Mutations in the TORNADO2 gene affect cellular decisions in the peripheral zone of the shoot apical meristem of Arabidopsis thaliana

Plant Mol Biol. 2007 Apr;63(6):731-44. doi: 10.1007/s11103-006-9105-z. Epub 2007 Feb 16.


An EMS (ethyl methanesulfonate) mutagenesis effector screen performed with the STM:GUS marker line in Arabidopsis thaliana identified a loss-of-function allele of the TORNADO2 gene. The histological and genetic analyses described here implicate TRN2 in SAM function, where the peripheral zone in trn2 mutants is enlarged relative to the central stem cell zone. The trn2 mutant allele partially rescues the phenotype of shoot meristemless mutants but behaves additively to wuschel and clavata3 alleles during the vegetative phase and in the outer floral whorls. The development of carpels in trn2 wus-1 double mutant flowers indicates that pluripotent cells persist in floral meristems in the absence of TRN2 function and can be recruited for carpel anlagen. The data implicate a membrane-bound plant tetraspanin protein in cellular decisions in the peripheral zone of the SAM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Arabidopsis / genetics*
  • Arabidopsis / physiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / physiology
  • Cell Differentiation / drug effects
  • Cell Differentiation / genetics
  • Ethyl Methanesulfonate / toxicity
  • Flowers / genetics
  • Flowers / physiology
  • Gene Expression Regulation, Plant / drug effects
  • Genes, Plant / genetics*
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / physiology
  • In Situ Hybridization
  • Meristem / cytology
  • Meristem / genetics*
  • Meristem / physiology
  • Models, Biological
  • Mutation*
  • Phenotype
  • Plant Leaves / genetics
  • Plant Leaves / physiology
  • Plant Shoots / genetics
  • Plant Shoots / physiology


  • AT2G27250 protein, Arabidopsis
  • Arabidopsis Proteins
  • Homeodomain Proteins
  • WUSCHEL protein, Arabidopsis
  • Ethyl Methanesulfonate