Selection of β-carotene Enhanced Transgenic Soybean Containing Single-copy Transgene and Analysis of Integration Sites

Yang Qin, Soon-Jong Kweon, Young-Soo Chung, Sun-Hwa Ha, Kong-Sik Shin, Myung-Ho Lim, Taek-Ryoun Kwon, Hyun-Suk Cho, Soon Ki Park, and Hee-Jong Woo* National Academy of Agricultural Science, Rural Development Administration (RDA), Jeonju, 560-500, Korea National Institute of Crop Science, RDA, Suwon, 441-707, Korea Department of Genetic Engineering, Dong-A University, Busan, Korea Department of Genetic Engineering, KyungHee University, Yongin, 446-701, Korea School of Applied Biosciences, Kyungpook National University, Daegu, 702-701, Korea Abstract : The β-carotene biofortified transgenic soybean was developed recently through Agrobacterium-mediated transformation using the recombinant PAC (Phytoene synthase-2A-Carotene desaturase) gene in Korean soybean (Glycine max L. cv. Kwangan). GM crops prior to use as food or release into the environment required risk assessments to environment and human health in Korea. Generally, transgenic plants containing a copy of T-DNA were used for stable expression of desirable trait gene in risk assessments. Also, information about integration site of T-DNA can be used to test the hypothesis that the inserted DNA does not trigger production of unintended transgenic proteins, or disrupt plant genes, which may cause the transgenic crop to be harmful. As these reasons, we selected four transgenic soybean lines expressing carotenoid biosynthesis genes with a copy of T-DNA by using Southern blot analysis, and analyzed the integration sites of their T-DNA by using flanking sequence analysis. The results showed that, T-DNA of three transgenic soybean lines (7-1-1-1, 9-1-2, 10-10-1) was inserted within intergenic region of the soybean chromosome, while T-DNA of a transgenic soybean line (10-19-1) located exon region of chromosome 13. This data of integration site and flanking sequences is useful for the biosafety assessment and for the identification of the β-carotene biofortified transgenic soybean.