Gene transfer can provide plants with a novel source of disease resistance. Two different antibacterial peptides, Shiva-1 and lactoferrin, were tested in vitro for antibacterial activity. The former is from cecropin B in insects, and the latter from human or mammal fluids such as milk. Both peptides exhibited high antibacterial activity against all tested gram-negative phytopathogenic bacterial strains. Lactoferrin was more lethal than Shiva-1. A particular lactoferrin domain showed a much higher activity against bacterial strains. A gene encoding lactoferrin was then transferred to Nicotinia tabacum L. xanthi-nc to evaluate the gene expression using Agrobacterium. Stable transformation was confirmed by Southern, Northern, and Western blot analysis. Delayed wilting of the transgenic plants inoculated with Pseudomonas solanacearum was observed. A significant positive relationship between the gene expression levels and resistance was also found by either Northern or Western blotting. Biolistic transformation using a gene gun is currently underway to transfer this novel gene to common beans.