Ectopic expression of OsYAB1 causes extra stamens and carpels in rice

Plant Mol Biol. 2004 Sep;56(1):133-43. doi: 10.1007/s11103-004-2648-y.


Members in the YABBY gene family of proteins are plant-specific transcription factors that play critical roles in determining organ polarity. We have isolated a cDNA clone from rice that encodes a YABBY protein. This protein, OsYAB1, is similar to Arabidopsis YAB2 (50.3%) and YAB5 (47.6%). It carries a zinc-finger motif and a YABBY domain, as do those in Arabidopsis . A fusion protein between OsYAB1 and GFP is located in the nucleus. RNA gel-blot analysis showed that the OsYAB1 gene is preferentially expressed in flowers. In-situ hybridization experiments also indicated that the transcript accumulated in the stamen and carpel primordia. Unlike the Arabidopsis YABBY genes, however, the OsYAB1 gene does not show polar expression pattern in the tissues of floral organs. Our transgenic plants that ectopically expressed OsYAB1 were normal during the vegetative growth period, but then showed abnormalities in their floral structures. Spikelets contained supernumerary stamens and carpels compared with those of the wild types. These results suggest that OsYAB1 plays a major role in meristem development and maintenance of stamens and carpels, rather than in determining polarity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Nucleus / metabolism
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • Flowers / genetics*
  • Flowers / growth & development
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Plant
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • In Situ Hybridization
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Oryza / genetics*
  • Oryza / growth & development
  • Phylogeny
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Plants, Genetically Modified
  • RNA, Plant / genetics
  • RNA, Plant / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism


  • DNA, Complementary
  • Plant Proteins
  • RNA, Plant
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Green Fluorescent Proteins