Sensitivity of various phytates to beam damage during x-ray analysis

1990 ◽  
Vol 48 (4) ◽  
pp. 816-817
Author(s):  
Irene Ockenden ◽  
John N.A. Lott
Keyword(s):  
Phytic Acid ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
Spherical Particles ◽  
X Ray ◽  
Complexing Properties ◽  
Nutrient Reserves ◽  
Beam Damage ◽  
Acid Salts

Phytic acid (myoinositol hexaphosphoric acid) has 12 hydrolyzable hydrogens and forms salts with a variety of cations. Phytic acid salts are stored in seeds and act as nutrient reserves of elements such as Mg, K, Ca and P. In diets heavily dependent on grains, phytates have been implicated in reducing the bioavailability of elements such as zinc and iron. The complexing properties of phytates have made these compounds useful in a number of medical and industrial procedures.Phytin reserves in seeds often are localized in electron dense spherical particles called globoid crystals located within protein bodies. The characteristics of globoid crystals remain poorly defined. Energy-dispersive x-ray analysis of individual globoid crystals from various species has shown that there is considerable variation in the relative proportions of Mg, K, Ca and P species-to-species.

Thin-section, freeze-fracture, and energy dispersive x-ray analysis studies of the protein bodies of tomato seeds

1980 ◽  
Vol 58 (6) ◽  
pp. 699-711 ◽  
Author(s):  
Ernest Spitzer ◽  
John N. A. Lott
Keyword(s):  
Freeze Fracture ◽  
Protein Body ◽  
Cell Types ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
Elemental Content ◽  
Tomato Seed ◽  
Endosperm Tissue ◽  
X Ray ◽  
Edx Analysis

Protein bodies of dry seeds of tomato (Lycopersicon esculentum) from radicle, hypocotyl, cotyledon, and endosperm tissue were extensively studied using thin-sectioning, freeze-fracturing and energy dispersive x-ray (EDX) analysis. Protein bodies varied in size, were oval to circular in section, and generally consisted of a proteinaceous matrix, globoid crystal, and protein crystalloid components. Size, shape, and arrangements of globoid crystals and protein crystalloids varied even within the same cell. Globoid crystals were generally oval to circular in section. They were always surrounded by a proteinaceous matrix. In a given protein body the number present ranged from a few to numerous. A protein body generally contained only one protein crystalloid. In section, protein crystalloids were irregular or angular in shape. They were composed of substructural particles which formed lattice planes. EDX analysis of tomato seed globoid crystals revealed the presence of P, K, and Mg in all cases, a fact that is consistent with globoid crystals being phytin-rich. Rarely, small amounts of calcium were found along with P, K, and Mg in globoid crystals of each of the tissue regions considered. The distribution pattern of cells with Ca containing globoid crystals was random. Small amounts of Fe and Mn were also found in the globoid crystals of protein bodies from certain cell types. These two elements, unlike calcium, were specific in terms of their distribution. Globoid crystals from the protodermal cells often contained Mn and Fe. The globoid crystals from provascular tissue of radicle, hypocotyl, and cotyledon regions often contained Fe while globoid crystals in the first layer of large cells surrounding these provascular areas always contained Fe. Results from EDX analysis of the proteinaceous material from the protein bodies are presented and discussed as are variations in elemental content due to different fixations.

Elemental composition of globoids in the perisperm tissue of various seeds

1995 ◽  
Vol 73 (6) ◽  
pp. 954-957 ◽  
Author(s):  
M. Marcia West ◽  
Derrick T. Flannigan ◽  
John N.A. Lott
Keyword(s):  
Energy Dispersive ◽  
Mineral Nutrient ◽  
Piper Nigrum ◽  
X Ray ◽  
Phytate Phosphorus ◽  
Transmission Electron ◽  
Yucca Brevifolia ◽  
Nutrient Reserves ◽  
Mature Seeds ◽  
Potassium Magnesium

The mature seeds of some angiosperms contain perisperm tissue derived from remains of the nucellus tissue of the ovule. In our transmission electron microscopy studies, the perisperm tissues of the seeds of Yucca brevifolia, Coffea arabica, Beta vulgaris, Piper nigrum, and Zostera capricorni contained naturally electron-dense globoids. Energy dispersive X-ray analysis of globoids from the perisperm tissues of these seeds revealed varying levels of phosphorus, potassium, magnesium, and calcium, results that are consistent with the presence of the mineral nutrient store called phytate. Phosphorus, potassium, magnesium, calcium, and other mineral nutrients, likely stored as phytate, have routinely been located in globoids of endosperm, female gametophyte, and embryo tissues of seeds. Key words: perisperm, globoids, mineral nutrient reserves, phosphorus, seeds, energy dispersive X-ray analysis.

