Glucosinolate Profiles, Myrosinase and Peroxidase Activity in Horseradish (Armoracia lapathifolia Gilib.) Plantlets, Tumour and Teratoma Tissues

In vitro grown plantlets, tumour and teratoma tissues of horseradish (Armoracia lapathifolia Gilib.) were compared with regard to glucosinolate profiles. Plantlets produced significantly higher amounts of total glucosinolates than tumour and teratoma tissues. The aliphatic glucosinolate sinigrin was quantitatively dominant. Plantlets also contained lower amounts of an aromatic glucosinolate, gluconasturtiin and indole compounds: glucobrassicin, 4-methylglucobrassicin and 4-hydroxyglucobrassicin. In tumour and teratoma tissues only these indole glucosinolates were detected. The activity of enzyme myrosinase (β-thioglucosidase) was significantly higher in plantlets than in teratoma. No myrosinase activity was recorded in tumour. Total peroxidase activity was 30–50 times higher in tumour and teratoma than in plantlets. The hypothesis that teratoma tissue with shoots is more similar to plantlets than to unorganised tumour has not been confirmed neither for glucosinolate profiles nor for peroxidase activity, but only for myrosinase activity.