Postharvest Physiology
Biochemical and Molecular Analysis of Ripening and Senescence in Horticultural Crops
Staff
 | Prof. Dr. USHIJIMA Koichiro E-mail： ushijima (please add @okayama-u.ac.jp) Specialty: Molecular Physiology, Plant Genetics Self-incompatibility of Plant and its Application |
Research Topics
We focus on a molecular understanding of fruit ripening and senescence using the omics approach, gene engineering and genetic analysis in fruit, vegetables and flowers. Based on the basic understanding, we develop functional technology to improve quality and to reduce postharvest loss of horticultural crops, which are useful in both developed and developing countries.
Ethylene dependent ripening and senescence
The gaseous plant hormone, ethylene, regulates many important aspects of plant growth and development including fruit ripening, senescence and response to environmental stress. Genetic engineering of ethylene signaling pathway can inhibit ripening process in tomato and a potent inhibitor of ethylene perception, 1-methycycropropene (1-MCP) is useful to extend both storage and shelf life of climacteric fruit such as apples, tomatoes, pears, melons and persimmons.
Ethylene independent ripening and senescence
Non-climacteric fruit, such as citrus, grape and cherry can ripen without ethylene signals. Most part of vegetables senesce in an independent way from ethylene. As pollination triggers the senescent program of flowers, the understanding of self-incompatibility can contribute to extending their shelf life. Recently, we found low temperature can induce ripening in kiwifruit in an ethylene independent way.
Publications
・Yan R.,N. Yokotani, T. Yamaoka, K. Ushijima, R. Nakano, K. Yano, K. Aoki, Y. Kubo. 2013.Characterization of ripening-associated genes using a tomato DNA macroarray, 1-methylcyclopropene, and ripening-impaired mutants. Postharvest Biol.Technol. 86, 159-170.
・Mworia, E. G., T. Yoshikawa, N. Salikon, C. Oda, W. O. Asiche, N.Yokotani, D. Abe, K. Ushijima, R. Nakano and Y. Kubo. 2012. Low-temperature-modulated fruit ripening is independent of ethylene in ‘Sanuki Gold’ kiwifruit. J. Exp. Bot. 63, 963-971.
・Ushijima K., R. Nakano, M. Bando, Y. Shigezane, K. Ikeda, Y. Namba, S. Kume, T. Kitabata, H. Mori and Y. Kubo. 2012.Isolation of the floral morph-related genes in heterostylous flax (Linum grandiflorum): the genetic polymorphism and the transcriptional and post-transcriptional regulations of the S locus. Plant J. 69, 317-331.
・Yokotani, N., R. Nakano, R. Imanishi, M. Nagata, A. Inaba and Y. Kubo.2009. Ripening-associated ethylene biosynthesis in tomato fruit is autocatalytically and developmentally regulated. J. Exp. Bot. 60，3433-3442.
・Nishiyama, K., M. Guis, J.K.C. Rose, Y. Kubo, A. Inaba, M. Bouzayen and A.B. Bennett. 2007. Ethylene regulation of fruit softening and cell wall disassembly in Charentais melon. J. Exp. Bot. 58:1281-1290.