Biochemical mechanism of indole-3-acetic acid biosynthesis in plants

• Project/Area Number: 25660091
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Bioorganic chemistry
• Research Institution: Tohoku University (2015); The Institute of Physical and Chemical Research (2013-2014)
• Principal Investigator: MASHIGUCHI KIYOSHI 東北大学, 生命科学研究科, 助教 (00569725)
• Research Collaborator: KASAHARA HIROYUKI 東京農工大学, グローバルイノベーション研究院, 教授 (00342767)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000); Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2013: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 植物ホルモン / オーキシン / アミノ基転移酵素 / フラビン含有モノオキシゲナーゼ / 生合成 / インドール酢酸

Outline of Final Research Achievements

Auxins are a class of plant hormones that are essential for growth and development. In this study, we analyzed the biochemical mechanism of the natural auxin indole-3-acetic acid (IAA) biosynthesis. IAA is biosynthesized from tryptophan via indole-3-pyruvic acid by TAA aminotransferase and YUCCA flavin-containing monooxygenase families. We found that YUCCAs efficiently converted aromatic amino acid-derived pyruvates to their carboxylic acid forms, suggesting that the substrate specificity of YUCCAs is not strict. We further showed that the enzymatic action of YUCCAs is metabolically linked to that of TAAs. Although we could not confirm protein-protein interaction between TAAs and YUCCAs, the cooperative action of TAAs and YUCCAs may play important roles in the selective synthesis of IAA at the sites of auxin production.

Research Products

• [Journal Article] Distinct Characteristics of Indole-3-Acetic Acid and Phenylacetic Acid, Two Common Auxins in Plants. (2015)
  • Author(s): Sugawara, S., Mashiguchi, K., Tanaka, K., Hishiyama, S., Sakai, T., Hanada, K., Kinoshita-Tsujimura, K., Yu, H., Dai, X., Takebayashi, Y., Takeda-Kamiya, N., Kakimoto, T., Kawaide, H., Natsume, M., Estelle, M., Zhao, Y., *Hayashi, K., Kamiya, Y.,Kasahara, H.
  • Journal Title: Plant Cell Physiol Volume: 56 Issue: 8 Pages: 1641-1654
  • DOI: 10.1093/pcp/pcv088
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] オーキシン生合成に関わるフラビン酵素YUCCAの機能解明 (2014)
  • Author(s): 増口潔
  • Journal Title: 植物の生長調節 Volume: 49 Pages: 18-24
• [Journal Article] オーキシンの生合成と信号伝達経路“植調剤の標的として” (2013)
  • Author(s): 増口潔, 林謙一郎
  • Journal Title: 植調 Volume: 47 Pages: 197-206
• [Presentation] シロイヌナズナにおけるインドール-3-酢酸生合成機構の解析 (2014)
  • Author(s): 増口潔, 神谷勇治, 榊原均, 笠原博幸
  • Organizer: 植物化学調節学会第49回大会
  • Place of Presentation: 京都大学 (京都)
  • Year and Date: 2014-10-18 – 2014-10-19
• [Presentation] A biochemical framework for auxin biosynthesis in Arabidopsis (2014)
  • Author(s): Mashiguchi K., Zhao Y., Sakakibara H., Kamiya Y. and Kasahara H.
  • Organizer: The 38th Naito Conference
  • Place of Presentation: 札幌 (北海道)
  • Year and Date: 2014-10-07 – 2014-10-10
• [Presentation] 植物のオーキシン恒常性維持のメカニズム-生合成と代謝における最近の話題から- (2014)
  • Author(s): 増口潔
  • Organizer: 日本農芸化学会東北支部シンポジウム
  • Place of Presentation: 山形大学 (山形)
  • Year and Date: 2014-07-19
  • Invited
• [Presentation] Biochemical mechanism of indole-3-acetic acid biosynthesis in Arabidopsis (2014)
  • Author(s): Mashiguchi K., Sakakibara H., Kamiya Y. and Kasahara H.
  • Organizer: 2014 Plant Growth Regulation Society of America Annual Conference
  • Place of Presentation: San Francisco (USA)
  • Year and Date: 2014-07-13 – 2014-07-17
• [Presentation] 植物におけるインドール-3-酢酸生合成機構の解析 (2014)
  • Author(s): 増口潔, 神谷勇治, 榊原均, 笠原博幸
  • Organizer: 日本農芸化学会2014年度大会
  • Place of Presentation: 明治大学, 神奈川県
• [Presentation] オーキシン生合成に関わるフラビン酵素YUCCAの機能解明 [奨励賞] (2013)
  • Author(s): 増口潔
  • Organizer: 植物化学調節学会
  • Place of Presentation: 新潟大学, 新潟県
• [Remarks] 東北大学生命科学研究科活性分子動態分野
  • URL: http://labo.lifesci.tohoku.ac.jp/biomol/