39.イネ由来ブラシノステロイド不活性化酵素の酵素化学的解析(口頭発表)

• 川邉 綾美

  京都大・化研

• 清水 文一

  京都大・化研

• 嶋田 幸久

  理研・PSC

• 藤岡 昭三

  理研・中央研

• 坂本 知昭

  名大・高等研究所

• 水谷 正治

  京都大・化研

書誌事項

タイトル別名

• 39. Biochemical characterization of rice CYP734As involved in brassinosteroid catabolism

抄録

Brassinosteroids (BRs) are inactivated by cytochrome P450 monooxygenases in plants. It is known that Arabidopsis CYP734A1 (BAS1) and tomato CYP734A7 inactivate BRs by C26 hydroxylation of castasterone and brassinolide. Rice (Oriza sativa) has four CYP734A homologues (CYP734A2, A4, A5, and A6). Transgenic rice plants overexpressing these CYP734As, except for CYP734A5, showed a severe dwarf phenotype, and their endogenous BR levels were decreased. In order to investigate BR inactivation mechanism in rice, we have prepared the recombinant CYP734As expressed using a baculovirus insect cells system, and performed the enzyme assays with various BR-biosynthetic intermediates as a substrate. Rice CYP734As showed wide substrate specificities for BRs and exhibited high activity for BR intermediates located at the upstream of BR biosynthetic pathway. Futhermore, CYP734As catalyzed a three-step-oxidation of BR intermediates to the corresponding alcohols, aldehydes, and carboxylic acids. These results suggest that BR inactivation mechanism in rice is different from that in Arabidopsis and tomato.

収録刊行物

• 植物化学調節学会 研究発表記録集

  植物化学調節学会 研究発表記録集 43 (0), 53-, 2008

  一般社団法人 植物化学調節学会

詳細情報

• CRID: 1390282679400145408
• NII論文ID: 110007468213
• DOI: 10.18978/jscrpanb.43.0_53
• ISSN: 21896313
• ISSN: 09191887
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可