Effects of methyl jasmonate and salicylic acid on the production of tropane alkaloids and the expression of PMT and H6H in adventitious root cultures of Scopolia parviflora

Abstract

The effects of methyl jasmonate (MJ) and salicylic acid (SA) on the production of tropane alkaloids (TA) and the expression of putrescine N-methyltransferase (PMT) and hyoscyamine 6β-hydroxylase (H6H) were studied in adventitious root cultures of Scopolia parviflora. MJ treatments increased the amounts of both scopolamine and hyoscyamine, with growth inhibition of the roots, while SA increased the amount of scopolamine without negative effects on growth. Regarding both MJ and SA, their concentrations and exposure times were factors that strongly affected the production of TA. Western blot analysis showed that treatments with MJ or SA regulated the expression of the key enzymes PMT and H6H and the biosynthesis of TA. The results from this study suggest that MJ and SA regulated directly or indirectly the expression of PMT or the H6H gene and, finally, increased the production of TA and stimulated the excretion of TA into the culture medium.