Influence of Differentiation State, Salt Stress and Methyl Jasmonate on in Vitro Production of Cucurbitacins from Tissue Cultures of Ecballium elaterium and Cucumis prophetarum Endemic to Egypt

The best medium for callus proliferation from hypocotyl and cotyledon explants of aseptically grown seedlings of two Egyptian landraces of rare wild plants, Ecballium elaterium and Cucumis prophetarum was found to be Murashige and Skoog (MS) medium supplemented with 0.1-0.5 mg/l NAA in combination with BA at 2 mg/l. On the other hand, MS medium supplemented with 2 mg/l BA, 60 mg/l adenine sulfate and 170 mg/l KH2PO4 was the best medium for shoot proliferation after a phase of callus formation. The content of cucurbitacins in suspension cultures was elicited by application of different concentrations of NaCl (salt stress) and methyl jasmonate (MeJA). The highest yield of cucurbitacins (0.1898%) was reached after three days of culture in liquid medium containing 200 μM MeJA. _____________________________________________________________________________________________________________