Arsenic is classified to be a heavy metal that severely contaminates human foods, drinking water and the environment in many regions of the world. Long term exposure to arsenic can create chronic poisoning of human health leading to many life threatening and lethal diseases such as cancer, keratosis, gangrene, damage of lung, kidney and liver and also many other neuro vascular disorders.

To cope with this problem, the researchers of the Biotechnology Research group at the University of Skövde has previously identified and isolated a bacterial strain Lysinibacillus sphaericus sp. B1-CDA from arsenic contaminated soil. These strains are resistant to arsenic, can uptake arsenic from the contaminated source and store it inside the cells thus reducing the arsenic content in the contaminated source. Genome sequencing of this strain revealed that the bacterium harbors several arsenic responsive genes. The research group has also performed several in silico studies on these genes to determine their molecular functions. Two of these genes arsB and arsC were predicted to be involved in uptake and storage of arsenics inside the cells. In this thesis work the arsB and arsC genes were cloned from the genomic DNA of bacterium by PCR using database sequences as primers. These genes were then transferred into two cloning vectors pMAN1080 and pMAN0385, respectively. The pCAMBIA1301 vector was utilized to construct the binary vectors for transferring these genes to tobacco plants by using Agrobacterium tumefaciens T-DNA mediated gene transfer. Two binary vectors each harboring the respective arsenic responsive genes arsB and arsC were successfully constructed. Transgenic calli derived from leaf disk transformation were successfully selected. Transgenic shoots were generated but with a very low transformation frequency (<6%).