1. Graduate School of Energy Science, Kyoto University, Kyoto 606-8501, Japan
2. Life Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
3. Division of Forestry and Biomaterials, Kyoto University, Kyoto 606-8502, Japan
4. Department of Plant & Environmental New Resources, Kyung Hee University, Yongin-si 446-701, Republic of Korea