Application of Gamma Ray-Responsive Genes for Transcriptome-Based Phytodosimetry in Rice

Area of Science:

• Plant Science
• Genetics
• Environmental Science

Background:

• Transcriptome-based phytodosimetry uses DNA damage response (DDR) genes to assess gamma radiation genotoxicity.
• Previous studies focused on dicots like Arabidopsis thaliana; monocot models were needed.

Purpose of the Study:

• Characterize gamma ray-responsive marker genes in rice (Oryza sativa L.) for transcriptome-based phytodosimetry.
• Compare phytodosimetry models between rice and Arabidopsis using multiple genotoxicity assays.

Main Methods:

• Quantitative transcriptomic assays to identify and analyze dose-response curves of marker genes (OsGRG, OsMutS, OsRAD51, OsRPA1 in rice).
• Gamma-H2AX and comet assays for conventional genotoxicity assessment.
• Comparative analysis of dose-dependency across species and assays.

Main Results:

• Transcriptome-based dose-response curves for rice genes reliably fitted mathematical models (r² > 0.99).
• Rice showed higher dose-dependency in comet signals and OsRAD51 transcription compared to Arabidopsis.
• Arabidopsis exhibited greater gamma-H2AX induction dose-dependency.
• Transcriptional changes of selected genes were consistent across vegetative stages in both species.

Conclusions:

• Transcriptome-based phytodosimetry models require correction with conventional genotoxicity or DDR-based models.
• The relative weighting of genes in integrated transcriptome models needs careful consideration based on transcriptional trends and amplitude.