The suspensor is a terminally differentiated embryonic region that connects the embryo to surrounding tissues during early seed development. Most seed-bearing plant embryos contain suspensor regions, which occur in a wide variety of sizes and shapes, and suspensor-like structures are present in the embryos of some lower land plants. Recent technological advances, including novel genomics approa...

The first structure that differentiates during plant embryogenesis is the extra-embryonic suspensor that positions the embryo in the lumen of the seed. A central role in nutrient transport has been ascribed to the suspensor in species with prominent suspensor structures. Little is known, however, about what impact the size of the rather simple Arabidopsis (Arabidopsis thaliana) suspensor has on...

The first structure that differentiates during plant embryogenesis is the extra-embryonic suspensor that positions the embryo in the lumen of the seed. A central role in nutrient transport has been ascribed to the suspensor in species with prominent suspensor structures. Little is known, however, about what impact the size of the rather simple Arabidopsis (Arabidopsis thaliana) suspensor has on...

The zygote in flowering plants usually divides transversely to form a terminal cell, which gives rise to the embryo proper, and a vacuolated basal cell, which often divides rapidly to form a structure known as the suspensor. Angiosperm suspensors vary widely in size and morphology from a single cell to a massive column of several hundred cells (Maheshwari, 1950; Wardlaw, 1955; Lersten, 1983). I...

Little is known about the molecular mechanisms by which the embryo proper and suspensor of plant embryos activate specific gene sets shortly after fertilization. We analyzed the upstream region of the scarlet runner bean (Phaseolus coccineus) G564 gene to understand how genes are activated specifically within the suspensor during early embryo development. Previously, we showed that the G564 ups...

In Arabidopsis thaliana, zygotic embryo divisions are highly regular, but it is not clear how embryo patterning is established in species or culture systems with irregular cell divisions. We investigated this using the Brassica napus microspore embryogenesis system, where the male gametophyte is reprogrammed in vitro to form haploid embryos in the absence of exogenous growth regulators. Microsp...

BACKGROUND AND AIMS Owing to large-scale collecting, the lady's slipper orchid, Paphiopedilum delenatii, is under threat of extinction. Asymbiotic germination provides a useful way to re-establish plants in the wild and for commercial propagation. A detailed study of embryo development would provide information on subsequent germination events and aid in the propagation of the species. METHOD...

The terminal differentiation and elimination of the embryo-suspensor is the earliest manifestation of programmed cell death (PCD) during plant ontogenesis. Molecular regulation of suspensor PCD remains poorly understood. Norway spruce (Picea abies) embryos provide a powerful model for studying embryo development because of their large size, sequenced genome, and the possibility to obtain a larg...

One of the major unsolved issues in plant development is understanding the regulatory networks that control the differential gene activity that is required for the specification and development of the two major embryonic regions, the embryo proper and suspensor. Historically, the giant embryo of scarlet runner bean (SRB), Phaseolus coccineus, has been used as a model system to investigate the p...

Cytological processes of differentiation in the embryo suspensor of Sedum acre L. were compared with the development of the embryo proper. The zygote undergoes an asymmetric division to produce an apical cell and a basal cell, which becomes the basal cell of the suspensor. The mature differentiated suspensor consists of a large haustorial basal cell and 3–4 chalazal cells. The basal cell nucleu...