scholarly journals Life in space isn't easy, even if you are green

2017 ◽  
Vol 39 (6) ◽  
pp. 10-13 ◽  
Author(s):  
Richard Barker ◽  
Simon Gilroy

In order for terrestrial life to expand beyond the confines of our earthbound existence to bodies such as the moon or Mars it will have to tackle a barrage of stresses, some that it has encountered and adapted to over millions of years of evolution, but some that it will meet for the very first time. Whether reliable, sustainable biology-based (bio-regenerative) life support systems can be developed for long-duration spaceflight and extraterrestrial colonies has therefore become an important area of research. These systems would almost certainly centre on plants and microbes and so questions of how such organisms respond to reduced gravity and radiation become critical. Current research, using approaches ranging from gene expression and protein profiling to detailed growth analyses, suggests spaceflight triggers complex stress responses in these organisms, but that biology has a remarkable ability to cope with the life of a space alien.

2021 ◽  
Author(s):  
Gengxin Xie ◽  
Yuanxun Zhang ◽  
Jing Yang ◽  
Dengyun Yu ◽  
Maozhi Ren ◽  
...  

Abstract Understanding how terrestrial life responds to planet microgravity is essential for humankind’s ambitious solar system exploration. Using the life-regeneration ecosystem carried by Chang’e 4 probe landed on the Moon, for the first time in human history, we followed the life trajectory of an earth cotton seed germination, development, and final fate after long term exposure to super cold temperature. We compared this life trajectory on the moon to that on earth in a controlled environment with matching parameters, except that the gravity is different. We found that 1/6 g Moon gravity causes no significant interruption to seed germination speed, but slows down seedling growth and contributes to an apparently shortened hypocotyl and thinner cotyledon. Most surprisingly, Moon seedling showed expeditious acclimation to super-freezing under 1/6 g microgravity, remaining erect and green after exposure to long term super cold temperature during the lunar night. We propose plausible mechanisms for the cold resilience based on moon-microgravity induced cellular and molecular responses. These unique findings will extend our understanding of plant adaptive responses to space suboptimal environments.


2021 ◽  
Vol 55 (6) ◽  
pp. 61-67
Author(s):  
I.V. Shumilina ◽  

For the 17- and 120-day isolation campaigns within project SIRIUS, the stock of personal hygiene items (PHIs), underwear and clothes was supplied in compliance with the current ISS rates of consumption. Over 120 questionnaires filled by the human subjects made possible estimation of the total weight of these provisions in a mission to the Moon, and get feedback about the hygienic means and methods. The hygienic comfort of 6 crewmembers of the 120-d isolation campaign required more than 500 kg of underwear, bedclothes, towels, personal hygiene items, pieces of toilet and household essentials, which are also musts in a mission to the Moon and back. Long-duration missions and sojourns on lunar and Mars bases will call for designing arrangements for personal hygiene, shower, dish washing and laundry integrated with regenerative life support systems. Results of the investigation showed effectiveness of the sanitation and hygiene system and its functional significance.


Author(s):  
Boris F. ZARETSKIY ◽  
Arkadiy S. GUZENBERG ◽  
Igor A. SHANGIN

Life support for first manned spaceflights was based on supplies of consumables. Crew life support systems based on supplies of water and oxygen, in spite of their simplicity, are extremely inefficient in orbital space missions and are unfeasible in deep space missions because of mass and volume constraints. Therefore, there are currently developed and are to be used on space stations the life support systems that are based on chemical and physical regeneration of water and oxygen extracted from human waste. In view of further advances in long-duration orbital stations, and the prospects of establishment of planetary outposts and deep space exploration, the problem of constructing an automated system for controlling a suite of regenerative LSS becomes urgent. The complexity of solving the problem of constructing an efficient control system in this case owes to the existence of a large number of effectiveness criteria. The paper proposes a system of consolidated global efficiency criteria, which allows to break up this problem into a series of sub-problems of optimization in order to solve this problem. The proposed criteria are longevity, cost, comfort. The paper presents a series of specific examples of using the proposed principles with necessary generalizations. Key words: space life support systems, atmosphere revitalization equipment, automated control system, global generalized efficiency criteria, longevity, cost, comfort.


2019 ◽  
Vol 70 (19) ◽  
pp. 5355-5374 ◽  
Author(s):  
Dandan Zang ◽  
Jingxin Wang ◽  
Xin Zhang ◽  
Zhujun Liu ◽  
Yucheng Wang

Abstract Plant heat shock transcription factors (HSFs) are involved in heat and other abiotic stress responses. However, their functions in salt tolerance are little known. In this study, we characterized the function of a HSF from Arabidopsis, AtHSFA7b, in salt tolerance. AtHSFA7b is a nuclear protein with transactivation activity. ChIP-seq combined with an RNA-seq assay indicated that AtHSFA7b preferentially binds to a novel cis-acting element, termed the E-box-like motif, to regulate gene expression; it also binds to the heat shock element motif. Under salt conditions, AtHSFA7b regulates its target genes to mediate serial physiological changes, including maintaining cellular ion homeostasis, reducing water loss rate, decreasing reactive oxygen species accumulation, and adjusting osmotic potential, which ultimately leads to improved salt tolerance. Additionally, most cellulose synthase-like (CSL) and cellulose synthase (CESA) family genes were inhibited by AtHSFA7b; some of them were randomly selected for salt tolerance characterization, and they were mainly found to negatively modulate salt tolerance. By contrast, some transcription factors (TFs) were induced by AtHSFA7b; among them, we randomly identified six TFs that positively regulate salt tolerance. Thus, AtHSFA7b serves as a transactivator that positively mediates salinity tolerance mainly through binding to the E-box-like motif to regulate gene expression.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Guiomar Martín ◽  
Yamile Márquez ◽  
Federica Mantica ◽  
Paula Duque ◽  
Manuel Irimia

