Preparation and Outline of Space-Based Studies on Gravity Responses and Cell Wall Formation in Plants

The Japan Aerospace Exploration Agency (JAXA) recently conducted two space-based plant physiology experiments utilizing the European Modular Cultivation System (EMCS) facility of the European Space Agency (ESA). These experiments were named Cell Wall and Resist Wall (CWRW), and were designed to investigate the formation of plant cell walls and gravity resistance in plants. The CWRW experiments were taken aboard the International Space Station (ISS) by space shuttle mission STS-123 (1J/A) on March 11, 2008 and performed between March 30 and May 23, 2008. However, a number of failures in the EMCS environmental control system resulted in the experiments being performed differently than planned. On June 14, 2008, Arabidopsis plants grown in the CWRW experiments were recovered to Earth in the space shuttle mission STS-124 (1J) and are currently being analyzed. In this article, we elaborate on the timeline of the CWRW experiments from selection to performance. We also describe experiment unique equipments, the onboard operations by the ISS crew, the process by which the experiments were monitored from the ground and brief information about plants germination and growth stage under microgravity conditions in space. We conclude with lessons learned for future plant physiology experiments conducted in space.