We investigated gene activity within the giant embryos of the scarlet runner bean (Phaseolus coccineus) to gain understanding of the processes by which the apical and basal cells become specified to follow different developmental pathways after division of the zygote. We identified two mRNAs, designated G564 and C541, that accumulate specifically within the suspensor of globular-stage embryos. ...

We have isolated PcGA3ox1, a cDNA clone from developing runner bean (Phaseolus coccineus) seeds that shows significant amino acid homology with the gibberellin (GA) 3-oxidases. A recombinant fusion protein of PcGA3ox1 converted GA20 and GA9 to GA1 and GA4, respectively. In situ hybridization results showed that transcripts of this gene accumulate specifically within the suspensor of globular-st...

The plant embryo is supported by a lifeline known as a suspensor that acts like an umbilical cord, connecting the embryo to surrounding tissues in the seed and ferrying in vital nutrients and growth factors. Although scientists have for a century known that the suspensor is a temporary organ, the molecular trigger for its demise was unknown. Now Mengxiang Sun at Wuhan University in China and hi...

Division of the Arabidopsis zygote defines two fundamentally different developmental domains, the proembryo and suspensor. The resulting boundary separates domain-specific gene expression, and a signal originating from the proembryo instructs the suspensor to generate the root stem cell niche. While root induction is known to require the phytohormone auxin and the Auxin Response Factor MONOPTER...

Gibberellins (GAs) in suspensors and embryos of Phaseolus coccineus seeds at the heart stage of embryo development were analyzed by combined gas chromatography-mass spectrometry (GC-MS). From the suspensor four C,9-GAs, GA1, GA4, GA5, GA6, and one C2o GA, GA44, were identified. From the embryo, five C1gGAs GA,, GA4, GAs, GAs, GAo0 and two C20 GAs, GA1,9 and GA4 were identified. The data, in rel...

Although animals eliminate apoptotic cells using macrophages, plants use cell corpses throughout development and disassemble cells in a cell-autonomous manner by vacuolar cell death. During vacuolar cell death, lytic vacuoles gradually engulf and digest the cytoplasmic content. On the other hand, acute stress triggers an alternative cell death, necrosis, which is characterized by mitochondrial ...

Maternal gene products deposited in the egg regulate early embryogenesis before activation of the embryonic genome in animals. While in higher plants, it is believed that genes of parental origin contribute to early embryogenesis. However, little is known regarding the particular processes in which genes of parental origin are involved during early embryogenesis. Previously, we found that the i...

Plant zygote divides asymmetrically into an apical cell that develops into the embryo proper and a basal cell that generates the suspensor, a vital organ functioning as a conduit of nutrients and growth factors to the embryo proper. After the suspensor has fulfilled its function, it is removed by programmed cell death (PCD) at the late stages of embryogenesis. The molecular trigger of this PCD ...

In contrast to angiosperms, pines and other gymnosperms form well-developed suspensors in somatic embryogenic cultures. This creates a useful system to study suspensor biology. In a study of gene expression during the early stages of conifer embryogenesis, we identified a transcript, PtNIP1;1, that is abundant in immature loblolly pine (Pinus taeda) zygotic and somatic embryos, but is undetecta...

In contrast to angiosperms, pines and other gymnosperms form well-developed suspensors in somatic embryogenic cultures. This creates a useful system to study suspensor biology. In a study of gene expression during the early stages of conifer embryogenesis, we identified a transcript, PtNlPl;l, that is abundant in immature Pinus taeda zygotic and somatic embryos, but is undetectable in later-sta...