Protein bodies in Datura stramonium seeds: structure and mineral nutrient composition

1991 ◽  
Vol 69 (11) ◽  
pp. 2545-2554 ◽  
Author(s):  
Sara Maldonado ◽  
John N. A. Lott
Keyword(s):  
Distribution Patterns ◽  
Cell Types ◽  
Datura Stramonium ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
Mineral Nutrient ◽  
Electron Microscopic ◽  
Element Analysis ◽  
X Ray ◽  
Endosperm Protein

The structure of protein bodies in the endosperm and embryo of Datura stramonium was studied with a variety of light-and electron-microscopic techniques. Protein bodies had one to several globoid crystals and one or two protein crystalloids in the proteinaceous matrix. Although the embryo protein bodies rarely had more than two globoid crystals, the endosperm protein bodies had varying sizes and numbers of globoid crystals, even within the same cell. Energy-dispersive X-ray analysis of globoid crystals revealed the presence of P, K, and Mg in all cases. Traces of Fe, Mn, and Zn were also found in globoid crystals of protein bodies from certain cell types. The distribution patterns of these three elements were quite specific; for example, Mn traces were found only in the globoid crystals of the protoderm. Neutron-activation analysis of endosperm and embryo tissues was used to quantitatively measure the concentration of Ca, Cl, Cu, I, K, Mg, Mn, Na, and S. The results from structural studies and the element analysis studies are discussed in the context of solanaceous seeds in particular but also with relation to seeds in general. Key words: protein bodies, Datura stramonium, seed, globoid crystals, energy-dispersive X-ray analysis, Solanaceae.

Manganese and Iron in Globoid Crystals of Protein Bodies From Avena and Casuarina

1978 ◽  
Vol 5 (5) ◽  
pp. 631 ◽  
Author(s):  
MS Buttrose
Keyword(s):  
Chemical Analysis ◽  
Avena Sativa ◽  
Storage Protein ◽  
Major Elements ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
X Ray ◽  
Plant Seeds

The storage protein bodies of plant seeds usually contain globoid crystals with a high content of phytin, a rich store of Mg, P, K and Ca. By energy dispersive X-ray analysis, Mn and Fe have now been located in the globoid crystals of protein bodies in the seed embryos of Avena sativa and Casuarina species. Their levels in sections of globoids, relative to the levels of the major elements present, is consistent with their relative levels stored in whole seeds of various species as determined by chemical analysis.

ENERGY DISPERSIVE X-RAY ANALYSIS OF FIELD PEAS WITH DIFFERENT COOKING QUALITY

1983 ◽  
Vol 63 (4) ◽  
pp. 1071-1074 ◽  
Author(s):  
J. CHONG ◽  
S. T. ALI-KHAN ◽  
B. B. CHUBEY ◽  
G. H. GUBBELS
Keyword(s):  
Statistical Analysis ◽  
Pisum Sativum ◽  
Cooking Quality ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
X Ray ◽  
Pisum Sativum L ◽  
Field Peas ◽  
Freeze Dried ◽  
High Concentrations

An energy dispersive X-ray (EDX) analytical method was used to study the freeze-dried powder of seeds of field peas (Pisum sativum L.) with good and poor cooking quality. EDX analysis of the electron-dense particles in the freeze-dried powder revealed the presence of high concentrations of Mg, P, and K, suggesting that the particles were protein bodies. Seeds with different cooking quality were compared with respect to the ratios of these elements in the dense particles. Statistical analysis indicated a significant correlation between these ratios and cooking quality.Key words: Pisum sativum, protein bodies, elemental analysis

Composition and Microstructure of a Furnace Ash Deposit from a Coal-Fired Utility Boiler

1980 ◽  
Vol 102 (3) ◽  
pp. 692-697
Author(s):  
R. R. Fessler ◽  
A. J. Skidmore ◽  
H. R. Hazard ◽  
J. P. Dimmer
Keyword(s):  
Iron Oxide ◽  
Low Temperature ◽  
Energy Dispersive ◽  
Spherical Particles ◽  
Tube Surface ◽  
X Ray ◽  
Melting Temperatures ◽  
Coal Particles ◽  
Wide Range ◽  
Ash Deposit

