Extended Data Fig. 2. MPRA construct sequence layout.

The layout of the constructs used in the MPRA assay, based on a published design²⁰, for both p35S-based (a) and pTRP1-based (b) versions. ‘No insertion’ control constructs are displayed at the top, followed by constructs with upstream and downstream insertions (dark blue). Each construct includes a GFP coding region (green) with an IV2 intron, as well as a 15 bp barcode (red). Distances and lengths of genomic attributes are provided. (a) The p35S-based construct incorporates the minimal CaMV 35S core promoter (light blue), followed by the SynJ synthetic 5′ UTR (light brown)⁵⁸, with the upstream insertion placed just before the minimal core promoter. (b) The pTRP1-based construct consists of the 791 bp genomic sequence preceding the coding region of the TRP1 gene (purple), which includes upstream proximal promoter, the core promoter, and 5′ UTR. The upstream insertion site is situated within this sequence, 118 bp upstream of the major TSS and 40 bp upstream of the TSS annotation in the TAIR10 database.