Studies on molecular mechanism underlying photoperiodic compensation

2016 Fiscal Year Annual Research Report

• Project/Area Number: 25440141
• Research Institution: International Christian University
• Principal Investigator: 溝口 剛 国際基督教大学, 教養学部, 教授 (70281623)
• Co-Investigator(Kenkyū-buntansha): 楢本 悟史 東北大学, 生命科学研究科, 助教 (30612022)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: シロイヌナズナ / 光合成 / 葉緑体 / 既日時計 / LHY / CCA1 / 光周性

Outline of Annual Research Achievements

植物にとって、光は最も重要な情報の一つである。それを効率的に利用するために、約24時間周期の内生リズムを作り出す機構（概日時計）が重要な働きをしている。シロイヌナズナにおける概日時計の主要な構成因子であるLATE ELONGATED HYPOCOTYL（LHY）とCIRCADIAN CLOCK ASSOCIATED 1 (CCA1)　の二重欠損変異体（lhy;cca1）では、恒明条件下で概日リズム制御機能が著しく低下し、花成遅延や胚軸・葉柄の短縮及び、顕著な濃緑色葉の形質が表れる。葉の緑色は、クロロフィルという光合成色素由来であり、クロロフィルはアンテナタンパク質に結合して葉緑体内で光エネルギーを集める働きをしている。アンテナタンパク質は光ダメージによる分解と生産を繰り返しているが、概日時計による制御機構は殆ど着目されていない。この分子メカニズムを明らかにするため、恒明条件下でlhy;cca1が示す濃緑色葉形質に着目して研究を行った。野生型(WT)は明期長が異なる光周期下で生育させても、クロロフィル含量はほぼ一定であった。我々はこの機構を光周期補償性と定義した。一方、興味深いことにlhy;cca1では明期の長さに依存してクロロフィル含量が増加した。これに伴って、アンテナタンパク質である、Light Harvesting Complex（LHC）のタンパク質量が増加していること分かった。さらに、lhy;cca1では葉緑体内膜構造のうち、グラナの重層数が著しく増加していることを透過型電子顕微鏡観察により明らかにした。

