A 100 bp GAGA motif-containing sequence in AGAMOUS second intron is able to suppress the activity of CaMV35S enhancer in vegetative tissues

PLoS One. 2020 Mar 5;15(3):e0230203. doi: 10.1371/journal.pone.0230203. eCollection 2020.

Abstract

Flower-specific promoters enable genetic manipulation of floral organs to improve crop yield and quality without affecting vegetative growth. However, the identification of strong tissue-specific promoters is a challenge. In addition, information on cis elements that is able to repress gene expression in vegetative tissues remains limited. Here, we report that fusing a 35S enhancer to the stamen- and carpel-specific NtAGIP1 promoter derived from the tobacco AGAMOUS second intron (AGI) can significantly increase the promoter activity. Interestingly, although the activity of the new promoter extends to sepals and pedicles, it does not cross the boundary of the reproductive organs. Serial deletion of the AGI and chromatin immunoprecipitation (ChIP) assay reveal a 100-bp fragment that contains a conserved GAGA factor binding motif contributes to the flower specificity by mediating histone H3 lysine 27 trimethylation (H3K27me3) modification of the promoter. Furthermore, this fragment shows significant suppressive effect on the activity of the 35S enhancer in vegetative tissues, consequently, resulting in a significant increase of the activity of 35S enhancer:AGI chimeric promoter without sacrifice of its specificity in inflorescence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AGAMOUS Protein, Arabidopsis / genetics*
  • Enhancer Elements, Genetic / genetics*
  • Flowers / genetics
  • Gene Expression Regulation, Plant / genetics
  • Histones / genetics
  • Inflorescence / genetics
  • Introns / genetics*
  • Methylation
  • Nicotiana / genetics
  • Plant Proteins / genetics*
  • Plants, Genetically Modified / genetics
  • Promoter Regions, Genetic / genetics

Substances

  • AGAMOUS Protein, Arabidopsis
  • Histones
  • Plant Proteins

Grants and funding

This research was supported by the Chinese Ministry of Science and Technology of China (Grant 2016YFD0100505). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.