Fig. 8. Two scenarios for LFY action during maintenance of floral meristem identity. Diagrams show levels of LFY activity and expression levels of shoot identity genes along with levels of an intermediate regulator. If LFY’s primary activity in this process is as a transcriptional activator, LFY:VP16 should be more potent than wild-type LFY, and reversion should not occur, because levels of shoot identity genes remain low. If LFY’s primary activity is as a transcriptional repressor, LFY:VP16 should have the opposite effect of wild-type LFY, and cause elevated shoot identity gene expression, similar to a reduction in LFY activity in lfy heterozygotes. In the latter case, a scenario without an intermediate activator is formally equivalent.