Research Products

• [Journal Article] Density effects on late flowering mutants of Arabidopsis thaliana under continuous light. (2016)
  • Author(s): Yamamoto K, Takahashi K, Hara M, Miyata K, Hayama R, Mizoguchi T*
  • Journal Title: Plant Biotechnology Volume: 33 Pages: 323-331
  • DOI: 10.5511/plantbiotechnology.16.0622a
  • Peer Reviewed
• [Journal Article] Density effects on semi-dwarf and early flowering mutants of Arabidopsis thaliana under continuous light. (2016)
  • Author(s): Takahashi K, Hara M, Miyata K, Hayama R, Mizoguchi T*
  • Journal Title: Plant Biotechnology Volume: 33 Pages: 333-339
  • DOI: 10.5511/plantbiotechnology.16.0912a
  • Peer Reviewed
• [Journal Article] A loss-of-function mutateon in the DWARF4/PETANKO5 gene enhances the late-flowering and semi-dwarf phenolypes of the Arabidopsis clock mutant lhy-12;cca1-101 under continuous light without affecting FLC expression. (2016)
  • Author(s): Suzuki S, Miyata K, Hara M, Niinuma K, Tsukaya H, Takase M, Hayama R, Mizoguchi T*
  • Journal Title: Plant Biotechnology Volume: 33 Pages: 315-321
  • DOI: 10.5511/plantbiotechnology.16.0601a
  • Peer Reviewed
• [Journal Article] Environmental responses of plants: Biological interactions in the homogenyous population or community (mixed populations). (2016)
  • Author(s): Mizoguchi T*, Funabashi M.
  • Journal Title: Plant Biotechnology Volume: 33 Pages: 211-212
  • DOI: 10.5511/plantbiotechnology.16.0000p
  • Peer Reviewed
• [Journal Article] The FT-like gene PehFT in petunia responds to photoperiod and light quality but is not the main gene promoting light quality-associated flowering. (2016)
  • Author(s): Tsukamoto A, Hirai T, Chin DP, Mii M, Mizoguchi T*, Mizuta D, Yoshida H, Olsen J, Ezura H, Fukuda N.
  • Journal Title: Plant Biotechnology Volume: 33 Pages: 297-307
  • DOI: 10.5511/plantbiotechnology.16.0620a
  • Peer Reviewed
• [Presentation] Circadian rhythm gating of transcription factors implicated in salinity stress in Solanum lycopersicum (2016)
  • Author(s): Coyne K, Hayama R, Mullen DM, Mizoguchi T*
  • Organizer: JSOL 2016, The 13th Japan Solanaceae Consortium
  • Place of Presentation: 国際基督教大学（東京都三鷹市）
  • Year and Date: 2016-11-25
  • Int'l Joint Research
• [Presentation] Gibberellic acid and PTA7 may control flowering time via a common genetic pathway in Arabidopsis thaliana. (2016)
  • Author(s): Miyata K, Kobayashi M, Murayama Y, Hayama R, Ito E, Choi SW, Mizoguchi T*
  • Organizer: JSOL 2016, The 13th Japan Solanaceae Consortium
  • Place of Presentation: 国際基督教大学（東京都三鷹市）
  • Year and Date: 2016-11-25
  • Int'l Joint Research
• [Presentation] Natural variation in the photoperiodic response of elf3;gi between Landsberg erecta and Columbia ecotypes in Arabidopsis thaliana. (2016)
  • Author(s): Murayama Y, Kuroki K, Sakamoto S, Fujiwara S, Hara M, Natsui Y, Takahashi K, Miyata K, Hayama R, Ito E, Choi SW, Mizoguchi T*
  • Organizer: JSOL 2016, The 13th Japan Solanaceae Consortium
  • Place of Presentation: 国際基督教大学（東京都三鷹市）
  • Year and Date: 2016-11-25
  • Int'l Joint Research
• [Presentation] Effect of night break on flowering time and FT expression in elf3;gi, an SDP-type mutant of Arabidopsis thaliana. (2016)
  • Author(s): Nakai H, Hara M, Takahashi K, Ariga H, Murayama Y, Hayama R, Ito E, Choi SW, Mizoguchi T*
  • Organizer: JSOL 2016, The 13th Japan Solanaceae Consortium
  • Place of Presentation: 国際基督教大学（東京都三鷹市）
  • Year and Date: 2016-11-25
  • Int'l Joint Research
• [Presentation] Inversion of photoperiodic response by double loss-of-function mutations in EARLY FLOWERING 3 and GIGANTEA in Arabidopsis thaliana. (2016)
  • Author(s): Hara M, Natsui Y, Murayama Y, Kuroki K, Takahashi K, Miyata K, Chiba Y, Hayama R, Ito E, Choi SW, Mizoguchi T*
  • Organizer: JSOL 2016, The 13th Japan Solanaceae Consortium
  • Place of Presentation: 国際基督教大学（東京都三鷹市）
  • Year and Date: 2016-11-25
  • Int'l Joint Research
• [Presentation] Involvement of SELF PRUNING 5G in the floral and sympodial regulation in a day-neutral plant tomato. (2016)
  • Author(s): Kato K, Oikawa J, Ishigami Y, Shimoyama S, Shiba T, Tatsuzawa F, Yoshida R, Hiwasa-Tanase K, Wang N, Ariizumi T, Mizoguchi T*, Ezura H
  • Organizer: JSOL 2016, The 13th Japan Solanaceae Consortium
  • Place of Presentation: 国際基督教大学（東京都三鷹市）
  • Year and Date: 2016-11-25
  • Int'l Joint Research
• [Presentation] Analysis of subcellular localization of Pleckstrin-homology domain-cintaining protein, PH15. (2016)
  • Author(s): Arimoto S, Choi SW, Ebine K, Mizoguchi T*, Nakano A, Ueda T, Ito E
  • Organizer: JSOL 2016, The 13th Japan Solanaceae Consortium
  • Place of Presentation: 国際基督教大学（東京都三鷹市）
  • Year and Date: 2016-11-25
  • Int'l Joint Research
• [Presentation] Diverse floral responses to day length among tomato species and difference within the regulatory mechanisms. (2016)
  • Author(s): Hayama R, Hoshikawa K, Mizoguchi T*
  • Organizer: JSOL 2016, The 13th Japan Solanaceae Consortium
  • Place of Presentation: 国際基督教大学（東京都三鷹市）
  • Year and Date: 2016-11-25
  • Int'l Joint Research
• [Presentation] Density effects on late and early flowering mutants of Arabidopsis thaliana under continuous light. (2016)
  • Author(s): Takahashi K, Yamamoto K, Hara M, Miyata K, Hayama R, Ito E, Choi SW, Mizoguchi T*
  • Organizer: JSOL 2016, The 13th Japan Solanaceae Consortium
  • Place of Presentation: 国際基督教大学（東京都三鷹市）
  • Year and Date: 2016-11-25
  • Int'l Joint Research