Final and Fatal Step of Tracheary Element Differentiation
Section snippets
INTRODUCTION
Most terminally differentiated cells fulfill specialized functions until they die, but for some cell types, function does not begin until after death. The developmental programs producing such functional cell corpses involve the coordination of cell differentiation with PCD. The classic example of terminal differentiation in plants is the tracheary element (TE), a functional cell corpse that forms a single unit of the water-conducting vessels of the xylem. We previously used a cell-culture
Plants, cell culture, and chemicals
Seedlings of zinnia (Zinnia elegans L. cv Green Envy; Stokes Seed, Buffalo, NY) were grown in a growth chamber at 25 °C and 60% RH with 14 h of light (110 μmol photons m2 s2) per day. Cells were isolated by the method described by Fukuda and Komamine19 using modifications described by Groover and Jones9.
Protein extraction
Intracellular proteins were isolated by homogenizing cells in extraction buffer (50 mM Tris-HCl, pH 7.5, 2 mM DTT, 250 mM sucrose) at 4 °C, followed by centrifugation at 12,000 X g at 4 °C for 15 min to
Cell Death Is Marked by the Rapid Collapse of the Vacuole and Leads to Autolysis and nDNA Fragmentation
The first morphological manifestation of differentiation occurs approximately 72 h after cell isolation, when nascent TEs synthesize an elaborate secondary cell wall between their primary cell wall and the plasma membrane. Approximately 6 h after the appearance of visible cell wall thickenings, the large central vacuole collapses rapidly and cytoplasmic streaming ceases simultaneously1, marking the irreversible termination of normal metabolism and providing a distinct morphological marker of a
REFERENCES (28)
- et al.
Calcium-mediated apoptosis in a plant hypersensitive disease resistance response
CurrBiol.
(1996) - et al.
Identification of paracaspases and metacaspases: two ancient families of caspase-like proteins, one of which plays a key role in MALT lyphoma
Molecular Cell
(2000) - et al.
Establishment of an experimental system for the study of tracheary element differentiation from single cells isolated from the mesophyll of Zinnia elegans
Plant Physiol
(1980) - et al.
Suppression of ICE in mammary epithelial cells by extracellular matrix
Science
(1995) - et al.
Signaling pathways that establish the dorsal-ventral pattern of Drosophila melanogaster
Annu Rev Genet.
(1995) - et al.
Programmed cell death of plant tracheary elements differentiating in vitro
Protoplasma
(1997) - et al.
Identification and purification of a nuclease from Zinnia elegans: a potential molecular marker for xylogenesis
Planta
(1989) - et al.
Isolation and characterization of cDNAs encoding xylogenesis-associated and wounding-induced ribonucleases in Zinnia elegans
Plant Mol Biol
(1996) - et al.
Induction of cysteine and serine proteases during xylogenesis in Zinnia elegans
Plant Mol Biol
(1996) - et al.
Transient and specific expression of a cysteine endopeptidase associated with autolysis during the differentiation of Zinnia mesophyll cells into tracheary elements
Plant Cell Physiol
(1995)