Arg1 functions in the physiological adaptation of undifferentiated plant cells to spaceflight

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.

本研究通过转录组分析，旨在深入探讨Altered response to gravity-1（Arg1）基因在太空飞行适应中的作用。Arg1基因是一种已知影响地球植物对重力反应的基因。研究比较了从野生型（WT）栽培品种Col-0衍生出的拟南芥（Arabidopsis thaliana）培养系的表达谱与敲除编码（ARG1 KO）基因的突变体在地面和太空环境中的表达谱。这些细胞系作为BRIC17太空飞行任务中细胞表达逻辑（CEL）实验的一部分，被搭载在SpaceX CRS-2火箭上。培养的细胞系在直径为60mm的Petri培养皿中，通过Petri Dish Fixation Units（PDFUs）进行固定培养，而PDFUs则安置在生物研究舱（BRIC）硬件中。太空飞行样本在轨道上固定。在太空飞行环境与地面对照环境、野生型（WT）与ARG1 KO两个基因型之间，鉴定出差异表达基因。每个基因型在生理适应太空飞行环境时，都激活了独特的基因，两者之间重叠甚少。在太空飞行中WT细胞中表达改变的基因大多数被发现与Arg1基因相关，这表明该基因在未分化细胞适应太空飞行生理过程中起着至关重要的作用。