Abstract: RNA was isolated from pericarp of ripe tomato (Lycopersicum esculentum Mill. ) fruit and purified. The first strand of cDNA using oligo (dT) as primer was synthesized and a 1.5 kb DNA fragment was obtained by PCR technique. The restriction map of the DNA fragment was analyzed and its whole nucleic acid sequence was determined after it was cloned into pBluescript. The results show that the entire cDNA encoding polygalacturonase has been cloned. The DNA sequence and deduced amino acid sequence reported here were compared with that published abroad and found 99. 3% and 98. 7% homologous respectively. The gene was inserted into binary vector in reverse orientation and transformed first into agrobacterium then tomato cotyledons. Now authors have obtained transgenic plants.

Key words: Polygalacturonase, Polymerase chain reaction, cDNA clone, Antisense, Plant transformation