Agrobacterium–mediated genetic transformation system has been developed for two tomato (Solanum Lycopersicum) genotypes. Prior to the establishment of transformation, protocol explants of cotyledons from the two varieties were cultured to obtain genotype independent in vitro regeneration. Healthy multiple shoot regeneration was obtained from explants of cotyledon cultured on MS medium containing 2.0 mg/l BAP and 0.1 mg/l IAA. The maximum root induction from the regenerated shoots was achieved on half the strength of MS medium supplemented with 0.1 mg/l NAA. The in vitro grown plantlets were successfully transplanted into soil where they flowered and produced fruits identical to those developed by control plants. Oxo-phytodienoate reductase (OPRs) are enzymes codes for a group of related flavoenzymes. The name is derived from the only member for which the function has been established, i.e. OPR3 that catalyzes the reduction of 12-oxo-phytodienoic acid (OPDA) in the octadecanoid pathway for jasmonic acid (JA) biosynthesis. Transformed cotyledon explants were found to produce multiple shoots on MS containing 2.0 mg/l BAP and 0.1 mg/l IAA. Selection of the transformed shoots was carried out by gradually increasing the concentration of kanamycin to 100 mg/l since kanamycin resistant gene was used for transformation experiments. Shoots that survived under selection pressure were subjected to rooting. Transformed rooted plantlets were transferred to soil. Stable expression of AtOPR1 gene was detected in the various tissues from putatively transformed plantlets. The transgenic plants exhibited an enhanced level of resistance to salt stress during seed germination.