Journal ArticleDOI
The ultrastructure of the fertilized embryo sac of petunia
Van Went
- Vol. 19, Iss: 4, pp 468-480
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TLDR
The ultrastructural changes of the embryo sac of Petunia during and after fertilization are described, indicating a changing metabolic activity.Abstract:
SUMMARY
The ultrastructural changes of the embryo sac of Petunia during and after fertilization are described. The pollen tube enters the embryo sac by growing through the filiform apparatus and discharges its content into one of the synergids (penetrated synergid). The volume of the penetrated synergid increases and the cell bursts at its chalazal pole. The synergid and discharged pollen tube cytoplasm merge and subsequently degenerate. The degeneration is marked by the darkening of the cytoplasm and the disappearance of organelles. A complex rough endoplasmic reticulum and numerous small spheres remain discernible longest. Two degenerating nuclei are present in the penetrated synergid.
The ultrastructure of the zygote changes slightly during its early development. 50 hrs after pollination (10–15 hrs after fertilization) the nucleus does not contain chromatin clumps any more and is surrounded by a shell of plastids.
The primary endosperm cell shows a number of marked changes after the formation of its nucleus. The ribosomes become aggregated into large polysomes and the plasma matrix becomes homogeneously electron-dense. Both the mitochondria and dictyosomes change in ultrastructure and shape. Plastids, without starch, appear as the endoplasmic reticulum becomes very extensive. This ultrastructural differentiation indicates a changing metabolic activity.read more
Citations
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Journal ArticleDOI
Elimination of plastids during spermatogenesis and fertilization in the plant kingdom.
TL;DR: Ulastructural and genetic investigations involving diverse species of plants have demonstrated that plastids may be transmitted either biparentally or maternally during sexual reproduction, suggesting that this inheritance pattern may have evolved independently many times in response to different selective pressures in different phyletic lineages.
Book ChapterDOI
The Female Gametophyte
M. T. M. Willemse,J. L. van Went +1 more
TL;DR: The female gametophyte develops from the megaspore formed in the nucellar tissue of the ovule, which consists, after cytokinesis, of an egg apparatus, a central cell, and antipodal cells.
Journal ArticleDOI
Mitochondrial GFA2 Is Required for Synergid Cell Death in Arabidopsis
Cory Christensen,Steven W. Gorsich,Ryan H. Brown,Linda G. Jones,Jessica C.S. Brown,Janet M. Shaw,Gary N. Drews +6 more
TL;DR: The identification and phenotypic analysis of 31 new FG mutants in Arabidopsis are reported, indicating that FG-expressed genes govern essentially every step of FG development and suggesting a role for mitochondria in cell death in plants.
Journal ArticleDOI
Fertilization in Arabidopsis thaliana wild type: Developmental stages and time course
TL;DR: It is shown that the timing of synergid degeneration and pollen tube release correlate well, suggesting that either the synergid cell degenerates at the time of pollen tube discharge or very shortly before it.
Journal ArticleDOI
The cytological basis of the plastid inheritance in angiosperms
R. Hagemann,M. B. Schröder +1 more
TL;DR: The mechanism behind plastid exclusion during the first haploid mitosis and its role in sperm cell formation or development is still unclear.
References
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Journal ArticleDOI
Capsella embryogenesis: the egg, zygote, and young embryo
Journal ArticleDOI
Cotton embryogenesis: The entrance and discharge of the pollen tube in the embryo sac.
TL;DR: An analysis of the entrance and discharge of the pollen tube into the embryo sac of Gossypium hirsutum was made with the light and electron microscopes to explain the passage of the sperm nuclei into the egg and central cell.
Journal ArticleDOI
Fine structural development of the megagametophyte of zea mays following fertilization
TL;DR: The changes in cytoplasmic fine structure during the interval between pollination and zygotic division in the megagametophyte of Zea mays are reported and are interpreted to reflect a presumed increase in metabolic rate relative to growth.
Journal ArticleDOI
Fertilization in barley
David D. Cass,William A. Jensen +1 more
TL;DR: Degenerate vegetative and synergid nuclei remain in the synergid after fertilization, constituting what are considered to be X-bodies in barley.