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.

The aspartic proteinase is expressed in Arabidopsis thaliana seeds and localized in the protein bodies

1999 ◽  
Vol 9 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Asuman Mutlu ◽  
Xia Chen ◽  
Sridhar M. Reddy ◽  
Susannah Gal
Keyword(s):  
Arabidopsis Thaliana ◽  
Seed Storage Protein ◽  
Protein Body ◽  
Seed Storage ◽  
Cell Types ◽  
Aspartic Proteinase ◽  
Protein Bodies ◽  
Marker Enzyme ◽  
Antigenic Peptides ◽  
2S Albumin

AbstractWe have been studying a seed aspartic proteinase, termed AtAP, from Arabidopsis thaliana. In previous work, we purified the proteinase, analysed its activity and isolated the cDNA sequence. In this paper, the expression of the mRNA for the aspartic proteinase was analysed in seed tissues both by Northern blots for overall regulation and by in situ hybridization to follow cell-specific localization of message. We found a 1.9 kb aspartic proteinase message in dry seeds and seed pods. This message was expressed in many different cell types of the mature dry seed. The localization of the protein within these cells was also determined. Antibodies were raised against the AtAP and purified using affinity chromatography on an AtAP–immobilized-pepstatin A–agarose column. This purified antibody recognized several AtAP peptides in seeds. To localize the enzyme in cells, we isolated protein bodies from the dry seeds of Arabidopsis using a non-aqueous isolation method. The AtAP activity and antigenic peptides were found to be highest in the protein body fraction and co-localized with the seed storage protein 2S albumin and the vacuolar marker enzyme α-mannosidase. This protein body localization of the AtAP was confirmed with immunocytochemical localization by electron microscopy and shows that the protein is not secreted by these cells.

Seasonally dependent formation of protein-storage vacuoles in the inner bark tissues of Salix microstachya

1990 ◽  
Vol 68 (8) ◽  
pp. 1747-1755 ◽  
Author(s):  
John S. Greenwood ◽  
Cobi Demmers ◽  
Suzanne Wetzel
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Protein Body ◽  
Protein Bodies ◽  
Electron Microscopic ◽  
Protein Storage ◽  
Inner Bark ◽  
Protein Storage Vacuoles ◽  
Body Development ◽  
Microscopic Studies

The inner bark tissues of temperate hardwoods often act in the temporary storage of reduced nitrogen as protein during the overwintering period. Electron microscopic studies reported here demonstrate the analogy between the protein-storage vacuoles of the inner bark tissues and protein bodies in seeds. Development of these organelles parallels that of protein body formation seen in many dicotyledonous seeds. Coincident with the synthesis and sequestering of specific proteins, the large central vacuoles of the phloem parenchyma cells are slowly replaced over a 3- to 4-week period with numerous smaller protein-storage vacuoles (protein bodies). These arise via the subdivision of the larger vacuole and subsequent filling of the smaller vacuoles with protein. During this process there is a proliferation of both free ribosomes and rough endoplasmic reticulum in the ground cytoplasm. Stacks of rough endoplasmic reticulum are present in the peripheral cytoplasm and surround the smaller vacuoles as proteinaceous material is deposited. Golgi complexes, although not numerous, are present in the ground cytoplasm during the filling of the protein storage vacuoles. Key words: protein-storage vacuoles, protein body development, Salix microstachya, hardening, nitrogen storage, dormancy onset.

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.

Involvement of the Golgi apparatus in crystalloid protein deposition in Ricinus communis cv. Hale seeds

1990 ◽  
Vol 68 (11) ◽  
pp. 2353-2360 ◽  
Author(s):  
M. J. Brown ◽  
J. S. Greenwood
Keyword(s):  
Storage Protein ◽  
Castor Bean ◽  
Protein Transport ◽  
Storage Proteins ◽  
Ricinus Communis ◽  
Protein Body ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Protein Bodies ◽  
11S Globulin

The developing endosperm of castor bean has been used extensively as a model system for studies of storage-protein synthesis and processing, yet the path of transport of the storage proteins to the protein bodies has not been elucidated. In this study, immunolocalization of the 11S globulin (crystalloid protein) was performed on sections of acrolein–glutaraldehydefixed, resin-embedded, developing castor bean endosperm. Acrolein allowed rapid fixation of the tissue necessary for preserving the ultrastructure of the endomembrane system while maintaining adequate antigenicity of the target protein. Crystalloid protein was localized in the rough endoplasmic reticulum, the known site of synthesis, and in the dense proteinaceous inclusions within the protein bodies. In addition, significant labelling of Golgi complexes and associated vesicles, 65-nm diameter coated vesicles, and larger 220-nm diameter cytoplasmic vesicles was obtained. The findings provide the first direct evidence that the storage parenchyma cells of developing castor bean endosperm possess well-developed, functional Golgi complexes. This is consistent with previous observations of seed storage proteins in other plant species. The study further suggests that two distinct classes of vesicles are involved in the transport of the 11S globulin to the protein bodies. Key words: Golgi, immunolocalization, protein body, Ricinus communis, storage protein, transport (protein).

