An ancient mechanism controls the development of cells with a rooting function in land plants. by Menand, B, Yi, K, Jouannic, S, Hoffmann, L, Ryan, E, Linstead, P, Schaefer, D, Dolan, L

“…The phylogeny of land plants supports the hypothesis that early land plants were bryophyte-like and possessed a dominant gametophyte and later the sporophyte rose to dominance. If this hypothesis is correct, our data suggest that the increase in morphological complexity of the sporophyte body in the Paleozoic resulted at least in part from the recruitment of regulatory genes from gametophyte to sporophyte.…”

Body building on land: morphological evolution of land plants. by Dolan, L

“…The life cycle of the land plant body comprises two multicellular stages -- one haploid (gametophyte) and the other diploid (sporophyte). Recent discoveries suggest that the genes controlling diploid development in ancestral green algal zygotes diversified in the land plant lineage where they control the development of the diploid body plan. …”

Morphological evolution in land plants: new designs with old genes. by Pires, N, Dolan, L

“…The evolution of plants on land was itself characterized by a series of radical transformations of their body plans that included the formation of three-dimensional tissues, de novo evolution of a multicellular diploid sporophyte generation, evolution of multicellular meristems, and the development of specialized tissues and organ systems such as vasculature, roots, leaves, seeds and flowers. …”

The evolution of root hairs and rhizoids. by Jones, V, Dolan, L

“…Root hairs form on the surface of roots of sporophytes (the multicellular diploid phase of the life cycle) in vascular plants. …”