Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5
نویسندگان
چکیده
To evaluate the environmental impact of uranium (U) contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress) were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed.
منابع مشابه
Induction of oxidative stress related responses in Arabidopsis thaliana following uranium exposure
The reactive oxygen species (ROS)-signaling pathway is very important in heavy metal toxicity. Induction of the antioxidative defense mechanism, comprising ROS-scavenging enzymes and metabolites, in plants after environmental uranium contamination has been insufficiently studied in the past. This study aimed to analyze oxidative stress related responses in Arabidopsis thaliana after uranium exp...
متن کاملLeaf Age-Dependent Photoprotective and Antioxidative Response Mechanisms to Paraquat-Induced Oxidative Stress in Arabidopsis thaliana
Exposure of Arabidopsis thaliana young and mature leaves to the herbicide paraquat (Pq) resulted in a localized increase of hydrogen peroxide (H2O2) in the leaf veins and the neighboring mesophyll cells, but this increase was not similar in the two leaf types. Increased H2O2 production was concomitant with closed reaction centers (qP). Thirty min after Pq exposure despite the induction of the p...
متن کاملGene transcriptomic profile in arabidopsis thaliana mediated by radiation-induced bystander effects
Background: The in vivo radiation-induced bystander effects (RIBE) at the developmental, genetic, and epigenetic levels have been well demonstrated using model plant Arabidopsis thaliana (A. thaliana). However, the mechanisms underlying RIBE in plants are not clear, especially lacking a comprehensive knowledge about the genes and biological pathways involved in the RIBE in plants. Materials and...
متن کاملNegative control of Strictisidine synthase like-7 gene on salt stress resistance in Arabidopsis thaliana
Strictosidine synthase-like (SSL) is a group of gene families in the Arabidopsis genome, which whose orthologues in other plants are key enzymes in mono-terpenoid indole-alkaloid biosynthesis pathway. The SSL7 is upregulated upon treatments of Arabidopsis plants with signaling molecules such as SA, methyl jasmonate and ethylene. To find the functional role of the gene, a T-DNA-mediated knockout...
متن کاملA Review on Toxicodynamics of Depleted Uranium
Depleted uranium (DU) is an important by product in uranium enrichment process. Due toits applications in civilian and also military activity, DU emerged as environmental pollutant.The exposure to DU can occur via external or internal pathways. In external exposure, mainlybeta radiation from the decay products contributes to DU toxicity. Internal exposure to DUis more im...
متن کامل