Artemisia annua L. cell cultures as tools for the production of bioactive compounds with healthful properties

Plant cell cultures are valuable bioreactors for the production of bioactive compounds. Artemisia annua L. cell suspension cultures established for producing the antimalarial artemisinin (AN) were exploited to investigate the biosynthesis of other healthful phytochemicals. Culture supplementation with the putative elicitors ß-cyclodextrins (ß-CDs) was successful to increase intracellular and extracellular levels of AN. Other bioactive isoprenoid compounds, known for their antioxidant activity, were also investigated in the supplemented A. annua cell cultures by using metabolomic and transcriptomic analyses. In particular, the application of ß-CDs was useful to induce a considerable significant increase of lutein, quinones (Q9 and Q10) intracellular contents compared to untreated cell cultures. Moreover, the release of carotenoids and quinones into the culture medium of ß-CDs-treated cell cultures was significantly enhanced. Real Time PCR analysis revealed an up-regulation of 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) gene, suggesting that the ß-CDs induced increase of isoprenoid compounds could be due to the enhancement of the plastidial isoprenoid biosynthetic route. In addition, protoplasts derived from Artemisia suspension cultures were explored to engineer subcellular compartmentalization using a modified SNARE protein as a molecular tool for biotechnological metabolite accumulation.