Factors affecting transformation of Zanthoxylum piperitum DC. var. inerme Makino via Agrobacterium tumefaciens.

In order to establish an Agrobacteriummediated genetic transformation system for Zanthoxylum piperitum DC.var.inerme Makino,using petioles and stems as explants, we examined several influencing factors of transformation efficiency, including precultivation time, optimum bacterium concentration and inflection period, and cocultivation time. The efficient transformation system obtained was 3 days precultivation time, 10 minutes inflection using bacterium at the concentration of OD600 0.5~0.8, followed by 3 days cocultivation. Selection of the transgenic plants was carried out after 7 days regeneration using gradient kanamycin at 30 and 50 mg/L, respectively. Adding 100 μmol/L acetosyringone in the resuspending solution and cocultivation medium increased the transformation efficiency to 24.6%. Transgenic plants were confirmed by GUS histochemical assays and polymerase chain reaction. The results suggest that an efficient Agrobacteriummediated transformation system for stable integration of foreign genes into Z. piperitum DC. var. inerme Makino has been developed, which could be applied in future studies on transferring economically important genes into Z. pipertum DC. var. inerme Makino.