Abstract
Japan Aerospace Exploration Agency(JAXA） has two plant physiological space experiments that utilize the European Modular Cultivation System（EMCS) facility of European Space Agency（ESA). The theme of the two experiments, namely, Cell Wall and Resist Wall（CWRW）are aimed at understanding the formation of plant cell wall and the mechanism of gravity resistance in plants. A ground-based study for monitoring the germination and growth of Arabidopsis, science test, was performed for 50 days in the EMCS experiment reference model(ERM), as a preparation of the onboard CWRW space experiment. Four strains of Arabidopsis seeds were germinated and the seedlings were cultivated in the dedicated plant cultivation chamber(PCC) in the EMCS ERM until the inflorescence stems grew to approximately 10-cm long.. The objective of this science test was to successfully grow Arabidopsis seedlings in the EMCS ERM for determining the approximate duration of the onboard CWRW space experiment. As a result, the PCC could be used to grow three strains, i.e., wild type, lefty mutant, and gene modified pCesA7::GUS, Arabidopsis plants from seeds to 10-cm-long inflorescence stems within 50 days. This science test confirmed that the PCC is biocompatible and a good support system for these strains growth during the entire experiment. On the other hand, the hmg mutant seeds, which are more delicate and susceptible to outer environment than other strains, failed to germinate. Therefore, increase the number of sowing hmg mutant seeds into the PCC and germination test using the PCC and the germination test using the PCC for selection the hmg mutant seeds with best germination rate were essential for the future onboard CWRW space experiment.
