Expression and activity analysis of β Gallinacin-3 in Arabidopsis

β Gallinacin-3 (β Gal-3) is an antimicrobial peptide with strong antibacterial activity against Escherichia coli, Staphylococcus aureus and Salmonella typhimurium. In this study, the β Gal-3 gene was transferred into a plant genome by genetic engineering techniques. These transgenic plants can be used as feed additives to prevent poultry diseases and them might replace the antibiotics used in poultry industry. To ensure the β Gal-3 expresses effectively in Arabidopsis seeds, the expression was driven by promoter Ppha cloned from the β-phaseolin storage protein gene. A total of 294 transgenic lines were obtained by Agrobacterium-mediated transformation into Arabidopsis, and five transgenic lines were selected in which the expression levels of β Gal-3 were more than 0.10% of the total soluble proteins. The transgenic lines with single locus were identified by Southern blotting. The expression of β Gal-3 and the highest protein accumulation level (about 4.76 mg/g fresh weight with a maximum of 0.27% of total soluble proteins) was measured by Western blotting and ELISA, respectively. After ultrafiltration by centrifugation, the purity of recombinant β Gal-3 was up to 73%. Taken together, our data showed that expression of β Gal-3 with antimicrobial activity is possible and effective in Arabidopsis seeds.