Poster: Transcription Regulation

Abs # 1039: Engineering Synthetic Transcriptional Enhancer Cassettes

Presenter:	Cazzonelli, Christopher I, ccazzonelli@lbk.ars.usda.gov
Authors	Cazzonelli, Christopher I (A)   Velten, Jeff  (A)
Affiliations:	(A): usda-ars

Plant viruses have provided many of the strongest trancriptional promoters used to drive transgene expression in genetically modified plants. Based upon the observation that promoter control elements are often duplicated within highly active promoters, the intragenic regions from multiple, fully sequenced, plant viral genomes were scanned for repeated sequence motifs. The identified sequences were fused to a minimal CaMV35s promoter-luciferase reporter gene fusion and screened for their ability to enhance luciferase activity using an Agrobacterium-based, in vivo, transient assay system optimised in tobacco leaves. Sequence elements that demonstrate enhancer activity were multimerised and/or combined to create novel transcriptional enhancer cassettes. Research currently focuses on determining the relative strength and expression characteristics of synthetic promoters containing the enhancer cassettes. Aside from providing new tools for the expression and control of transgene expression in plants, analysis of the identified sequence elements will provide additional insights into plant and viral transcriptional control mechanisms.