EFFECTS OF IONIZING RADIATION EXPOSURE ON ARABIDOPSIS THALIANA

The effects of ionizing radiation on Arabidopsis thaliana were investigated using 6 MV x-rays produced by a linear accelerator. Photosynthesis and respiration rates, chlorophyll fluorescence (fv/fm ratio and yield), plant height, total leaf area, stem mass, leaf mass, and above-ground biomass were measured to evaluate both physiological and physical impacts of ionizing radiation. The statistical analysis examined the radiation effects with respect to four different total doses (0.5 Gy, 5 Gy, 50 Gy, and 150 Gy), two different treatment types (single and fractionated), and irradiation at one of three different life stages (15 days, 20 days, and 25 days old). Results indicate that the age at the time of radiation exposure plays an important role in integrating radiation effects, and the irradiated A. thaliana indicated greater divergences in terms of physical growth compared to the internal physiological reactions. The results suggest that flowering plants like A. thaliana are capable of being utilized as a biodosimeter and further studies can be performed on specific areas, such as microscopic analysis of a plant's internal structure in order to assess the effects of ionizing radiation for a practical application. Health Phys. 99(1):49-57; 2010