As a unique form of abiotic stress, the environmental conditions of outer space are expected to induce changes in plant genomes, proteomes and metabolic pathways. However, the effect of outer space conditions on the overall physiology of plants at the protein level has yet to be reported. To investigate the effects of outer space conditions on the growth- and development-related physiological processes and metabolic pathways of rice different stages, the seeds of rice variety DN423 were sent into orbit for 12.5 d aboard the SJ-10 Returning Satellite, and then the seedlings of both treated and control rice were compared at the three-leaf stage (TLS) and tillering stage (TS). In addition to comparing plant growth and reactive oxygen species (ROS) levels, seedling proteomes were also compared using isobaric tags for relative and absolute quantitation (iTRAQ). Space flight increased TLS plant height by 20%, reduced and increased ROS levels of the TLS and TS seedlings, respectively, and affected the expression of 36 and 323 proteins in TLS and TS leaves, respectively. Furthermore, the functions of the differentially abundant proteins were mainly associated with metabolism, energy, and protein synthesis and degradation. These results suggested that the exposure of seeds to outer space conditions affects the subsequent abundance of key signaling proteins, gene expression, and the processes of protein synthesis and degradation, thereby affecting metabolic processes and promoting adaptation to the abiotic stress of outer space. As such, the present study sheds light on the effects of space flight on plants and contributes to a more comprehensive understanding of extraterrestrial biology.

作为非生物胁迫的一种独特形式，外层空间的环境条件有望诱导植物基因组，蛋白质组和代谢途径的变化。然而，在蛋白质水平上外空条件对植物总体生理的影响尚未报道。为了研究外空条件对水稻不同阶段与生长发育相关的生理过程和代谢途径的影响，将水稻品种DN423的种子送入SJ-10返回卫星12.5 d，然后送入轨道。在三叶期（TLS）和分ing期（TS）比较处理和对照水稻的幼苗。除了比较植物生长和活性氧（ROS）的水平外，还使用等压标记对幼苗蛋白质组进行了相对和绝对定量（iTRAQ）比较。太空飞行使TLS植株高度增加20％，分别降低和增加TLS和TS幼苗的ROS水平，并分别影响TLS和TS叶片中36和323蛋白的表达。此外，差异丰富的蛋白质的功能主要与代谢，能量以及蛋白质的合成和降解有关。这些结果表明，种子暴露于外层空间条件会影响随后的关键信号蛋白，基因表达以及蛋白质合成和降解的过程，从而影响代谢过程并促进对外层空间非生物胁迫的适应。因此，