@inproceedings{oai:jaxa.repo.nii.ac.jp:00013246,
 author = {辰巳, 仁史 and 豊田, 正嗣 and 古市, 卓也 and 曽我部, 正博 and Tatsumi, Hitoshi and Toyota, Masatsugu and Furuichi, Takuya and Sokabe, Masahiro},
 book = {宇宙利用シンポジウム, Space Utilization Research: Proceedings of Space Utilization Symposium},
 month = {Mar},
 note = {第25回宇宙利用シンポジウム(2009年1月14日-15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-fifth Space Utilization Symposium (January 14-15, 2009: ISAS/JAXA Sagamihara, Japan), Plants respond to a large variety of environmental signals, including changes in the gravity vector (gravistimulation). Previous studies have demonstrated that gravistimulation induces increases in cytoplasmic pH in root columella cells (Massa et al., 2003) and InsP3 level in inflorescence stems (Perera et al., 2001) of Arabidopsis thaliana. Recently, gravistimulation is also known to increase the cytoplasmic free calcium concentration ([Ca(sup 2+)](sub c)) in Arabidopsis seedlings (Plieth and Trewavas, 2002). However, organs responsible for the [Ca(sup 2+)](sub c) increase and the underlying cellular/molecular mechanisms remain to be solved. Previously using Arabidopsis seedlings expressing apoaequorin, a Ca(sup 2+)-sensitive luminescent protein in combination with an ultrasensitive photon counting camera, we clarified the organs where [Ca(sup 2+)](sub c) increases in response to gravistimulation and characterized the physiological and pharmacological properties of the [Ca(sup 2+)](sub c) increase (Toyota et al., 2008). When the seedlings were gravistimulated by turning 180 deg, they showed a transient biphasic [Ca(sup 2+)](sub c) increase in their hypocotyls and petioles. The second peak of the [Ca(sup 2+)](sub c) increase depended on the angle but not the speed of rotation, whereas the initial peak showed diametrically opposite characters. This suggests that the second [Ca(sup 2+)](sub c) increase is specific for changes in the gravity vector. Here, we made a control experiment; the gravi-stimulation in 1 g ground condition and the same gravi-stimulation in 1 g-flight experiments before making parabolic flight experiments to examine the properties of the second [Ca(sup 2+)](sub c) increase. We could record the [Ca(sup 2+)](sub c) increase in 1 g-flight experiments but the amplitude of the [Ca(sup 2+)](sub c) increase was diminished ca. 30 % presumably due to the vibration during the flight, but was large enough to analyze., 形態: カラー図版あり, 資料番号: AA0064297002},
 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 = {植物の重力受容の分子機構},
 volume = {25},
 year = {2009}
}