Analyses of the transcriptional repression mechanism of TFL2,an HP1 homologue in Arabidopsis.

• Project/Area Number: 15370098
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Developmental biology
• Research Institution: Research Institute for Biological Sciences, Okayama
• Principal Investigator: GOTO Koji Research Institute for Biological Sciences, Okayama, Dept of Molecular Genetics, Senior Researcher, 専門研究員(室長) (00251489)
• Project Period (FY): 2003 – 2004
• Project Status: Completed (Fiscal Year 2004)
• Budget Amount: ¥15,500,000 (Direct Cost: ¥15,500,000); Fiscal Year 2004: ¥4,800,000 (Direct Cost: ¥4,800,000); Fiscal Year 2003: ¥10,700,000 (Direct Cost: ¥10,700,000)
• Keywords: Arabidopsis / Morphogenesis / Epigenetics / Flowering / Transcriptional regulation / Hetgerochromatin / Development / Microarray

Research Abstract

Arabidopsis terminal flower2(tfl2) mutants show photoperiod insensitive early-flowering phenotype, as well as several other pleiotropic phenotypes. We found that the early flowering of tfl2 is caused mainly by ectopic expression of the FT gene, a floral pathway integrator and that TFL2 competitively counteracts the activity of CO, an FT activator to repress ectopic FT expression. Molecular cloning of TFL2 showed that it encodes a Heterochromatin Protein 1(HP1) homolog. Gene expression analyses using DNA microarrays, however, did not show an increase in the expression of heterochromatin genes in tfl2 mutants but instead showed the upregulation of the several floral homeotic genes. This multiple genes repression by TFL2 causes the pleiotropic phenotype of the tfl2 mutant. We also examined the subcellular localization of TFL2 protein and found that it does not co-localized with the heterochromatic region of nuclei. Our results demonstrate that despite its homology to HP1,TFL2 is involved in the repression of specific euchromatin genes and not heterochromatin genes in Arabidopsis.

Research Products

• [Journal Article] Arabidopsis TERMINAL FLOWER2 gene encodes a Heterochromatin Protein 1 homolog and represses both FLOWERING LOCUS T to regulate flowering time and several floral homeotic genes (2003)
  • Author(s): Toshihisa Kotake, Shinobu Takada, Kenji Nakahigashi, Masaaki Ohto, Koji Goto.
  • Journal Title: Plant & Cell Physiology. 44 Pages: 555-564
  • NAID: 40007298261
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] TERMINAL FLOWER2,an Arabidopsis Homolog of HETEROCHROMATIN PROTEIN1,Counteracts the Activation of FLOWERING LOCUS T by CONSTANS in the Vascular Tissues of Leaves to Regulate Flowering Time (2003)
  • Author(s): Shinobu T, Koji Goto
  • Journal Title: The Plant Cell 15 Pages: 2856-2865
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Functional Analysis of Isoforms of NADPH : Protochlorophyllide Oxidoreductase(POR),PORB and PORC, in Arabidopsis thaliana. (2003)
  • Author(s): Tatsuru Masuda, Naoki Fusada, Naoki Oosawa, Kenfichi Takamatsu, Yoshiharu Y., Yamamoto, Masaaki Ohto, Kenzo Nakamuia, Koji Goto, Daisuke Shibata, Yumiko Shirano, Hiroaki Hayashi, Tomohiko Kato, Satoshi Tabata, Hiroshi Shimada, Hiroyuki Ohta, Ken-ichiro Takamiya.
  • Journal Title: Plant & Cell Physiology. 44 Pages: 963-974
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Arabidopsis TERMINAL FLOWER 2 gene encodes a Heterochromatin Protein 1 homolog and represses both FLOWERING LOCUS T to regulate flowering time and several floral homeotic genes. (2003)
  • Author(s): Toshihisa Kotake, Shinobu Takada, Kenji Nakahigashi, Masaaki Ohto, Koji Goto
  • Journal Title: Plant & Cell Physiology 44 Pages: 555-564
  • NAID: 40007298261
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] TERMINAL FLOWER2,an Arabidopsis Homolog of HETEROCHROMATIN PROTEIN 1, Counteracts the Activation of FLOWERING LOCUS T by CONSTANS in the Vascular Tissues of Leaves to Regulate Flowering Time. (2003)
  • Author(s): Shinobu Takada, Koji Goto
  • Journal Title: The Plant Cell 15 Pages: 2856-2865
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Functional Analysis of Isoforms of NADPH : Protochlordphyllide Oxidoreductase (FOR), PORB and PORC, in Arabidopsis thaliana. (2003)
  • Author(s): Tatsuru Masuda, Naoki Fusada, Naoki Oosawa, Ken-ichi Takamatsu, Yoshiharu Y.Yamamoto, Masaaki Ohio, Kenzo Nakamura, Koji Goto, Daisuke Shibata, Yumiko Shirano, Hiroaki Hayashi, Tomohiko Kato, Satoshi Tabata, Hiroshi Shimada, Hiroyuki Ohta, Ken-ichiro Takamiya.
  • Journal Title: Plant Cell Physiol. 44 Pages: 963-974
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Toshihisa Kotake, Shinobu Takada, Kenji Nakahigashi, Masaaki Ohto, Koji Goto: "Arabidopsis TERMINAL FLOWER 2 gene encodes a Heterochromatin Protein 1 homolog and represses both FLOWERING LOCUS T to regulate flowering time and several floral homeotic genes"Plant & Cell Physiology.. 44. 555-564 (2003)
• [Publications] Shinobu Takada, Koji Goto: "TERMINAL FLOWER2, an Arabidopsis Homolog of HETEROCHROMATIN PROTEIN1, Counteracts the Activation of FLOWERING LOCUS T by CONSTANS in the Vascular Tissues of Leaves to Regulate Flowering Time"The Plant Cell. 15. 2856-2865 (2003)
• [Publications] Tatsuru Masuda, Naoki Fusada, Naoki Oosawa, Ken'ichi Takamatsu, Yoshiharu Y.Yamamoto, Masaaki Ohto, Kenzo Nakamura, Koji Goto, Daisuke Shibata, Yumiko Shirano, Hiroaki Hayashi, Tomohiko Kato, Satoshi Tabata, Hiroshi Shimada, Hiroyuki Ohta, Ken-ichiro Takamiya: "Functional Analysis of Isoforms of NADPH : Protochlorophyllide Oxidoreductase (POR), PORB and PORC, in Arabidopsis thaliana."Plant & Cell Physiology.. 44. 963-974 (2003)