The effect of nitrate and ammonium concentrations on growth and alkaloid accumulation of Atropa belladonna hairy roots

Abstract

The growth, the alkaloid production, as well as the scopolamine/hyoscyamine ratio of two clones of belladonna hairy roots were studied. The effects of nitrate and ammonium concentrations on these cultures were investigated. A rise in ammonium concentration caused the decline of the hairy roots, while nitrate had a marked effect on the alkaloid content. The alkaloid production obtained with 15.8 mM of NO 3 − and 20.5 mM of NH 4 + was 1.2–1.4 times higher than that obtained when the roots were grown in the standard Murashige and Skoog medium (MS medium, 39.5 mM of NO 3 − and 20.5 mM of NH 4 +). The nitrate and ammonium concentrations in the culture medium also had a strong influence on the scopolamine/hyoscyamine ratio. When nitrate or ammonium concentrations were raised, that ratio also was increased 2–3-fold. The hairy root clones originating from transformations with two distinct strains of Agrobacterium had similar responses.