Study of biological effects and oxidative stress related responses in gamma irradiated Arabidopsis thalianaplants

¹ Belgian Nuclear Research Centre, Biosphere Impact Studies, 2400 Mol, Belgium
² Hasselt University, Centre for Environmental Sciences, 3590 Diepenbeek, Belgium

Abstract

This study aimed at investigating biological effects in Arabidopsis thalianaleaves and roots irradiated for 72 h with 3.5 Gy or 30 Gy of gamma radiation, and to unravel oxidative stress related responses to achieve a better understanding of the importance of the cellular redox balance as a modulator in gamma radiation stress. A. thaliana performs like a rather radioresistant plant species as no alterations on growth and only minor alterations in the nutrient profile were observed. Gamma irradiation did not seem to induce an NADPH mediated oxidative burst and lipid peroxidation appeared to be directly induced by ionizing radiation rather than mediated through LOX activity. As ionizing radiation can cause indirect damage via water radiolysis, H₂O₂ is hypothesized to be an important reactive oxygen species under radiation stress. Although most H₂O₂-scavenging enzymes remained unchanged, important alterations were observed for CAT1, CAT2 and CAT3expression.