Characterization of the regulatory elements of the maize P-rr gene by transient expression assays

Plant Mol Biol. 1999 Jan;39(1):11-9. doi: 10.1023/a:1006172815663.


The maize P-rr gene conditions floral-specific flavonoid pigmentation, especially in the kernel pericarp and cob. We analyzed the P-rr promoter by transient expression assays, in which segments of the P-rr promoter were fused to the GUS reporter gene and introduced into maize cells by particle bombardment. A basal P-rr promoter fragment (-235 to +326) gave low, but significant, levels of GUS reporter gene expression. Interestingly, two widely spaced segments containing enhancer-like activity were found. When tested individually, both the proximal (-1252 to -236) and distal (-6110 to -4842) segments boosted expression of the basal P-rr promoter::GUS construct about five-fold. A 1.6 kb segment of the P-rr promoter (-1252 to +326) containing the proximal enhancer and the 5'-untranslated leader driving the GUS reporter gene showed preferential expression in BMS and embryogenic suspension cell cultures vs. endosperm-derived suspension cell cultures. These results demonstrate the application of transient assay techniques for the identification of regulatory elements responsible for floral-specific regulation of the complex P-rr gene promoter in maize.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • DNA, Plant / chemistry
  • DNA-Binding Proteins / genetics*
  • Gene Expression*
  • Genes, Regulator*
  • Plant Proteins / genetics*
  • Promoter Regions, Genetic
  • Restriction Mapping
  • Zea mays / genetics*


  • DNA, Plant
  • DNA-Binding Proteins
  • P protein, Zea mays
  • Plant Proteins