The floral regulator LEAFY evolves by substitutions in the DNA binding domain

The plant-specific transcription factor LEAFY controls general aspects of the fife cycle in a basal plant, the moss Physcomitrella patens. In contrast, LEAFY has more specialized functions in angiosperms, where it specifically induces floral fate during the reproductive phase. This raises the question of a concomitant change in the biochemical function of LEAFY during the evolution of land plants. We report that the DNA binding domain of LEAFY, although largely conserved, has diverged in activity. On the contrary, other, more rapidly evolving portions of the protein have few effects on LEAFY activity.
LEAFY (LFY) is found in all land plants, which evolved during the past 400 million years. The proteins are remarkably well conserved with two blocks of similarity, in the N- [...]