| Abstrakt: |
Introduction: The space environment is mutagenic and may induce genomic and phenotypic variations. Exploring the changes in transposon activity in the rice genome under space radiation is of great significance. Methods: To analyze the activation characteristics of Ty3-retrotransposons and genetic stability of insertion sites in rice progeny after spaceflight, seeds of Nipponbare, DN416, and DN423 were exposed on board the SJ-10 recoverable satellite for 12.5 days. The differential methylation and transcription levels of Ty3-retrotransposons in the genome of Nipponbare's F0 generation after spaceflight, as well as the genetic stability of Ty3-retrotransposon insertion sites in DN416 and DN423 from F3 to F5 generations, was analyzed. Results: The study found that the retrotransposons of ancient and young transposon families underwent demethylation from the tillering to heading stages of Nipponbare plants, which were F0 generation of space-exposed seeds, when the Nipponbare seeds were hit by single space high charge and energy (HZE) particles with LET ≥ 100 keV/μm. the transcription levels significantly increased in ancient transposon families (osr30, osr40, and rire10) and young transposon families (dagul, rn215-125, osr37, RLG_15, osr34, rire8, rire3, rire2, and hopi) (p ≤ 0.05) when LET > 100 keV/μm. Furthermore, the young Ty3-retrotransposons, which included the hopi, squiq, dasheng, rire2, rire3, rire8, osr34, rn_215-125, dagul, and RLG_15 families, underwent 1 to 8 transpositions in the F3 to F5 of DN416 and DN423 mutants, and some of these transposon insertion sites were stably inherited. Discussion: The research holds great significance for understanding the activation characteristics of Ty3-retrotransposons in the rice genome induced by space radiation and the genetic characteristics of transposon insertion sites in its progeny. [ABSTRACT FROM AUTHOR] |
