Table 10.
Gene expression changes in various plant organisms in response to spaceflight. Use of in-flight controls (FC) or ground-based controls (GC) is indicated.
| Organism | Gene Regulation | Tissue | Microgravity | Reference |
|---|---|---|---|---|
|
Arabidopsis thaliana (Col-0) |
Upregulated: DNA replication, DNA repair, far red/red light response, photosynthesis, secondary metabolite biosynthesis Downregulated: Abscisic acid, response to stress, amino acid catabolism, sucrose starvation, absence of light, ribosome biogenesis, translation Notes: Unfolded protein response seems to play a minor role in spaceflight adaptation. |
Whole seedlings, 14 days old | BRIC hardware on the ISS, 14 days of µg. (GC) |
[241] |
|
Arabidopsis thaliana (Col-0 and Ws-0) |
Differential alternative splicing in response to spaceflight in 48 genes in Ws-0 and 27 genes in Col-0. | Roots, 4 and 8 days old | VEGGIE system on the ISS, up to 8 days of µg. (GC) |
[255] |
|
Arabidopsis thaliana (Col-0 and Ws-0) |
Col-0 vs. spr1: Less DEGs in spr1 than in Col-0 WT during spaceflight. Enriched categories: Response to salicylic acid, carbon fixation, RuBisCo genes, apoplast-localized genes Ws-0 vs. sku5: 2–5 times more DEGs in sku5 than in Ws-0 WT during spaceflight Enriched categories: Abscisic acid signaling, response to stress, seed development, post-embryonic development |
Roots, 4 and 8 days old | VEGGIE system on the ISS, up to 8 days of µg. (GC) |
[236] |
|
Arabidopsis thaliana (Col-0, Ler-0, Ws-2, Cvi-0) |
Upregulation across all ecotypes: HSP101, HSP70, HSP23.5, HSP81.1, AT2G32120.2 Downregulation across all ecotypes: AT5G44417.1, RCI3, AT1G64370.1, AtPrx22 Notes: Enrichment of 21 upregulated heat shock protein/factor transcripts and 14 downregulated peroxidase transcripts across some but not all ecotypes show characteristics of oxidative stress. |
Whole seedlings, 8 days old | BRIC hardware on the ISS, 8 days of µg. (GC) |
[237] |
|
Arabidopsis thaliana (Ler-0) |
Enriched GO categories per g-level: µg—response to light, photosynthesis 0.1g—response to stress, chemicals 0.3g—cell wall, membrane, plastid Decrease in DEGs with higher g-levels Changes in expression along the g-gradient: Mitochondria, plastid, cell wall, and cell membrane-related processes. F-box/RMI-like/FDB-like domain family genes (AT5G44980, AT5G56370, AT5G56380, AT5G42460) Notes: Highest number of DEGs in 0.1 g condition with mostly stress-related pathways. Authors suggest competition of weak phototropism with weak gravitropism leading to stress. |
Whole seedlings, 6 days old | EMCS hardware on the ISS, 6 days of µg, 0.1g, 0.3g, 0.5g, 0.8g, and 1g. Blue light stimulus for the last 48 h. (FC) |
[240] |
|
Arabidopsis thaliana (Col-0) |
Enriched categories: Cell wall organization (transcripts downregulated, proteins upregulated) Redox homeostasis and ROS signaling (increased transcript regulation, no protein regulation) Protein degradation (only transcripts) Auxin-related genes (PIN, LAX, IAA, ARF, TIR1-family) Post-transcriptional regulation (upregulation of DCP5 and AGO4) Plastid translation, import to stroma, targeting to chloroplast, plastid organization, chlorophyll biosynthetic process (only transcripts) Notes: Large discrepancy between transcript changes and protein changes in plastids, suggesting plastid dysregulation under µg. |
Whole seedlings, 3 days old | BRIC hardware on the ISS, 3 days of µg. (GC) |
[249] |
|
Arabidopsis thaliana (Col-0 and Ws-0) |
Network analysis reveals 5 strongly regulated hub genes of the cell wall-modifying XTH-family. | Whole seedlings and root tips, 11–12 days old | ABRS hardware on the ISS, up to 12 days of µg. (GC) |
[238] |
|
Arabidopsis thaliana (Col-0) |
Identification of 101 genes with dosage-dependent response to g-level. Enriched categories: Transcription factors (20 genes) Chaperones (9 genes) Defense response (12 genes) Cell wall associated (16 genes) Root development (8 genes) Auxin-related (3 genes) |
Roots, 5 days old | EMCS hardware on the ISS, 5 days of µg, 0.53g, 0.65g, and 0.88g. (FC) |
[239] |
|
Arabidopsis thaliana (Ler-0) |
Upregulated categories: Ribosome synthesis Oxidative phosphorylation Downregulated categories: Photosynthesis/antenna proteins Porphyrin and chlorophyll metabolism Protein processing in ER Starch and sucrose metabolism Carotenoid biosynthesis |
Whole seedlings, 6 days old | EMCS hardware on the ISS, 6 days of µg and 1g. Blue light stimulus for the last 48 h. (FC) |
[251] |
|