scholarly journals Role of the endoplasmic reticulum in the synthesis of reserve proteins and the kinetics of their transport to protein bodies in developing pea cotyledons.

1982 ◽  
Vol 93 (1) ◽  
pp. 5-14 ◽  
Author(s):  
M J Chrispeels ◽  
T J Higgins ◽  
S Craig ◽  
D Spencer
Keyword(s):  
Amino Acids ◽  
Endoplasmic Reticulum ◽  
Protein Body ◽  
Protein Glycosylation ◽  
Protein Bodies ◽  
Marker Enzyme ◽  
Tissue Extracts ◽  
Reserve Protein ◽  
Rough Er ◽  
Nadh Cytochrome

Developing pea (Pisum sativum L.) cotyledons were labeled with radioactive amino acids, glucosamine, and mannose in pulse an pulse-chase experiments to study the synthesis, glycosylation, and transport of the reserve proteins vicilin and legumin to the protein bodies. Tissue extracts were fractionated on sucrose gradients to isolate either the endoplasmic reticulum (ER) or the protein bodies. Immunoaffinity gels were used to determine radioactivity in the reserve proteins (legumin and vicilin). After pulse-labeling for 45 min with amino acids, about half the total incorporated radioactivity coincided closely with the position of the ER marker enzyme NADH-cytochrome c reductase at a density of 1.13 g . cm-3 on the sucrose gradient. Both radioactivity and enzyme activity shifted to a density of 1.18 g . cm-3 in the presence of 3 mM MgCl2 indicating that the radioactive proteins were associated with the rough ER. Approximately half of the incorporated radioactivity associated with the rough ER was in newly synthesized reserve protein and this accounted for 80% of the reserve protein synthesized in 45 min. Trypsin digestion experiments indicated that these proteins were sequestered within the ER. In pulse-chase experiments, the reserve proteins in the ER became radioactive without appreciable lag and radioactivity chased out of the ER with a half-life of 90 min. Radioactive reserve proteins became associated with a protein body-rich fraction 20-30 min after their synthesis and sequestration by the ER. Pulse-chase experiments with radioactive glucosamine and mannose in the presence and absence of tunicamycin indicated that glycosylation of vicilin occurs in the ER. However, glycosylation is not a prerequisite for transport of vicilin from ER to protein bodies. Examination of the reserve protein polypeptides by SDS PAGE followed by fluorography showed that isolated ER contained legumin precursors (Mr 60,000-65,000) but not the polypeptides present in mature legumin (Mr 40,000 and 19,000) as well as the higher molecular weight polypeptides of vicilin (Mr 75,000, 70,000, 50,000, and 49,000). The smaller polypeptides of vicilin present in vicilin extracted from protein bodies (Mr 12,000-34,000) were absent from the ER. The results show that newly synthesized reserve proteins are preferentially and transiently sequestered within the ER before they move to the protein bodies, and that the ER is the site of storage protein glycosylation.

Immunocytochemical analysis of protein body formation in seeds of Sorghum bicolor

1989 ◽  
Vol 67 (10) ◽  
pp. 2850-2856 ◽  
Author(s):  
Hari B. Krishnan ◽  
Jerry A. White ◽  
Steven G. Pueppke
Keyword(s):  
Endoplasmic Reticulum ◽  
Sorghum Bicolor ◽  
Rough Endoplasmic Reticulum ◽  
Protein A ◽  
Sodium Dodecyl ◽  
Protein Body ◽  
Electrophoretic Analysis ◽  
Protein Bodies ◽  
Aleurone Layer ◽  
Dark Staining

