Fig. 5.

A short region of the SULTR2;2 promoter that is necessary for expression in the bundle sheath and vein tissue. (A) Schematic representation of deletions made to region 2 of the SULTR2;2 promoter (left) and quantitative analysis of expression from each construct based on the GUS activity assay (right). Activity was no longer detectable when subregions 4 and 5 were removed. (B–F) Histochemical staining of leaves indicated that subregion 3 is required for expression in the bundle sheath. (G) Schematic representation of 3′ deletion constructs placed upstream of the minimal CaMV35S promoter (left) and quantitative analysis of expression from each construct based on the GUS activity assay (right). (H–I) Nucleotides from −1845 to −1495 are sufficient to drive expression in the bundle sheath of leaves (H) and cotyledons (I), respectively. (J) Deletion of nucleotides −1692 to −1312 abolishes accumulation of GUS in the BS. Data from GUS activity assays include the median (M) indicated by red lines and the number (n) of independent lines. Statistical significance for each pairwise comparison is marked by a bracket to the right (ns, non-significant; **P<0.01). (K) Sequence of the 350 bp region that is sufficient for expression in bundle sheath strands of Arabidopsis. Histological GUS assays were allowed to proceed for 4 h (B), 47 h (C), 4 h (D) 6 d (E, F), 5 d (H), 2 d (I), and 29 h (J). Scale bars: 50 µm.