Understanding the molecular mechanisms by which plants sense and adapt to changes in the space environment is essential for generating plants that are better adapted to withstand space flight microgravity and other adverse conditions encountered in space. The objective of our spaceflight experiment x93Plant Signaling in Microgravity x94 (carried out on the International Space Station ISS) was to compare transcript profiles of wild type and transgenic InsP 5-ptase plants with compromised InsP3 signaling. The transgenic Arabidopsis plants constitutively express the mammalian type I inositol polyphosphate 5-phosphatase (InsP 5-ptase) an enzyme that specifically hydrolyzes the lipid-derived second messenger inositol 1,4,5-trisphosphate (InsP3). These transgenic plants exhibit normal growth and morphology; however their responses to environmental stimuli including gravity and drought are altered. Seedlings were grown for 5 days under continuous light in experimental containers placed in the European Modular Cultivation system (EMCS) onboard the ISS. The EMCS consists of two rotors within a controlled chamber allowing for a x931g x94 control in space. After sample retrieval from the ISS RNA was isolated from shoot and root tissue and subjected to RNA sequencing. Two-way comparisons of micro g versus x931 x94g have uncovered regulatory mechanisms that are both conserved and altered between the wild type and transgenic seedlings.

Life in spaceflight demonstrates remarkable adaptive processes within the specialized environments of space vehicles which are subject to the myriad of attending and unique environmental issues associated with orbital trajectories. To examine the adaptive processes that occur in plants in space leaves and roots from Arabidopsis seedlings that were grown from seed for 12 days on the International Space Station and preserved on orbit in RNAlater were returned to earth and analyzed using iTRAQ broad scale proteomics procedures.

Life in spaceflight demonstrates remarkable adaptive processes within the specialized environments of space vehicles which are subject to the myriad of attending and unique environmental issues associated with orbital trajectories. To examine the adaptive processes that occur in plants in space leaves and roots from Arabidopsis seedlings that were grown from seed for 12 days on the International Space Station and preserved on orbit in RNAlater were returned to earth and analyzed using iTRAQ broad scale proteomics procedures.

The project focuses on understanding the transcriptional and post-transcriptional mechanisms that regulate early seedling development in spaceflight and microgravity. One of the goals of the PRR experiment was to study the role of small regulatory RNAs in plant response to the space environment using Arabidopsis thaliana.

Physical forces greatly influence the growth and function of an organism. Altered gravity can perturb normal development and induce corresponding changes in gene expression. Understanding this relationship between the physical and biological realms is important for NASA s space travel goals. We use combined RNA-Seq and qRT-PCR to profile changes in early Drosophila melanogaster pupae exposed to chronic hypergravity (3 g three times Earth s gravity) to highlight gravity-dependent pathways and gene products. Robust transcriptional response was evident among the pupae developed in a hypergravity environment compared to control. 1,513 genes showed significantly (p < 0.05) altered gene expression in the 3 g samples. These findings were supported with qRT-PCR data. Major biological processes affected include ion transport redox homeostasis immune and humoral stress response proteolysis and cuticle development.

The extent to which plants can enhance human life support on other worlds depends on the ability of plants to thrive in extraterrestrial environments using in situ resources. Using samples from Apollo 11, 12 and 17, we show that the terrestrial plant Arabidopsis thaliana germinates and grows in diverse lunar regoliths. However, our results show that growth is challenging; the lunar regolith plants were slow to develop, expressed genes indicative of ionic stresses, and many showed severe stress morphologies. Therefore, although in situ lunar regolith can be useful for plant production in lunar habitats, they are not benign substrates. The interaction between plants and lunar regolith will need to be further elucidated, and likely mitigated, to enable efficient use of lunar regolith for life support.

