Development of marker-free transgenic potato hairy roots using Agrobacterium rhizogenes

Abstract

Agrobascterium rhizogenes KCTC2744 and A. tumefaciens LBA4404 harboring the binary vector pBIl21 were used to transform potato plants. Transformation efficiency was monitored by detecting the β-glucuronidase (GUS) transcripts and the enzyme activity. The GUS expression of potato hairy roots regenerated by A. rhizogenes-mediated transformation was found to be approximately two-fold higher than that by A. tumefaciens-mediated transformation. All hairy roots were induced by A. rhizogenes on Murashige and Skoog medium without antibiotics. The hairy roots were transformed to pBI121 and pCAMbar-by A. rhizogenes KCTC2744. The GUS expression patterns, including hairy roots regeneration and staining characteristics, were investigated. No significant differences were observed between the general transgenic hairy roots and the selectable marker-free transgenic hairy roots. The polymerase chain reaction amplification and Southern blots confirmed a stable integration of foreign genes into all of the marker-free transgenic hairy roots. This is the first genetic engineering approach to the transgenic potato hairy roots genome without the use of a selectable marker gene.