The ultrastructural, histochemical, and biochemical development of the post-fertilization megagametophyte and the zygotic embryo of Pseudotsugamenziesii

1993 ◽  
Vol 23 (5) ◽  
pp. 816-827 ◽  
Author(s):  
John N. Owens ◽  
Sheila J. Morris ◽  
Santosh Misra
Keyword(s):  
Zygotic Embryo ◽  
Soluble Sugars ◽  
Protein Body ◽  
Dry Weight ◽  
Protein Bodies ◽  
Lipid Bodies ◽  
Embryo Maturation ◽  
Seed Maturity ◽  
Biochemical Development ◽  
Mature Seeds

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) megagametophyte and embryo development were studied from fertilization until seed maturity, a period of about 71 days. The most important morphogenetic events occurred during the first 43 days. During this time lipid bodies and protein bodies increased rapidly in the megagametophyte. Lipids, proteins, and starch became evident in the embryo toward the end of the morphogenetic phase. The subsequent embryo maturation phase showed slight increases in size and number of megagametophyte lipid bodies and protein bodies, as well as an increase in protein body complexity. Later, in the mature seed, lipids and proteins were distributed uniformly in the megagametophyte. Starch was abundant in some regions of the embryo but not abundant in the megagametophyte. In mature seeds soluble sugars made up 2 and 3%, proteins 16 and 11%, and lipids 60 and 45% of the megagametophyte and embryo dry weight, respectively. Histochemical and ultrastructural observations confirmed these amounts of lipids and proteins and showed their distribution in megagametophytes and embryos during development.

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.

Structural Aspects of Protein Accumulation in Developing Pea Cotyledons. II. Three-Dimensional Reconstructions of Vacuoles and Protein Bodies From Serial Sections

1980 ◽  
Vol 7 (3) ◽  
pp. 329 ◽  
Author(s):  
S Craig ◽  
DJ Goodchild ◽  
C Miller
Keyword(s):  
Three Dimensional ◽  
Protein Body ◽  
Protein Bodies ◽  
Dimensional Structure ◽  
Protein Accumulation ◽  
Serial Sections ◽  
Seed Maturity ◽  
Spherical Structures ◽  
A Cell ◽  
Structural Aspects

The three-dimensional structure of vacuoles and protein bodies seen in developing cotyledons from pea (Pisum sativum L.) have been reconstructed from serial sections. At days 12 and 15 after flowering, serial sections 1 �m thick of epoxy-embedded seed tissue were used to determine vacuole morphology while, at day 20, serial sections 0.25 �m thick were examined by electron microscopy to ascertain protein body morphology. At day 12 there are one or two large vacuoles having extremely complex protrusions emanating from a larger central vacuolar volume. This gives rise to up to 20 apparently discrete vacuole profiles in a given section through a cell. By day 15, there are many smaller, approximately spherical, vacuoles and also some that are more complex. At day 20 most protein bodies are discrete, spherical structures, although a few irregularly shaped bodies are seen. The results support the concept of a large highly convoluted central vacuole fragmenting to give rise to the protein bodies seen towards seed maturity.

Ultrastructural and histochemical postfertilization megagametophyte and zygotic embryo development of white spruce (Picea glauca) emphasizing the deposition of seed storage products

1993 ◽  
Vol 71 (1) ◽  
pp. 98-112 ◽  
Author(s):  
Marek J. Krasowski ◽  
John N. Owens
Keyword(s):  
Endoplasmic Reticulum ◽  
Picea Glauca ◽  
Zygotic Embryo ◽  
Smooth Endoplasmic Reticulum ◽  
Protein Body ◽  
Seed Storage ◽  
White Spruce ◽  
Variable Number ◽  
Protein Bodies ◽  
Cytoplasmic Vesicles

Deposition of major storage substances in the megagametophyte and embryo of white spruce (Picea glauca (Moench) Voss) was studied ultrastructurally and histochemically during seed development. Lipid bodies appeared to be secreted by the smooth endoplasmic reticulum. In the megagametophyte they were deposited rapidly from the club-shaped embryo stage until the early organogenesis of the embryo. Major lipid accumulation in the embryo took place during rapid cotyledon development and simultaneously with the buildup of protein bodies. Formation of protein bodies in the megagametophyte and in the embryo was first detected approximately 6 and 29 days after fertilization, respectively. It is suggested that in the megagametophyte, this process proceeded by (i) deposition of amorphous protein clumps onto tonoplasts of subdividing vacuoles during early stages of protein body formation, (ii) fusion of small cytoplasmic vesicles possibly derived from the rough endoplasmic reticulum, and (iii) deposition of protein around dense, membrane-bound vesicles attached to tonoplasts. The third process was not observed in the embryo. During advanced formation, fusion of cytoplasmic vesicles into developing protein bodies was the only process observed in the megagametophyte and in the embryo. White spruce seed protein bodies contained a variable number of crystalloids and globoid cavities except in the embryo in which only single globoid cavities were observed. Key words: Picea, ultrastructure, histochemistry, megagametophyte, embryo, seed.

