Morphogenesis and molecular basis on naked seed rice, a novel homeotic mutation of OsMADS1 regulating transcript level of AP3 homologue in rice

Planta. 2006 Apr;223(5):882-90. doi: 10.1007/s00425-005-0141-8. Epub 2005 Oct 28.


The floral organs are formed from floral meristem with a regular initiation pattern in angiosperm species. Flowers of naked seed rice (nsr) were characterized by the overdeveloped lemma and palea, the transformation of lodicules to palea-/lemma-like organs, the decreased number of stamens and occasionally extra pistils. Some nsr spikelets contained additional floral organs of four whorls and/or abnormal internal florets. The floral primordium of nsr spikelet is differentiated under an irregular pattern and an incomplete determination. And molecular analysis indicated that nsr was a novel homeotic mutation in OsMADS1, suggesting that OsMADS1 played a distinct role in regulating the differentiation pattern of floral primordium and in conferring the determination of flower meristem. The gain-of-function of OsMADS1 transgenic lines presented the transformation of outer glumes to lemma-/palea-like organs and no changes in length of lemma and palea, but loss-of-function of OsMADS1 transgenic lines displayed the overdeveloped lemma and palea. Both findings revealed that OsMADS1 played a role in specifying lemma and palea and acted as a repressor of overdevelopment of lemma and palea. Moreover, it was indicated that OsMADS1 upregulated the transcript level of AP3 homologue OsMADS16, using real-time PCR analysis on gain- and loss-of-function of OsMADS1 transgenic lines.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis Proteins
  • Flowers / growth & development*
  • Flowers / ultrastructure
  • Genes, Homeobox
  • MADS Domain Proteins
  • Microscopy, Electron, Scanning
  • Morphogenesis
  • Mutation
  • Oryza / genetics
  • Oryza / growth & development*
  • Oryza / ultrastructure
  • Plants, Genetically Modified
  • RNA Interference
  • Up-Regulation


  • APETALA 3 protein, Arabidopsis
  • Arabidopsis Proteins
  • MADS Domain Proteins