Phytoremediation of Trichloroethylene And Dichlorodiphenyltrichloroethane—Polluted Water Using Transgenic Sesbania Grandiflora and Arabidopsis Thaliana Plants Harboring Rabbit Cytochrome P450 2E1

Abstract

Sesbania grandiflora (L.) pers (Fabaceae) and Arabidopsis thaliana (L.) (Brassicaceae) were genetically engineered to constitutively express the rabbit cytochrome p450 2E1 enzyme aiming at increasing their activity toward trichloroethylene (TCE) and dichlorodiphenyltrichloroethane (DDT) removal. Successful generation of Sesbania and Arabidopsis transgenic plants was verified using p450 2E1 specific PCR and confirmed by western blot analysis. Gas chromatography (GC) analysis revealed that small cuttings of Sesbania and third generation (F3) Arabidopsis transgenic plants exposed to TCE and DDT in small hydroponics’ vessels accumulated more TCE and DDT compared to plants transformed with the empty vector. Furthermore, both transgenic plants were more effective in breaking down TCE and DDT with a 2-fold increase in TCE metabolism. Two independent Arabidopsis lines showed that DDT was metabolized about 4-fold higher than that detected in non transformed plants. Similarly, S. grandiflora cuttings removed 51 to 90% of the added DDT compared with only 3% removal in controls transformed with the null vector. Notably, stability of rabbit cytochrome p450 2E1 was confirmed using third generation Arabidopsis plants that displayed higher potential for the removal of two important pollutants, TCE and DDT compared with the controls.

KEY WORDS:

• Agrobacterium-mediated transformation
• Sesbania grandiflora
• Phytoremediation
• TCE
• DDT
• Cytochrome p450 2E1

ACKNOWLEDGMENTS

The authors thank the Director General of AECS and the Head of Biotechnology Department for their support. Thanks are also extended to Dr. Doty (University of Washington, USA) for generously providing the constructs. Thanks are also due to James R. Lowty (UW Tech Transfer Invention Licensing).