Enhanced translocation of uranium, strontium and cesium by transgenic Sesbania and Arabidopsis plants harboring the rabbit CYP2E1 gene

Raghad Mouhamad, Kadhim Ibrahim and Antonious Al-Daoude

Abstract

Genetically modified S. grandiflora and A. thaliana confer P450 2EI enzyme were examined for accumulating Cs, Sr and U. The absorption of these radionuclides (¹³⁷Cs, ⁹⁰Sr and ²³⁸U) by the generated transgenic plants was analyzed through quantitative gamma assay. Both transgenic plants which derived from homozygous T3 were grown in soil containing ¹³⁷Cs 17600 Bq/g, ⁹⁰Sr 147±7 mg/kg and supplemented with uranium at 25 mM. Transgenic plants with a high CYP2E1 expression level as proved by Western Blot analysis that the absorption of radioactive nuclides increased significantly in comparison with wild type plants or GUS transgenic plants (control). Arabidopsis and Sesbania transgenic plants were able to accumulate 80% and 70%, respectively of the available ²³⁸U versus control plants and thus, ²³⁸U concentration was significantly decreased in the soil by 50% and 60%, respectively versus the soils cultivated with control or wild type plants. Similarly, ⁹⁰Sr accumulation levels recorded 70% and 60% increase in transgenic Arabidopsis and Sesbania plants, respectively which led to an important decrease in ⁹⁰Sr by 50%. Similarly, 70% and 60% increases in ¹³⁷Cs levels were recorded in transgenic plants, respectively leading to 40% and 30% decreases in ¹³⁷Cs in correlated soils. The CYP2E1 gene improves plants ability to resist radioactive pollutants and may open a new avenue for resisting other pollutants such as U, Cs and Sr through the utilization and deployment of transgenic flowering plants. However, the mechanism by which CYP2E1 enhances the uptake of these radioactive nuclides still to be investigated and examined.