Poster: Transcription Regulation
Abs #
1042: Novel flower specific promoters
Genetic engineering of plants does not only require the identification of the appropriate target gene(s) but depends also from highly specific promoters with regard to their spatial and temporal expression pattern. Using these promoters will also overcome problems associated with gene silencing resulting from promoter duplication. As alternatives to promoters originating from viral or bacterial plant pathogens plant-derived promoters will also increase public acceptance of genetically engineered plants and products.
We are collaborating with Robert Martienssen (CSHL, NY) in the characterization of their collection of Arabidopsis thaliana plants tagged with two different transposon constructs (gene traps and enhancer traps). Simple GUS staining is used to visualize the expression pattern of the tagged gene and TAIL-PCR enables identification of the insertion site. The results of our screening program are summarized in a database comprising these data for thousands of plant lines.
15 gene trap lines with flower-specific GUS expression were identified and 3 novel flower-specific promoters could be isolated. 1kb and 2kb fragments of the putative promoters were cloned and A. thaliana plants carrying these promoter::GUS fusions confirmed the highly flower-specific GUS expression. Comparing the expression pattern conferred by the endogenous promoters and the isolated promoter fragments revealed that the shorter fragments are more flower-specific. Real time PCR and MUG assays indicated that the promoters are able to drive expression levels in a range between 10-30% of the CaMV 35S promoter. In transient assays, GUS expression could also be shown in Calendula petals but not in leaves.
