Quantitative Analysis of Cis-Regulatory Element Activity Using Synthetic Promoters in Transgenic Plants

Synthetic promoters, introduced stably or transiently into plants, are an invaluable tool for the identification of functional regulatory elements and the corresponding transcription factor(s) that regulate the amplitude, spatial distribution, and temporal patterns of gene expression. Here, we present a protocol describing the steps required to identify and characterize putative cis-regulatory elements. These steps include application of computational tools to identify putative elements, construction of a synthetic promoter upstream of luciferase, identification of transcription factors that regulate the element, testing the functionality of the element introduced transiently and/or stably into the species of interest followed by high-throughput luciferase screening assays, and subsequent data processing and statistical analysis.