The wild type WS plants and the Sku5 mutant plants in the WS background were germinated on ISS or on the ground and the gene expression profiles in roots at 4 days or 8 days were established. The Sku5 gene (AT4G12420) codes for a multi-copper oxidase-like protein SKU5 protein that is involved in directed root tip growth. The Sku5 protein is glycosylated GPI-anchored and localizes to the plasma membrane and the cell wall. The Sku5 gene is expressed most strongly in expanding tissues. The development of WS and Sku5 plants on orbit differs from that on the ground as demonstrated by the comparison of the gene expression profiles between 4 days old to 8 days old plant in the two environments. However the development of Sku5 mutant plants also differs from WS at either age and in either environment suggesting the role of the genetic background in these developmental decisions. The 4 days old Sku5 roots in orbit engaged substantially more genes than the 4 days old WS roots in orbit but also more than the 4 days old Sku5 roots on the ground. Overall the 4 days old roots differentially expressed more genes in spaceflight relative to ground than the 8 days old roots of either genotype. Finally the 4 days old Sku5 roots in orbit differ in 862 genes from the 8 days Sku5 roots in orbit while on the ground there is merely half of the number of genes differentially expressed between the 4 days and 8 days developmental stages of the Sku5 roots. APEX03-2 (Advanced Plant Experiment 03-2) also identified as TAGES-Isa (Transgenic Arabidopsis Gene Expression System xe2 x80 x94Intracellular Signaling Architecture) was launched on SpaceX mission CRS-5 on 10 January 2015. Dry sterilized Arabidopsis seeds were planted aseptically on the surface of 10-cm2 solid media plates and remained dormant until removed from cold stowage and exposed to light at the initiation of the experiment on the ISS (International Space Station). The plates were grown in the Vegetable Production System (VPS/Veggie) hardware on the Columbus Module of the ISS with the overhead LED lighting of the VPS. At four or for the second experimental set at eight days seedlings were harvested by an astronaut into KFT (Kennedy Fixation Tube) containing RNAlater solutions. Upon return to Earth the harvested material was used to compare the transcriptomes of each genotype and each age using RNAseq technology. The patterns of gene expression was compared between treatments (spaceflight versus ground control) within each genotype of same age or between two ages within same genotype and within same treatment. For 4 day old roots 5-8 roots were combined to serve as one biological replica. For 8 day old roots 2-3 roots were used to form one biological replica. In each case the four biological replicas were used for the transcriptomic analysis.

Interaction of COP1 and UVR8 which regulate UV-B-induced photomorphogenesis and stress acclimation in Arabidopsis thaliana.

The wild type Col-0 plants and the Sku-6 mutant plants of the Col-0 background were germinated on ISS or on the ground and the gene expression profiles in roots at 4 days or 8 days were established. The Sku6 gene (At2g03680) codes for a protein that localizes to microtubule within the cortical array and putatively acting as an intramolecular linker. The development of Col-0 and Sku-6 plants on orbit differs from that on the ground as demonstrated by the comparison of the gene expression profiles between 4 days old to 8 days old plant in the two environments. However the development of Sku-6 mutant plants also differs from Col-0 at either age and in either environment suggesting the role of the genetic background in these developmental decisions. The 4 days old Sku-6 roots in orbit engaged more genes than the 4 days old Col-0 roots in orbit but also more than the 4 days old Sku-6 roots on the ground. Overall the 4 days old roots differentially expressed more genes in spaceflight relative to ground than the 8 days old roots of either genotype.

The Heat Shock Factor A2 (HsfA2) as a part of the HSF network is essential to the plant s response to almost any environmental stress and to the cellular homeostatic control mechanisms. Plant cell cultures disabled in HsfA2 function were grown aboard the International Space Station (ISS) in order to ascertain whether or not they use the same terrestrially effective systems to adapt to the novel environment of spaceflight. Cultured lines of Arabidopsis thaliana derived from wild type (WT) cultivar Col-0 and from a knock-out line deficient in the gene encoding HSFA2 (HSFA2 KO) were launched to the ISS on SpaceX-2 as part of the Cellular Expression Logic (CEL) experiment of the BRIC17 spaceflight mission and were fixed in-flight after 10 days on orbit. Microarray gene expression data were analyzed using a two-part comparative approach. First differentially expressed genes were identified between the environments (spaceflight to ground) within cells of the same genotype which represented physiological adaptation to the spaceflight environment. Second gene expression profiles were identified between the genotypes (HSFA2 KO to WT) within the same environment defining genes uniquely required by the two genotypes in the ground and spaceflight adapted states. The physiological state of the cells as a result of disabling a gene has tremendous control over the mechanisms induced to adapt to the environment of spaceflight. The HsfA2 demonstrated a role in the physiological adaptation to the spaceflight environment since the cells disabled in the HsfA2 gene used substantially different genes to achieve the spaceflight adapted state than the WT cells. The endoplasmic reticulum (ER) stress and unfolded protein response (UPR) define the HSFA2 KO cells physiological state regardless of the environment and likely result from the deficiency in the chaperone-mediated protein folding machinery. HsfA2 seems to have a universal stress response role but also specific roles in the physiological adaptation to spaceflight through cell wall remodeling signal perception and transduction and starch biosynthesis. Implementation of knock-out cells identified a set of genes with a required expression level in order for a cell to achieve a spaceflight-adapted state. The HSFA2 KO cells helped to unravel the HsfA2-dependent genes of the adaption of wild type cells to the environment of spaceflight.

