THE MADS-BOX FLORAL HOMEOTIC GENE LINEAGES PREDATE THE ORIGIN OF SEEDPLANTS - PHYLOGENETIC AND MOLECULAR CLOCK ESTIMATES

Flower development in angiosperms is controlled in part by floral home otic genes, many of which are members of the plant MADS-box regulatory gene family. The evolutionary history of these developmental genes wa s reconstructed using 74 loci from 15 dicot, three monocot, and one co nifer species. Molecular clock estimates suggest that the different fl oral homeotic gene lineages began to diverge from one another about 45 0-500 mya, around the time of the origin of land plants themselves.