A simple and efficient Agrobacterium-mediated procedure for transformation of tomato.

We describe a highly efficient and reproducible Agrobacterium-mediated transformation protocol applicable to several varieties of tomato (Solanum lycopersicum, earlier known as Lycopersicum esculentum). Conditions such as co-cultivation period, bacterial concentration, concentration of benzyl amino purine (BAP), zeatin and indole acetic acid (IAA) were optimized. Co-cultivation of explants with a bacterial concentration of 108 cells/ml for three days on 2 mg/l BAP, followed by regeneration on a medium containing 1 mg/ml zeatin resulted in a transformation frequency of 41.4%. Transformation of tomato plants was confirmed by Southern blot analysis and beta-glucuronidase (GUS) assay. The protocol developed showed very high efficiency of transformation for tomato varieties Pusa Ruby, Arka Vikas and Sioux. The optimized transformation procedure is simple, efficient and does not require tobacco, Petunia, tomato suspension feeder layer or acetosyringone.