Figure 1.

Diagram of promoter architecture in plants.

Plant promoters consist of a core promoter, a proximal promoter region, and distal promoter regions. Distal promoter regions contain enhancer, silencer, and insulator cis elements. The proximal promoter region contains cis elements bound by activator and repressor proteins. The core promoter generally spans from −50 bp to +50 bp and enables assembly of the transcription initiation complex. It contains a TATA box, TF ⅡB recognition elements, a Y patch, and downstream promoter elements (DPEs). There is a spacer sequence of no less than 50 bp between the core promoter and the proximal promoter region. TSS, transcription start site. BRE, TF ⅡB recognition element.