Molecular mechanism of the floral initiation by florigen and its application to breeding

• Project/Area Number: 26520307
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 特設分野
• Research Field: Food Cycle Research
• Research Institution: Kyoto University
• Principal Investigator: Ohki Izuru 京都大学, 工学研究科, 特定研究員 (80418574)
• Project Period (FY): 2014-07-18 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000); Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2015: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: X線結晶解析 / 植物 / 植物ホルモン / 花成 / フロリゲン / 立体構造解析 / 植物花成 / 育種 / 構造生物学

Outline of Final Research Achievements

In higher plants, florigen is a mobile hormone that determines the flowering time, but its regulatory mechanism of flowering remains unclear. In this study, we focused on an anti-florigen, which suppresses floral induction antagonizing with florigen, to clarify the role in flowering regulation. From structural and biochemical analysis, anti-florigen was found to form a stable complex with florigen receptor on target promoters and inhibited a formation of florigen-receptor complex. The bindings of florigen and anti-florigen to the receptor were exchangeable, suggesting that the balance of the two proteins is important for determining the timing of floral transition.

Research Products

• [Journal Article] The crystal structure of the plant small GTPase OsRacl reveals its mode of binding to NADPH oxidase. (2015)
  • Author(s): Kosami KI, Ohki I, Nagano M, Furuita F, Sugiki T, Kawano Y, Kawasaki T, Fujiwara T, Nakagawa A, Shimamoto K, Kojima C
  • Journal Title: The Journal of Biological Chemistry Volume: 289 Issue: 41 Pages: 28569-78
  • DOI: 10.1074/jbc.m114.603282
  • Description: (in press)(印刷中)
  • Peer Reviewed
• [Journal Article] Purification, crystallization and preliminary X-ray crystallographic analysis of a rice Rac/Rop GTPase, OsRac1 (2014)
  • Author(s): Kosami K
  • Journal Title: Acta Cryst. Volume: F70 Issue: 1 Pages: 113-115
  • DOI: 10.1107/s2053230x13033645
  • Peer Reviewed
• [Journal Article] メチル化リジンの化学シフトと塩橋との相関に関する理論的・実験的研究 (2014)
  • Author(s): 服部 良一、Jakub Sebera、Vladimir Sychrovsky、古板 恭子、大木 出、池上 貴久、藤原敏道、児嶋 長次郎
  • Journal Title: 日本核磁気共鳴学会機関誌 Volume: 5 Pages: 56-59
• [Presentation] 植物のメチル化DNA結合タンパク質の機能構造解析 (2017)
  • Author(s): 大木出、白川昌宏
  • Organizer: 第58回日本植物生理学会年会
  • Place of Presentation: 鹿児島大学郡元キャンパス（鹿児島県鹿児島市）
  • Year and Date: 2017-03-16
• [Presentation] 植物のメチル化DNA結合タンパク質の構造機能解析 (2016)
  • Author(s): 尾野有菜、大木出、竹下至、白川昌宏
  • Organizer: 第39回日本分子生物学会年会
  • Place of Presentation: パシフィコ横浜（神奈川県横浜市西区）
  • Year and Date: 2016-12-01
• [Presentation] 植物のメチル化DNA結合タンパク質の機能構造解析 (2016)
  • Author(s): 大木出、竹下至、白川昌宏
  • Organizer: 第16回日本蛋白質科学会年会
  • Place of Presentation: 福岡国際会議場（福岡県福岡市博多区）
  • Year and Date: 2016-06-09
• [Presentation] 植物のメチル化DNA結合タンパク質の機能解析 (2015)
  • Author(s): 竹下至、大木出、白川昌宏
  • Organizer: 日本分子生物学会
  • Place of Presentation: 神戸ポートアイランド（兵庫県神戸市中央区）
  • Year and Date: 2015-12-01