Effect of ultrasound on the isoflavonoid production in Genista tinctoria L. suspension cultures

BACKGROUND: Application of ultrasound (US) to biotechnology is relatively new but several processes that take place in the presence of cells or enzymes are activated by ultrasonic waves. Genista tinctoria L. (Fabaceae) is rich on various kind of flavonoids, including isoflavones with valuable estrogenic activity. OBJECTIVE: This study verified use of low-energy US elicitor to enhance secondary metabolite production in plant cell cultures. MATERIALS AND METHODS: Suspension cultures of G. tinctoria cells was exposed to low-power US (with fixed frequency 35 kHz and power level 0.1 mW/cm(3)) for period 1-5 min. RESULTS: The US exposure significantly stimulated genistin content (0.8 mg/g DW) after 3 min of US treatment (sampled after 72 h). The highest daidzein level (1.4 mg/g DW) was reached after US irradiation for 5 min and 168 h sampling. CONCLUSION: The achieved results suggest that US can act as a potent abiotic elicitor to induce the defense responses of plant cells and to stimulate secondary metabolite production in plant cell cultures.