Cotton is the most important fibre crop of the world. Pakistan is the fourth major contributor in cotton production. In our country a viral disease caused by cotton leaf curl virus (CLCuV) is the most important factor limiting cotton production of widely cultivated Gossypium hirsutum varieties since the induction of the disease in this region. Gossypium arboreum is the cotton species that is resistant to this disease. Cotton scientists are working to find the key genes in G. arboreum that confer resistance against cotton leaf curl disease (CLCuD). The present study is also an effort to find some potential biotic stress resistance genes from G. arboreum and the evaluation of some genes against CLCuV infection. Different approaches were employed to identify some potential biotic stress resistance genes from G. arboreum. These approaches include screening of G. arboreum leaf cDNA library, finding homologs of resistance genes in the ESTs database of G. arboreum and their screening in G. arboreum and CLCuV symtomatic and asymtomatic plants of G. hirsutum genotypes, cloning of resistance genes from G. arboreum and G. hirsutum using degenerate primers approach and isolation of full length putative biotic stress resistance genes from G. arboreum in RT-PCR. The identified full length genes were coding full length allene oxide synthase, hydroperoxide lyase and calreticulin proteins that were cloned in plant expression vector and were transformed in Nicotiana tabacum through Agrobacterium mediated transformation. The T1 generation of transgenic plants was inoculated with cotton leaf curl multan virus (CLCuMuV) through leaf infiltration. The virus presence and titre in inoculated plants was determined through conventional and realtime PCR respectively. No significant difference in virus titer was detected in all transgenic plants with respect to control plants. It is inferred that resistance against CLCuV might not be due to single gene. Multiple genes might be involved in conferring resistance against this disease. The various approaches adopted in this study to identify possible resistance genes against CLCuV infection resulted in identification and isolation of a set of genes. Theses genes are a valuable source to study their interaction against various coton pathogens and can be utilized to improve resistance level of susceptible G. hirsutum and other plant species.