@inproceedings{oai:jaxa.repo.nii.ac.jp:00013212,
 author = {藤井, 伸治 and 渡辺, 千秋 and 矢内, 健一 and 宮沢, 豊 and 高橋, 秀幸 and 西村, 岳志 and 小柴, 共一 and 山崎, 丘 and 石岡, 憲昭 and 鎌田, 源司 and 嶋津, 徹 and Fujii, Nobuharu and Watanabe, Chiaki and Yanai, Kenichi and Miyazawa, Yutaka and Takahashi, Hideyuki and Nishimura, Takeshi and Koshida, Tomokazu and Yamazaki, Takashi and Ishioka, Noriaki and Kamada, Motoshi and Shimazu, Toru},
 book = {宇宙利用シンポジウム, Space Utilization Research: Proceedings of Space Utilization Symposium},
 month = {Feb},
 note = {第26回宇宙利用シンポジウム(2010年1月25日-26日, 宇宙航空研究開発機構宇宙科学研究本部相模原キャンパス), The Twenty-sixth Space Utilization Symposium (January 25-26, 2010: ISAS/JAXA Sagamihara, Japan), When cucumber seeds are placed in a horizontal position for germination, resulting seedlings develop a specialized protuberance, termed the peg, on the lower side of the transition zone between the hypocotyl and the root, due to gravistimulation. On the other hand, in our spaceflight experiment of STS-95, cucumber seedlings grown under microgravity conditions developed a peg on each side of the transition zone, suggesting that gravistimulation was required for suppressing the peg formation on the upper side of the transition zone. We considered this as negative regulation of morphogenesis (peg formation) by gravity. We have shown that exogenous auxin induces peg formation and that indole-3-acetic acid (IAA) content in the upper side of the gravistimulated transition zone is less than that in the lower side. Furthermore, inhibition of auxin efflux by TIBA treatment induces the peg formation on the upper side of the transition zone in addition to the lower side. Therefore, we proposed that gravistimulation activates auxin efflux, decreases auxin level and suppresses peg formation on the upper side of the transition zone. To examine this hypothesis, we first investigated the localization pattern of auxin efflux carrier CsPIN1 proteins in endodermal cells that are thought to sense gravity. The results suggested that its localization pattern changed to transport auxin to the lower side of the transition zone 30 min after gravistimulation. We then analyzed IAA contents in the transition zone after gravistimulation using GC-SIM-MS. Results of our quantification of IAA contents indicated that asymmetric IAA distribution was induced 30 min after gravistimulation. These results suggested that auxin efflux carrier CsPIN1 proteins in endodermal cells would induce asymmetric auxin distribution in the transition zone and play an important role in negative regulation of peg formation by gravity., 共催: 日本学術会議, 著者人数: 11人, joint hosting: The Science Council of Japan, 資料番号: AA0064730065},
 publisher = {宇宙航空研究開発機構宇宙科学研究本部, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)},
 title = {キュウリ芽生えの重力応答によりネガティブに制御される形態形成におけるオーキシン勾配制御},
 volume = {26},
 year = {2010}
}