JXB Advance Access originally published online on July 12, 2005
Journal of Experimental Botany 2005 56(419):2345-2353; doi:10.1093/jxb/eri227
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
RESEARCH PAPER |
A variety of synergistic and antagonistic interactions mediated by cis-acting DNA motifs regulate gene expression in plant cells and modulate stability of the transcription complex formed on a basal promoter
National Botanical Research Institute, Rana Pratap Marg, Lucknow-226001, India
* To whom correspondence should be addressed. Fax: +91 522 2205836. E-mail: rakeshtuli{at}hotmail.com, rakeshtuli23{at}rediffmail.com
Several synthetic promoters containing a variety of commonly found cis-acting DNA sequence motifs were constructed to study the motifmotif and motifprotein interactions involved in gene expression in plants. Transient expression of the reporter gene gusA in tobacco leaves was used to demonstrate that several sequence elements can be arranged upstream of a basal promoter to function synergistically in enhancing gene expression. A cis-acting DNA motif could function as an activator by itself as well as a synergizing activator in the presence of other homologous as well as heterologous motifs in the neighbourhood. The function of a complex promoter comprising several activation motifs was arrested nearly completely in vivo, following titration with any one of the motifs. The results suggested a hierarchical assembly of several motif-binding factors, leading to the stabilization of the transcriptional complex formed on the TATA-box.
Key words: Cis motif interactions, gene regulation, plant promoters, transcription activation in plants, transcription factors