Study on the Effect of Biological Damage in Plant Caused by Low Energy Ion Beam Implantation

We compared the biological effects of 30 keV low energy nitrogen ion beam implanted in the seeds of plants. The curve of dose-response in seed germination ratio displayed falling and then rising with the increase of ion influx. It is different from the effect of high energy ion(Mev)implanted in plant. The low energy ion beam owns the characteristics of wide mutation spectrum and low damage. We have chosen some mutants of tomato, radish, rice and wheat to be used in plant breeding. And we detected the effect of cell signaling with OsRop GTPase after low energy ion beam implanting in rice using qRT-PCR. There exist seven OsRops in rice genome. The results showed that the response of each OsRop GTPase expressed significant differently by different ion flux. The expression levels of OsRop1, OsRop2 and OsRop3 were very sensitive at germination 24h, but they were severely down-regulated at germination 48h after low energy ion beam implanted. But OsRop3 expression level of control enhanced very much at 24h. OsRop4 expression level raised at 24h at the dosage of 4×10¹⁷ions/cm² and 72h 2×10¹⁷ions/cm². After 24h OsRop5 gene expression was more sensitive at the dosage 6×10¹⁷ions/cm, but it’s intensified in vacuum (no ions implanted) at 72h. OsRop6 and OsRop7 gene expression level were obviously up-regulated in vacuum at 6×10¹⁷ions/cm after 48h germination. It is interesting that OsRop7gene expression level was lower at 24h and 72h with low energy ion beam influx.