Genomic and proteomic analyses of plant response to radiation in the environment – an abiotic stress context

Genomic and proteomic techniques provide the opportunity to investigate plant response to ionising radiation in unprecedented detail. Understanding plant molecular responses to ionising radiation might be useful for radioprotection but also for understanding plant stress responses. This is because radioactivity was a primordial stressor to cells and many stress responses are highly conserved through evolution. DNA microarrays for Arabidopsis plants exposed to 40 µGy h -1 through a hydroponic solution revealed that, after 14 days, there are changes in gene expression primarily in roots. The genes that change are not associated with DNA repair, and correlations with responses to other stressors in public databases suggest that there are elements of plant stress response being activated. The number of genes and their fold changes are lower than those reported for many other stressors but have particular overlaps with oxidative stress responses. Proteomic analyses form similar experiments are ongoing but similarly show no change of abundance in proteins associated with DNA repair and more changes in roots than shoots at these exposures.