Close association between plastids and endoplasmic reticulum cisterns during pollen grain development in Lycopersicon peruvianum

1976 ◽  
Vol 57 (3) ◽  
pp. 260-265 ◽  
Author(s):  
E. Pacini ◽  
M. Cresti
Keyword(s):  
Endoplasmic Reticulum ◽  
Close Association ◽  
Pollen Grain ◽  
Lycopersicon Peruvianum ◽  
Grain Development

scholarly journals Meiosis and pollen grain development in Isolepis cernua f. cernua (Cyperaceae)

Caryologia ◽  
1999 ◽  
Vol 52 (3-4) ◽  
pp. 197-201 ◽  
Author(s):  
L.P. Dopchiz ◽  
L. Poggio
Keyword(s):  
Pollen Grain ◽  
Grain Development

Anatomy of the Unpollinated and Pollinated Watermelon Stigma

1982 ◽  
Vol 54 (1) ◽  
pp. 341-355
Author(s):  
M. SEDGLEY
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Light And Electron Microscopy ◽  
Freeze Fracture ◽  
Pollen Grain ◽  
Acidic Polysaccharides ◽  
Before And After ◽  
Em Autoradiography ◽  
Pollen Grain Wall ◽  
Stigma Secretion

The structure of the watermelon stigma before and after pollination was studied using light and electron microscopy, freeze-fracture and autoradiography. The wall thickenings of the papilla transfer cells contained callose and their presence prior to pollination was confirmed using EM-autoradiography, freeze-fracture and fixation. No further callose thickenings were produced following pollination. Pollination resulted in a rapid increase in aqueous stigma secretion and localized disruption of the cuticle, which appeared to remain on the surface of the secretion. Autolysis of the papilla cells, which had commenced prior to pollination, was accelerated and appeared to take place via cup-shaped vacuoles developed from distended endoplasmic reticulum. The reaction was localized to the papilla cells adjacent to the pollen tube only. Both pollen-grain wall and stigma secretion contained proteins, carbohydrates, acidic polysaccharides, lipids and phenolics.

scholarly journals Pollen, Tapetum, and Orbicule Development inColletia paradoxaandDiscaria americana(Rhamnaceae)

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
M. Gotelli ◽  
B. Galati ◽  
D. Medan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Ultrastructural Changes ◽  
Transmission Electron ◽  
The Family ◽  
Tapetal Cells ◽  
Grain Formation

Tapetum, orbicule, and pollen grain ontogeny inColletia paradoxaandDiscaria americanawere studied with transmission electron microscopy (TEM). The ultrastructural changes observed during the different stages of development in the tapetal cells and related to orbicule and pollen grain formation are described. The proorbicules have the appearance of lipid globule, and their formation is related to the endoplasmic reticulum of rough type (ERr). This is the first report on the presence of orbicules in the family Rhamnaceae. Pollen grains are shed at the bicellular stage.

Interaction of the smooth endoplasmic reticulum and mitochondria

2006 ◽  
Vol 34 (3) ◽  
pp. 370-373 ◽  
Author(s):  
J.G. Goetz ◽  
I.R. Nabi
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Close Association ◽  
Cytosolic Calcium ◽  
Functional Roles ◽  
Calcium Dependent ◽  
Motility Factor ◽  
Calcium Sequestration ◽  
Multiple Domains ◽  
The Relationship

The ER (endoplasmic reticulum) is composed of multiple domains including the nuclear envelope, ribosome-studded rough ER and the SER (smooth ER). The SER can also be functionally segregated into domains that regulate ER–Golgi traffic (transitional ER), ERAD (ER-associated degradation), sterol and lipid biosynthesis and calcium sequestration. The last two, as well as apoptosis, are critically regulated by the close association of the SER with mitochondria. Studies with AMFR (autocrine motility factor receptor) have defined an SER domain whose integrity and mitochondrial association can be modulated by ilimaquinone as well as by free cytosolic calcium levels in the normal physiological range. AMFR is an E3 ubiquitin ligase that targets its ligand directly to the SER via a caveolae/raft-dependent pathway. In the present review, we will address the relationship between the calcium-dependent morphology and mitochondrial association of the SER and its various functional roles in the cell.

Nuclear variations and tapetum polyploidy related to pollen grain development in Passiflora L. (Passifloraceae)

2021 ◽  
Author(s):  
Letícia M. Parteka ◽  
Jorge E. A. Mariath ◽  
André L. L. Vanzela ◽  
Adriano Silvério
Keyword(s):  
Pollen Grain ◽  
Grain Development

Extrusion of Nuclear Material During Oogenesis in Blatta Orientalis

1962 ◽  
Vol s3-103 (62) ◽  
pp. 141-145
Author(s):  
R.A. R. GRESSON ◽  
L. T. THREADGOLD
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Nuclear Membrane ◽  
Close Association ◽  
Nuclear Material ◽  
Blatta Orientalis ◽  
Nucleolar Material

That nucleolar material is extruded to the cytoplasm of the young oocyte of Blatta orientalis is confirmed by means of electron microscopy. The nucleolus and nucleolar extrusions are shown to contain RNA. In addition to the nucleolar extrusions, vesicle-like structures originate in the nuclear membrane and from there pass into the cytoplasm where they become indistinguishable from elements of the endoplasmic reticulum. When the nucleolar extrusions reach the cytoplasm they increase in size, come into close association with a few mitochondria, and migrate towards the periphery of the cell. It is concluded that the emission of material from the nucleolus and the passage of vesicles from the nuclear membrane to the cytoplasm are necessary prerequisites for the process of vitellogenesis.

scholarly journals Cowpea Mosaic Virus 32- and 60-Kilodalton Replication Proteins Target and Change the Morphology of Endoplasmic Reticulum Membranes

2002 ◽  
Vol 76 (12) ◽  
pp. 6293-6301 ◽  
Author(s):  
Jan E. Carette ◽  
Jan van Lent ◽  
Stuart A. MacFarlane ◽  
Joan Wellink ◽  
Ab van Kammen
Keyword(s):  
Endoplasmic Reticulum ◽  
Mosaic Virus ◽  
Close Association ◽  
Tobacco Rattle Virus ◽  
Viral Proteins ◽  
Cowpea Mosaic Virus ◽  
Replication Proteins ◽  
Replication Complex ◽  
Cytotoxic Proteins ◽  
Cowpea Protoplasts

ABSTRACT Cowpea mosaic virus (CPMV) replicates in close association with small membranous vesicles that are formed by rearrangements of intracellular membranes. To determine which of the viral proteins are responsible for the rearrangements of membranes and the attachment of the replication complex, we have expressed individual CPMV proteins encoded by RNA1 in cowpea protoplasts by transient expression and in Nicotiana benthamiana plants by using the tobacco rattle virus (TRV) expression vector. The 32-kDa protein (32K) and 60K, when expressed individually, accumulate in only low amounts but are found associated with membranes mainly derived from the endoplasmic reticulum (ER). 24K and 110K are freely soluble and accumulate to high levels. With the TRV vector, expression of 32K and 60K results in rearrangement of ER membranes. Besides, expression of 32K and 60K results in necrosis of the inoculated N. benthamiana leaves, suggesting that 32K and 60K are cytotoxic proteins. On the other hand, during CPMV infection 32K and 60K accumulate to high levels without causing necrosis.

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