Figure 4.

Leaf epidermal development: A gene regulating Arabidopsis trichome density. Scanning electron micrographs of (A) wild-type seedlings or (D) leaves show trichomes (leaf hairs) distributed on the top surface of true leaves (A and D) but not cotyledons (A). Reducing function of the GL3 transcription factor by (B) mutation or by (E) expressing a GL3 antisense construct results in fewer epidermal cells entering the trichome lineage. Introducing a wild-type copy of the gene restores trichome formation on true leaves in gl3-1 (C), and overexpressing GL3 in wild type results in excessive trichome formation (F). Figure modified from Payne et al. (2000).