Biolistic-mediated plasmid-free transformation for induction of hairy roots in tobacco plants

T-DNA of Ri-plasmid from Agrobacterium rhizogenes is able to trigger the hairy root syndrome in infected plants. This natural phenomenon is used to generate hairy root cultures predominantly only in dicotyledonous plants. We propose a new method of hairy roots induction without Agrobacterium-mediated transformation. The 5461 bp T-DNA region from A. rhizogenes A4 strain with all four rol genes was amplified using primers containing sequences for left and right T-DNA borders on their 3’-ends. This amplicon was used for direct transformation of tobacco leaf discs without A. rhizogenes and binary vectors. We showed the possibility of generation of hairy roots on tobacco leaf discs by biolistic transformation utilizing only rol genes amplicon.