A conspicuous feature of this stage and also at subsequent stages is that there are well-developed plasmodesmata between the neck canal cell and the central cell (Fig.
Well-developed plasmodesmata connect the ventral canal cell and the neck canal cell (Fig.
Well-developed plasmodesmata can be seen in the pore region (Fig.
Plasmodesmata diminishing and isolation of the egg.
However, the egg remains connected to the VCC by well-developed plasmodesmata
at the central region in its upper surface (Fig.
This multilayered tapetum does not develop plasmodesmata
at the pollen mother cell stage but the cell walls break down successively in the layers of tapetal cells, discharging protoplasm into the locule, where it is not enclosed by a perispore membrane [ILLUSTRATION FOR FIGURES 19-23, 34, 35 OMITTED].
But the presence of the virus in the plasmodesmata indicates more than mere movement with the food.
In somewhat older leaves, the virions occur in plasmodesmata connecting the sieve elements with adjacent parenchymatic cells.
The sequence of development of infection with the beet western yellows virus is as follows: (1) virions transported in sieve tubes, (2) virions passing through plasmodesmata into cells supporting viral synthesis, (3) appearance of single-membraned vesicles with fibrillar networks, (4) enclosure of the vesicles into ER, (5) union of the now double-membraned vesicles with the nuclear envelope, and (6) formation of new virus in the nucleus with some participation of the nucleolus.
1982) were reported, and changes in densities of plasmodesmata (Gunning, 1978) and in number and structure of chloroplasts (Whatley & Gunning, 1981) in differentiating root cells were described.
Age-related and origin-related control of the numbers of plasmodesmata in cell walls of developing Azolla roots.