The Evolution of Embryogeny in Seed Plants and the Developmental Origin and Early History of Endosperm

Friedman, William E.

doi:10.2307/2445320

Cited by 31 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Friedman (e.g. , , ), who conducted extensive studies of this hypothesis, argued that kin selection theory (Hamilton, , b) may account for embryo altruism and cooperation between products of double fertilization, i.e. a supernumerary embryo may have evolved into supportive tissue because of the inclusive fitness gained from the sister embryo (Queller, ; Friedman, ).…”

Section: Discussionmentioning

confidence: 99%

The embryo sac ofVanilla imperialis(Orchidaceae) is six-nucleate, and double fertilization and formation of endosperm are not observed

2014

View full text Add to dashboard Cite

Double fertilization and subsequent endosperm formation are two of the most important synapomorphies of the angiosperms. Endosperm is generally lacking in Orchidaceae, but Swamy reported the formation of up to ten endosperm nuclei in Vanilla planifolia in 1947. The observation was documented only by line drawings and has not been confirmed; however, assumptions about endosperm formation occurring in Orchidaceae are primarily founded on Swamy's study. The current study provides the first detailed description of embryo sac formation and early embryogeny in Vanilla since Swamy, and is the first using modern imaging techniques. Flowers of Vanilla imperialis were artificially pollinated at 1-week intervals and the resulting fruits were fixed, embedded and sectioned for light microscopy of embryo sac formation, fertilization and early development of the embryo. Three-dimensional reconstructions of embryo sacs were obtained using confocal laser scanning microscopy on fixed ovules. The mature embryo sac contains only six nuclei as a result of the arrested development of the chalazal nuclei prior to the formation of three antipodals and a polar nucleus. Fertilization was observed 7 weeks after pollination, but double fertilization and the formation of endosperm did not occur.

show abstract

Section: Discussionmentioning

confidence: 99%

The embryo sac ofVanilla imperialis(Orchidaceae) is six-nucleate, and double fertilization and formation of endosperm are not observed

2014

View full text Add to dashboard Cite

show abstract

“…Some TTN genes may have played an important role in endosperm evolution by modulating differences in mitotic cell cycles during embryo and endosperm development. The origin of the endosperm tissue during plant evolution has been the subject of considerable interest in recent years (Friedman 1994). The ttn mutants illustrate the dramatic effects that changes in single genes can have on endosperm morphology.…”

Section: Discussionmentioning

confidence: 99%

Thetitanmutants ofArabidopsisare disrupted in mitosis and cell cycle control during seed development

1998

View full text Add to dashboard Cite

SummaryWe describe in this report a novel class of mutants that should facilitate the identification of genes required for progression through the mitotic cell cycle during seed development in angiosperms. Three non-allelic titan (ttn) mutants with related but distinct phenotypes are characterized. The common feature among these mutants is that endosperm nuclei become greatly enlarged and highly polyploid. The mutant embryo is composed of a few giant cells in ttn1, several small cells in ttn2, and produces a normal plant in ttn3. Condensed chromosomes arrested at prophase of mitosis are found in the free nuclear endosperm of ttn1 and ttn2 seeds. Large mitotic figures with excessive numbers of chromosomes are visible in ttn3 endosperm. The ttn1 mutation appears to disrupt cytoskeletal organization because endosperm nuclei fail to migrate to the chalazal end of the seed. How double fertilization leads to the establishment of distinct patterns of mitosis and cytokinesis in the embryo and endosperm is a central question in plant reproductive biology. Molecular isolation of TITAN genes should help to answer this question, as well as related issues concerning cell cycle regulation, chromosome movement and endosperm identity in angiosperms.

show abstract

“…The most interesting synapomorphy is double fertilization, presumably of the type documented in Gnetales (22,61), where both sperm produced by the male gametophyte fuse with nuclei in the female gametophyte but the second fusion produces an extra zygote rather than triploid endosperm. This implies that endosperm originated later on the angiosperm line, probably from the extra embryo (62).…”

Section: Angiosperms and Gnetalesmentioning

confidence: 96%

Phylogeny of Vascular Plants

Doyle

1998

Annu. Rev. Ecol. Syst.

155

100

View full text Add to dashboard Cite

Morphological and molecular analyses resolve many aspects of vascular plant phylogeny, though others remain uncertain. Vascular plants are nested within bryophytes; lycopsids and zosterophylls are one branch of crown-group vascular plants, and euphyllophytes (Psilophyton, sphenopsids, ferns, seed plants) are the other. In Filicales, Osmundaceae are basal; water ferns and Polypodiaceae sensu lato are both monophyletic. Seed plants are nested within progymnosperms, and coniferophytes are nested within platyspermic seed ferns. Morphology indicates that angiosperms and Gnetales are related, but detailed scenarios depend on uncertain relationships of fossils; molecular data are inconsistent but indicate that both groups are monophyletic. Amborella, Nymphaeales, Austrobaileya, and Illiciales appear basal in angiosperms. Groups with tricolpate pollen form a clade (eudicots), with ranunculids and lower hamamelids basal. Most eudicots belong to the rosid and asterid lines, with higher hamamelids in the rosid line and dilleniids scattered in both. Alismids, Arales, and Acorus are basal in monocots; palms are linked with Commelinidae.

show abstract

The Evolution of Embryogeny in Seed Plants and the Developmental Origin and Early History of Endosperm

Cited by 31 publications

References 0 publications

The embryo sac ofVanilla imperialis(Orchidaceae) is six-nucleate, and double fertilization and formation of endosperm are not observed

The embryo sac ofVanilla imperialis(Orchidaceae) is six-nucleate, and double fertilization and formation of endosperm are not observed

Thetitanmutants ofArabidopsisare disrupted in mitosis and cell cycle control during seed development

Phylogeny of Vascular Plants

Contact Info

Product

Resources

About