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.

SOLUBLE SUGAR CHANGES OCCURRING DURING COLD HARDENING OF SPRING WHEAT, FALL RYE AND ALFALFA

1983 ◽  
Vol 63 (2) ◽  
pp. 415-420 ◽  
Author(s):  
D. G. GREEN
Keyword(s):  
Spring Wheat ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Weight Basis ◽  
Cold Hardening ◽  
Spring Type

Alfa, a relatively nonhardy alfalfa cultivar continued to accumulate, on a dry weight basis, fructose, α- and β-D-glucose, sucrose and maltose during the latter stages of cold hardening. Rambler, a hardier alfalfa cultivar conversely showed a decrease for these soluble sugars with hardening. Frontier rye, a very hardy winter habit cereal showed decreases in these soluble sugars plus melibiose during the same hardening period. These results support the hypothesis that hardy cereals and alfalfa undergo a decrease in soluble sugars with hardening, while less hardy cereals and alfalfa continue to increase in content of soluble sugars. Manitou wheat appeared not to fit this hypothesis and showed the decreased soluble sugars usually associated with hardy cultivars. Although Manitou is a spring type wheat, one of its parents, Thatcher, does contain gene(s) for the winter habit.Key words: Sugar, cold hardening, wheat, rye, alfalfa

scholarly journals Relationship of Hull Mesocarp Color to Seed Germination and Vigor in Large-Seeded Virginia-Type Peanuts

1995 ◽  
Vol 22 (1) ◽  
pp. 22-26 ◽  
Author(s):  
J. F. Spears ◽  
G. A. Sullivan
Keyword(s):  
Accelerated Aging ◽  
Dry Weight ◽  
Seed Moisture Content ◽  
Physiological Maturity ◽  
Seed Maturity ◽  
Seed Moisture ◽  
Arachis Hypogaea L ◽  
Maturity Class ◽  
Relationship Of

Abstract Classification of peanuts (Arachis hypogaea L.) based on pod mesocarp color has become a popular means of estimating maturity of runner peanuts. This study was initiated to determine if the hull mesocarp color is related to seed maturity of virginia-type peanuts and to evaluate changes in quality as seed mature. Cultivars NC 7 and NC 9 peanuts were harvested by hand in 1990, 1991, and 1992. Pods were separated according to mesocarp color. Seed moisture content and dry weight within a maturity class varied with cultivar and production year. Germination of NC 7 seed grown in 1990 and 1992 increased as seed approached maturity. Immature NC 9 seed grown in 1991 and 1992 had substantially lower germination than seed from mature pods. There was no increase in germination during maturation of NC 7 seed harvested in 1991 or NC 9 from 1990. Seed leakage during imbibition, measured by electrical conductivity, decreased as seed matured. The lowest leakage levels occurred when seed had reached physiological maturity. Germination following accelerated aging (AA) increased as seed matured. Maximum AA germination of NC 7 occurred when seed had reached 77, 84, and 100% of their final dry weight in 1990, 1991, and 1992, respectively. NC 9 seed achieved maximum germination following AA after the seed amassed at least 90% of their final dry weight.

scholarly journals Salt-tolerance screening in Limonium sinuatum varieties with different flower colors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaojing Xu ◽  
Yingli Zhou ◽  
Ping Mi ◽  
Baoshan Wang ◽  
Fang Yuan
Keyword(s):  
Salt Tolerance ◽  
Photosynthetic Rate ◽  
Large Scale ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Salt Gland ◽  
Salt Glands ◽  
Chlorophyll Contents ◽  
Relative Water ◽  
Whole Plants

