HDA6 affects the expression level and pattern of ETC1 and GL2. A, Expression levels of pattern genes were analyzed in root tips of axe1-4, HDA6 complementation line, and HDA6 overexpression line compared with Col. Error bars represent sd values from at least three biological replicates each consisting of three technical replicates. **, P < 0.01 and *, P < 0.05, Student’s t test. B, Root epidermal view of 7-d-old seedlings bearing the GL2pro:GFP reporter gene. Bars = 50 μm. C, Root epidermal view of 7-d-old seedlings bearing the WERpro:GFP reporter gene. Bars = 50 μm. D, Seven-day-old seedlings bearing the ETC1pro:GUS reporter gene were stained for GUS activity. Bars = 50 μm. E, Seven-day-old seedlings bearing the CPCpro:GUS reporter gene were stained for GUS activity. Bars = 50 μm. In B to E, N indicates nonhair cell position, H indicates hair cell position, and asterisks indicate ectopic reporter gene-expressing cells. F, ETC1 and GL2 expression levels are significantly increased in the root tip of gl3/egl3/axe1-4 compared with gl3/egl3. Error bars represent sd values from at least three biological replicates each consisting of three technical replicates. *, P < 0.05, Student’s t test; N.S., no significance.