Whole seedlings of wild type (4d) and atm mutants (4d) have been analyzed after a gamma ray irradiation of 0.75h 1.5h 3h & 5h (time course). Roots of wt (4d) atm (3d) and atr (4d) mutants have been analyzed after a 1h irradiation. Ataxia Telangiectasia Mutated (ATM) encodes a large protein with a phosphatidylinositol 3-kinase (PI3K)-like domain at the C terminus (reviewed by Rotman and Shiloh 1998). PI3K-related proteins make up a large family of Ser-Thr protein kinases numerous members of which are involved in the regulation of cell cycle progression responses to DNA damage and the maintenance of genomic stability (Hoekstra 1997). AtATM plays an essential role in meiosis and in the somatic response to DNA damage in plants similar to the function of ATM in mammals and other eukaryotes. Ataxia telangiectasia-mutated and Rad3-related (ATR) plays a central role in cell-cycle regulation transmitting DNA damage signals to downstream effectors of cell-cycle progression.

The Cosmic Ray Exposure Sequencing Science (CRESS) payload system is a proof of concept experiment to assess the genomic impact of space radiation on seeds. CRESS was designed as a secondary payload for the December 2016 high-altitude high-latitude and long-duration balloon flight carrying the Boron And Carbon Cosmic Rays in the Upper Stratosphere (BACCUS) experimental hardware. Investigation of the biological effects of Galactic Cosmic Radiation (GCR) particularly those of ions with High-Z and Energy (HZE) is of interest due to the genomic damage this type of radiation inflicts. The biological effects of upper-stratospheric mixed radiation above Antarctica (ANT) were sampled using Arabidopsis thaliana seeds and were compared to those resulting from a controlled simulation of GCR at Brookhaven National Laboratory (BNL) and to laboratory control seed. The payload developed for Antarctica exposure was broadly designed to 1U CubeSat specifications (10cmx10cmx10cm <1.33kg) maintained 1 atm internal pressure and carried an internal cargo of four seed trays (about 580,000 seeds) and twelve CR-39 Solid-State Nuclear Track Detectors (SSNTDs). The irradiated seeds were recovered sterilized and grown on Petri plates for phenotypic screening. BNL and ANT M0 seeds showed significantly reduced germination rates and elevated somatic mutation rates when compared to non-irradiated controls with the BNL mutation rate also being significantly higher than that of ANT. Genomic DNA from mutants of interest was evaluated with whole-genome sequencing using PacBio SMRT technology. Sequence data revealed the presence of an array of genome structural variants in the genomes of M0 and M1 mutant plants.

Understanding plant adaptive responses to the space environment is a requisite for enabling space farming. Spaceflight produce deleterious effects on plant cells particularly affecting ribosome biogenesis a complex stress-sensitive process coordinated with cell division and differentiation known to be activated by red light. Here we have used mutants from the two nucleolin genes in Arabidopsis (NUC1 and NUC2) encoding the main regulator of the ribosome biogenesis in the nucleolus in order to better understand their role in adaptive response mechanisms to stress. Thus we show that nucleolin stress-related gene NUC2 can compensate the environmental stress provided by darkness in nuc1 plants while nuc2 plants are not able to provide a complete response to red light. These ground control findings as part of the ESA/NASA Seedling Growth spaceflight experiments will determine the basis for the identification of a genetic background enabling an adaptive advantage for plants in future space experiments.

Plants exhibit a robust transcriptional response to gamma radiation which includes the induction of transcripts required for homologous recombination and the suppression of transcripts that promote cell cycle progression. Various DNA damaging agents induce different spectra of DNA damage as well as collateral damage to other cellular components and therefore are not expected to provoke identical responses by the cell. Here we study the effects of two different types of ionizing radiation (IR) treatment HZE (1 GeV Fe26+ high mass high charge and high energy relativistic particles) and gamma photons on the transcriptome of Arabidopsis thaliana seedlings. Both types of IR induce small clusters of radicals that can result in the formation of double strand breaks (DSBs) but HZE also produces linear arrays of extremely clustered damage. We performed these experiments across a range of time points (1.5-24 h after irradiation) in both wild-type plants and in mutants defective in the DSB-sensing protein kinase ATM. The two types of IR exhibit a shared double strand break-repair-related damage response although they differ slightly in the timing degree and ATM-dependence of the response. The ATM-dependent DNA metabolism-related transcripts of the DSB response were also induced by other DNA damaging agents but were not induced by conventional stresses. Both Gamma and HZE irradiation induced at 24 h post-irradiation ATM-dependent transcripts associated with a variety of conventional stresses; these were overrepresented for pathogen response rather than DNA metabolism. In contrast only HZE-irradiated plants at 1.5 h after irradiation exhibited an additional and very extensive transcriptional response shared with plants experiencing extended night. This response was not apparent in gamma-irradiated plants.

Omics analyses of RNA and protein isolated from heads of microgravity reared adult Drosophila.

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.