@inproceedings{oai:jaxa.repo.nii.ac.jp:00013489,
 author = {保尊, 隆享 and 曽我, 康一 and 榊, 剛 and 村中, 俊哉 and 橋本, 隆 and 園部, 誠司 and 小竹, 敬久 and Hoson, Takayuki and Soga, Koichi and Sakaki, Takeshi and Muranaka, Toshiya and Hashimoto, Takashi and Sonobe, Seiji and Kotake, Toshihisa},
 book = {宇宙利用シンポジウム　第24回　平成19年度, Space Utilization Research: Proceedings of the Twenty-fourth Space Utilization Symposium},
 month = {Mar},
 note = {Resistance to the gravitational force is a principal graviresponse in plants, comparable to gravitropism. Nevertheless, only limited information has been obtained for this graviresponse. The present study aims to clarify the mechanism of signal transformation and transduction processes, with reference to the roles of the plasma membrane and cortical microtubules. Under hypergravity conditions, the expression of genes encoding 3-Hydroxy-3-MethylGlutaryl-Coenzyme A Reductase (HMGR) was up-regulated, and the level of membrane sterols was kept higher, without influencing the level or composition of other membrane components. On the other hand, the expression of the majority of alpha- and beta-tubulin genes was up-regulated and the percentage of cells with longitudinal cortical microtubules was increased by hypergravity. Also, increases in the level and molecular size of anti-gravitational xyloglucans and 1, 3, 1, 4-beta-glucans by gravity were brought about by suppression of their breakdown with their constant or enhanced biosynthesis. We have further examined the role of membrane sterols and cortical microtubules in gravity resistance using Arabidopsis mutants. Elongation growth of both hmg and tubulin mutants was suppressed even under 1 g conditions, and hypergravity did not influence their growth, suggesting that the mutation made plants hypersensitive to the gravitational force. The analysis with mutants has also revealed that the signal transduction process via membrane sterols is distinct from that via cortical microtubules. These results indicate that membrane sterols (rafts) and cortical microtubules are deeply and independently involved in maintenance of normal growth capacity against the gravitational force., 資料番号: AA0063706113},
 pages = {390--393},
 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/ISAS)},
 title = {植物の抗重力反応におけるシグナル変換・伝達機構の解明},
 year = {2008}
}