Fig. 5. Response to spore inducers in culminants. Cells of the indicated wild-type and mutant strains were developed on filters and harvested at the mid-culmination stage. The fruiting bodies were dissociated and the cells washed before plating a density of 10⁴ cells/cm² in cAMP buffer. The cells were then treated with no addition (none), 100 nM discadenine (disc), 100 nM isopentenyl adenine (iP), 1 µM zeatin, 10 pM synthetic SDF-1, 10 pM synthetic SDF-2 or 1 µM GABA. Spores were counted after 1 hour for most factors. Cells treated with SDF-1 were scored after 90 minutes.