J Integr Plant Biol. ›› 2015, Vol. 57 ›› Issue (2): 162-170.

• Molecular Physiology •

### Structural and functional analysis of an asymmetric bidirectional promoter in Arabidopsis thaliana

Shi-Juan Liu1,2, Qiu-Juan Yue2 and Wei Zhang1*

1. 1Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education; School of Life Sciences, Shandong University, Jinan, China
2College of Life Science, Qufu Normal University, Qufu, China
• Received:2014-06-10 Accepted:2014-11-02 Published:2014-11-04
• About author:*Correspondence: E-mail: weizhang@sdu.edu.cn

Abstract:

Bidirectional promoters are relatively abundant in eukaryotic genomes, suggesting that they have an important biological significance. As yet, few of these promoters have been characterized in detail. Here, using a promoter::GUS transgene approach has revealed that the intergenic region of Arabidopsis thaliana divergent genes At1g71850 and At1g71860 is an asymmetric bidirectional promoter, which exhibits an orientation-dependent expression profile. The strength of the forward promoter was greater than that of the reverse promoter, and their tissue specificities were not identical. Deletion analyses revealed that this bidirectional promoter could be divided into three functional regions. The basal level and tissue specificity of the promoter in the reverse orientation were regulated positively by region II and negatively by region III, whereas promoter activity in the forward orientation was regulated negatively by region II and positively by region I. Thus the 52-bp stretch of region II had a dual function, enhancing expression in the reverse orientation and suppressing it in the forward orientation. These results demonstrated that the activity of the At1g71850-At1g71860 bidirectional promoter was modulated by complex interactions between both positive and negative cis-acting elements. These findings will enhance our understanding of the regulatory mechanisms of plant bidirectional promoters.

Liu SJ, Yue QJ and Zhang W (2015) Structural and functional analysis of an asymmetric bidirectional promoter in Arabidopsis thaliana. J Integr Plant Biol 57: 162–170. doi: 10.1111/jipb.12308

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