An exploratory study of the structure and composition of furnace-ash deposits was carried out using optical metallography, electron microprobe analysis, scanning electron microscopy, and energy-dispersive X-ray analysis. The results of these analyses were supplemented by studies of particulate melting temperatures using hot-stage microscopy to measure melting temperatures, and energy-dispersive X-ray analyses to measure composition of melted particles. It was found that the general structure of the ash deposit was a matrix of glassy, spherical particles having a wide range of compositions in which unfused particles containing iron oxide and calcium oxide were dispersed. At the imprint of the tube surface a considerable concentration of calcium, sulfur, and iron was found. Near the fused outer surface of the deposit, the glassy materials had melted into a porous, glassy slag containing spherical globules of iron oxide combined with other materials. There were no systematic compositional gradients from the tube surface to the fused outer layer except for the sulfur layer found only at the tube surface. However, there were significant differences in composition from particle to particle, and these differences were similar to those found in the coal mineral matter as isolated by low-temperature ashing. Single particles of low-temperature ash were found having low fusion temperatures, in the range of fusion temperatures for particles in furnace ash. Thus, the glassy spheres found in furnace deposits could originate from single coal particles, without the need for interactions among coal particles or ash particles.

An energy dispersive x-ray analysis study of elemental loss from globoid crystals in protein bodies as a result of osmium tetroxide fixation

1978 ◽  
Vol 56 (19) ◽  
pp. 2408-2414 ◽  
Author(s):  
J. N. A. Lott ◽  
J. S. Greenwood ◽  
C. M. Vollmer
Keyword(s):  
Osmium Tetroxide ◽  
Juglans Regia ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
X Ray ◽  
Edx Analysis ◽  
Freeze Dried ◽  
Major Loss ◽  
Degree Of Extraction ◽  
Helichrysum Bracteatum

This study was undertaken to discover what elemental losses, if any, were occurring from globoid crystals in seed protein bodies during glutaraldehyde – osmium tetroxide fixation. Unfixed cotyledon and radicle tissue of Cucurbita maxima seed, or tissue after glutaral–dehyde–OsO4 treatment, was quick frozen in liquid N2, ground with a cold mortar and pestle, and low-temperature freeze-dried. Globoid crystals in the freeze-dried powder were subjected to energy dispersive x-ray (EDX) analysis. OsO4 fixation resulted in a major loss of P, Mg, and K from cotyledon globoid crystals and a major loss of P, Mg, K, and Ca from radicle globoid crystals. Despite the loss of elements, the OsO4-fixed globoid crystals were still electron dense. When globoid crystals from glutaraldehyde-fixed, dehydrated, and embedded cotyledon tissue were compared with globoid crystals from glutaraldehyde–OsO4-fixed, dehydrated, and embedded tissue, some extraction was found. The degree of extraction varied from complete loss of P, K, and Mg to loss of K only.Effects of glutaraldehyde–OsO4 fixation upon elemental composition of globoid crystals in several other species was also determined. Brazil nut (Bertholletia excelsa) radicle tissue or cotyledon tissue from walnut (Juglans regia), hazelnut (Corylus avellana), sunflower (Helianthus annuus), golden everlasting daisy (Helichrysum bracteatum), cashew (Anacardium occidentale), pistachio (Pistacia vera), and the Western Australian red-capped gum (Eucalyptus erythrocorys) were fixed either in glutaraldehyde or in glutaraldehyde–OsO4. In these species, EDX analysis of globoid crystal sections showed that OsO4 fixation results in major loss of Mg, K, and Ca. Generally, phosphorus levels were reduced from control values as well. When carrying out EDX analysis studies of globoid crystals, we recommend (1) avoiding any use of OsO4, (2) keeping all fixation, washing, and dehydration times as short as possible, and (3) checking all observations with freeze-dried powders.

