The data gained using the yeast mitotic activator, Spcdc25, expressing plants clearly argue for the existence and importance of activatory dephosphorylation at G2/M transition and its interaction with cytokinin signalling in plants. The observed cytokinin-like effects of Spcdc25 expression are consistent with the concept of interaction between cell cycle regulators and phytohormones during plant development.
The G2/M control of plant cell cycle, however, remains an elusive issue as doubts persist about the mode of activatory dephosphorylation, which in other eukaryotes is provided by Cdc25 phosphatase serving as a final all-or-nothing mitosis regulator.