XVI International Botanical Congess

After recovery from plasmolysis, many of the component cells of fern gametophytes will regenerate to form a new gametophyte. Our aim was to test the inhibition of cell-cell transport by plasmolysis, and to correlate any inhibition with regeneration from component cells. With increasing plasmolysis of Microsorium postulatum protonemata in solutions of CaCl2 or mannitol, there was increasing blockage of cell-cell transport. Reduced cell-cell transport was correlated with increased frequency of cell regeneration. However, only 47% of severely plasmolysed cells produced new protonemata, and in some cases, after recovery from plasmolysis there was one cell that had not formed a protonema between two cells that had, implying that this cell had not been plasmolysed. These results suggest that the mechanism inhibiting outgrowth in untreated protonemata is not only a signal from the apex but may involve an interaction between the cell wall and plasma membrane of individual cells.