Studies of metal uptake, especially iron, into protein bodies of Capsella and Lycopersicon seeds

1980 ◽  
Vol 58 (11) ◽  
pp. 1244-1249 ◽  
Author(s):  
Ernest Spitzer ◽  
John N. A. Lott ◽  
Catherine M. Vollmer
Keyword(s):  
Contaminated Soil ◽  
Metal Contamination ◽  
Metal Uptake ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
X Ray

Energy dispersive X-ray analysis was used to investigate metal uptake into the globoid crystals of Capsella and Lycopersicon seeds. Capsella seeds were taken from the curbside of a major roadway where metal contamination was highest, 5 m from the curb where less metal contamination occurs, and from an area well away from any roadways. Globoid crystals in Capsella protein bodies generally contained P, K, Ca, and Mg. No uptake of Pb or any other toxicant metals into the globoid crystals was found. Globoid crystals from the radicles and cotyledons of seeds produced by plants growing near the curb generally contained Fe whereas seeds of plants growing 5 m back from the curb contained traces of Fe in globoid crystals in certain tissues. Seeds of plants growing farthest from any roadway contained no Fe in their globoid crystals. Seeds of Lycopersicon were grown in metal-contaminated soil obtained near a smelter, a 1:1 mixture of this contaminated soil and regular potting soil, and a control. Globoid crystals from control seeds generally contained P, K, and Mg, while Ca, Mn, and (or) Fe were present occasionally. Control endosperm globoid crystals did not contain Fe. No pollutant metals were taken up into the globoid crystals. Iron which was present in the contaminated soil was found in the globoid crystals of the endosperm in those seeds obtained from plants grown in contaminated soil. Also, although Fe-containing globoid crystals were specifically located throughout the embryo in control seeds, there was no evidence that seeds of plants grown in contaminated soil contained more Fe in these areas.

Studies of mature seeds of eleven Pinus species differing in seed weight. II. Subcellular structure and localization of elements

1993 ◽  
Vol 71 (4) ◽  
pp. 577-585 ◽  
Author(s):  
M. M. West ◽  
J. N. A. Lott
Keyword(s):  
Seed Weight ◽  
Female Gametophyte ◽  
Protein Body ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
Body Structure ◽  
X Ray ◽  
Tissue Weight ◽  
Membrane Bound ◽  
Mature Seeds

Seed tissues of 11 species of Pinus, varying greatly in seed weight, all contained protein bodies with one or more protein crystalloids and (or) one or more globoid crystals. Protein body structure and the types of elements stored in globoid crystals of protein bodies were similar between female gametophytes and their embryos. Energy dispersive X-ray analysis of globoid crystals revealed the presence of P, K, and Mg, a finding consistent with their being phytate rich. Traces of Ca and Fe were also detected in globoid crystals of some tissues. The P and Mg levels in globoid crystals of embryo and female gametophyte tissues decreased as interspecific seed tissue weight increased. High levels of Fe and significant levels of P, K, and Mg were detected in small, often ≤ 0.33 μm, naturally electron-dense particles distributed in all tissues of the embryo and female gametophyte. Unlike conventional phytate-rich globoid crystals, these Fe-rich particles were not contained in typical protein bodies but were contained within membrane-bound structures that may be plastids. Iron levels of the Fe-rich particles of Pinus seed tissues decreased as seed tissue weight increased. Key words: Pinus, seed weight, energy dispersive X-ray analysis, globoid crystals, Fe-rich particles.

Occurrence of Globoid Crystals in Cotyledonary Protein Bodies of Pisum sativum as Influenced by Experimentally Induced Changes in Mg, Ca and K Contents of Seeds

1985 ◽  
Vol 12 (4) ◽  
pp. 341 ◽  
Author(s):  
JNA Lott ◽  
PJ Randall ◽  
DJ Goodchild ◽  
S Craig
Keyword(s):  
Electron Microscopy ◽  
Pisum Sativum ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
Rare Occurrence ◽  
Review Of Literature ◽  
X Ray ◽  
K Concentration ◽  
Induced Changes ◽  
Experimentally Induced

In many species globoid crystals in protein bodies of seeds are very common while in other species they are rarely observed. A review of literature suggested that the balance between divalent (Mg2+ and Ca2+) and monovalent (K+) cations may be important in determining whether or not globoid crystals will form. To test this hypothesis, experiments were carried out to add Mg and Ca, or Ca alone, to pods developing on K-deficient pea plants. While it was possible to cause a reduction in K concentration and increases in Mg and Ca concentrations, any changes to the normal mineral storage pattern in pea cotyledons were remarkably small. In some treatments, statistically significant increases in the ratio (Mg + Ca)/K were obtained and the sample with the greatest increase was examined in detail by electron microscopy and energy dispersive X-ray analysis. In this sample globoid crystals were common, in contrast to their normally rare occurrence in pea cotyledonary tissue.

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