Plant Molecular Biology

, Volume 74, Issue 3, pp 293–305

Both the constitutive Cauliflower Mosaic Virus 35S and tissue-specific AGAMOUS enhancers activate transcription autonomously in Arabidopsis thaliana



The expression of eukaryotic genes from their cognate promoters is often regulated by the action of transcriptional enhancer elements that function in an orientation-independent manner either locally or at a distance within a genome. This interactive nature often provokes unexpected interference within transgenes in plants, as reflected by misexpression of the introduced gene and undesired phenotypes in transgenic lines. To gain a better understanding of the mechanism underlying enhancer/promoter interactions in a plant system, we analyzed the activation of a β-glucuronidase (GUS) reporter gene by enhancers contained within the AGAMOUS second intron (AGI) and the Cauliflower Mosaic Virus (CaMV) 35S promoter, respectively, in the presence and absence of a target promoter. Our results indicate that both the AGI and 35S enhancers, which differ significantly in their species of origin and in the pattern of expression that they induce, have the capacity to activate the expression of a nearby gene through the promoter-independent initiation of autonomous transcriptional events. Furthermore, we provide evidence that the 35S enhancer utilizes a mechanism resembling animal- and yeast-derived scanning or facilitated tracking models of long-distance enhancer action in its activation of a remote target promoter.


Enhancer 35S promoter AGAMOUS second intron Transcription initiation Long-distance activation of gene expression Arabidopsis thaliana 

Copyright information

© U.S. Government 2010

Authors and Affiliations

  • Stacy D. Singer
    • 1
    • 2
  • Kerik D. Cox
    • 2
  • Zongrang Liu
    • 1
  1. 1.USDA-ARS Appalachian Fruit Research StationKearneysvilleUSA
  2. 2.Department of Plant Pathology, New York State Agricultural Experiment StationCornell UniversityGenevaUSA

Personalised recommendations