Fig. 3.

GUS histochemical staining of seedlings and plants derived from an enhancer trap line with an insertion 300 bp upstream of the AtrbohB start codon. (A) Four-day-old seedling with staining in cotyledons, hypocotyl, and root tip. (B) Ten-day-old plantlet. Staining remains visible in cotyledons. (C) Enlarged image of root tip of 4-d-old seedling. Note that staining is confined to the cells which do not undergo elongation. (D) Plant at 24 d. No major areas of the adult plant show staining. The inset image shows that the cotyledons are still stained.