Areas of interest:

Mechanism and function of terpenoids in woody plants, especially conifers. The constituents of these essential oils and resins are used in pharmaceuticals, nutraceuticals, flavors, fragrances, and as industrial raw materials. Terpenoids also provide a means of chemical defense and communication in plants.

Current projects:

DNA analysis for monoterpene chemotypes in Japanese cypress

Monoterpene chemotypes are known in “hinoki” Japanese cypress (Chamaecyparis obtusa). To clarify transcriptional elements of monoterpene synthase genes, DNA analysis of Japanese cypress is being carried out as follows:
Random Amplified Polymorphic DNA (RAPD) is being analyzed for detecting RAPD markers among representative monoterpene chemotypes.
Sequence Tagged Sites (STS) are being constructed for recognizing specific sequences with reproducibility by subcloning specific DNA fragments into a cloning vector.
The specific sequences are being compared among the DNA of representative monoterpene chemotypes in Japanese cypress.

Relationship between terpenoid composition and resistance to resinous canker in Japanese cypress

This work is being carried out in Shimane Prefecture in cooperation with the Shimane Prefecture Forest Research Center. Several Japanese cypress forests severely damaged by resinous canker are being investigated by analyzing head-space monoterpene compositions emitted from needles and the essential oils of needles. The compositions of terpenoid are being compared with the percentage suffering.

Recent Publications:

• Katoh, S. and Furuno T. 2000: Individual variation in low boiling point (LBP) monoterpenes emitted from hinoki (Chamaecyparis obtusa) needles. J. Wood Sci., 46(5): 381-384.
• Bohlmann J., Phillips, M., Ramachandiran V., Katoh, S., and Croteau R. 1999: cDNA cloning, characterization, and functional expression of four new monoterpene synthase members of the Tpsd gene family from grand fir (Abies grandis). Archives of Biochemistry and Biophysics, 368(2): 232-243.
• Lewinsohn E., Katoh S., and Croteau R. 1999: Conifer chemical defenses against bark beetles. The modulation of monoterpene biosynthesis by wounding, environmental stress and ethylene. Plant Responses to Environmental Stresses, H. R. Lerner (ed.), Marcel Dekker, Inc. New York: 659-681.
• Steele C. L., Katoh, S., Bohlmann, J. and Croteau R. 1998: Regulation of Oleoresinosis in Grand Fir (Abies grandis), Differential Transcriptional Control of Monoterpene, Sesquiterpene and Diterpene Synthase Genes in Response to Wounding. Plant Physiology, 116: 1497-1504.
• Katoh S. and Croteau R. 1998: Individual Variation in Constitutive and Induced Monoterpene Biosynthesis in Grand fir. Phytochemistry, 47(4): 577-582.