Single-Dose Oral Toxicity Study of β-Glucosidase 1 (AtBG1) Protein Introduced into Genetically Modified Rapeseed (Brassica napus L.)

Rapeseed (Brassica napus L.) is an oil crop classified as Brassicaceae and is widely grown in the world. To develop a drought-resistant rapeseed, β-glucosidase 1 (AtBG1) gene was introduced into rapeseed because Arabidopsis was reported that the drought and salt-resistance phenotypes when AtBG1 gene was over-expressed in arabidopsis. New developed genetically modified crop is required to be proven that it is safe because it does not have any information about its safety. The safety assessment is based historical usage and scientific report of the crop. In this study, we have examined the potential acute oral toxicity of AtBG1 protein expressed in genetically modified (GM) repeseed and to calculate the minimum lethal dose at 6-weeks ICR mice using both male and female. AtBG1 protein was fed at a dose of 2,000 mg/kg body weight in five male or five female mice according to marginal capacity concentration of OECD, 2,000 mg/15 ml/kg. Mortalities, clinical findings and body weight changes were monitored to 14 days after dosing and the postmortem necropsy were performed at 14. From this study, we showed that the test group was not observed death case and AtBG1 protein did not cause the variation of common symptoms, the body weight and postmortem between two groups. This showed that minimum lethal dose of AtBG1 protein expressed in transgenic rapeseed was evaluated to exceed the 2,000 mg/kg body weight in both sexes.