Plants are primary producers of food and oxygen on Earth and will likewise be indispensable to the establishment of large-scale sustainable ecosystems and human survival in space. To contribute to the understanding of how plants respond to spaceflight stress, we examined the significance of the unfolded protein response (UPR), a conserved signaling cascade that responds to a number of unfavorable environmental stresses, in the model plant Arabidopsis thaliana. To do so, we performed a large-scale comparative transcriptome profiling in wild type and various UPR-defective mutants during the SpaceX-CRS12 mission to the International Space Station. We established that orbital culture substantially alters the expression of hundreds of stress-related genes compared with ground control conditions. Although expression of those genes varied in the UPR mutants on the ground, it was largely similar across the genotypes in the spaceflight condition. Our results have yielded new information on how plants respond to growth in orbit and support the hypothesis that spaceflight induces the activation of signaling pathways that compensate for the loss of UPR regulators in the control of downstream transcriptional regulatory networks.

中文翻译：

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拟南芥中未折叠蛋白反应与航天诱导的转录重编程的相关性

植物是地球上食物和氧气的主要生产者，同样对于建立大规模可持续生态系统和人类在太空中生存必不可少。为了有助于了解植物如何应对太空飞行压力，我们检查了模式植物拟南芥中未折叠蛋白反应 (UPR) 的重要性，这是一种保守的信号级联反应，对许多不利的环境压力作出反应. 为此，我们在 SpaceX-CRS12 国际空间站任务期间对野生型和各种 UPR 缺陷突变体进行了大规模比较转录组分析。我们确定，与地面控制条件相比，轨道培养显着改变了数百个与压力相关的基因的表达。尽管这些基因的表达在地面上的 UPR 突变体中有所不同，但在太空飞行条件下的基因型中基本相似。我们的研究结果提供了关于植物如何响应轨道生长的新信息，并支持太空飞行诱导信号通路激活的假设，这些信号通路补偿了 UPR 调节器在控制下游转录调控网络中的损失。