Tissue-specifically regulated site-specific excision of selectable marker genes in bivalent insecticidal, genetically-modified rice

Biotechnol Lett. 2013 Dec;35(12):2177-83. doi: 10.1007/s10529-013-1310-7. Epub 2013 Aug 24.

Abstract

Marker-free, genetically-modified rice was created by the tissue-specifically regulated Cre/loxP system, in which the Cre recombinase gene and hygromycin phosphotransferase gene (hpt) were flanked by two directly oriented loxP sites. Cre expression was activated by the tissue-specific promoter OsMADS45 in flower or napin in seed, resulting in simultaneous excision of the recombinase and marker genes. Segregation of T1 progeny was performed to select recombined plants. The excision was confirmed by PCR, Southern blot and sequence analyses indicating that efficiency varied from 10 to 53 % for OsMADS45 and from 12 to 36 % for napin. The expression of cry1Ac and vip3A was detected by RT-PCR analysis in marker-free transgenic rice. These results suggested that our tissue-specifically regulated Cre/loxP system could auto-excise marker genes from transgenic rice and alleviate public concerns about the security of GM crops.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus thuringiensis Toxins
  • Bacterial Proteins / genetics
  • Cloning, Molecular
  • Endotoxins / genetics
  • Genes, Plant / genetics
  • Genetic Markers / genetics*
  • Genetic Vectors / genetics
  • Hemolysin Proteins / genetics
  • Integrases / genetics
  • Oryza / genetics*
  • Pest Control, Biological / methods*
  • Plants, Genetically Modified / genetics*
  • Promoter Regions, Genetic / genetics
  • Recombination, Genetic / genetics

Substances

  • Bacillus thuringiensis Toxins
  • Bacterial Proteins
  • Endotoxins
  • Genetic Markers
  • Hemolysin Proteins
  • Vip3A protein, Bacillus thuringiensis
  • insecticidal crystal protein, Bacillus Thuringiensis
  • Cre recombinase
  • Integrases