Atropa belladonna is a perennial herbaceous plant and most importantly commercial source to acquiring pharmaceutical tropane alkaloids such as hyoscyamine and scopolamine that are anticholinergic drugs. The effect of Piriformospora indica, a plant growth-promoting root endophyte fungus, on growth, tropane alkaloids production and expression of two ratelimiting enzyme genes including Putrescine N-methyltransferase (pmt) and Hyoscyamine 6--hydroxylase (h6h) were studied in micropropapated A. belladonna plantlets. The results showed that inoculation of P. indica signif icantly increased the growth parameters, total alkaloids, and hyoscyamine and scopolamine amounts recorded by HPLC analysis in aerial parts of the plantlets. Furthermore, an increase in the gene expression of the two enzymes i.e. pmt and h6h which play a distinct role in tropane alkaloids production was observed in the roots of treated plantlets. The current study provides an effective approach for commercially production of hyoscyamine and scopolamine by P. indica inoculation in A. belladonna plants.
