Department of Biosphere Resources Science

Division of Resources Cycling System


Fax: +81-52-789-4022
Prof. YAMAUCHI, Akira D. Agr. ayama@
Lecturer MITSUYA, Shiro D. Agr. mitsuya@
Des. Asst. Prof. NAKATA, Mana D. Agr. mnakata@
Plant root is equipped with various structures that regulate water and solute movement from soil to root and within a root.

Our main research interests currently lie in the plant-root relationship with special emphasis on the development and function of plant root. Resource cycling in biosphere is inherently regulated by the roots that constitutes an interface between plants and soils. Understanding biological, chemical and physical processes of the relationship is essential for the fundamentals for crop production and soil environmental management.

Specifically, the following research subjects are now being studied;

Abiotic tolerance of crop plants like drought, O2 deficiency, soil moisture fluctuation, nutrient deficiency.
Developmental and physiological responses of roots to environmental stresses. Genetic basis for root system development and function using chromosome segment substitution line and mutant.
Anatomical, developmental and physiological bases for water flow from soil to roots and within a root.
Industrial waste utilization for sustainable crop production and soil management.

International research collaborations are in progress with several institutions like International Rice Research Institute, PhilRootcrop, Leyte State University in the Philippines.

Recent Publications:

  1. Ogawa, A. and A. Yamauchi 2006. Root Osmotic Adjustment under Osmotic Stress Conditions in Maize Seedlings. 1. Transient response of growth and water relations in roots to osmotic stress. Plant Production Science 9 (1): 27-38.
  2. Wang, H. and A. Yamauchi. 2006. Growth and Function of Roots under Abiotic Stress in Soil. In Plant-Environment Interactions (3rd) (ed. Huang, B.). CRC Press, New York. pp. 271-320.
  3. Siopongco, J. D. L. C., K. Sekiya, A. Yamauchi, J. Egdane, A. M. Ismail and L. J. Wade. 2008. Stomatal Responses in Rainfed Lowland Rice to Partial Soil Drying; Evidence for Root Signals. Plant Production Science. 11: 28-41.
  4. Suralta, R. R. and Yamauchi, A. 2008. Root growth, aerenchyma development, and oxygen transport in rice genotypes subjected to drought and waterlogging. Environmental and Experimental Botany 64:75–82.
  5. Suralta, R. R., Inukai Y. and Yamauchi, A. 2008. Utilizing chromosome segment substitution lines (CSSLs) for evaluation of root responses under transient moisture stresses in rice. Plant Production Science 11: 457-465.
  6. Wang, H., Siopongco, J. D. L. C, Wade, L. J. and Yamauchi, A. 2009. Fractal Analysis on Root Systems of Rice Plants in Response to Drought Stress. Environmental and Experimental Botany. 65: 338-344.


FAX: +81-52-789-4137
Prof. WATANABE, Akira D. Agr. akiraw@

Current main research interests are chemical structure, function, and dynamics of natural organic matter, in particular humic substances, dissolved organic matter (DOM), and black carbon (C). An accumulation of organic matter or C in soil is very important in both aspects of global C cycle/balance related to global warming and improvement of soil fertility (plant production ability). Stabilization process of soil organic matter and relationship between degradation rate and structural property of natural organic matter are studied. Effects of forest type, land use type, or soil type on the quality and quantity of DOM and DOM-metal complex, which are exported from pedosphere to hydrosphere and essential for maintaining aquatic ecosystems, are also investigated. Other research topics include dynamics of silicate in a rice paddy and sustainable agricultural use of tropical peatland.

