Expression of flgK flagellin from Salmonella Typhimurium in tobacco seeds

In the epidemiology of Salmonella Typhimurium, recognized as major zoonotic pathogens of animals and humans, swine plays an reservoir role. Novel methods are requires to control salmonellosis in livestock, and vaccination represent an efficacious way to prevent the disease, reducing antibiotic treatments, as suggested by EC Regulation 1831/2003. In this contest plants have considerable potential and represent a promising alternative for biopharmaceutical protein (plant-vaccine). For these reasons the aim of this study was to engineer tobacco plants in order to induce the seed specific expression with correct folding of flgK protein from Salmonella typhimurium for the subsequent utilization as edible vaccine or as an advantageous system of production. flgK gene was isolated by a polymerase chain reaction (PCR) from a wild type Salmonella typhimurium strain, and transferred into a expression cassettes under control of seed-specific GLOB promoter in order to induce, after agroinfection, the expression of flgK in seeds. Transformed plants showed a correct transcription of flgK gene and the estimated amount of expressed flgk was about 0.6 mg per gram of seeds corresponding to 0.3% of the total soluble protein. In conclusion our data showed flgK flagellin could be expressed in tobacco seeds and stably incorporated into plant genoma.