Functional analysis of a sensor kinase gene family implicated in cytokinin signaling in higher plants

• Project/Area Number: 13640644
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 植物生理
• Research Institution: Nagoya University
• Principal Investigator: UEGUCHI Chiharu Nagoya University, Bioscience Center, Associated Professor, 生物分子応答研究センター, 助教授 (20232738)
• Project Period (FY): 2001 – 2002
• Project Status: Completed (Fiscal Year 2002)
• Budget Amount: ¥3,500,000 (Direct Cost: ¥3,500,000); Fiscal Year 2002: ¥1,700,000 (Direct Cost: ¥1,700,000); Fiscal Year 2001: ¥1,800,000 (Direct Cost: ¥1,800,000)
• Keywords: Cytokinin / Phytohormone / Sensor kinase / Signal Transduction / Shoot / シュート / 文化・成長

Research Abstract

We identified a set of structurally related genes, AHK2 3 and 4, each encoding a sensor histidine kinase in Arabidopsis thaliana. We identified a loss-of-function mutation of the AHK4 gene. The mutant exhibited the cytokinin-resistant phenotype not only in inhibition of root growth by cytokinin but also in greening and shoot induction of calli. Moreover, AHK4 expressed in budding yeast showed histidine kinase activity in a manner dependent on the presence of cytokinin. These results strongly suggested that AHK4 is involved in the cytokinin-signaling pathway, as a direct receptor. We then screened and isolated loss-of function mutations of the AHK2 and 3 genes. Two independent alleles of ahk3 mutations exhibited the cytokinin-insensitive phenotype in greening and shoot induction of calli, indicating that AHK3 is also a cytokinin receptor. Although two independent alleles of ahk2 showed normal growth and cytokinin sensitivity, the ahk2/ 3 double mutant exhibited semi-dwarf phenotype in the above-ground tissues. These results suggest that AHK2 and 3 also function as cytokinin receptors and that cytokinins act as positive regulators in cell division activity in vivo.

Research Products

• [Publications] Suzuki T., Sakurai K., Ueguchi C., Mizuno T.: "Two types of putative nuclear factors that physically interact with histidine-containing phosphotransfer (HPt) domains, signaling mediators in His-to-Asp phosphorelay, in Arabidopsis thaliana"Plant & Cell Physiology. 42. 37-45 (2001)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Ueguchi C., Koizumi H., Suzuki T., Mizuno T.: "Novel family of sensor histidine kinase genes in Arabidopsis thaliana"Plant & Cell Physiology. 42. 231-235 (2001)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Ueguchi C., Sato S., Kato T., Tabata S.: "The AHK4 gene is involved in the cytokinin-signaling pathway as a direct receptor molecule in Arabidopsis thaliana"Plant & Cell Physiology. 42. 751-755 (2001)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Takeda T., Suwa Y., Suzuki M., Kitano H., Ueguchi-Tanaka M., Ashikari M., Matsuoka M., Ueguchi C.: "The OsTB1 gene negatively regulates lateral branching in rice"The Plant Journal. 33. 513-520 (2003)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] 上口智治: "二成分制御系 「植物の形作り」蛋白質 核酸 酵素 47 分担執筆"共立出版. 6 (2002)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Ueguchi C., Misonou N.and Mizuno T.: "Negative control of rpoS expression by phosphoenolpyruvate : carbohydrate phosphotransferase system (PEP : PTS) in Escherichia coli"J.Bacteriol. 183. 520-527 (2001)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Suzuki T., Sakurai K., Ueguchi C.and Mizuno T.: "Two types of putative nuclear factors that physically interact with histidine-containing phosphotransfer (HPt) domains, signaling mediators in His-to-Asp phosphorelay, in Arabidopsis thaliana"Plant Cell Physiol. 42. 37-45 (2001)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Ueguchi C., Koizumi H., Suzuki T.and Mizuno T.: "Novel family of sensor histidine kinase genes in Arabidopsis thaliana"Plant Cell Physiol. 42. 231-235 (2001)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Izutsu, K., Wada, C., Komine, Y., Sako, T., Ueguchi, C., Nakura, S., and Wada, A.J.: "Escherichia coli ribosome-associated protein SRA, which increases during stationary phase"Bacteriol. 183. 2765-2773 (2001)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Majumder, A., Fang, M., Tsai, K-J., Ueguchi, C., Mizuno, T., and Wu, H-Y.: "LeuO expression in response to starvation for branched-chain amino acids"J.Biol.Chem.. 276. 19046-19051 (2001)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Ueguchi C., Sato S., Kato T.and Tabata S.: "The AHK4 gene involved in the cytokinin-signaling pathway as a direct receptor molecule in Arabidopsis thaliana"Plant Cell Physiol. 42. 751-755 (2001)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Takeda T., Suwa Y., Suzuki M., Kitano H., Ueguchi-Tanaka M., Ashikari M., Matsuoka M.and Ueguchi C.: "The OsTBl gene negatively regulates lateral branching in rice"Plant J.. 33. 513-520 (2003)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Takeda T., Suwa Y., Suzuki M., Kitano H., Ueguchi-Tanaka M., Ashikari M., Matsuoka M., Ueguchi C.: "The OsTB1 gene negatively regulates lateral branching in rice"The Plant Journal. 33. 513-520 (2003)
• [Publications] Suzuki T., Sakurai K., Ueguchi C., Mizuno T.: "Two types of putative nuclear factors that physically interact with histidine-containing phosphotransfer (HPt) domains, signaling mediators in His-to-Asp phosphorelay,in Arabidopsis thaliana"Plant & Cell Physiology. 42. 37-45 (2001)
• [Publications] Ueguchi C., Koizumi H., Suzuki T., Mizuno T.: "Novel family of sensor histidine kinase genes in Arabidopsis thaliana"Plant & Cell Physiology. 42. 231-235 (2001)
• [Publications] Ueguchi C., Sato S., Kato T., Tabata S.: "The AHK4 gene is involved in the cytokinin-signaling pathway as a direct receptor molecule in Arabidopsis thaliana"Plant & Cell Physiology. 42. 751-755 (2001)