| Understanding the development of plants grown within space craft in the microgravity of orbit is a critical step in developing successful crop plant systems from the bioregenerative life support systems that will be critical for maintaining human life during long-duration spaceflight missions. In this study, we analyzed wild-type seedlings grown in BRIC hardware during Space Shuttle Mission STS-131 (BRIC-16). We collected and analyzed data on germination rates, gross morphology, anatomical features, subcellular structure, and the transcriptome of seedlings in microgravity. We compared the results of our transcriptome with those wild-type seedlings from investigative teams that used the same spaceflight hardware during the STS-131 mission. We determined that germination rates were high and noted a unidirectional skewing of roots and shoots grown in microgravity. We also noted that amyloplasts were present in the endodermal layer of the meristematic region of the shoot and within the petioles of the leaves. A statistically significant roundness was observed in the cells of the endodermis of spaceflight-grown petioles, suggesting an effect on the cell wall. In addition, genes involved in cytoskeleton rearrangement were up-regulated in the transcriptome of spaceflight-grown shoots. In a comparison of the transcriptomes collected from the seedlings of all investigative groups from the BRIC-16 space project, genes involved in cell wall development and stress response were consistently differentially regulated. In conclusion, spaceflight has several significant effects on the morphology and gene expression profiles of plants grown in microgravity. |