On Earth plants are constantly exposed to a gravitational field of 1G. Gravity affects a plant in every step of its development. Germinating seedlings orient their radicle and hypocotyl and growing plants position organs at a specific Gravitropic Set-point Angle dictated by the asymmetric distribution of auxin depending on the gravity vector. Hence gravitropism is one of the fundamental growth responses in plants. For any experiment studying the effects of gravity on plants, the ultimate control is the microgravity in space. In this study, Arabidopsis seeds were flown to the International Space Station and allowed to germinate and grow for 3 days in microgravity. Arabidopsis Wild Type Col-0 seeds were plated onto twenty-two 60mm Petri plates, loaded into PDFUs and inserted 4 Biological Research in Canisters (BRICs). Approximately 800 seeds were sterilized, plated on each 60mm Petri plates and cold stratified for 16 hours followed by 2 hours of white light treatment. The BRICs were maintained at 4C until spaceflight to ensure seed germination in microgravity. After 3 days of germination and growth, the seedlings were fixed by injecting RNAlater into the chamber. They were kept at ambient temperature for 12 hours followed by freezing at -80C. An additional 22 plates were used as ground controls. After the spaceflight, tissue from five plates was pooled to make each of three replicates. Both membrane and soluble proteins were extracted from the pooled seedlings. Proteins were trypsin digested, labelled with iTRAQ and identified using tandem mass spectrometry.

In this study transcriptome profiling was used to gain insight into the spaceflight adaptation role of Altered response to gravity-1 (Arg1) a gene known to affect gravity responses in plants on Earth. The study compared expression profiles of cultured lines of Arabidopsis thaliana derived from wild type (WT) cultivar Col-0 to profiles from a knock-out line deficient in the gene encoding (ARG1 KO) both on the ground and in space. The cell lines were launched on SpaceX CRS-2 as part of the Cellular Expression Logic (CEL) experiment of the BRIC17 spaceflight mission. The cultured cell lines were grown within 60mm Petri plates in Petri Dish Fixation Units (PDFUs) that were housed within the Biological Research In Canisters (BRIC) hardware. Spaceflight samples were fixed on orbit. Differentially expressed genes were identified between the two environments (spaceflight and comparable ground controls) and the two genotypes (WT and ARG1 KO). Each genotype engaged unique genes during physiological adaptation to the spaceflight environment with little overlap. Most of the genes altered in expression in spaceflight in WT cells were found to be Arg1-dependent suggesting a major role for that gene in the physiological adaptation of undifferentiated cells to spaceflight.

This experiment compared the spaceflight transcriptomes of four commonly used natural variants (ecotypes) of Arabidopsis thaliana using RNAseq. In nature Arabidopsis is a native of Europe/Asia/Northwestern Africa and is found across the globe growing in a wide range of environments. The geographical spread of these various populations has led to a slow divergence leading to distinct ecotypes. Understanding the impact of this ecotypic variability is an important factor when using Arabidopsis as a model. Seeds of the ecotypes Col_0 Ler-2 Ws-2 and Cvi-0 were flown to the International Space Station as part of CRS-4 mission in the Biological Research in Canister (BRIC) hardware. The seeds were germinated on orbit grown for 8 days and then fixed in RNAlater and frozen in the MELFI freezer for return to Earth. Once returned RNA was isolated and RNAseq performed to catalog the transcriptional patterns of the plants grown in space. An identical set of samples were grown in parallel on the ground to provide controls to allow assessment of transcriptional changes specifically associated with the spaceflight environment. This data release includes 48 out of 56 sample expression files with the remaining 8 files to be released at a later date.

On Earth plants are constantly exposed to a gravitational field of 1G. Gravity affects a plant in every step of its development. Germinating seedlings orient their radicle and hypocotyl and growing plants position organs at a specific Gravitropic Set-point Angle dictated by the asymmetric distribution of auxin depending on the gravity vector. Hence gravitropism is one of the fundamental growth responses in plants. For any experiment studying the effects of gravity on plants the ultimate control is the microgravity in space. In this study Arabidopsis seeds were flown to the International Space Station and allowed to germinate and grow for 3 days in microgravity. Arabidopsis Wild Type Col-0 seeds were plated onto twenty-two 60mm Petri plates loaded into PDFUs and inserted 4 Biological Research in Canisters (BRICs). Approximately 800 seeds were sterilized plated on each 60mm Petri plates and cold stratified for 16 hours followed by 2 hours of white light treatment. The BRICs were maintained at 4C until spaceflight to ensure seed germination in microgravity. After 3 days of germination and growth the seedlings were fixed by injecting RNAlater into the chamber. They were kept at ambient temperature for 12 hours followed by freezing at -80C. An additional 22 plates were used as ground controls. After the spaceflight tissue from five plates was pooled to make each of three replicates. Both membrane and soluble proteins were extracted from the pooled seedlings. Proteins were trypsin digested labelled with iTRAQ and identified using tandem mass spectrometry.