Electrophoretic analysis of sorghum (Sorghum bicolor (L.) Moench) seed prolamines in the presence of sodium dodecyl sulfate reveals major proteins of 27 and 25 kDa and two other proteins of 18 and 12 kDa. Antibodies were raised against this prolamine fraction and used to examine the subcellular distribution of the proteins in developing sorghum seeds. Protein bodies in the starchy endosperm and subaleurone cells usually are round in cross section and contain darkly staining materials arranged in concentric rings. Protein bodies in the first two layers beneath the aleurone layer are irregular in shape and contain discrete pockets of light and dark staining inclusions. Prolamines were detected in both types of protein bodies by immunolabeling. Other oganelles, including Golgi complexes, mitochondria, and amyloplasts, were not labeled. The protein bodies, which have ribosomes attached to their surfaces, are directly connected to the rough endoplasmic reticulum. In some instances, this endoplasmic reticulum was specifically labeled with protein A – gold particles. Based on these observations, we suggest that the rough endoplasmic reticulum serves as the site of both synthesis and accumulation of sorghum prolamines.

Endosperm Morphology and Protein Body Formation in Developing Wheat Grain

1981 ◽  
Vol 8 (1) ◽  
pp. 5 ◽  
Author(s):  
WP Campbell ◽  
JW Lee ◽  
TP O'brien ◽  
MG Smart
Keyword(s):  
Endoplasmic Reticulum ◽  
Culture Medium ◽  
Sucrose Concentration ◽  
Light And Electron Microscopy ◽  
Starch Synthesis ◽  
Protein Body ◽  
Protein Bodies ◽  
Wheat Grain ◽  
Body Formation ◽  
Intact Plants

The development of wheat grain from intact plants and from detached ears growing in culture has been studied by light and electron microscopy. Provided the sucrose concentration was at a level sufficient to maintain a normal rate of starch synthesis, the endosperm morphology of grain from cultured ears was essentially identical to that of endosperm from intact plants. If, however, sucrose concentration in the culture medium was very low (0.25%), some morphological abnormalities occurred in the endosperm near the crease and adjacent to the seed coat. The synthesis of storage protein in the endosperm is believed to occur largely on polyribosomes attached to endoplasmic reticulum even at the earliest stages of development. Protein bodies are always surrounded by a single membrane, the origin of which may vary. Some protein bodies arise by distention of the endoplasmic reticulum and clearly the membrane here represents the sac into which the protein is discharged after synthesis. In other cases the bounding membrane may be that of a true vacuole or it may be dictyosomal in origin. The methods by which it is suggested that protein bodies are formed in wheat endosperm have parallels in other seeds, although there are some significant differences.

In Vitro Induction of Crystals of MT Protein by Vinblastine-Colcemid in Mouse Spermatids

1974 ◽  
Vol 32 ◽  
pp. 132-133
Author(s):  
John J. Wolosewick ◽  
John H. D. Bryan
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Nuclear Ring ◽  
Rough Er ◽  
Distal Direction ◽  
In Vitro Induction

Early in spermiogenesis the manchette is rapidly assembled in a distal direction from the nuclear-ring-densities. The association of vesicles of smooth endoplasmic reticulum (SER) and the manchette microtubules (MTS) has been reported. In the mouse, osmophilic densities at the distal ends of the manchette are the organizing centers (MTOCS), and are associated with the SER. Rapid MT assembly and the lack of rough ER suggests that there is an existing pool of MT protein. Colcemid potentiates the reaction of vinblastine with tubulin and was used in this investigation to detect this protein.

Hepatic Ultrastructure Changes Induced by Lithocholic Acid

1967 ◽  
Vol 25 ◽  
pp. 162-163 ◽  
Author(s):  
F. G. Zaki
Keyword(s):  
Endoplasmic Reticulum ◽  
Lithocholic Acid ◽  
Smooth Endoplasmic Reticulum ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Electron Microscopic ◽  
Hydropic Degeneration ◽  
Hepatic Cells ◽  
Low Protein ◽  
Microscopic Studies

Addition of lithocholic acid (LCA), a naturally occurring bile acid in mammals, to a low protein diet fed to rats induced marked inflammatory reaction in the hepatic cells followed by hydropic degeneration and ductular cell proliferation. These changes were accompanied by dilatation and hyperplasia of the common bile duct and formation of “gallstones”. All these changes were reversible when LCA was withdrawn from the low protein diet except for the hardened gallstones which persisted.Electron microscopic studies revealed marked alterations in the hepatic cells. Early changes included disorganization, fragmentation of the rough endoplasmic reticulum and detachment of its ribosomes. Free ribosomes, either singly or arranged in small clusters were frequently seen in most of the hepatic cells. Vesiculation of the smooth endoplasmic reticulum was often encountered as early as one week after the administration of LCA (Fig. 1).

Sign in / Sign up

Export Citation Format

Share Document