Plant synthetic promoters and transcription factors.

Synthetic promoters and transcription factors (TFs) have become incredibly powerful and efficient components for precise regulation of targeted plant transgene expression. Synthetic promoters can be rationally designed and constructed using specific type, copy number and spacing of motifs placed upstream of synthetic or native core promoters. Similarly, synthetic TFs can be constructed using a variety of DNA binding domains (DBDs) and effector domains. Synthetic promoters and TFs can provide tremendous advantages over their natural counterparts with regards to transgene expression strength and specificity. They will probably be needed for coordinated transgene expression for metabolic engineering and synthetic circuit applications in plants for bioenergy and advanced crop engineering. In this article we review the recent advances in synthetic promoters and TFs in plants and speculate on their future.