Abstract
When tobacco BY-2 cells are grown in the standard culture medium that contains auxin, they proliferate rapidly but remain small and undifferentiated. However, when they are grown in a modified culture medium that contains cytokinin instead of auxin, they hardly proliferate but become large and develop amyloplasts. For the BY-2 cells grown in the modified medium, we also observed 1) increased secretion activities accompanied by an increase in the number of dictyosomes per cell, 2) appearance of specific secreted proteins in the medium, 3) weaker cell-to-cell adhesion, and 4) earlier and more frequent cell death. These characteristics of BY-2 cells grown in the modified medium apparently resemble to, at least in part, those of cells within a root cap. To access this idea, we are now further examining the behavior of BY-2 cells in the modified medium in detail, especially secretion activity and mode of cell death.
