Zeng Deyong, Cui Jie, Yin YiShu, Xiong Yi, Liu Mengyao, Guan Shuanghong, Cheng Dayou, Sun Yeqing, Lu Weihong
Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, China.
National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, Harbin Institute of Technology, Harbin, China.
Front Plant Sci. 2021 Jun 30;12:700267. doi: 10.3389/fpls.2021.700267. eCollection 2021.
Spaceflight is a special abiotic stress condition. In recent years, it has been confirmed that the spaceflight caused the stress response of rice seeds, and the protein level, transcription level, and methylation level will change during the planting process after returning to the ground. However, the changes at the metabolome level are not very clear. In this study, two kinds of rice seeds, Dongnong423 (DN3) and Dongnong416 (DN6), were carried on the ShiJian-10 retractable satellite (SJ-10) for 12.5 days in orbit, returned to the ground and planted in the field until the three-leaf (TLP) and tillering stage (TS). The results of antioxidant enzyme activity, soluble sugar, and electron leakage rate revealed that the spaceflight caused the stress response of rice. The TLP and TS of DN3 identified 110 and 57 different metabolites, respectively, while the TLP and TS of DN6 identified 104 and 74 different metabolites, respectively. These metabolites included amino acids, sugars, fatty acids, organic acids and secondary metabolites. We used qRT-PCR technology to explore the changes of enzyme genes in the tricarboxylic acid cycle (TCA) and amino acid metabolism pathway. Combined with the results of metabolomics, we determined that during the TLP, the TCA cycle rate of DN3 was inhibited and amino acid metabolism was activated, while the TCA cycle rate of DN6 was activated and amino acid metabolism was inhibited. In TS, the TCA cycle rate of DN3 was inhibited, and amino acid metabolism was not significantly changed, while the TCA cycle rate of DN6 was activated and amino acid metabolism was inhibited. These results suggested that the response mechanisms of the two different rice strains to spaceflight stress are different, and these differences may be reflected in energy consumption and compound biosynthesis of rice in different growth and development stages. This study provided new insights for further exploring the effects of spaceflight.
太空飞行是一种特殊的非生物胁迫条件。近年来，已证实太空飞行会引发水稻种子的应激反应，并且在返回地面后的种植过程中，蛋白质水平、转录水平和甲基化水平都会发生变化。然而，代谢组水平的变化尚不清楚。在本研究中，两种水稻种子，东农423（DN3）和东农416（DN6），搭载实践十号返回式卫星（SJ - 10）在轨道上飞行12.5天，返回地面后种植于田间直至三叶期（TLP）和分蘖期（TS）。抗氧化酶活性、可溶性糖和电子渗漏率的结果表明太空飞行引发了水稻的应激反应。DN3的三叶期和分蘖期分别鉴定出110种和57种不同代谢物，而DN6的三叶期和分蘖期分别鉴定出104种和74种不同代谢物。这些代谢物包括氨基酸、糖类、脂肪酸、有机酸和次生代谢物。我们使用qRT - PCR技术探究三羧酸循环（TCA）和氨基酸代谢途径中酶基因的变化。结合代谢组学结果，我们确定在三叶期，DN3的TCA循环速率受到抑制，氨基酸代谢被激活，而DN6的TCA循环速率被激活，氨基酸代谢受到抑制。在分蘖期，DN3的TCA循环速率受到抑制，氨基酸代谢无显著变化，而DN6的TCA循环速率被激活，氨基酸代谢受到抑制。这些结果表明两种不同水稻品种对太空飞行胁迫的响应机制不同，这些差异可能体现在水稻不同生长发育阶段的能量消耗和化合物生物合成中。本研究为进一步探索太空飞行的影响提供了新的见解。
