Figure 7.

Expression patterns of AtHO1 and 2 using promoter-GUS fusions. The coding region for GUS, under the control of either the AtHO1 or the AtHO2 promoter, was introduced into wild-type WS (AtHO1) or wild-type Col (AtHO2). Plants were stained for GUS activity using the substrate 5-bromo-4-chloro-3-indolyl β-d-GlcUA; staining times for AtHO2 plants were increased to provide staining equivalent to that of AtHO1 plants. Top, Ten-day-old light-grown plants. Insert shows a magnification of a root tip. Bottom, Etiolated 4-d-old seedlings. Arrows point to cotyledons (cot), hypocotyls (hy), leaf (lf), roots (r), root tip (rt), and seed (sd).