Effect of water stress and nitrogen fertilization on the content of hyoscyamine and scopolamine in the roots of deadly nightshade (Atropa belladonna)

The study intended to elaborate the optimal environmental conditions of water supply and nitrogen fertilization for maximum content of hyoscyamine (% dw) and scopolamine (% dw). Plants grown from seeds of Slovene autochthonous population of deadly nightshade (Atropa belladonna), were treated with different water regimes (35-95% depletion of available soil water) together with enhanced nitrogen supply (0.37-1.60 g/pot N) in a greenhouse experiment. Dry plant extracts from 32-week old roots were analysed with capillary electrophoresis (CE) for the presence of tropane alkaloids (hyosciamyne, scopolamine). The results of the plant treatment responses showed that the maximal yield of tropane alkaloids (hyoscyamine: 54 mg/plant; scopolamine: 7 mg/plant) was achieved in plants grown under an optimal irrigation regime (35% depletion of available soil water) accompanied with total nitrogen supply of 0.37 g/pot. By contrast, the maximal content of alkaloids was achieved with 95% depletion of available soil water and a nitrogen supply of 1.60 g/pot. (C) 1999 Elsevier Science B.V. All rights reserved.