OsRAA1 expression patterns. A, OsRAA1 northern blot of RNA from tissues of young shoots, roots, young spikes, and leaves in wild-type plants. Young spikes were harvested from 70-d-old plants grown in a growth chamber. The remaining materials were from plants grown for 14 d. Ethidium bromide (EtBr) staining shows equal RNA loading. B to G, In situ localization of OsRAA1 transcript in wild-type rice with an antisense probe. B, Longitudinal section of young root with lateral root. C, Longitudinal section of young root with lateral root primordium. D, Longitudinal section of young shoot, including the junction part between shoot and roots. E, Longitudinal section of young spike. F, Longitudinal sections of root tip. G, Details of young root meristem zone. b, e, and g are the control sections with a sense probe of OsRAA1 corresponding to B, E, and G sections, respectively. C and D photos were taken after mounting of slides using resin, so signals are blue. The remaining photos were taken before mounting of the slide, therefore, signals are brown.