The focus of my research has been to investigate the Agrobacterium-mediated genetic transformation process of plants by determining interaction between plant proteins VIP1, AtKAPa and Ask1 and Agrobacterium proteins VirD2, VirE2 and VirF that occur during transformation and by determining the localization of these proteins in a plant cell. The yeast-two hybrid system was the method used to determine interaction between proteins. Plasmids were constructed to carry a desired protein gene, a DNA binding gene or a promoter activation domain gene and the tryptophan and leucine genes by the method of DNA Reconstruction. The plasmids were then transformed into E.coli where they could propagate. Afterwards, the plasmids were extracted, purified and transformed into yeast. Two plasmids of different genes were transformed into one yeast cell. The yeast was spotted on selective media that excluded amino acids histidine, leucine and tryptophan. While this was the experimental plate the control plate was a media that excluded only leucine and tryptophan, which would allow growth on all the yeast since it was constructed to contain the leucine and tryptophan gene. Production of the histidine amino acids was necessary for yeast growth on the experimental plates. Interaction between the two proteins in the yeast cells would result in growth because interaction activates the production of histidine amino acids. Localization of the proteins was determined by the method of DNA bombardment. DNA of the desired proteins was fused with a marker gene, which was either Gus or GFP. The DNA was prepared in a mixture with micron gold and made into bullets. The DNA bullets were then shot into white Spanish onion layers and observed under a microscope. The control in this experiment was the bullets that contained only Gus or GFP, which resided both in the nucleus and cytoplasm of the onion cells. Results of the protein-protein interaction experiment reveal that plant protein AtKAPa interacts with plant protein Ask1, VIP1, itself and FIP1 ( a plant protein introduced to my study while experimentation was in its duration) and itself as well as Agrobacterium protein VirF. Agrobacterium protein VirE2 was shown to interact with Ask1, VIP1 and VirF. The protein Ask1 was also shown to interact with VirF. FIP1 was seen in the results to interact with VirF, AtKAPa and VIP1. Although protein localization is still being investigated recent results suggest that Agrobacterium proteins VirE2 ande VirD2 as well as plant proteins VIP1 and Ask1 are all nuclear proteins. Localization of VirF is yet to be determined. The experiments performed wer unprecedented and thus no hypothesis of the outcome could have been made prior to experimentation. Because of this the conclusions made after experimentation reflect exactly what the results reveal. This study was aided by grants given by the National Institutes of Health, National Science Foundation Functional Genomic Initiative, US Department of Agriculture and the US-Israel Binational Research and Development Fund (BARD).