s):  
Arshad Ali ◽  
M. Salim Badr-u-Zaman ◽  
Rahmatullah Badr-u-Zaman
Keyword(s):  
Nutrient Solution ◽  
Block Design ◽  
High Concentration ◽  
Solution Ph ◽  
Positive Role ◽  
Low Concentration ◽  
Salinity Levels ◽  
Half Strength ◽  
Calcium Supply ◽  
Hydroponic Study

SUMMARY A hydroponic study was conducted to investigate the influence of Ca supply on K+/Na+ selectivity of sunflower at 0, 75 and 150 mM NaCl in root medium. Sunflower (Helianthus annuus L. cv. Hysun-33) seeds were germinated in moist quartz sand and twelve-day old seedlings were foam-plugged in lids of plastic pots each containing 2.5 l of continuously aerated half strength Hoagland's nutrient solution without calcium salts. The solution pH was adjusted to 5.9 by adding HCl and NaOH. There were three salinity levels (0, 75 and 150 mM NaCl) and two calcium levels (5 and 10 mM CaCl2). The experiment was organized in a randomized complete block design (RCBD) in three replicates. At low concentration of calcium (5 mM), sunflower growth decreased drastically with increasing concentration of NaCl in nutrient solution. On the other hand, plants grown in high concentration of NaCl experienced less damage with relatively higher concentration of calcium. At relatively higher concentration of calcium (10 mM Ca), sunflower plants absorbed and translocated relatively more potassium and less sodium, than at low concentration of calcium (5 mM Ca), demonstrating the positive role of calcium in alleviating the hazardous effects of salinity on sunflower growth.

The structure of the caudate nucleus of the cat: light and electron microscopy

1971 ◽  
Vol 262 (845) ◽  
pp. 383-401 ◽  
Keyword(s):  
Electron Microscope ◽  
Caudate Nucleus ◽  
Dendritic Spines ◽  
Light And Electron Microscopy ◽  
Cell Types ◽  
High Concentration ◽  
Size Groups ◽  
Golgi Technique ◽  
Intrinsic Neurons ◽  
Cell Somata

The caudate nucleus of the cat appears to be homogeneous when examined with the light or electron microscope, except for a layer beneath the ependyma where there is a high concentration of glial cells and few neurons. In sections of brains stained with thionin the nerve cells in the caudate nucleus fall into three size groups: less than 8 μm, 9 to 18 μm, greater than 20 μm. Examination of material impregnated with the Golgi technique shows that there are six cell types (one small, four medium and one large), and these are distinguishable on the basis of the size of the cell somata and the appearance and arrangement of their dendrites. One type of medium cell with many dendritic spines forms over 95 % of the cell population. The large and one medium cell type are tentatively identified as the source of the efferent fibres of the nucleus. These efferent fibres and the axons of the remaining medium cell types have collateral branches. Three groups of possible afferent fibres have been identified, and these and the collateral branches of the intrinsic neurons form a dense plexus whose individual fibres cross dendrites rather than lie parallel to them. Six cell types may also be distinguished with the electron microscope, and four of these can be correlated directly with those seen in Golgi impregnated material. Several kinds of dendrites are present, the commonest having numerous spines. Fewer spines are present on other varieties of dendrite, and those dendrites which are varicose have no spines. Numerous fine, nonmyelinated axons are present.

Coupling of anodic oxidation and adsorption by granular activated carbon for chemical oxygen demand removal from 4,4′-diaminostilbene-2,2′-disulfonic acid wastewater

2010 ◽  
Vol 62 (11) ◽  
pp. 2669-2677 ◽  
Author(s):  
Lizhang Wang ◽  
Yuemin Zhao
Keyword(s):  
Activated Carbon ◽  
Chemical Oxygen Demand ◽  
Residence Time ◽  
Applied Voltage ◽  
Oxygen Demand ◽  
Granular Activated Carbon ◽  
Cod Removal ◽  
Disulfonic Acid ◽  
High Concentration ◽  
Solution Ph

Experiments were performed to reduce chemical oxygen demand (COD) from 4,4′-diaminostilbene-2,2′-disulfonic (DSD) acid manufacturing wastewater using electrochemical oxidation coupled with adsorption by granular activated carbon. The COD removal is affected by the residence time and applied voltage. When the residence time is increased, lower value of COD effluent could be obtained, however, the average current efficiency (ACE) decreased rapidly, and so does the applied voltage. In addition, aeration could effectively enhance COD removal efficiency and protect anodes from corrosion. Furthermore, the acidic condition is beneficial to the rapid decrease of COD and the values of pH effluent are independent of the initial solution pH. The optimization conditions obtained from these experiments are applied voltage of 4.8 V, residence time of 180 min and air–liquid ratio of 4.2 with the COD effluent of about 690 mg L−1. In these cases, the ACE and energy consumption are 388% and 4.144 kW h kg−1 COD, respectively. These perfect results from the experiments illustrate that the combined process is a considerable alternative for the treatment of industrial wastewater containing high concentration of organic pollutants and salinity.

Selective Voltammetric Detection of Dopamine in the Presence of Ascorbic Acid at Poly(p-methoxyphenol)-Modified Electrode

2020 ◽  
Vol 18 (3) ◽  
pp. 222-226
Author(s):  
Gamze Erdoğdu
Keyword(s):  
Ascorbic Acid ◽  
Detection Limit ◽  
Modified Electrode ◽  
Oxidative Polymerization ◽  
Phosphate Buffer Solution ◽  
Relative Sensitivity ◽  
High Concentration ◽  
Buffer Solution ◽  
Solution Ph ◽  
Voltammetric Detection

A gold electrode was modified with electropolymerized films of p-methoxyphenol by its oxidative polymerization from an alkaline solution by cyclic voltammetry. The modified electrode was then used to determine dopamine (DA) in the presence of a high concentration of ascorbic acid (AA) by differential pulse voltammetry. The peak positions as well as relative sensitivity DA/AA were affected by the potential window used for the polymerization. For polymerization between 0 and 1.0 V, the peak potentials recorded in a phosphate buffer solution (pH = 7.2) were 516 and 312 mV versus Ag/AgCl for DA and AA, respectively. In addition to the effects of pH and the type of electrolyte on the linearity range and detection limit are investigated. The detection limit for 3s-test is 0.1 nM. The high selectivity and sensitivity for DA was found to be due to charge discrimination/analyte accumulation.

scholarly journals The Fine Structure of the Wheat Scutellum During Germination

1972 ◽  
Vol 25 (3) ◽  
pp. 469 ◽  
Author(s):  
JG Swift ◽  
TP O'brien
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Light And Electron Microscopy ◽  
Cell Types ◽  
Wall Material ◽  
Cytological Evidence ◽  
Starch Grains ◽  
Parenchyma Cells ◽  
Cytological Changes

The cytological changes that take place in the scutellar epithelium and parenchyma during the first 5 days of germination are described by light and electron microscopy. Within 6 hr small starch grains appear in the plastids of both cell types and the size and number of starch grains increase gradually as germination proceeds. Later in germination starch disappears again from the plastids in the epithelial cells, but large starch grains still remain in the parenchyma cells. The reserves of the protein bodies are hydrolysed and the residual vacuoles undergo extensive coales-cence. Modifications in the appearance of the wall material of the epithelial cells as these cells elongate are illustrated and possible functional bases for these changes are suggested. The cells of the scutellar epithelium show no cytological evidence for their known functions of diastase secretion and nutrient absorption.

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