Transcriptional activity is inducible in the cauliflower mosaic virus 35 S promoter engineered with the heat shock consensus sequence

Designer promoter: an artwork of cis engineering

Advances in systematic computational biology and rapid elucidation of synergistic interplay between cis and trans factors governing transcriptional control have facilitated functional annotation of gene networks. The generation of data through deconstructive, reconstructive and database assisted promoter studies, and its integration to principles of synthetic engineering has started an era of designer promoters. Exploration of natural promoter architecture and the concept of cis engineering have not only enabled fine tuning of single or multiple transgene expression in response to perturbations in the chemical, physiological and environmental stimuli but also provided researchers with a unique answer to various problems in crop improvement in the form of bidirectional promoters.

Synthetic promoters: genetic control through cis engineering

Technological advances in plant genetics integrated with systems biology and bioinformatics has yielded a myriad of novel biological data and insights into plant metabolism. This unprecedented advance has provided a platform for targeted manipulation of transcriptional activity through synthetic promoter engineering, and holds great promise as a way to further our understanding of regulatory complexity. The challenge and strategy for predictive experimental gene expression is the accurate design and use of molecular 'switches' and modules that will regulate single or multiple plant transgenes in direct response to specific environmental, physiological and chemical cues. In particular, focusing on cis-motif rearrangement, future plant biotechnology applications and the elucidation of cis- and trans-regulatory mechanisms could greatly benefit from using plant synthetic promoters.