Mechanisms regulating brassinosteroid biosynthesis and sensitivity

• Project/Area Number: 17570045
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 植物生理・分子
• Research Institution: RIKEN
• Principal Investigator: SHIMADA Yukihisa RIKEN, Plant Science Center, Senior Researcher, ゲノム機能統合化研究チーム, 上級研究員 (30300875)
• Project Period (FY): 2005 – 2006
• Project Status: Completed (Fiscal Year 2006)
• Budget Amount: ¥3,500,000 (Direct Cost: ¥3,500,000); Fiscal Year 2006: ¥1,700,000 (Direct Cost: ¥1,700,000); Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
• Keywords: brassinosteroid

Research Abstract

We examined whether Aux/IAA proteins, which are key players in auxin-signal transduction, are involved in brassinosteroid (BR) responses. Iaa7laxr2-1 and iaal7laxr3-3 mutants showed aberrant BR sensitivity and aberrant BR-induced gene expression, which were observed organ-dependently. Two auxin inhibitors were tested in terms of BR responses. Yokonolide B inhibited BR responses, whereas p-Chlorophenoxyisobutyric acid did not inhibit BR responses. DNA microarray analysis revealed that 108 genes were up-regulated, while only eight genes were down-regulated in iaa7. Among the genes that were up-or down-regulated in axr2, 22% were BL-inducible genes, 20% were auxin-inducible genes, and the majority were sensitive neither to BR nor to auxin. An inhibitor of BR biosynthesis, brassinazole, inhibited auxin induction of DR5-GUS gene, which is consisted of a synthetic Auxin-Response Element, a minimum promoter, and a β-glucuronidase. These results suggest that the Aux/IAA proteins function in auxin-and BR-signaling pathways, and that the IAA proteins function as the signaling components modulating BR sensitivity in a manner dependent on organ type.

Research Products

• [Journal Article] GAMYB Controls Different Sets of Genes and Is Differentially Regulated by microRNA in Aleurone Cells and Anthers (2006)
  • Author(s): Tsuji H, Aya K, Ueguchi-Tanaka M, Shimada Y, Nakazono N, Watanabe R, Nishizawa N, Gomi K, Shimada A, Kitano H, AshikariM, Matsuoka M
  • Journal Title: Plant Journal 47 Pages: 427-444
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Arabidopsis Aux/IAA genes are involved in Brassinosteroid-mediated growth responses in a manner dependent on organ type (2006)
  • Author(s): Nakamura A, Nakajima N, Goda H, Shimada Y, Hayashi K, Nozaki H, Asami T, Yoshida S, Fujioka S
  • Journal Title: Plant Journal 45 Pages: 193-205
  • NAID: 130006987634
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Arabidopsis Aux/LAA genes are involved in Brassinosteroid-mediated growth responses in a manner dependent on organ type (2006)
  • Author(s): Nakamura A, Nakajima N, Goda H, Shimada Y, Hayashi K, Nozaki H, Asami T, Yoshida S, Fujioka S
  • Journal Title: Plant Journal 45 Pages: 193-205
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] GAMYB Controls Different Sets of Genes and Is Differentially Regulated by microRNA in Aleurone Cells and Anthers (2006)
  • Author(s): Tsuji H, Aya K, Ueguchi-Tanaka M, Shimada Y, Nakazono N, Watanabe R, Nishizawa N, Gomi K, Shimada A, Kitano H, Ashikari M, Matsuoka M
  • Journal Title: Plant Journal 47 Pages: 427-444
• [Journal Article] Chemical regulation of abscisic acid catabolism in plants by cytochrome P450 inhibitors. (2005)
  • Author(s): Kitahata N, Saito S, Miyazawa Y, Umezawa T, Shimada Y, Min YK, Mizutani M, Hirai N, Shinozaki K, Yoshida S, Asami T
  • Journal Title: Bioorg Med Chem. 13 Pages: 4491-4498
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] BAS1 and SOB7 act redundantly to modulate Arabidopsis photomorphogenesis viaunique brassinosteroid inactivation mechanisms (2005)
  • Author(s): Turk, EM, Fujioka, S, Seto, H, Shimada, Y, Takatsuto, S, Yoshida, S, Wang, H, Torres, QI, Ward, JM, Murthy, G, Zhang J, Walker JC, Neff MM
  • Journal Title: Plant Journal 42 Pages: 23-34
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] BAS1 and SOB7 act redundantly to modulate Arabidopsis photomorphogenesis via unique brassinosteroid inactivation mechanisms (2005)
  • Author(s): Turk, EM., Fujioka, S., Seto, H., Shimada, Y., Takatsuto, S., Yoshida, S., Wang, H., Torres, (N., Ward, JM., Murthy, G., Zhang J., Walker JC., Neff MM
  • Journal Title: Plant Journal 42 Pages: 23-34
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] BAS1 and SOB7 act redundantly to modulate Arabidopsis photomorphogenesis via unique brassinosteroid inactivation mechanisms (2005)
  • Author(s): Turk, EM, Fujioka, S, Seto, H, Shimada, Y, Takatsuto, S, Yoshida, S, Wang, H, Torres, QI, Ward, JM, Murthy, G, Zhang J, Walker JC, Neff MM
  • Journal Title: Plant Journal 42 Pages: 23-34