AbstractLimonium sinuatum, a member of Plumbaginaceae commonly known as sea lavender, is widely used as dried flower. Five L. sinuatum varieties with different flower colors (White, Blue, Pink, Yellow, and Purple) are found in saline regions and are widely cultivated in gardens. In the current study, we evaluated the salt tolerance of these varieties under 250 mmol/L NaCl (salt-tolerance threshold) treatment to identify the optimal variety suitable for planting in saline lands. After the measurement of the fresh weight (FW), dry weight (DW), contents of Na+, K+, Ca2+, Cl−, malondialdehyde (MDA), proline, soluble sugars, hydrogen peroxide (H2O2), relative water content, chlorophyll contents, net photosynthetic rate, and osmotic potential of whole plants, the salt-tolerance ability from strongest to weakest is identified as Pink, Yellow, Purple, White, and Blue. Photosynthetic rate was the most reliable and positive indicator of salt tolerance. The density of salt glands showed the greatest increase in Pink under NaCl treatment, indicating that Pink adapts to high-salt levels by enhancing salt gland formation. These results provide a theoretical basis for the large-scale planting of L. sinuatum in saline soils in the future.

scholarly journals The Rhodococcus opacus PD630 Heparin-Binding Hemagglutinin Homolog TadA Mediates Lipid Body Formation

2010 ◽  
Vol 76 (21) ◽  
pp. 7217-7225 ◽  
Author(s):  
Daniel P. MacEachran ◽  
M. E. Prophete ◽  
A. J. Sinskey
Keyword(s):  
Kinetic Studies ◽  
Lipid Body ◽  
Dry Weight ◽  
Rhodococcus Opacus ◽  
Lipid Bodies ◽  
Heparin Binding ◽  
Tag Biosynthesis ◽  
Tag Accumulation

ABSTRACT Generally, prokaryotes store carbon as polyhydroxyalkanoate, starch, or glycogen. The Gram-positive actinomycete Rhodococcus opacus strain PD630 is noteworthy in that it stores carbon in the form of triacylglycerol (TAG). Several studies have demonstrated that R. opacus PD630 can accumulate up to 76% of its cell dry weight as TAG when grown under nitrogen-limiting conditions. While this process is well studied, the underlying molecular and biochemical mechanisms leading to TAG biosynthesis and subsequent storage are poorly understood. We designed a high-throughput genetic screening to identify genes and their products required for TAG biosynthesis and storage in R. opacus PD630. We identified a gene predicted to encode a putative heparin-binding hemagglutinin homolog, which we have termed tadA (triacylglycerol accumulation deficient), as being important for TAG accumulation. Kinetic studies of TAG accumulation in both the wild-type (WT) and mutant strains demonstrated that the tadA mutant accumulates 30 to 40% less TAG than the parental strain (WT). We observed that lipid bodies formed by the mutant strain were of a different size and shape than those of the WT. Characterization of TadA demonstrated that the protein is capable of binding heparin and of agglutinating purified lipid bodies. Finally, we observed that the TadA protein localizes to lipid bodies in R. opacus PD630 both in vivo and in vitro. Based on these data, we hypothesize that the TadA protein acts to aggregate small lipid bodies, found in cells during early stages of lipid storage, into larger lipid bodies and thus plays a key role in lipid body maturation in R. opacus PD630.

Effect of Cytokinins on the Expansion and Metabolism of Excised Cucumber Cotyledons

1980 ◽  
Vol 7 (3) ◽  
pp. 227
Author(s):  
C Tsui ◽  
Tao Guo-qing ◽  
Chen Hui-ying ◽  
Son Yan-ru ◽  
Lian Han-ping ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Acid Synthesis ◽  
Cell Number ◽  
Cucumis Sativus L ◽  
Biochemical Processes ◽  
Dna And Rna ◽  
Lag Period ◽  
Hydrolysis Of

Expansion of excised cucumber (Cucumis sativus L.) cotyledons was stimulated by treatment with cytokinin, and commenced after a lag period of about 4 h. Expansion induced by benzyladenine (BA) was due mainly to increase of fresh weight, but cell number increased slightly. Hydrolysis of protein and lipid was stimulated by BA, and soluble sugars increased simultaneously. However, there was no significant change in the dry weight of cotyledons during the period of expansion. It is assumed that the transformation of lipid to sugar in the cotyledon is stimulated by BA. The respiration of cotyledons was evidently stimulated by BA and was entirely inhibited by respiratory inhibitors, e.g. NaN,, malonate and dinitrophenol. Inhibitors of protein and nucleic acid synthesis, such as chloramphenicol and actinomycin D, inhibited only the BA-induced expansion. They had no effect on the expansion of controls. These results suggest that different biochemical processes are involved in the expansion of cotyledons induced by BA and in controls. The former is related not only to respiration but also to the synthesis of protein and nucleic acid. BA increased DNA and RNA content per cotyledon. The increase of total RNA is due mainly to the increase of 25 S and 18 S rRNA.

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