Conservation of Arabidopsis root hair morphogenesis genes in other plants. A differential matrix heat map was generated for the AtRHM-containing GreenPhyl gene families. Each species (from left to right: P.
patens, Selaginella, rice, maize, tomato, soybean, and cucumber; ordered by hierarchical clustering) was scored for its degree of conservation (blue = highest and red = lowest) based on the presence/absence of a gene and its expression profile, relative to the AtRHM gene in each family. Major categories of AtRHM genes are indicated; a detailed list of these is given in Supplemental Data Set S6.