Transfer of SOD2 or NDP kinase 2 genes into purebred lines of petunia

Abstract

The transfer of Mn-Superoxide Dismutase (SOD2) gene, complex gene (SA) of CuZnSOD and ascorbate peroxidase (APX), and NDP kinase 2 (NDPK2) gene into Korean 4 cultivars (cvs. Millenium White, Glory Blue, Glory Red, and Glory Purple) and 15 purebred lines of petunia was conducted using Agrobaterium-mediated technique. Two (Wongyo A2-16 and A2-36) of 15 purebred lines and one (cv. Glory Red) of 4 cultivars were effective for the transfer of SOD2 gene. The putative transgenic plants survived on the 2nd selection medium were 124. From PCR analysis, 118 (derived from 4 cultivars and 2 purebred lines) of 124 plants were confirmed to contain marker (npt II ) gene, while 58 of 118 plants did not have target genes. There were no plants with both npt II and SA genes. Twenty seven of 28 SOD2 transgenic plants were re-confirmed as transformants by Sothern analysis. SOD2 and NDPK2 genes were expressed in the transgenic petunias as the ratio of 77.8 to 100.0 % and 23.5%, respectively. T1 seeds were obtained from 36 acclimated transgenic plants (SOD2 34 plus NDPK2) in a glasshouse by self-pollination. *Corresponding author Tel 82-31-290-6198 Fax 82-31-290-6219 E-mail: lsy0504@rda.go.kr Introduction Petunia is one of major bedding plants over the world, and it mainly used to be planted on the side of road in company with pansy in Korea from spring to late in summer. A research project for breeding new cultivar of petunia was started in National Horticultural Research Institute (NHRI) (past name of National Institute of Horticultural & Herbal Science, NIHHS), rural development administration (RDA) of Korea, in 1992. After then, 26 cultivars had been developed by conventional breeding program of NHRI until 2002 (National Horticultural Research Institute 2006). One of characteristics, which should be improved in petunia, is resistance to abiotic stresses such as rainfall, humidity, and air pollution. Recently, there have been many reports to develop plants resistant to abiotic stresses through introduction of SOD or APX or NDPK genes (Fang et al. 2002; Haejeong et al. 2003; Tang et al. 2004a; Tang et al. 2004b; Tang et al. 2007; Kim et al. 2005). Successful transformation in most crops relies on genotypes (Shibata 2008), so, it will be necessary to use many genotypes for getting transgenic plant in petunia. By the way, considering patent, if possible, it will be desirable to use Korean domestic purebred lines or cultivars as materials for genetic transformation of petunia. Therefore, this study was executed to obtain transgenic petunia resistant to abiotic stresses through transfer of SOD2 and NDPK2 genes into Korean domestic purebred lines or cultivars of petunia by Agrobacterium-mediated transformation technique. Materials and methods