Fig. 3: The Y-patch and four distinct regions in the distal cis-regulatory module (CRM) are required for bundle sheath specific expression.

a–c, Nucleotides −980 and −829 from the SiR promoter pattern expression to the bundle sheath when linked with the PIP1;1 and NRT1.1 A core promoters containing Y-patches. a Schematics showing Y-patch and TATA-box in core promoters of ATPSb, PIP1;3, NRT1.1 A and PIP1;1 which have been used to initiate the transcription of nucleotides −980 and −829. b Representative cross sections of transgenic rice leaves after GUS staining, zoomed-in image of lateral veins shown in the right panel, bundle sheath cells highlighted with red dashed lines, the staining duration is displayed in the bottom-left corner, scale bars = 50 µm. c Promoter activity determined by the fluorometric 4-methylumbelliferyl-β-D-glucuronide (MUG) assay. d Schematics showing transcription factor binding sites between nucleotides −980 and −829. e Schematics showing consecutive deletions between nucleotides −980 and −829 fused to the GUS reporter. f Representative images of cross sections from transgenic lines after GUS staining, zoomed-in images of lateral veins shown in right panels, the staining duration is displayed in the bottom-left corner, bundle sheath cells highlighted with red dashed lines, scale bars = 50 µm. g Promoter activity determined by the fluorometric 4-methylumbelliferyl-β-D-glucuronide (MUG) assay. In (c, g) data were subjected to pairwise two-sided Wilcoxon rank-sum test with Benjamini-Hochberg correction. Lines with differences in activity that were statistically significant (adjusted P < 0.05) were labelled with different letters. Median catalytic rate of GUS indicated with red lines, n indicates total number of T₀ transgenic plants assessed. Source data are provided as a Source Data file.