Glucosinolates are known to occur mainly in differentiated tissues of Cruciferae plants. In an effort to improve the production of these compounds, regenerated plantlets were induced from horseradish embryoids. Subsequently, glucosinolate contents were compared with those found in the whole plant, suspension cells, embryoids and calli. Qualitative production of glucosinolates was similar in both regenerated plantlets and wild plants with regard to 2-phenylethyl- and 2-propenyl-glucosinolates. In contrast, thioglucoside contents changed with cell differentiation, because indoleglucosinolates occur only in calli, suspension cells and embryoids. Furthermore, it has been shown that the specific activity of myrosinase, which is the enzyme responsible for glucosinolates hydrolysis, declines with tissue age. Copyright (C) 1997 Elsevier Science Ltd.