Plant Productivity Systems Research Group

Our group will conduct studies on uptake and signaling of nitrogen, action mechanisms of phytohormones, and mechanisms of metal tolerance and accumulation to aim for development of innovation technology for low-input production of plants by saving nitrogen and water, and recovery and recycling of metals. We will also conduct studies for discovery of novel signaling molecules and key genes for plant productivity by using hormonome platform.

Research Fields

Biology & Biochemistry / Molecular Biology & Genetics / Agricultural Sciences / Plant & Animal Science / Environment & Ecology

• Identification of key genes regulating agronomical traits improving crop productivity
• Functional analysis of key genes regulating plant productivity, especially enzymes involved in cytokinin biosynthesis and metabolism
• Development of clean-up technology of heavy metal pollutants using bryophyte
• Identidfication of key genes in agricultural traits using high-throughput hormone analysis system

Publications

1. Kiba, T., Feria-Bourrellier, A.-B., Lafouge, F., Lezhneva, L., Boutet-Mercey, S., Orsel, M., Bréhaut, V., Miller, A., Daniel-Vedele, F., Sakakibara, H. and Krapp, A.
   "The Arabidopsis nitrate transporter NRT2.4 plays a double role in roots and shoots of nitrogen-starved plants"
   Plant Cell 24, 245-258 (2012).
2. Nakamichi, N., Kiba, T., Henriques, R., Mizuno, T., Chua, N.-H. and Sakakibara, H.
   "PSEUDO-RESPONSE REGULATORS 9, 7 and 5 are transcriptional repressors in the Arabidopsis circadian clock"
   Plant Cell 22, 594-605 (2010).
3. Kuroha, T., Tokunaga, H., Kojima, M., Ueda, N., Ishida, T., Nagawa, S., Fukuda, H., Sugimoto, K. and Sakakibara, H.
   "Functional analyses of LONELY GUY cytokinin-activating enzymes reveal the importance of the direct activation pathway in Arabidopsis"
   Plant Cell 21, 3152-3169 (2009).
4. Kojima, M., Kamada-Nobusada, T., Komatsu, H., Takei, K., Kuroha, T., Mizutani, M., Ashikari, M., Ueguchi-Tanaka, M., Matsuoka, M., Suzuki, K. and Sakakibara, H.
   "Highly-sensitive and high-throughput analysis of plant hormones using MS-probe modification and liquid chromatography-tandem mass spectrometry: an application for hormone profiling in Oryza sativa"
   Plant Cell Physiol. 50, 1201-1214 (2009).
5. Sugawara, H., Ueda, N., Kojima, M., Makita, N., Yamaya, T. and Sakakibara, H.
   "Structural insight into the reaction mechanism and evolution of cytokinin biosynthesis"
   Proc. Natl. Acad. Sci. U.S.A. 105, 2734-2739 (2008).
6. Kurakawa, T., Ueda, N., Maekawa, M., Kobayashi, K., Kojima, M., Nagato, Y., Sakakibara, H. and Kyozuka, J.
   "Direct control of shoot meristem activity by a cytokinin activating enzyme"
   Nature 445, 652-655 (2007).
7. Sakakibara, H.
   "Cytokinins: Activity, biosynthesis and translocation"
   Annu. Rev. Plant Biol. 57, 431-449 (2006).
8. Sakakibara, H., Kasahara, H., Ueda, N., Kojima, M., Takei, K., Hishiyama, S., Asami, T., Okada, K., Kamiya, Y., Yamaya, T., and Yamaguchi, S.
   "Agrobacterium tumefaciens increases cytokinin production in plastids by modifying the biosynthetic pathway in the host plant"
   Proc. Natl. Acad. Sci. U.S.A. 102, 9972-9977 (2005).
9. Ashikari, M., Sakakibara, H., Lin, S.-Y., Yamamoto, T., Takashi, T., Nishimura, A., Angeles, E. R., Qian, Q., Kitano, H. and Matsuoka, M.
   "Cytokinin oxidase regulates rice grain production"
   Science 309, 741-745 (2005).
10. Takei, K., Yamaya, T. and Sakakibara, H.
    "Arabidopsis CYP735A1 and CYP735A2 encode cytokinin hydroxylases that catalyze the biosynthesis of trans-zeatin"
    J. Biol. Chem. 279, 41866-41872 (2004).