Y. Ahmadi Moghadam - Department of Biotechnology, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Islamic Republic of Iran.
Kh. Piri - Department of Biotechnology, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Islamic Republic of Iran.
B. Bahramnejad - Department of Agricultural Biotechnology,University of Kurdistan, Sanandaj, Islamic Republic of Iran.
T. Ghiyasvand - Center of Molecular Researches of Medicine, Medical Sciences University, Hamedan, Islamic Republic of Iran.

An efficient transformation system for the medicinal plant Portulaca oleracea was established using agropine-type Agrobacterium rhizogenes ATCC۱۵۸۳۴. Hairy roots were obtained directly from cotyledon leaves explants seven days after inoculation with the bacteria. The highest transformation efficiency was obtained from cotyledon leaves explants, and amounted to ۵۳.۳% within two weeks. Roots grew rapidly on solid growth regulator free ½ Murashige and Skoog medium and demonstrated characteristics of transformed roots such as fast growth and high lateral branching. Successful and stable transfer of rolB gene was illustrated by PCR using specific primers of the gene. The hairy roots showed an ability to synthesize natural and medicinal product, dopamine. Elicitation of dopamine production in P. oleracea hairy roots was tested using different concentrations of methyl jasmonate (۰, ۱۰۰, ۱۵۰, ۲۰۰ μM) and salicylic acid (۰, ۱۲۵, ۲۵۰, ۵۰۰ μM), added to the hairy root cultures during the late growth phase. The results showed that the various concentrations of the methyl jasmonate significantly increased the dopamine content, but, at concentration of ۱۰۰ μM, its impact was the most pronounced. Salicylic acid had no significant influence on dopamine production in hairy roots of P. oleracea.

Portulaca oleracea, Agrobacterium rhizogenes, Hairy roots, Dopamine, Methyl jasmonate