Methyl jasmonate stimulates 20-hydroxyecdysone production in cell suspension cultures of Achyranthes bidentata

20-Hydroxyecdysone (20E), one of major phytoecdysteroids (i.e. analogues of insect steroid hormones) in plants, has important agrochemical, medicinal and pharmaceutical uses. In order to develop a sustainable source of 20E, cell suspension cultures were established from shoot cultures of Achyranthes bidentata. When cultivated in Murashige & Skoog medium supplemented with 1.5 mg/l 1-naphthlcetic acid (NAA) and 1.5 mg/l 6-benzyladenine (6-BA), A. bidentata cells in suspension culture grew rapidly, yielding 20E (5.4 mg/l) after 24 days. The increase of 20E was dependent on the growth stage of cell cultures as well as on the dose of methyl jasmonate (MeJA) applied. When cells of 18-day-old cultures were exposed to 0.6 mM MeJA for 6 days, it was found that total (intracellular and extracellular) 20E production reached the maximum yield 7.5 mg/l, a 2.6-fold increase over the control. This is the first report of 20E production in cell suspension cultures of A. bidentata.