Optimization of an Efficient Non-Tissue Culture Transformation Method for Brassica Juncea

The major hurdles in successful in vitro transformation of Brassica juncea through standard tissue culture (STC) method are: culture contamination, somaclonal variations, and lack of expertise. Moreover, the current STC method is time consuming and needs continuous electricity. In the present study, the in planta transformation method through floral dip with or without vacuum infiltration was optimized for successful transformation of B. juncea. The B. juncea CV RAYA Anmol was used for transformation through Agrobacterium tumefaciens strain GV3101 harboring the binary vector plasmid pBinGlyBar4-EADcT. Based on the resistance reaction to the herbicide Basta, 20 and 40 resistant seedlings were obtained from 2000 seed germinated from the plants transformed through floral dip and vacuum infiltration methods, respectively. The PCR analyses further confirmed the presence of transgene in 3 floral dipped plants without vacuum infiltration and 17 floral dipped plants with vacuum infiltration, giving the transformation frequencies of 1.5*10/sup -3/ and 8.5*10/sup -3/, respectively. This method, which avoids tissue culture, will reduce the somaclonal variation accompanying prolonged culture of cells in a dedifferentiated state, will facilitate functional genomics and improvement of Brassica juncea with novel desirable traits while reducing time and expense. (author)