[Regeneration of transgenic Lespedeza thunbergii expressing levansucrase gene (Sac B) from Bacillus subtilis].

The Bacillus subtilis Sac B gene with the vacuolar targeting signal sequence driven by 35S promotor was transferred into Lespedeza thunbergii by Agrobacterium mediated method. Total 62 Kan-resistant plants were obtained, of which 5 plants were proved to be transgenic plants. The transgenic plants were characterized by PCR amplification, PCR-Southern hybridization and RT-PCR. The physiological assay results showed that the transgenic plants were more tolerant to stress than the controls under the condition of 200mmol/L NaCl and 5% PEG, respectively, and that the content of soluble sugar in trnsgenic plants was significantly higher than that of controls in the period of tests (5-15 days) under salt and PEG stress.