Poster: Regulation of gene expression

Abs # 738: Systematic analysis of activity profile of ABA response complex 1 (ABRC1) in transgenic rice

Presenter:	Hong, Chwan-Yang , d86621103@ntu.edu.tw
Authors	Hong, Chwan-Yang  (A) (C)  Ho, Tuan-hua David  (A)   Yu, Su-May  (B)   Liu, Li-Fei  (C)
Affiliations:	(A): Institute of Botany, Academia Sinica, Taipei, Taiwan (B): Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan (C): Department of Agronomy,National Taiwan University, Taipei, Taiwan

ABRC1 (ABA Response Complex 1), a cis-acting promoter complex from the barley HVA22 gene, is necessary and sufficient for ABA induction of gene expression (Shen and Ho, 1995; Su et al., 1998). However, systematic analysis of the ABA or stress induced activity profile of ABRC1 in transgenic plants is still lacking. In this study, four plasmids with one to four copies of ABRC1 together with the alpha-amylase 64 minimal promoter (Amy64) were constructed and used for stable expression of GUS gene in transgenic rice plants. PCR and Southern blot analysis indicated stable integration of transgene into rice genome. GUS activity analysis revealed that transgenic rice harboring 3 copies of ABRC1 showed the highest response to ABA, salt, and drought stress among all the constructs. Histochemical analysis showed that GUS is preferentially expressed in the vascular tissue of leaves and roots upon ABA treatment. In the reproductive organs, GUS accumulated in embryo and aleurone layer of mature seeds and the pollen. Stable expression of GUS activity in one transgenic line was observed through 3 generations. These data indicate that ABRC1 could be a promising promoter element to use in generating salt and drought-stress resistant transgenic plants.