Genome-wide transcriptome profiling of ROS scavenging and signal transduction pathways in rice (Oryza sativa L.) in response to different types of ionizing radiation

Abstract

Ionizing radiation directly and indirectly affects gene expression within the plant genome. To access the antioxidant response of rice to different types of ionizing radiation, rice seeds were exposed to gamma-ray, cosmic-ray and ion beam radiation. Exposure to ionizing radiation dramatically decreased the shoot length in all plants but not the root length compared with a non-irradiated plant. Electron spin resonance, confirmed that the number of free radicals in cell was greatly increased by different types of ionizing radiation. The measurement of the MDA, chlorophyll, carotenoids contents and activity of antioxidant enzymes revealed that gamma-ray and cosmic-ray, but not ion beam, ionization deceased chlorophyll and carotenoids contents, while all three ionization treatments increased the activities of peroxidase, ascorbate peroxidase, and superoxide dismutase compared with the non-irradiated plants. Microarray analysis using Affymetrix GeneChip was used to establish the gene transcript profiles of rice genes regarding ROS scavenging and signal transduction pathways after ionization treatment. Many of the rice genes involved in ROS scavenging and signal transduction pathways showed induction or repression that had increased more than twofold after ionization treatment. In particular, genes associated with electron transport, such as NADPH oxidase-like and alternative oxidase, were often down-regulated by more than twofold in response to the ionization treatments. In our transcriptomic profile analysis, we confirmed that the expression of rice genes associated with ROS scavenging and signal transduction pathways was induced or repressed to different degrees by the different types of ionizing radiations, as in other environmental stresses.

Biochemical Responses of Soybean (Glycine max L. Merr.) to Proton Beam Irradiation

“…Above 200 Gy, the total activity reported for Pungsannamul was higher than that for Kwangan. According to Kim et al (2012), diverse antioxidant response systems in higher plants have evolved, and different mechanisms exist for scavenging ROS generated by water radiolysis when exposed to different ionization treatments. This is because radio-sensitivity depends on chromosome density, DNA contents, the ability to restore damaged DNA, the activity of antioxidant enzymes, and the moisture content of a species or cultivar (Oh et al 2003).…”

“…POD activity was measured using the method described by Kim et al (2012). The reaction mixture contained 100 mM potassium phosphate (pH 6.0), 100 mM pyrogallol, and 100 mM H2O2.…”

“…SOD acts as the first enzyme in the scavenging process, converting superoxide radicals to H2O2 (Kim et al 2012). APX and POD play important roles in H2O2 detoxification in cells (Foyer and Noctor 2005;Wi et al 2007).…”

Influence of Continuous Gamma Irradiation on Morpho-agronomic Characteristics of <i>Amaranthus caudatus</i> in M1 and M2 Generations

“…The results doesn't show any significant increase in the average shoot and root length per plant in M1 generation, however a slight enhancement in the shoot length was recorded by the seedlings subjected to 60KRC gamma Amaranthus caudatus in M1 and M2 Generations irradiation dose but it was not significant ( Table 1). The average number of leaves and leaf area per plant ( 12). An overall two fold enhancement of these parameters was recorded in M2 generation.…”

“…Gamma rays produce free radicals, which can damage various important compounds in plant cells and brings changes in morphology, growth, biochemical and physiological level [5][6]. Some of these include visible changes such as abnormal shape or appearance, reduced growth and reduced reproductive capacity [7][8], and physiological alterations such as accumulation of anthocyanin, expansion of root radial cells, induction of trichome formation, dilation of thylakoid membranes, change of photosynthesis, modulation of antioxidative system [9][10][11][12][13]. Several positive mutations have been created in agricultural crops by using gamma irradiations.…”