[Study on differences in metabolism and transcription of ginseng seeds after morphological post ripening by space flight].

To explore the difference in metabolism and transcription between seeds experiencing space flight and ground seeds after morphological post ripening, this study utilized ginseng seeds experiencing space flight and ground seeds as materials. Metabolomics and transcriptomics analyses were conducted using ultra-high performance liquid chromatography-mass spectrometry(UPLC-MS) and high-throughput transcriptome sequencing(RNA-seq) technologies, so as to identify differential terpenoid metabolites, differential endogenous hormones, and differentially expressed genes. The results showed that through metabolomics analysis, a total of 22 differential terpenoid metabolites were identified in the experimental and control groups, including chikusetsusaponin FK_7, ginsenoside F_2, ginseno-side K, majoroside R_1, ginsenoside Re_5, 12-hydroxyabietic acid, etc; through transcriptomics analysis, 15 differential terpenoid metabolism-related differentially expressed genes were identified in the experimental and control groups, including FCase, AACT, PMK, etc, and these genes were integrated into the pathway based on the MEP and MVA. At the same time, genes related to the seed germination process such as LEC2, PIPK, PUF, REC, QUD, and PIR were screened. In the detection of endogenous hormones, a total of 17 differential hormone metabolites were obtained, including IAA, CK, JA, ABA, GA, and SA. Among them, the content of CK increased in the SP group, while the content of GA and SA decreased in the SP group. Genes related to CK, GA, and SA were also screened. This study laid the foundation for further exploration of the biosynthesis of terpenoid metabolites in ginseng seeds and the key endogenous hormones and enzyme genes involved in the seed germination process, and it provided a reference for the application of space flight mutagenesis technology in ginseng.