Abstract Background Alternative splicing (AS) is a widespread regulatory mechanism in multicellular organisms. Numerous transcriptomic and single-gene studies in plants have investigated AS in response to specific conditions, especially environmental stress, unveiling substantial amounts of intron retention that modulate gene expression. However, a comprehensive study contrasting stress-response and tissue-specific AS patterns and directly comparing them with those of animal models is still missing. Results We generate a massive resource for Arabidopsis thaliana, PastDB, comprising AS and gene expression quantifications across tissues, development and environmental conditions, including abiotic and biotic stresses. Harmonized analysis of these datasets reveals that A. thaliana shows high levels of AS, similar to fruitflies, and that, compared to animals, disproportionately uses AS for stress responses. We identify core sets of genes regulated specifically by either AS or transcription upon stresses or among tissues, a regulatory specialization that is tightly mirrored by the genomic features of these genes. Unexpectedly, non-intron retention events, including exon skipping, are overrepresented across regulated AS sets in A. thaliana, being also largely involved in modulating gene expression through NMD and uORF inclusion. Conclusions Non-intron retention events have likely been functionally underrated in plants. AS constitutes a distinct regulatory layer controlling gene expression upon internal and external stimuli whose target genes and master regulators are hardwired at the genomic level to specifically undergo post-transcriptional regulation. Given the higher relevance of AS in the response to different stresses when compared to animals, this molecular hardwiring is likely required for a proper environmental response in A. thaliana.


2021 ◽  
Vol 22 (3) ◽  
pp. 1022
Author(s):  
Tatyana P. Makalish ◽  
Ilya O. Golovkin ◽  
Volodymyr V. Oberemok ◽  
Kateryna V. Laikova ◽  
Zenure Z. Temirova ◽  
...  

The urgency of the search for inexpensive and effective drugs with localized action for the treatment of rheumatoid arthritis continues unabated. In this study, for the first time we investigated the Cytos-11 antisense oligonucleotide suppression of TNF-α gene expression in a rat model of rheumatoid arthritis induced by complete Freund’s adjuvant. Cytos-11 has been shown to effectively reduce peripheral blood concentrations of TNF-α, reduce joint inflammation, and reduce pannus development. The results achieved following treatment with the antisense oligonucleotide Cytos-11 were similar to those of adalimumab (Humira®); they also compared favorably with those results, which provides evidence of the promise of drugs based on antisense technologies in the treatment of this disease.


Author(s):  
Huaming He ◽  
Jordi Denecker ◽  
Katrien Van Der Kelen ◽  
Patrick Willems ◽  
Robin Pottie ◽  
...  

Abstract Signaling events triggered by hydrogen peroxide (H2O2) regulate plant growth and defense by orchestrating a genome-wide transcriptional reprogramming. However, the specific mechanisms that govern H2O2-dependent gene expression are still poorly understood. Here, we identify the Arabidopsis Mediator complex subunit MED8 as a regulator of H2O2 responses. The introduction of the med8 mutation in a constitutive oxidative stress genetic background (catalase-deficient, cat2) was associated with enhanced activation of the salicylic acid pathway and accelerated cell death. Interestingly, med8 seedlings were more tolerant to oxidative stress generated by the herbicide methyl viologen (MV) and exhibited transcriptional hyperactivation of defense signaling, in particular salicylic acid- and jasmonic acid-related pathways. The med8-triggered tolerance to MV was manipulated by the introduction of secondary mutations in salicylic acid and jasmonic acid pathways. In addition, analysis of the Mediator interactome revealed interactions with components involved in mRNA processing and microRNA biogenesis, hence expanding the role of Mediator beyond transcription. Notably, MED8 interacted with the transcriptional regulator NEGATIVE ON TATA-LESS, NOT2, to control the expression of H2O2-inducible genes and stress responses. Our work establishes MED8 as a component regulating oxidative stress responses and demonstrates that it acts as a negative regulator of H2O2-driven activation of defense gene expression.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marisa Maia ◽  
António E. N. Ferreira ◽  
Rui Nascimento ◽  
Filipa Monteiro ◽  
Francisco Traquete ◽  
...  

Abstract Vitis vinifera, one of the most cultivated fruit crops, is susceptible to several diseases particularly caused by fungus and oomycete pathogens. In contrast, other Vitis species (American, Asian) display different degrees of tolerance/resistance to these pathogens, being widely used in breeding programs to introgress resistance traits in elite V. vinifera cultivars. Secondary metabolites are important players in plant defence responses. Therefore, the characterization of the metabolic profiles associated with disease resistance and susceptibility traits in grapevine is a promising approach to identify trait-related biomarkers. In this work, the leaf metabolic composition of eleven Vitis genotypes was analysed using an untargeted metabolomics approach. A total of 190 putative metabolites were found to discriminate resistant/partial resistant from susceptible genotypes. The biological relevance of discriminative compounds was assessed by pathway analysis. Several compounds were selected as promising biomarkers and the expression of genes coding for enzymes associated with their metabolic pathways was analysed. Reference genes for these grapevine genotypes were established for normalisation of candidate gene expression. The leucoanthocyanidin reductase 2 gene (LAR2) presented a significant increase of expression in susceptible genotypes, in accordance with catechin accumulation in this analysis group. Up to our knowledge this is the first time that metabolic constitutive biomarkers are proposed, opening new insights into plant selection on breeding programs.


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