RNAi-mediated silencing of OsGEN-L (OsGEN-like), a new member of the RAD2/XPG nuclease family, causes male sterility by defect of microspore development in rice

Plant Cell Physiol. 2005 May;46(5):699-715. doi: 10.1093/pcp/pci090. Epub 2005 Mar 25.


We have cloned a new member of the RAD2/XPG nuclease family, OsGEN-L (OsGEN-like), from rice (Oryza sativa L.). OsGEN-L possesses two domains, the N- and I-regions, that are conserved in the RAD2/XPG nuclease family. Database searches and phylogenetic analyses revealed that OsGEN-L belongs to class 4 of the RAD2/XPG nuclease family, and OsGEN-L homologs were found in animals and higher plants. To elucidate the function of OsGEN-L, we generated rice OsGEN-L-RNAi transgenic plants in which OsGEN-L expression was silenced. Most of the OsGEN-L-RNAi plants displayed low fertility, and some of them were male-sterile. OsGEN-L-RNAi plants lacked mature pollen, resulting from a defect in early microspore development. A OsGEN-L-green fluorescent protein (GFP) fusion protein was localized in the nucleus, and the OsGEN-L promoter was specifically active in the anthers. Furthermore, a recombinant OsGEN-L protein possessed flap endonuclease activity and both single-stranded and double-stranded DNA-binding activities. Our results suggest that OsGEN-L plays an essential role in DNA metabolism required for early microspore development in rice.

MeSH terms

  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Deoxyribonucleases / genetics
  • Deoxyribonucleases / isolation & purification
  • Deoxyribonucleases / metabolism*
  • Flap Endonucleases / genetics*
  • Flap Endonucleases / isolation & purification
  • Flap Endonucleases / metabolism
  • Flowers / genetics
  • Flowers / metabolism
  • Gene Expression Regulation, Plant / genetics
  • Gene Silencing / physiology*
  • Molecular Sequence Data
  • Oryza / genetics*
  • Plant Proteins / genetics*
  • Plant Proteins / isolation & purification
  • Plant Proteins / metabolism
  • Plants, Genetically Modified
  • RNA Interference / physiology*
  • RNA, Small Interfering / genetics*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Reproduction / genetics
  • Ribonucleases / genetics
  • Ribonucleases / isolation & purification
  • Ribonucleases / metabolism
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid


  • DNA-Binding Proteins
  • Plant Proteins
  • RNA, Small Interfering
  • Recombinant Fusion Proteins
  • Deoxyribonucleases
  • Flap Endonucleases
  • Ribonucleases