Determination of heavy metal uptake in transgenic plants harbouring the rabbit CYP450 2E1 using X-ray fluorescence analysis

摘要

Transgenic Sesbania grandiflora (L.) pers (Fabaceae) and Arabidopsis thatiana (L.) (Brassicaceae) plants harbouring the rabbit cytochrome p450 2E1 enzyme were evaluated for their ability to accumulate heavy metals, potassium (K), calcium (Ca), manganese (Mn), zinc (Zn), copper (Cu), iron (Fe), lead (Pb) and bromine (Br), using X-ray Fluorescence analysis. When grown for 15 days on heavy metal-contaminated soils, transgenic cuttings of S. grandiflora and T3 A. thaliana plants recorded higher dry and fresh weight compared with their respective controls (A. thaliana and 5. grandiflora plants transformed with an empty vector). Dry weight of transgenic S. grandiflora plants (0.321 g) was seven times higher than that of the wildtype (0.049 g), and the fresh weight (4.421 g) was about 4.6 times higher. Likewise, the dry weight of CYP450 2EI A. thaliana (0.198g) was more than eight times higher than that seen in the control (0.024 g). Moreover, Fe, Mn, K, and Ca concentrations in transgenic plants were significantly higher than those in their corresponding controls. For instance, concentrations of accumulated K (～3000 and 2000 mg/kg dry weight in S. grandiflora and A. thaliana, respectively) were significantly higher than those recorded in their corresponding controls (2500 and 1500 mg/kg, respectively). In the same vein, translocation of all studied metals from soils cultured with transgenic plants was higher than in those cultured with the control plants. In conclusion, the obtained results show the potential in using transgenic Sesbania and Arabidopsis plants harbouring the rabbit CYP450 2E1 for phytoremediation of mixed environmental contaminants.