Deciphering the molecular transcriptomic mechanisms of carbon ion beams and X-ray on rice seedlings

Ionizing radiation (IR) is an abiotic stress factor that can be not only a means to explore plant resistance but also a potent mutagen in agricultural breeding. The diverse physical parameters of different types of IR result in varying effects on plants, which in turn leads to differences in the spectrum of genetic variations in the offspring. Investigating plant response mechanisms to different IR is crucial for enhancing plant resistance and comprehending of the differences in mutation generation from various physical mutagenic sources in mutation breeding. Nevertheless, the mechanism underlying the complex responses of plants to different IR are not yet fully comprehended.

we conducted transcriptome sequencing on rice seedlings that exhibited a relative root length of approximately 69% after being exposed to carbon ion beams (CIBs) and X-ray respectively. The results revealed that X-ray induced a greater number of differentially expressed genes (DEGs) than CIBs, with 5681 and 2198 DEGs were identified respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that DNA replication, damage repair, phytohormone signaling, and antioxidant pathways were implicated in the response of rice seedling to IR. These pathways demonstrated diverse response patterns following different IR. Additionally, through two IR with different linear energy transfer (LET), we found some common DEGs that contribute to the radiation response in rice seedlings, such as LOC4331062, LOC4333870.

This study offers insights into the molecular transcriptomic mechanisms underlying the impacts of IR on rice seedlings. It provides a new perspective for further exploration of irradiation-induced damage repair factors and understanding the reasons for the differences in mutations created by different mutagenic sources in plants.