An improved protocol for rapid and efficient agrobacterium mediated transformation of tomato for salt tolerance (solanum lycopersicum l.)

Transformation of tomato with heterologous genes requires rapid and efficient transformation protocols. Agrobacterium mediated transformation protocol of tomato (Solanum lycopersicum L.) cv. 'Pusa Ruby' using Pg NHX1, AVP1 and co-expression of Pg NHX1+AVP1 gene under 35S promoter and poly A signal of CaMV in pBI121 binary vector was optimized by varying parameters such as type of explant, combination of hormones, concentration of antibiotic, bacterial culture and co-cultivation period. Cotyledons were found to be the best explants for shoot regeneration in tomato compared to Hypocotyls with 96.95% and 95.90% shoot regeneration, respectively. The hormonal concentration Zeatin (1mg/l), IAA (0.1mg/l), Adenine sulphate (25 mg/l) produced higher shoot regeneration. The selection of transformants on antibiotic kanamycin was standardized at 100mg/l and the transformation efficiency was optimized at Acetosyringone concentration of 375 µM and bacterial culture of 1 x 108 at 72 h incubation was standardized to obtain the transformation efficiency of 38.81%. With this modified protocol it was possible to obtain transformed plants within a period of 65 to 75 days with a high regeneration and transformation efficiency.