Efficient Tissue Culture and Regeneration Systems for the Medicinal Plant Tanacetum parthenium

Tanacetum parthenium L. Schultz-Bip. is an important medicinal plant with valuable secondary metabolites such as parthenolide. Due to the low amount of active parthenolide in plant tissues, the establishment of cell and plant lines with larger amounts of this metabolite through genetic engineering is essential for cost-effective production at the commercial level. Having a reliable tissue culture and regeneration protocol is critical to the success of plant genetic engineering. In this study, we report reliable in vitro shoot regeneration protocols for T. parthenium from leaf and internode explants. Using MS as the basal medium, among the 16 hormonal combinations tested, the highest regeneration rate from leaf fragments (more than 98%) was obtained on medium containing 0.2 mg L-1 BAP cytokinin and 0.02 mg L-1 NAA auxin. Also, internodes showed the highest percentage of regeneration (85%) in auxin-free medium containing 0.2 mg L-1 BAP. For both explants, the highest number of regenerated shootlets per explant was observed in the same media as above. Regenerated plants efficiently performed root formation and acclimatization to greenhouse condition. Transient expression of GUS gene in leaf explants via gene gun method proved their suitability for use in gene transfer experiments for molecular breeding programs.