Search results for "Phragmosome"
showing 3 items of 3 documents
Cell Cycle in Potentially Dedifferentiating Cereal Mesophyll Protoplasts Cultured in vitro II. Behaviour of the Cytoskeleton
1993
Summary Following up on the recent finding that mesophyll protoplasts of wheat and oats were able to reenter the cell cycle when cultured in vitro , the behaviour of the cytoskeleton was studied. The aim was to elucidate whether changes in the cytoskeletal patterns correlate with the abnormal progression through the cycle observed previously. Protoplasts freshly isolated from mature mesophyll tissue (type B) exhibited very few, fragmented microtubules, whereas mesophyll protoplasts isolated from immature leaf tissue (type A) showed an abundant network fo microtubules. Type B protoplasts of wheat, which were able to reenter but recalcitrant to complete S-phase, failed to reestablish a microt…
The First Cell Division Cycle in Nicotiana Mesophyll Protoplasts Cultured in vitro II. Microtubules and the Plane of Division
1991
Summary Reorganization of the microtubular cytoskeleton prior to and during the first cell division cycle of Nicotiana mesophyll protoplasts was investigated using immunofluorescence microscopy. Bands of microtubules reminiscent of PPBs were found. However, their structure was comparatively diffuse. In addition, frequencies were low compared to those in meristem cells of organized tissues. Abnormalities during phragmoplast and cell plate formation were observed. The question is raised whether the formation of abnormal PPBs is related to strategic difficulties in co-ordinating the formation of a coherent plate of cytoplasm (phragmosome) traversing the vacuole to permit smooth bisecting of th…
Microtubules and the First Cell Cycle in Cultured Mesophyll Protoplasts of Nicotiana
1990
When a protoplast is excised and cultured in vitro, an organized pattern of cell divisions must be reestablished to permit organogenesis, including plant regeneration. However, in a number of species protoplasts have proved to be very recalcitrant with regard to cell division and/or plant regeneration. In an attempt to find means to overcome the regeneration problem in recalcitrant species we are investigating the processes leading to cell division and morphogenesis in mesophyll protoplasts of the model system Nicotiana. Of particular interest are the initiation of the cell cycle and the coordination of progress through the cycles as a prerequisite for subsequent morphogenesis. Mesophyll pr…