scholarly journals Energy-dispersive x-Ray Analysis of Phosphorus, Potassium, Magnesium, and Calcium in Globoid Crystals in Protein Bodies from Different Regions of Cucurbita maxima Embryos

1978 ◽  
Vol 61 (6) ◽  
pp. 984-988 ◽  
Author(s):  
John N. A. Lott ◽  
John S. Greenwood ◽  
Catherine M. Vollmer ◽  
Mark S. Buttrose
1980 ◽  
Vol 58 (6) ◽  
pp. 699-711 ◽  
Author(s):  
Ernest Spitzer ◽  
John N. A. Lott

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.


1995 ◽  
Vol 73 (6) ◽  
pp. 954-957 ◽  
Author(s):  
M. Marcia West ◽  
Derrick T. Flannigan ◽  
John N.A. Lott

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.


1991 ◽  
Vol 69 (11) ◽  
pp. 2545-2554 ◽  
Author(s):  
Sara Maldonado ◽  
John N. A. Lott

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.


1978 ◽  
Vol 5 (5) ◽  
pp. 631 ◽  
Author(s):  
MS Buttrose

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.


1983 ◽  
Vol 63 (4) ◽  
pp. 1071-1074 ◽  
Author(s):  
J. CHONG ◽  
S. T. ALI-KHAN ◽  
B. B. CHUBEY ◽  
G. H. GUBBELS

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


1978 ◽  
Vol 56 (19) ◽  
pp. 2408-2414 ◽  
Author(s):  
J. N. A. Lott ◽  
J. S. Greenwood ◽  
C. M. Vollmer

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.


Author(s):  
Irene Ockenden ◽  
John N.A. Lott

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.


1980 ◽  
Vol 58 (11) ◽  
pp. 1244-1249 ◽  
Author(s):  
Ernest Spitzer ◽  
John N. A. Lott ◽  
Catherine M. Vollmer

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.


1996 ◽  
Vol 74 (6) ◽  
pp. 838-847 ◽  
Author(s):  
Penny Beecroft ◽  
John N. A. Lott

Energy dispersive X-ray analysis was used to study the element composition of globoids from the cotyledons of Cucurbita maxima and Cucurbita andreana seeds and seedlings at various stages of growth. The influence of light and mineral nutrient conditions on changes in globoid composition was also investigated. The element composition of globoids changed markedly during early seedling growth. In both species, regardless of light and mineral nutrient conditions, K decreased markedly, Mg, Ca, Fe, Mn, and Zn generally increased, and P remained relatively constant. There were differences in globoid composition changes between the two species that could be attributed, at least in part, to differences in the Ca content of the mature, dry embryos. In C. andreana, which had a higher initial Ca content, there was a large increase in the Ca content of the globoids during seedling growth and no significant increase in Mn. In C. maxima globoids, there was only a slight increase in Ca, but there was a much larger increase in Fe, Zn, and Mn than occurred in C. andreana. Light conditions alone did not have a significant influence on the changes in globoid composition. Light, in combination with mineral nutrients, resulted in a more rapid degradation of globoids in the later stages of growth. Mineral nutrient conditions affected mostly elements that were initially present in large amounts. There were very large, globoid-like particles present in some later stage samples of both species, from each of the different growth conditions. These particles had element compositions that were consistent with their being composed of phytate. Keywords: Cucurbita, energy dispersive X-ray analysis, globoids, mineral nutrient reserves, large particles.


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