Marked enhancement in the artemisinin content and biomass productivity in Artemisia annua L. shoots co-cultivated with Piriformospora indica

A significant enhancement in artemisinin content, an important anti-malarial compound, has been achieved in Artemisia annua L. shoots by co-cultivating with Piriformospora indica, a mycorrhiza-like fungus. The in vitro shoots derived from nodal cultures of A. annua were implanted on four different culture media namely, (i) Murashige & Skoog (MS) basal, (ii) MS + 5 μM indole-3-butyric acid (IBA), (iii) MS + P. indica and, (iv) MS + 5 μM IBA + P. indica. After 2 months, it was observed that the cultures reared on MS + 5 μM IBA + P. indica showed optimum growth in terms of shoot and root proliferation over those cultured without P. indica. The average shoot number on MS + 5 μM IBA + P. indica was 17.83 ± 1.01 and on MS + P. indica alone was 12.75 ± 1.10. A drastic decline in shoot number was observed without P. indica which was 2.0 ± 0.12 on basal and 4.9 ± 1.52 on 5 μM IBA. Similarly, a maximum average of 16.83 ± 0.82 roots were achieved on MS + 5 μM IBA + P. indica which declined to 10.75 ± 1.02 on MS + P. indica. A further decrease in root number occurred in shoots without P. indica, their average being 2.5 ± 0.12 on basal and 8.91 ± 1.57 on 5 μM IBA. HPLC analysis of the aforesaid cultures revealed that the quantity of artemisinin was significantly higher (1.30 ± 0.03 %) in shoots cultured on 5 μM IBA + P. indica compared to those of control (0.80 ± 0.01 %).