RNA sequencing of root zones from superrosid species adopting the Type III root epidermal cell pattern

Root epidermal cells of most land plants differentiate into root hair cells and non-hair cells. Three distribution patterns of the two types of cells have been identified, namely Type I, Type II, and Type III. Species in the superrosid clade have been reported to adopt either the Type I or Type III pattern. The Type III pattern in the model plant Arabidopsis thaliana has been studied intensively and a gene regulatory network consisting of multiple patterning genes has been identified. However, little is known about the molecular basis of the Type III pattern in other superrosid species. Here we identified Rhodiola rosea and Boehmeria nivea as adopting the Type III pattern and performed root zonation RNA sequencing for these two species. The resulting data allowed us to compare expression profiles of genes, especially homologs of the Arabidopsis patterning genes, among these Type III superrosid species. These data allowed us to investigate the molecular mechanism underlying the Type III pattern and evolution of this pattern in the superrosid clade.