THE DEVELOPMENT OF SPACEFLIGHT EXPERIMENTS WITH ARABIDOPSIS AS A MODEL SYSTEM IN GRAVITROPISM STUDIES

Experiments with Arabidopsis have been developed for spaceflight studi es in the European Space Agency's Biorack module. The Biorack is a mul tiuser facility that is flown on the United States Space Shuttle and s erves as a small laboratory for studying cell and developmental biolog y in unicells, plants, and small invertebrates. The purpose of our spa ceflight research was to investigate the starch-statolith model for gr avity perception by studying wild-type (WT) and three starch-deficient mutants of Arabidopsis. Since spaceflight opportunities for biologica l experimentation are scarce, the extensive ground-based testing descr ibed in this paper is needed to ensure the success of a flight project . Therefore, the specific aims of our groundbased research were: (1) t o modify the internal configuration of the flight hardware, which orig inally was designed for large lentil seeds, to accommodate small Arabi dopsis seeds; (2) to maximize seed germination in the hardware; and (3 ) to develop favorable conditions in flight hardware for the growth an d gravitropism of seedlings. The hardware has been modified, and growt h conditions for Arabidopsis have been optimized. These experiments we re successfully flown on two Space Shuttle missions in 1997.