Family name:
Present address:
Bioscience and Biotechnology Center, Nagoya University
Faculty of Agriculture, Nagoya University
Awarded the degree of BSc in Agriculture
Graduate school of Agricultural Sciences, Nagoya University
Awarded the degree of MSc in biological chemistry
Graduate school of Agricultural Sciences, Nagoya University
Awarded the degree of PhD in biological chemistry for a thesis entitled
"Mechanism of the increase in cytochrome c oxidase activity in dry cotyledons
during seed hydration."
Professional Experience:
Researcher, National Institute of Plant Virus Research
Researcher, National Institute of Agrobiological Resources
Senior researcher (as above)
Visiting fellow, Div. of Plant Industry, CSIRO
Associate professor, School of Science, Tsukuba University
Professor, BioScience Center, Nagoya University
Professor, Bioscience and Biotechnology Center, Nagoya University
Young Investigator award of JSPP
Gold Medal of Tokyo Techno Forum 21
Prize by Kihara Foundation For The Advancement Of Life Science
Membership of learned societies:
American Society of Plant Physiologists
Japan Society of Bioscience, Biotechnology, and Agrochemistry
Japanese Society of Breeding
Japanese Society of Plant Physiologists
Molecular Biology Society of Japan
Outline of research
We have studied biosynthesis and signal
transduction pathways of phytohormones
such as gibberellin (GA), brassinosteroid
(BR) and cytokinin (CK), and demonstrated
a number of novel findings. We have also
developed molecular breeding using phytohormone-related genes, and have succeeded
in increasing the yield of rice.
1. Clarification of GA signal transduction pathway
We isolated a nuclear receptor for GA. This receptor interacts with a
control factor, which specifically and negatively controls the GA signal
transduction pathway, and is degraded by GA-dependent interaction with the
receptor. We found that this degradation is dependent on ubiquitination
mediated by the SCF complex.
2. Clarification of GA biosynthesis mechanism and molecular breeding
We characterized the mechanism of GA biosynthesis in rice. In the course
of this study, we found that functional deficiency of the GA20 oxidase gene,
which dwarfs rice, was the mutation responsible for the "miracle rice" used
in "the Green Revolution" in the latter half of 20th century. Based on this
discovery, we genetically manipulated rice to regulate plant height.
3. Isolation of yield determining genes in rice
We isolated a QTL gene which involves yield determination in rice, and
demonstrated that the gene encodes an enzyme involving degradation of CK.
Based on combination of the seed-number control gene and the Green
Revolution gene designed using QTL pyramiding, we also succeeded in
modifying a Japanese rice variety, "Koshihikari," that increased yield by
20% over the original strain in real fields.
1. Shimada A. et al. (2008) Structural basis for gibberellin recognition by
its receptor GID1. Nature, 456: 520-523.
2. Takeda S. & Matsuoka M. (2008) Genetic approaches to crop improvement:
responding to environmental and population changes. Nat. Rev. Genet., 9:
3. Ueguchi-Tanaka M. et al. (2008) Release of the Repressive Activity of Rice
DELLA Protein SLR1 by Gibberellin Does Not Require SLR1 Degradation in the
gid2 Mutant. Plant Cell, 20: 2437-2446.
4. Hirano K. et al. (2008) Comprehensive transcriptome analysis of
phytohormone biosynthesis and signaling genes in microspore/pollen and
tapetum of rice. Plant Cell Physiol., 49: 1429-1450.
5. Sakamoto T. et al. (2006) Erect leaves caused by brassinosteroid deficiency
increase biomass production and grain yield in rice. Nat. Biotechnol., 24:
6. Ueguchi-Tanaka M. et al. (2005) GIBBERELLIN INSENSITIVE DWARF1 encodes a
soluble receptor for gibberellin. Nature, 437: 693-698.
7. Ashikari M. et al. (2005) Cytokinin oxidase regulates rice grain production.
Science, 309: 741-745.
8. Sakamoto T. et al. (2003) Genetic manipulation of gibberellin metabolism
in transgenic rice. Nat. Biotechnol., 21: 909-913.
9. Sasaki A. et al. (2003)Accumulation of phosphorylated repressor for
gibberellin signaling in an F-box mutant. Science, 299: 1896-1898.
10. Sasaki A. et al. (2002) A mutant gibberellin-synthesis gene in rice. Nature,
416: 701-702.