Agrobacterium rhizogenes is a useful transporter for introducing T-DNA of the binary plasmid into the chrysanthemum, Dendranthema grandiflorum Kitamura, genome

Abstract

Agrobacterium rhizogenes was used for efficient transformation of chrysanthemum. Two types of Agrobacterium, A. rhizogenes (A-13) and A. tumefaciens (LBA4404), which harbor pIG121-Hm, were employed for infection. In the A. rhizogenes-infected explants, hairy roots were not observed on any tested medium or culture condition. When explants were cultured on shoot induction medium, calli were formed at the cutting edge within 4–6 weeks of culture, and shoot primordia were observed on the callus surface after 2 weeks of callus formation. Consequently, with gus introduction, a significantly higher transformation rate was observed for A. rhizogenes (6.0%) compared with A. tumefaciens (3.3%). However, only 0.6% of the frequency of rol insertion was exhibited in A. rhizogenes mediation. These results indicate that A. rhizogenes effectively introduces T-DNA of the binary plasmid into the chrysanthemum genome by introducing Ri T-DNA at a low frequency. It also indicates that the system is a useful alternative for the transformation of chrysanthemum.