Arabidopsis thaliana (Ler-0) |
Enriched categories and pathways: Transcription factors (WRKY, ERF, NAC, MYB) Plastidic transcription (enriched only in µg) Auxin (GH3 and SAUR genes, activated in µg, inhibited at 0.3g + darkness) Cytokinins (activated in µg, inhibited at 0.3g) ABA (activated in all conditions except µg + darkness) Brassinosteroid (inhibited by upregulation of BRI1 suppressor 1) Jasmonic acid (upregulation of repressors) Notes: Hormone pathways are more affected by g-level than light conditions. At 0.3g, red light can reverse auxin pathway inhibition. Stress-related pathways are more activated at 0.3g than in µg. |
Whole seedlings, 6 days old | EMCS hardware on the ISS, 6 days of µg and 0.3g. Red light or darkness for the last 48 h. (GC) |
[252] |
|
Arabidopsis thaliana (Col-0) |
Upregulated categories: Metabolic process, response to stress, temperature and wounding, protein stabilization Downregulated categories: Response to stimulus, reproductive developmental process, regulation of the metabolic process, circadian rhythm, gibberellins, mRNA processes Notes: Flowering genes (53) were mostly downregulated under µg, affecting the flowering hub genes FT and SOC1. Delay of flowering time in µg by 20 days. |
Rosette leaves, 48 days old | Plant culture box hardware on the Chinese spacelab TG-2, 48 days of µg. (GC) |
[230] |
|
Arabidopsis thaliana (Col-0) |
Altered gene methylation in DNA methylation-associated genes, cell-wall modification genes, hormone signaling-related genes and transposable elements. Induction of transposable elements by unstable methylations in response to spaceflight. |
Whole seedlings, 8.5 days old |
Cultivation units on the recoverable satellite SJ-10, 60 h of µg after 6 days of pre-culturing on the ground. (GC) |
[247] |
|
Arabidopsis thaliana (Col-0) |
Altered gene methylation and expression in the first offspring generation after spaceflight in the abscisic acid-activated pathway, protein phosphorylation, and nitrate signaling pathway. Partial retention of phenotypic differences and differentially methylated regions in the following generation. Notes: Could not confirm methylation changes in parent generation from previous study. |
Whole seedlings, 11 days old, multiple generations | Cultivation units on the recoverable satellite SJ-10, 11 days of µg after 6 days of pre-culturing on the ground. (GC) |
[246] |
|
Arabidopsis thaliana (Col-0) |
Altered gene methylation and expression of pectin methylesterase regulator gene AtPMEPCRA in parent and offspring generation after spaceflight. | Whole seedlings, 11 days old, multiple generations | Cultivation units on the recoverable satellite SJ-10, 11 days of µg after 6 days of pre-culturing on the ground. (GC) |
[244] |
|
Arabidopsis thaliana (Ws-0) |
Portion of differentially expressed genes, that are also differentially methylated: Leaves: 143 of 743 Roots: 21 of 75 Increased methylation in CHG and CHH contexts in leaves during spaceflight. Notes: Nearly half of all differentially expressed genes in leaves were reactive oxygen signaling-related. |
Leaves and roots, 11 days old | VEGGIE system on the ISS, 11 days of µg. (GC) |
[245] |
| Oryza sativa | Differential regulation of 8 cell-wall-related transcripts and 3 aquaporins. | Calli, 17.5 days old | SIMBOX hardware on the Shenzhou 8, 324 h of µg and 1g. (FC + GC) |
[243] |
|
Oryza sativa (Koshihikari) |
Upregulation of endo-1,3:1,3-β-glucanase (OsEGL1) under µg, leading to a reduced 1,3:1,3-β-glucan content in the cell wall. | Shoots, 4–5 days old | CBEF hardware on the ISS, 99 h, 127 h and 136 h of µg and 1g. (FC) |
[242] |
| Glycine max (T75 and Z9) | Increased activity of transposable elements and genomic plasticity after space mutation. Enriched gene categories affected by genomic restructuring: Stress response and stimulus—278 genes Cell wall-related—27 genes Auxin metabolism and transport—26 genes General signal transduction—77 genes |
Leaves, 15 days old, 6 years of breeding after space mutation | Space mutation for 15 days of µg aboard recoverable satellite Shijian 8. (GC) |
[248] |
Abbreviations: Biological research in canisters (BRIC); Cape Verde Islands (Cvi); Columbia (Col); differentially expressed genes (DEGs); European modular cultivation system (EMCS); flight control (FC); gene ontology (GO); ground control (GC); Landsberg erecta (Ler); Taiwan 75 (T75); science in microgravity box (SIMBOX); vegetable production system (VEGGIE); Wassilewskija (Ws); Zhexian 9 (Z9).