Poster: Regulation of gene expression

Abs # 795: Monocotyledonous gene promoters direct constitutive and tissue-specific transcription in dicot plants

Presenter:	Eitas, Timothy K, hongluo@hybrigene.com
Authors	Eitas, Timothy K (B)   Lickwar, Colin  (A)   Kausch, Albert P (A) (B)  Chandlee, Joel M (B)   Luo, Hong  (A) (B)
Affiliations:	(A): HybriGene, Inc. (B): University of Rhode Island

The development of methods for the production of transgenic plants has led to rapid progress in plant research and biotechnology. Exogenous nucleotide sequences can be inserted into the plant genome to study the function and regulation of genes, and to achieve trait modifications of important crop species. Usually, the DNA coding region for the foreign gene is linked to a constitutive or tissue-specific promoter region to ensure the expression of the foreign gene in the transgenic cell. We have studied the potential of using gene regulatory elements from monocot species to drive foreign gene expression in dicot plants. The activity of ubiquitin promoters isolated from rice and maize was evaluated in spinach and Arabidopsis using various chimeric reporter gene constructions. Data from both transient assays and stable transformation experiments indicated that these promoters were fully functional in dicot plants, driving very high levels of constitutive expression of foreign genes. Furthermore, we have also demonstrated that an anther-specific promoter from rice, when fused with a ribonuclease gene barnase, was able to drive tissue-specific expression of this cytotoxic gene in Arabidopsis, conferring male sterility to the transgenic plants. Molecular analysis confirmed the tissue specificity of this rice promoter in driving foreign gene expression in Arabidopsis. Our results suggest that monocot and dicot plants may share, to certain extent, versatile mechanisms in gene regulation. This presents new insights into the utility of the promoter sequences of genes to drive both constitutive and tissue-specific levels of gene expression among various members of the angiosperm family.