@article{oai:jaxa.repo.nii.ac.jp:00022660,
 author = {若林, 和幸 and 曽我, 康一 and 保尊, 隆享 and 小竹, 敬久 and 山崎, 丘 and 東端, 晃 and 石岡, 憲昭 and 嶋津, 徹 and 福井, 啓二 and 長田, 郁子 and 笠原, 春夫 and 鎌田, 源司 and Wakabayashi, Kazuyuki and Soga, Kouichi and Hoson, Takayuki and Kotake, Toshihisa and Yamazaki, Takashi and Higashibata, Akira and Ishioka, Noriaki and Shimazu, Toru and Fukui, Keiji and Osada, Ikuko and Kasahara, Haruo and Kamada, Motoshi},
 issue = {9},
 journal = {PLoS ONE},
 month = {Sep},
 note = {Network structures created by hydroxycinnamate cross-links within the cell wall architecture of gramineous plants make the cell wall resistant to the gravitational force of the earth. In this study, the effects of microgravity on the formation of cell wall-bound hydroxycinnamates were examined using etiolated rice shoots simultaneously grown under artificial 1 g and microgravity conditions in the Cell Biology Experiment Facility on the International Space Station. Measurement of the mechanical properties of cell walls showed that shoot cell walls became stiff during the growth period and that microgravity suppressed this stiffening. Amounts of cell wall polysaccharides, cell wall-bound phenolic acids, and lignin in rice shoots increased as the shoot grew. Microgravity did not influence changes in the amounts of cell wall polysaccharides or phenolic acid monomers such as ferulic acid (FA) and p-coumaric acid, but it suppressed increases in diferulic acid (DFA) isomers and lignin. Activities of the enzymes phenylalanine ammonia-lyase (PAL) and cell wall-bound peroxidase (CW-PRX) in shoots also increased as the shoot grew. PAL activity in microgravity-grown shoots was almost comparable to that in artificial 1 g-grown shoots, while CW-PRX activity increased less in microgravity-grown shoots than in artificial 1 g-grown shoots. Furthermore, the increases in expression levels of some class III peroxidase genes were reduced under microgravity conditions. These results suggest that a microgravity environment modifies the expression levels of certain class III peroxidase genes in rice shoots, that the resultant reduction of CW-PRX activity may be involved in suppressing DFA formation and lignin polymerization, and that this suppression may cause a decrease in cross-linkages within the cell wall architecture. The reduction in intra-network structures may contribute to keeping the cell wall loose under microgravity conditions., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: PA1610034000},
 title = {Suppression of Hydroxycinnamate Network Formation in Cell Walls of Rice Shoots Grown under Microgravity Conditions in Space},
 volume = {10},
 year = {2015}
}