scholarly journals Morphology and Taxonomic Application of Orbicules (Ubisch Bodies) in the GenusEuphorbia

Grana ◽  
1993 ◽  
Vol 32 (sup002) ◽  
pp. 26-32 ◽  
Author(s):  
Gamal El-Ghazaly ◽  
Ram Chaudhary
Keyword(s):  
Ubisch Bodies

Ultrastructural aspects of gymnosperms reproductive organs tissues due to their functional condition

1978 ◽  
Vol 36 (2) ◽  
pp. 440-441
Author(s):  
G. M. Kozubov
Keyword(s):  
Metabolic Activity ◽  
Functional Condition ◽  
Reproductive Organs ◽  
Considerable Change ◽  
Complicated Structure ◽  
Tetrad Stage ◽  
Ubisch Bodies ◽  
Similar Organization ◽  
Female Reproductive Organs ◽  
High Metabolic Activity

The ultrastructure of reproductive organs of pine, spruce, larch and ginkgo was investigated. It was found that the male reproductive organs possess similar organization. The most considerable change in the ultrastructure of the microsporocytes occur in meiosis. Sporoderm is being laid at the late tetrad stage. The cells of the male gameto-phyte are distinguished according to the metabolic activity of the or- ganells. They are most weakly developed in the spermiogenic cell. Ta-petum of the gymnosperms is of the periplasmodic - secretorial type. The Ubisch bodies which possess similar structure in the types investigated but are specific in details in different species are produced in tapetum.Parietal and subepidermal layers are distinguished for their high metabolic activity and are capable of the autonomous photosynthesis. Female reproductive organs differ more greatly in their struture and have the most complicated structure in primitive groups. On the first stages of their formation the inner cells of nucellus are transformed into the nucellar tapetum in which the structures similar to the Ubisch bodies taking part in the formation of the sporoderm of female gametophyte have been found.

The Ultrastructure and Ontogeny of Pollen in Helleborus Foetidus L

1968 ◽  
Vol 3 (2) ◽  
pp. 161-174
Author(s):  
P. ECHLIN ◽  
H. GODWIN
Keyword(s):  
Cell Wall ◽  
Tapetal Cell ◽  
Pollen Grains ◽  
Ultrastructural Level ◽  
Low Molecular Weight ◽  
Cell Organelles ◽  
Helleborus Foetidus ◽  
Ubisch Bodies ◽  
Ubisch Body ◽  
Development Proceeds

The ontogeny of the tapetum and Ubisch bodies in Helleborus foetidus L. has been examined at the ultrastructural level, and their development has been closely linked with that of the sporogenous cell and pollen grains. During development the tapetum passes through successive phases of synthesis, maturity and senescence, ending in complete dissolution. During the anabolic phase of growth, precursors of the Ubisch bodies are formed as spheroidal vesicles of medium electron density within the tapetal cytoplasm; they are associated with a zone of radiating ribosomes, which, as development proceeds, can clearly be seen to be situated on strands of endoplasmic reticulum. The callose special wall round the microspores and the tapetal cell wall now disintegrate and the pro-Ubisch bodies are extruded through the cell membrance of the tapetal cells, where they remain on the surface of the anther cavity and soon become irregularly coated with sporopollenin. Deposition of sporopollenin continues on the Ubisch bodies at the same time as upon the exines of the developing pollen grains. In both cases, the later stages of sporopollenin deposition are associated with electron-transparent layers of unit-membrane dimensions appearing in section as white lines of uniform thickness. Continuing deposition of sporopollenin leads to the formation of compound or aggregate Ubisch bodies. It is conjectured that the sporopollenin is synthesized from the compounds of low molecular weight released into the anther loculus by the breakdown of the callose special wall and the tapetal cell wall. The final stages of tapetal autolysis involve the disappearance of all the cell organelles. An attempt is made to relate the findings to those described in other recent studies on Ubisch body formation and to combine them in a common ontogenetic pattern.

Role of Ubisch bodies secreted by tapetum in Ca2+ transprot

2000 ◽  
Vol 45 (7) ◽  
pp. 630-634 ◽  
Author(s):  
Xianghong Meng ◽  
Jianbo Wang ◽  
Rongqian Li
Keyword(s):  
Ubisch Bodies

scholarly journals TDR INTERACTING PROTEIN 3 , encoding a PHD ‐finger transcription factor, regulates Ubisch bodies and pollen wall formation in rice

2019 ◽  
Vol 99 (5) ◽  
pp. 844-861 ◽  
Author(s):  
Zhengfu Yang ◽  
Lianping Sun ◽  
Peipei Zhang ◽  
Yingxin Zhang ◽  
Ping Yu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Pollen Wall ◽  
Interacting Protein ◽  
Phd Finger ◽  
Wall Formation ◽  
Ubisch Bodies

scholarly journals Origin and structure of Ubisch bodies in Pinus sylvestris

2014 ◽  
Vol 56 (2) ◽  
pp. 215-227 ◽  
Author(s):  
John R. Rowley ◽  
Björn Walles
Keyword(s):  
Plasma Membrane ◽  
Pinus Sylvestris ◽  
Minimal Surface ◽  
Surface Area ◽  
Body Wall ◽  
Current State ◽  
Ubisch Bodies ◽  
Ubisch Body ◽  
Tapetal Cells ◽  
Minimal Surface Area

In <em>Pinus sylvestris</em> Ubisch bodies are produced repeatedly, and each crop is formed at a distinct phase in the secretory cycles of tapetal cells. While each production has a Ubisch body wall similar to the then current state of the exine with regard to thickening and ornamentation, the survivers of previous productions do not change. Examples of all the structurally different Ubisch body wall forms can be seen when terminally, at the time of pollen shedding, the relict Ubisch bodies become spatially concentrated on the minimal surface area of the senescent cells of the tapetum. In angiosperms after one or a few periods of initiation Ubisch bodies may remain in association with the surface of tapetal cells where the Ubisch body wall undergoes changes like those of the maturing pollen exine. We conclude that as a consequence of Ubisch body detachment from the plasma membrane of tapetal cells there is in <em>Pinus sylvestris</em> no updated information for modification of the wall and the Ubisch body wall remains static.

A fossil flower with in situ Pistillipollenites from the Eocene of British Columbia

1988 ◽  
Vol 66 (2) ◽  
pp. 313-318 ◽  
Author(s):  
Ruth A. Stockey ◽  
Steven R. Manchester
Keyword(s):  
British Columbia ◽  
Convergent Evolution ◽  
Middle Eocene ◽  
New Taxon ◽  
Floral Structure ◽  
Ubisch Bodies ◽  
Spherical Hollow

A single actinomorphic flower has been found in the Horsefly Mine Top Section (Middle Eocene) of British Columbia. The flower, 2.1 cm in diameter, has six sepals, probably a superior ovary, and six stamens, one opposite each sepal. The pollen is morphologically identical with that of the dispersed grain of Pistillipollenites macgregorii Rouse. Grains, 22 μm in diameter, have numerous gemmae supported by columellae and a finer ornamentation of nanoverrucae. The grains are triporate with gemmae around apertures. Spherical hollow Ubisch bodies indicative of a secretory tapetum underlie remains of tapetal membranes. The floral structure of this new taxon, Pistillipollianthus wilsonii gen. et sp. nov., is distinctly different from the only other Pistillipollenites-producing flower described from the Eocene of Texas. The current study indicates that Pistillipollenites grains identified in sediments from the Cretaceous to the Eocene probably represent pollen from different angiosperm families, and it adds to the evidence that this type of gemmate grain may have evolved several times through convergent evolution.

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