Recent Publications:

  1. Ikeya, K., Sleighter, R.L., Hatcher, P.M., and Watanabe, A. 2015: Characterization of composition of soil humic acids using Fourier transform ion cyclotron resonance mass spectrometry. Geochim. Cosmochim. Acta, 153, 169-182.
  2. Kawasaki, S., Ikeya, K., Sugiura, Y., and Watanabe, A. 2015: Changes in the composition of humic acids in various upland field soils with a continuous organic amendment as revealed by fractional precipitation analysis. Soil Sci. Plant Nutr., 61, 450-460.
  3. Watanabe, A. 2015: Cultivation management and environment. In The Sago Palm―The Food and Environmental Challenges of the 21st Century. Ed. The Society of Sago Palm Studies, p. 191-198, Kyoto Univ. Press, Kyoto, Japan.
  4. Watanabe, A., Ikeya, K., Kanazaki, Y., Makabe, S., Sugiura, Y., and Shibata, A. 2014: Five crop seasons’ records of greenhouse gas fluxes from upland fields with repetitive applications of biochar and cattle manure.J. Environ. Manage., 144, 168-175.
  5. Watanabe, A., Tsutsuki, K., Inoue, Y., Maie, N., Melling, L., and Jaffe, R. 2014: Composition of dissolved organic nitrogen in rivers associated with wetlands. Sci. Total Environ., 493, 220-228.


Assoc. Prof. IMAI, Takanori D. Agr. takaimai@

Isolation and structural elucidation, determination of the biosynthesis, and visualization of the distribution of wood extractives.

Recent Publications:

  1. Visualization of the distribution of flavonoids in Larix kaempferi wood by fluorescence microscopy, Y. Kawanishi, N. Bito, R. Nakada, T. Imai, Mokuzai Gakkaishi, 61, 297-307 (2015).
  2. Isolation and structural elucidation of norlignan polymers from the heartwood of Cryptomeria japonica. Y. Yanase, K. Sakamoto, T. Imai, Holzforschung, 69, 281-296 (2014).
  3. Lignification of ray parenchyma cells in the xylem of Pinus densiflora. Part I: Microscopic investigation by POM, UV microscopy, and TOF-SIMS. P. Zheng, D. Aoki, M. Yoshida, Y. Matsushita, T. Imai, K. Fukushima, Holzforschung, 68, 897-905 (2014)
  4. The accumulation pattern of ferruginol in the heartwood-forming Cryptomeria japonica xylem as determined by time-of-flight secondary ion mass spectrometry and quantity analysis. K. Kuroda, T. Fujiwara, K.Hashida, T. Imai, M. Kushi, K. Saito, K. Fukushima, Annals of Botany, 113, 1029-1036 (2014).
  5. The cryo-TOF-SIMS/SEM system for the analysis of the chemical distribution in freeze-fixed Cryptomeria japonica wood. K. Kuroda, T. Fujiwara, T. Imai, R. Takama, K. Saito, Y. Matsushita, K. Fukushima, Surface and Interface Analysis, 45, 215-219 (2013).
  6. Clonal variation in heartwood norlignans of Cryptomeria japonica: evidence for independent control of agatharesinol and sequirin C biosynthesis. N. Bito, R. Nakada, E. Fukatsu, Y. Matsushita, K.Fukushima, T. Imai, Annals of Forest Science, 68, 1049-1056 (2011).
  7. In vitro hydroxylation of a norlignan: from agatharesinolto sequirin C and metasequirin C with a microsomal preparation from Cryptomeria japonica. T. Imai, K. Asai, M.Takino, K. Fukushima, Phytochemistry Letters, 2, 196-200 (2009).
  8. Heartwood extractives from the Amazonian trees Dipteryx odorata, Hymenaea courbaril, and Astronium lecointei and their antioxidant activities. T. Imai, S. Inoue, N. Ohdaira, R. Suzuki, Y. Matsushita, M. Sakurai, J. M. Henriques, S. K. Ozaki, Z. Finger, K. Fukushima, Journal of Wood Science, 54, 471-475 (2008).
  9. Discriminating the indistinguishable sapwood from heartwood in discolored ancient wood by direct molecular mapping of specific extractives using time-of-flight secondary ion mass spectrometry. K. Saito, T. Mitsutani, T. Imai, Y. Matsushita, K. Fukushima, Analytical Chemistry, 80, 1552-1557 (2008).
  10. Application of ToF-SIMS to the study on heartwood formation in Cryptomeria japonica trees. K. Kuroda, T. Imai, K. Saito, K. Fukushima, Applied Surface Science, 255, 1143-1147(2008).